Is Beer Fattening?

 Posted by on March 12, 2010  Add comments
Mar 122010

This is a subject very close to my heart, in so many ways.

How fattening is beer?

People will tell you that a pint of beer is like having a meal.  Doctors have told me that.  Educated men and women.  Clever folk.

And so I decided to have a little think about it.

Now, even though we’re all metric these days, everyone still measures their height and their weight in Imperial units: feet, inches and pounds, so that’s what we’ll have to go with, especially since we measure out our beer in the noblest Imperial measure of all.  The pint.

Your average pint of beer contains about 4% alcohol.  It might be a bit more or a bit less, but for the sake of discussion, that’s what we’ll call it.  To put it another way, in order to consume a full pint of raw alcohol, you’d have to swallow 25 pints of beer.

Over a week, that wouldn’t be too hard, so let’s say you drink three and a half pints a day, every day, and at the end of the week, you’ve consumed your full pint of ethanol.

Now, a pint of water weighs 20 ounces, but alcohol is about 20% lighter than water.  Therefore, after a week of beer drinking, you’ve swallowed 16 ounces of alcohol.  A pound.

Mass can neither be created nor destroyed, and therefore consuming a pound of any substance can not make you a pound and a half heavier.  At most it can add a pound to your weight, provided every last bit of it is converted to fat.  Forget calories: your belly is not made of calories.  It’s made of molecules, and those molecules have to come from somewhere, in this instance beer.

Every last bit of the alcohol, however, is not converted to fat.  Much of it is metabolised and eliminated.  You piss it up against the wall.

Now, after drinking your 25 pints of beer during the week, you’ve consumed a pound of alcohol which at the absolute maximum can add a pound to your weight.

In the same week, how much food did you swallow?

Was it a pound?  If so, you’re in deep trouble because you’re starving.  You’re going to die very soon from lack of nutrition.

The chances are, provided you’re not an obese supersized burger-eating knacker, that your daily meals weighed at least a pound each, and probably more.  Two pounds, perhaps.  Maybe three.

For the sake of argument, let’s assume that you eat no more than two pounds of food a day.  At the end of the week, you  have consumed fourteen pounds of material.

Now I know that not all of that material has the potential to turn into fat, but this isn’t a scientific treatise.  I’m just trying to to work out how fattening beer is.

One way or the other, at the end of the week, you have consumed a pound of alcohol with the potential to add a theoretical maximum of one pound to your weight, and fourteen pounds of other substances, much of which will be water.  Let’s exclude that.  If we say it’s half of the total, you have still consumed solids with the potential to add a maximum of seven pounds to your weight.

And this is why I think beer has a bad name.

Every pint of beer you drink contains less than an ounce of alcohol, not all of which will add to your weight, while every burger you eat contains about four times the weight in pure fat, every bit of which is ready to enlarge that belly of yours.

Now look.  I don’t claim to be a nutritionist, or a physician, or anything special.  I’m just a guy who wonders how a beer can be as fattening as a full meal when you add up the sums.

Tell me where I’m wrong.  I’ll believe you.


  88 Responses to “Is Beer Fattening?”

Comments (88)

    Cheers! I love you. Pint?


    Trying to get my head around this… You’ve accounted for the 4% alcohol in the pint, but what about the other 96% liquid in the pint glass? Is this what you reckon is all converted into piss or am I missing something? Don’t mean to nitpick, it’s just an interesting thought for a Friday morning you’ve provided…


    I think the real “beer is fattening” problem is

    a) the greasy burger you scarfed down after 10 pints (you know, the one which “must have been bad” because otherwise, why would you be so dog-sick the next day :)

    b) the way alcohol causes your body to metabolize fat inefficiently. So when you eat your dinner, and then have a few pints, your body ends up storing more of the fat from the dinner.

    c) being less likely to get up for a nice walk/jog even when you only have a slight hangover.

    That’s what I think anyway


    You may be simplifying a bit Bock, however on the whole you are probably right. By simplifying I mean not taking account of things like, say, beer (alcohol) slowing your metabolism so that more of the food you eat is converted to fat. Not that I’m an expert or anything. An uncle of mine drank at least 10 pints a day for over 30 years, and got thinner and thinner over that time. He ate hardly anything. He is as close to living proof of your theory as I can imagine.


    Paulie — Apart from traces of hop flavvouring and maybe a tiny amount of residual yeast, the rest of the pint is water.


    Bock, next time I’ll allow myself breakfast and a cup o’ coffee before I post. I’ll show myself out…


    Beer makes you a fat bastard, but beer is also good, as written on Homers coffee mug. Beer is Good it reads. No ambiguity there, like DeNiro in the Deer Hunter. “This is this”, said he.


    I think it’s 170 calories in a pint of guinness.

    And 3,500 calories in a pound of gut blubber.

    So assuming you were getting your calorific need from ‘other’ food, 20.5 pints = 1lb fat.

    That right?


    This post is encouraging people to drink. It’s just not right. You have a responsibility, Bock, to come out with a positive and helpful message to people and I just don’t think you’re doing that. Beer is fine if taken in moderation. Your average should be no more than 2 units a day. I go out with the Missus every Sunday after mass and I have a handy 4 or 5 pints and leave it like that. I think the government need to intervene and stop people drinking to excess.
    The problem is that when people are left to their own devices they cannot control themselves. If the government brought in a maximum limit of 5 pints, the country would be in much better shape.


    I love drinking!


    If you walk to the pub would you burn off the fat from the first pint?
    Would this mean a pub crawl would be fat nuteral.


    It’s very fattening on good fridays.


    Ipso fatso, why are beer swillers so tubby?
    Me thinks the belly doth defend too much, anybody up for a jog?


    Concerned sportsman, you would actually be technically binge drinking yourself with your handy 4-5 pints after mass on Sundays. 2 units per pint, 4-5 pints equals 8 to 10 units. Did you say your average should be no more than 2 units a day? You’re slightly exceeding that by a multiple of 3 or 4.. Why don’t you just go home after mass and pray for all us gluttons..
    “If the government brought in a maximum limit of 5 pints, the country would be in much better shape.” Ha.. go way and stop takin the piss.. did you ever read anything or see any movies on the effects of prohibition, no?


    Its a conundrum. I’ll say from the start that i’m not a Biologist or Nutritionist (although anyone can call themselves a nutritionist) but ill throw my understanding of the situation out there. I think the key to this is the total calories that you have consumed, if you have consumed more calories than your body needs it stores the excess calories as fat, generally. For men, this is usually in your gut. For 3,500 kilo calories in excess consumed your body will store 456g of fat, on average.
    Take a 550mL can of Stella Artois, it contains around 220 kilo calories, a 200g serving of egg fried rice contains 250 kc, a McHamburger has 254 kc. Its fairly easy and enjoyable to drink 6 pints, ~1300 kc, its fairly hard to eat the equivalent in fried rice and burgers, although easier if your pissed. Im not saying ethanol gets stored as fat, your quite right on that, it gets catabolised in the liver and you piss it out as acetic acid. But I think its the potential calorific value it injects into your system that stimulates the food that you have eaten to be stored as fat. There must be some carbohydrates in beer too, probably left over from fermentation. The energy content in 1 g of ethanol is around 7 kc which does alone account for the total calories in a pint.
    My own tipple, Murphys, has around 231 kc-bring on the gut!


    The calorific value is fine but it doesn’t change the fact that the beer contains only a certain physical mass of material to be converted to fat. No?

    I’m not a chemist, but that’s how I read it anyhow.


    “Fattening” is a completely unscientific term. Anything containing carbohydrates, fats or proteins, or substances which can be metabolised into the same can be fattening – or not. It’s a basic simple mathematical equation. You consume a certain amount of calories daily to produce the energy your body needs. If your intake is less than your than your production you’ll lose weight. If it’s more, you’ll – at least potentially – gain weight.

    Ok, the reality is a bit more complex, but that doesn’t really change the basic equation. There are body-types which metabolise very efficiently. Such types were, in terms of evolutionary history, at an advantage, since they were able to efficiently use every bit of potential energy in nutrition in order to help them to survive – a good thing, since for most of history, most people had to struggle to get enough nutrition to live, and the ability to store energy (in the form of fat) for times of scarcity was an evolutionary plus. That’s why so many of us have the tendency, in a life where obtaining enough calories to keep going is not a problem, to get fat. The whippets who can drink 12 pints and then eat a couple of large mixed grills without gaining a gram are, in fact, bad metabolisers – they finish up just shitting out a lot of potentially useful energy.

    One of the problems with alcohol is that the body can’t metabolise it for energy very easily. What it can do, however, is to convert it into another, chemically related form, which can be saved to be metabolised later at need. And that form is, unfortunately, fat. This wouldn’t be a problem if we regularly put our bodies in a situation where they would, in fact, burn this fat for necessary energy. But that doesn’t happen, since we continually treat our bodies to abundant amounts of ready-to-metabolise carbohydrates, which are much easier to use for energy. So the fat remains and increases, the body storing it up for a rainy day which never comes.


    Shakespeare once referred to an individual as ‘a man of unbounded stomach’! I think it quite likely it was said in a tavern.


    You forget to take into account the burning of calories created by the constant lifting of pint to mouth and back again. Not to mention the extra exercise caused by trips to the bathroom, particularly if stairs are involved. Unfortunately, the previous night’s workout may be ruined by the increased period of inactivity that accompanies the following day’s hangover. I agree that it’s not the beer or stout that is fattening, but the shit we eat on top of it at the end of the night


    Bock, drinking beer doesn’t make you fat! It makes you lean..
    against bars, chairs, tables, poles. :>)


    Seriously thin alkis don’t eat.They just drink.


    To be fair frantheman I don’t think the term fattening was put out as a scientific term, like Bock said its not a scientific treatise. It is a very inteteresting discussion and Bock’s post is very logical. While I agree with a good deal of your post I don’t agree with a couple of things that you said frantheman. I think the whippets you talk about have in fact higher than average metabolic rates and energy needs. They both need more calories and burn them at a higher rate than your average Joe, not that they’re bad metabolisers. You also described ethanol being converted to another chemically related form and stored? I’ve had a look at the ethanol degradation pathway and was wondering what this related chemical form is? All I can see is ethanol being oxidised to acetic acid, or to one of the more toxic intermediates and then excreted, never stored. Bock, I don’t think its just the mass of a pint thats important but the calories it contains and the offset this has on the other food that you may have eaten. Ethanol is not converted to fat so the mass balance of ethanol is not important-its the energy content of it. A calorie is a calorie and your body doesn’t necessarily discriminate where it comes from.
    I had a look in the literature and may have found some sort of explanation; during one of the last inter-conversions of ethanol to acetic acid a hydrogen ion (a proton) is whipped off to produce a molecule that makes ATP, which is the real energy currency of the body. For 1 molecule of ethanol catabolised 1 molecule of glucose floating around in your blood is stored as fat. Your body has already gotten energy from breaking down the molecule of ethanol and so does not need to break down the molecule of glucose for ATP, so instead stores it as fat for a later time of calorie restriction.
    Another important point is that ethanol is a toxin. Your body wants to get rid of it. Ethanol becomes the primary concern of the liver, it breaks it down exclusively, stopping the metabolism of fats, proteins and carbohydrates for energy. So you have a situation where your body is metabolising ethanol primarily and getting a bit of energy from it, while your blood is getting saturated with glucose thats not getting broken down for energy. This is assuming you had eaten that day and the food is being digested/metabolised. If your drinking a couple of pints a night and not eating too much (not going over your calorie threshold) I don’t reckon you would get fat at all. I could well be wrong, the body is beautifully complex and there may well be very subtle processes ticking away in the background. I certainly don’t think that beer is as fattening as “professionals” make it out to be, unless they can explain the mechanisms that make it so.


    25 pints a week for the love of god? Is it a diet that you’re on, Bock my good man?

    The oul fella lived on little more than black pints and milk stout throughout his working week. He paused only at weekends, when he would take 3 boiled eggs for his breakfast, and strong drink for his tea. He lived to the ripe old age of 35, and not a day older.

    Sadly, his liver lived to the age of 34 however.

    Me… I did the ‘nothing but’ Guinness and Ginster pastie diet for a full month. I put on not an ounce in all that time, but I did shit through the eye of a needle for the full 4 weeks.


    Hi Bock – sense your beer enjoyably.

    But, if I may?…. the calories in your beer come from sugars which the yeast did not get around to converting to alcohol. That is where its calories come from.

    Calories do not measure mass, but energy. Energy from food, in the form of calories, can be used, or stored in several forms, including glycogen, and fat. Using it immediately does not add to our body weight. Storing it does not necessarily add to our body weight over time, so long as we can find a use for it later on. Storing it may add something to our body weight if we cannot find a use for it within a specified timeframe. Using our stored reserves too quickly without replenishing them may reduce our body weight.

    The question of body mass is different. We construct our bodies from proteins which are remade inside our cells from the broken down bits of animal and plant proteins (amino acids) that we have absorbed. It only takes about 50-70 grammes of protein a day to keep our body tissues in good repair. But the constant breakdown and excretion of bits of old/damaged body tissues, and the build-up of new body tissues also takes energy (in the form of calories), which is why we are constantly burning calories even if we sit around all day (believe it or not). This is known as resting metabolism.

    It is probably entirely possible to lose weight by sticking to beer alone. An inactive man may still require 1800-2,500 calories a day (depending on other body factors), just to keep the cells ticking over. That would require 9-13 pints (at the 200 calorie level mentioned above) just to sit around on that barstool. If you fell off it on a regular basis before getting your quota, you’d start to lose weight. Plus, you wouldn’t be getting enough protein to repair your tissues.


    PS – It also helps to know that our metabolism regularly converts gases to liquids, liquids to solids and vice versa, so it is really not helpful to think about “masses of solids” as being the only part of our foods that can add weight. Some of the “solids” in our foods gets breathed out in the form of CO2, for example, and we lose lots of water invisibly by sweating. But we also incorporate water into our tissues and accomplish many other amazing chemical conversions all the time.


    I agree Scotlyn, there must be sugars floating around, the total calorie content of a ~5% beer is about four times the value of a shot of ~40% vodka. There is a disconnect. I once had a buddy tell me, in the midst of a beer festival, that drinking a pint is like eating a plate of potatoes. What a prick! If a person was to drink nothing but beer i’m sure scurvy and rickets would soon set in, a pint has empty calories-adding no nutritional benefit. I wouldn’t say our bodies are constructed from proteins Scotlyn, its more constructed from water than proteins! When you say resting metabolism do you mean basal metabolic rate or something else? I think its important to point out that our metabolisms do not change gases to liquids or carry out any other phase change, that i’m aware of. I believe you’re talking about dissolution/precipitation?
    If you put on any noticeable weight from drinking (which is going to be a slow process) its not going to be from beer-its going to be from the food you eat either before of after the pub. If you have no food in your stomach and go on the tear, eat nothing that night, you’re not going to put on any weight. Your body cannot physically convert ethanol to fat. As Bock mentioned above, energy cannot be created nor destroyed but changed from one form to another; ethanol is converted to acetic acid and there is an energy difference between these two molecules (there is a net increase in free energy)-the human body capitalises on this, captures some of this energy and uses it for metabolic processes. It cannot however store this energy as fat, it can store it as glycogen alright, but there is only so much of this that can be stored and you’re more than likely to be full up. All in all I think Bocks fundamental point is correct. Hence, a pint does not equal a dinner-very far from it!


    Irate chemist – I am not talking about phase changes – I am talking about the basics of organic chemistry and metabolism. Our bodies are made of proteins, fats, sugars, enzymes, etc. The main building blocks of these (other than various trace minerals) are Oxygen, Hydrogen, Nitrogen and Carbon – the first three of which, when in their elemental state are gases (although hydrogen is more comfortable appearing in liquid form in combination with oxygen as water) and the last of which can be found in a gaseous state when combined in certain molecules such as CO and CO2. These gases, in other words, when combined metabolically in the much larger molecular structures of organic tissues, become solids, while metabolic breakdown products of those solids can include gases – eg. CO2 – and liquids – H2O.

    Technically, all any living thing really needs to put on weight is air (O, N and CO2) and water (H2O), but we (along with all animals, fungi or non-photosynthesising bacteria) lack the requisite bag of tricks. Plants do it all the time, though, using sunlight to break the chemical bonds between H and O in water, and then building up complex sugars, starches, fats and some proteins from there on. However even plants are largely unable to avail of the plentiful N found in the air, and have to rely either on pre-fixed nitrogenous compunds int the soil, or on the activities of fungus symbionts in their roots that can fix the N out of the air.

    We need N, O, H and C, but must actually consume the C and the N and some of the H and O in the form of already constructed plant/animal sugars, starches, fats and proteins (solids), we can get some of the O from the air (but we cannot use a single molecule of the N), and some of the O and the H from water. The calorie content of a food represents how much of it can react with oxygen in our cells to produce ATP, which the cells can then use to break down and build up the thousands of chemical compounds needed for tissue repair, immune defense, detoxification, signalling, muscular activity, etc.

    Calories from beer are no different from those from food – the cells won’t ask a calorie whether it comes from beer or food! Beer’s calories do not come from the actual alcohol, though, which (as you point out iratechemist) our cells can’t combine with oxygen to make ATP, instead they come from the sugars which the yeast didn’t get around to digesting in time. (The alcohol content is the product of yeasty digestion – lovely thought! – a waste product to the yeast, and a potent source of merriment to us – but we cannot put it to use to build any part of our bodies or to provide energy.) Beer does contain a fair number of necessary trace elements and vitamins, but lacks any fats or proteins, both of which are necessary for normal functioning.

    In conclusion, then, man cannot live by beer alone. But it can be fun to live by beer in company.


    I forgot to say that all of the above was in answer to this, Bock:

    The calorific value is fine but it doesn’t change the fact that the beer contains only a certain physical mass of material to be converted to fat. No?

    So no, the “physical mass” is not a useful measure, at least not in the sense you mean. It is only useful if you can measure the total content of everything consumed (food, water, breath) vs the total content of everything excreted (breath, sweat, tears, spit, mucous, urine and faeces – and, vomit – which may be an important feature of the more beer-sodden occasions).

    Calories are handier to understand. Anything that can be broken down in the body for energy (sugars, starches, fats and proteins) can also be stored as fat, if the energy cannot be put to use immediately. Although the pathways are more difficult for some of these – eg. conversion of protein to fat is metabolically difficult and liable to produce toxic by-products). Likewise, fat can be broken down to make energy (but cannot be used reversibly to re-create proteins, for example). We are building up and tearing down our fat stores on a continual basis, but what matters in terms of weight loss or gain, is the net value of all caloric transactions.

    Resting metabolism (basal metabolic rate), is the rate at which we burn calories just to exist (sit in the chair, lie in the bed, etc.) This rate is an essential part of the story of any individual’s weight, as most of our calories are actually consumed in this way. The calories needed for activity/exercise add only a small load to the resting metabolic requirement, unless we are involved in extreme forms of athletic training. The key thing is that this resting rate can go up or down and is influenced by a huge number of factors – many individuals who gain or lose weight have not changed their habits at all – instead their basal metabolic rate has been reset. Hormonal changes are notorious for this, so are stress, inflammatory processes, tumour formation, and many other physical processes.


    This is getting very interesting.

    On a point of information, any decent beer beer is made exclusively from nalt and there’s no sugar involved. How does that afffect the point about sugars?


    Can’t make alcohol without sugar – fundamental requirement! Although starch will do in a pinch – but is harder – think of a starch as lots of sugar beads strung into a necklace – takes longer to pull apart, but still ends up sugar.


    Right. More enlightenment.

    What would happen in a beer where all the starch is converted to alcohol?


    PS – when I get around to it I’ll send you my “cheat” recipe for making cheap – and very decent – wine from grape juice – no fiddly or specialist equipment or ingredients needed. I haven’t actually got into the beer-making arena yet, but am told it is fundamentally similar. The reason beer has a lower alcohol content, though, is because it presents the yeast with starches instead of sugars, which the yeast cannot convert as readily.


    Beer and wine – fermentation products – can attain alcohol contents of around 4-12%, the more simple sugars, the more alcohol. At a certain point the yeast begin to die off, because they are swimming around in their own wastes, and cannot find anymore food (sugar). The yeast will never get all the way to the end of the sugar. At that point, though, if you want a higher alcohol content you can think – distilling. (But in this country, home fermenting is ok, home distilling will get you some sharp attention from the “Revenoo.”) This requires concentration of the alcohol by using fractional distillation techniques invented by arabic alchemists (thus the word al-cohol).


    One more thing, “malt” equals “malted grain.” The grain is starchy, and the malting process converts some of that starch to sugar before feeding it to your magical yeast.


    It’s very simple. Classier people drink wine instead of gallons of beer. Plus they eat better food and get exercise, unlike couch loving beer swigging layabouts, just sayin like


    We all drink wine when the beer runs out.


    Scotlyn, I agree with your fundamental points. I was correcting a statement that you had made in an earlier post that I thought may have mislead people, which I think you may not have intended:

    “It also helps to know that our metabolism regularly converts gases to liquids, liquids to solids and vice versa”

    To me, maybe i’m still on my weekend ether binge, but converting a gas to a liquid or vice-versa is a phase change. I never contested the elemental form of any of the elements either, but I was wondering how much more comfortable hydrogen is in appearing as water than it is as hydrogen gas?
    I just want to be sure that i’m interpreting what you’re saying is correct;

    “..and the last of which can be found in a gaseous state when combined in certain molecules such as CO and CO2. These gases, in other words, when combined metabolically in the much larger molecular structures of organic tissues, become solids..”

    Are you saying that the gaseous carbon dioxide & carbon monoxide that we breath in can/is incorporated into the various solid structural tissues in our bodies? Noting the fact that the carbon dioxide we breath in gets exhaled again, its not very likely to diffuse into the blood plasma, there is already enough of this in your plasma as a dissolved gas, there is a concentration gradient against its diffusion from the lungs.

    “The calorie content of a food represents how much of it can react with oxygen in our cells to produce ATP..”

    First of all, a calorie is a pre-SI unit of energy (replaced by the joule) and you’ve butchered it’s meaning. A calorie is based on the specific heat capacity of water and has nothing to do with oxygen, for good reason-what about our anaerobic metabolic pathway?! Food (glucose) does not react with oxygen in our cells, our prokaryote-symbiotic friends the mitochondria manufacture ATP using electrons taken from glucose metabolites (citric acid cycle), oxygen molecules are present to accept said used electron forming a free radical, which then recombines with a proton to form water (metabolite).

    “Beer’s calories do not come from the actual alcohol, though, which (as you point out iratechemist) our cells can’t combine with oxygen to make ATP..”

    I agree with you that a calorie is a calorie but I never said that calories in beer do not come from alcohol, quite the opposite actually, or that cells combine food with oxygen to form ATP, thats just wrong (as above). Ethanol DOES yield energy which the metabolic system DOES capture to produce ATP. Therefore, calories do come from alcohol, unless you can convince me otherwise.

    Plants can also get amines from the air after a thunder-storm, a lightening bolt has enough energy to and frequently does split the stubborn nitrogen-nitrogen triple bond.
    What trace elements (i assume you mean minerals, or do you actually mean elements like zinc and copper, co-factors for enzymes?) and vitamins are in beer? It might be a good idea for distilleries to start putting vitamins etc in beer, why haven’t they thought about this? It would be brilliant, get the antioxidants (that are of no real use to your body) from beer! Fortified with bullshit!
    By the way;

    “..ATP, which the cells can then use to break down and build up the thousands of chemical compounds needed for tissue repair, immune defense, detoxification, signalling, muscular activity..”

    There is no detoxification system in terms of basic human biochemistry-detox is a pseudoscientific cultural product that marketing companies peddle very well to people.

    Bock, each alcoholic drink be it beer, gin, wine, poitin is produced by yeast feeding on sugars from a particular source, malt/barley, juniper berries, grape, potatoes skins. Not all of this sugar is metabolised by the yeast and it remains in your beverage. I just wondered, maybe the disconnect between the calories in beer and spirits like vodka and gin etc is that these spirits are distilled. The sugar is not going to be carried across with the alcohol and hence not in the final product.


    I like this discussion. See what happens when you ask a simple question?

    Because I need things in a simple way, can I just reword all this in my Ladybird version?

    It seems that the alcohol is not converted directly to fat at all, but because it has a certain calorofic value, it allows other things to become fat. However, there may be residual sugars in the beer which also have a calorific value, which, these days we measure in Joules, but that’s all right because we know what we mean anyway, and we could say ergs if we wanted and still make sense.

    Now. How much sugar is in beer? I’d like to know that because I thought those smart brewers with al their chemists had turned the whole lot into alcohol.

    Do we have a figure?


    Thats how I see it Bock, if i’m wrong i’ll recant now and not on my deathbed.
    Just checked out a few websites; lucozade sport, a drink specially formulated to fuel recovery of glycogen quickly by delivering simple sugars has a carbohydrate content of ~6 g, ~3 g of which are sugars. gives a few examples of calories and carbohydrates in beer (note how they give the values for 12oz-which is around 340 mL, there are ~568 mL in our pint).. In budweiser, 340 mL, there is 10.6 g of carbohydrates, so there are ~18 g of carbohydrates in one of our pints. Nearly 3 times as much carbohydrates in a drink formulated to give you energy (calories) fast! I’m open to correction on this.
    I had a look on a few sites and they reckon fermentation is ~73-90% efficient. There may be physical limits involved that prevent complete fermentation, I bet the figures above, if correct, have been optimised using every trick in the book. Product is money after all. Maybe sugar is added for taste?


    See, that’s what I like about our contributors. You get a better-researched class of bullshit.

    But I have to say, I’m highly suspicious of all this isotonic stuff. It’s just sugary drinks in my opinion.


    Thats exactly what they are. You’re better off making some yourself. The reasoning behind it is that after/during exercise your glycogen levels are low, getting simple sugars into you fast replenishes your stores hence you will be recovered and ready for training the following day. If you do not refuel fast enough you run the risk of not replenishing your stores and not have 100% energy levels the next day. People just consume them as a normal drink, not realising how much sugar they contain.
    I don’t like using ergs as a unit, it reminds me of my rowing days and those memories are painful. I like the idea of using horsepower, it sounds great.


    Damn – I was halfway through a lengthy clarification of iratechemist’s clarifications, when I lost the post – so will start again.
    1. Bock – beer is about 92% water and about 4-5% ethanol. The remaining 3-4% is largely water soluble compounds such as sugars, also tiny amounts of essential amino acids, decent amounts of phosphorus, potassium and magnesium, as well as trace amounts of up to 25 or so other minerals, B vitamins in a good quantity, some A, D and E vitamin traces and polyphenols, believed to act as anti-oxidants. Brewers don’t want to turn it all into alcohol, as these added extras are essential parts of the flavour and character of beer. And, like I said, the yeast will start to die off before they can finish all the sugar in your mash. But if they did want to turn it all into alcohol they would have to add a distillation process to their fermentation process, and would then be makers of spirits, not brewers of beer. Distillation concentrates the ethanol – which was originally excreted by yeast after consuming sugar while reducing the proportion of both water, and of water-soluble compounds present in your original fermentation. Vodka, for example is high in ethanol, low in sugar, therefore low in “calories.”

    2. Iratechemist – you make good points, and I accept the charge of a too-loose use of language – just trying to convey some difficult concepts at “Ladybird II” level.

    So, some fine-tuning of your fine-tuning coming back at you.
    a. CO2 – we breathe in CO2 at a concentration of around 0.7% and breathe it out at around 4% (these figures approximate – don’t hold me to them). Of course we cannot metabolically use any of the CO2 which we breathe in (although photosynthesing bacteria and plants with their choroplast symbionts can), but the extra that we breathe out does come from the oxidative breakdown of carbon-containing molecules such as proteins, carbohydrates and fats in our cells. The term I should have used (instead of “conversion” – which incorrectly suggests phase changes, as you say) is chemical “transformation” – some might say biosynthesis, but I refer both to cellular processes which build up (synthesize) complex molecules from simpler building blocks, and those which break them down. The different elements involved, depending on the make-up of the molecule of which they are currently a part, may occur as a liquid, gas or solid. (This was in response to Bock’s idea that only the “solid” mass in beer could create “solid” mass in the body).
    2. The “comfort” level of hydrogen is of course a needless anthropomorphisation. However, hydrogen does not readily appear in its elemental (gaseous) form on our planet, but is most commonly found in H2O, among many other compounds.
    3. A food “calorie” is (you are correct) actually an old-style “kilocalorie” – a measure of the energy needed to raise the temperature of one kilogramme of water by one degree celsius. This can be measured in the lab by directly burning the substance to heat a measured quantity of water. However, in food terms, there are some caveats. While wood, for example, can quite credibly perform the “heating” trick in the lab, since we cannot digest it, we cannot use its “calories” in our cells. (Although if, like termites, we had the trick of digesting it, then its lab-measurable heating “calories” would be the same as its food “calories.”).
    4. Therefore, although I plead guilty to an incredibly loose use of terms, it is true to say that only those substances that the cells (more specifically our own lovely symbionts, the mitochondria) are able to break down and use in the manufacture of ATP can be said to provide food energy, formerly measurable as “calories”, now as “joules.”
    5. Ethanol can be broken down metabolically, and its breakdown products, including NADH, can slot into the cellular metabolic cycles, including that which manufactures ATP. However, the first step in the pathway to break ethanol down to CO2 and H2O, is endothermic (consumes ATP), the second stage produces some ATP and the unstable molecule acetaldehyde, which can easily break down into highly reactive oxydative species and other reactive molecules which can cause cell damage. The theoretical third stage, which is capable of manufacturing lots of ATP (and thus produce a net gain in cellular available energy), rarely happens, because at this stage we excrete most of it, without further breakdown, in the form of acetic acid in our urine. However, since ethanol can also interfere with both of the known ATP manufacturing pathways – glycolisation and mitochondrial oxidative phosphorylation – and such amounts of ATP as are produced by this pathway are not sufficient to carry out the repairs necessitated by the effects of the resulting reactive by-products, the net effect of ethanol consumption is to reduce the bio-availability of ATP within cells.
    6. I agree that the “detox” concept – in the therapeutic sense of “take this expensive substance or regime” – is a marketing scam. However, detoxification (as in breaking down potential toxins like alcohol through various enzyme-driven metabolic pathways, both within the cells in a general way, and within specialised organs, such as the liver and the kidney in a specific way) is definitely an essential biological activity. (If you have ever met a kidney or liver transplant candidate you will see what happens when the body cannot “detoxify.”)
    7. The reason we have enzymes that help us breakdown ethanol, is very interesting. These enzymes are very ancient, and are needed by all cells, as certain metabolic pathways such as fatty acid and bile acid synthesis and glycerolipid metabolism produce small amounts of ethanol as a waste product. The bacteria digesting our food by processes that include fermentation, provide us all with a daily dose of around 3g of ethanol (which is one reason a 0% blood alcohol level is hard to achieve). And of course, we’ve befriended our wonderful yeast, which pull off this trick so well, and put them to work making our beer – which, fortunately, contains ever so much more than ethanol – which is why many of its contents can be perfectly good for us – in moderation.
    8. I didn’t know that about lightning and usable atmospheric amines – very interesting – have you any references?


    This might well be the first time on Bock that people have argued about organic chemistry.


    Hi – in case of another accusation of loose language, when I said:

    Brewers don’t want to turn it all into alcohol, as these added extras are essential parts of the flavour and character of beer

    these “added extras” are, of course, not “additives”, but just what is still left in the brew after (a) the yeast have gone to work on the softened mix of malted grains they were fed, and (b) you strained it to remove all the non-solubles. Brewers don’t need to “add” vitamins, minerals, carbohydrates, etc – they are already there.


    Gotta argue about something…! We do need to up the level of scientific literacy in this country, and if a discussion on beer can do it, why not?


    I’ve been working on it for a while. Forcing people to think clearly whether they like it or not, the bastards.


    And who knew that beer could aid clear thinking !?! .. :)


    That was a lengthly post!
    I have a few further contributions, take them as corrections or thoughts for consideration.
    2. Hydrogen is one of the most abundant molecules in the universe. It is rare on earth, it is extremely reactive and it is very light-light enough to escape gravity on earth, it can rise up out of our atmosphere into space.
    3. The definition of calorie I stated is used to determine the calorie content of everything. There is also a food calorie, which is basically the same, except that it is expressed as a kilo calorie (modern, not old), I think due to raising the temperature of 1 kg of water by 1 degree C. The value of a calorie is found by raising the temperature of 1 g of water by 1 degree C? It can be confusing. I don’t mind using kilo calorie or Kilo Joule, they’re interconvertible.
    5. I never said Ethanol is broken down completely to carbon dioxide and water in the body, that doesn’t happen. From reading the clarification you made I don’t think you understand the basic organic chemistry thats occurring. I don’t intend this as an insult, but what you say does not make sense, its all muddled up, do you understand what your saying or are you just reproducing something from the web? If i’m mis-understanding try clarifying it please. Its during the last interconversion from acetaldehyde to acetic acid that a proton gets whipped off, completing the oxidation to acetic acid, in doing so converting NAD+ to NADH-correctly stated by you.This by-passes Krebs cycle and NADH is fed into the mitochondria (all hail the mitochondria) producing ATP. How I see it, ethanol is oxidised to acetic acid and along the way NAD+ nips in to accept a proton which ends up slipping through a mitochondrial pore, turning a molecular axle to make ATP (it is really a beautiful process). You say that acetaldehyde is unstable-why is this? We excrete acetic acid and don’t break it down further because thats as far as the oxidation, by the laws of chemistry, can go. Its undergraduate chemistry-a primary alcohol is oxidised to an aldehyde and then to a carboxylic acid. Acetic acid incidentally, can be used to generate ATP too but i’m not too familiar with the biochemistry, what do you think?
    6. Look in any decent medical text, go to the appendix and look for detox or detoxification, if you can find a chapter or page concerning it please let me know.
    7. Thats correct, fermentation occurs in our gut all the time. Maybe this is the reason we can process alcohol, it happened since day one, we used the genes to make the enzymes hence we kept the genes. Natural selection in operation. During the sequencing of the human genome it was noted that our genome has a good amount of the sequence required for making Vitamin C, why did we lose it? Its been postulated that because we were getting Vitamin C in our diets, were not using the gene sequence and so lost it. Space is important in the nucleus and it doesn’t tolerate time wasters.
    7. Im full of absolutely useless information. Do I need to supply you with a reference? Your a big boy/girl-if you can reproduce the material above you can open a junior-cert science text book or type it into a search engine. Here is a start


    Why did we retain the ability to process alcohol, or to be more specific, why do we have the ability at all? Surely it must indicate that we evolved from a sea of booze.

    And yes, I have to agree with you about detoxification it’s bollocks.


    I think its important for people to understand the scientific method for what it is, anyone can use it, except the clergy-it doesn’t suit them. Also, if a theory is incorrect it is corrected. There is a constant move forward, no clinging on to old ideas or beliefs.


    For sure. We’ve had some very serious fights on this site based on people’s total failure to understand rational thought.

    Here, for instance.


    It is, detox is a load of clap trap that should be exposed for the bollux it is. I guess we retained the genes for it due to ethanol being present in our stomach most of the time, as Scotlyn posted. We eat food and it sits in our stomach/intestine being digested. Bacteria inside our bodies feed on some of the food we have broken down (bastards), in the absence of oxygen (some bacteria). They metabolise this food we have broken down in a slightly different way and produce ethanol as a waste product (absolute bastards). So, our species have always had this problem-these bacteria presumably have always been in our gut and have always been producing small amounts of ethanol so our bodies always had to deal with breaking ethanol down. Where did we acquire the genes to make the enzymes to do so? Not sure, i’m out of my dept here but my best bet is on some form of natural selection. Lots of chimps floundering around in a sea of Pernod, those who had acquired the gene(s) survived and propagated, the ones that didn’t were promptly embalmed.


    So if you want to find the origin of mankind, search for a sea of Pernod.


    Or an Oasis of Buckfast.


    Hi Irate Chemist –
    You’ve turned this into an interesting – and challenging – thread – thanks.

    Just for clarification, since you challenge me on this score, I do not consider myself to be very knowledgeable about organic chemistry. Certainly I would rate my knowledge level as being poorer than anyone who has taken an introductory college level course more recently than the one I took in the late 1970’s. (I’m always happy to jump feet-first into a barney about beer, though!).

    However I do consider that I am (a) somewhat scientifically literate – ie capable of reading the scientific literature with a certain amount of basic understanding that is better than average, and (b) curious – which leads me on lots of forays into such literature on the hunt of any topic that currently fascinates. I use Google Scholar a lot, and love it when it leads to Free to View articles, and curse it when it presents me with a pay-wall, which I have no institutional keys (or funds) to by-pass. (I’m currently fascinated by the “metabolism first” theory of abiogenesis presented, for example, by this free to view paper by Martin and Russell.)

    I accept that you are much more knowledgeable on organic chemistry than I am, although I would rate my understanding as being better than maybe 7 out of 10 people who decide to discuss the finer intricacies of their beer in the pub.

    My understanding of the comparative usefulness to the cells of ethanol vs carbohydrates in terms of energy and nourishment is probably basic, and very possibly flawed, but if I was to be stranded for a week or so on a desert island, I think I would be correct in preferring to be left in possession of a crate of beer over a crate of vodka. But since you have – correctly I don’t doubt – challenged my hasty pronouncements on the metabolism of alcohol, I shall now go back and study the subject further and refrain from being so hasty in future.

    I do not understand your antagonism to the term “detoxification” as a basic cellular activity, though. A brief search on the words “detoxification” “cell” and “metabolism” in Google Scholar produces around 77,000 thousand articles. A brief sampling includes subjects such as sulfide detoxifying enzymes in the human colon, the role of glutathione in H2O2 detoxification in Kupffer cells, transport and detoxification of copper and manganese in plants, activation and detoxification of benzene metabolites in mice, etc, etc, etc. Detoxification is what cells do when they breakdown substances for transport and excretion which would otherwise be toxic.


    Irate chemist – just one other thing:

    We eat food and it sits in our stomach/intestine being digested. Bacteria inside our bodies feed on some of the food we have broken down (bastards), in the absence of oxygen (some bacteria). They metabolise this food we have broken down in a slightly different way and produce ethanol as a waste product (absolute bastards). So, our species have always had this problem-these bacteria presumably have always been in our gut and have always been producing small amounts of ethanol so our bodies always had to deal with breaking ethanol down.

    I would advance, for your consideration, the increasingly sophisticated view biologists now hold on our symbiotic relationships with the microbial world. For every cell in my body marked by a “Scotlyn” genetic tag, I carry 10X that number of co-habiting bacterial cells – lots in my gut, plus some more in every orifice, skin fold and hair follicle. For every “Scotlyn” gene I carry, there are 100X that number of bacterial genes working away within those bacteria within the circle of my daily physical existence. 99.99999……% of those bacteria are friendly to me, and a lesser, but still very large proportion, are essential for me to live. Without their presence in my gut, I would not be able to digest my food – they break it down for me so that I can absorb the resulting simpler molecules into the bloodstream for use by my “Scotlyn” tagged cells – not the other way around. They can put their 100 fold genes to use to break down foods and liberate their nutrients in novel ways that I cannot.

    Re the production of ethanol via certain cellular metabolic pathways, when I say “ancient” – I mean really ancient – long before apes, dinosaurs, tetrapods, and ediacarans. Possibly as ancient as the last universal ancestor. But what I don’t know, and have no idea whether it is possible to find it out, is whether the yeast that made our beer died happy, as their food supply shrank and they found themselves up to here in their own waste. What is it about ethanol that lifts our spirits?


    Don’t thank me, thank Bock, the reason why we are even having this discussion.
    I was challenging your post concerning those reactions because they were incorrect, its hard enough for someone to read a post heavy with synthetic chemistry when its also incorrect on a basic level.
    Congratulations on getting stuck into scientific literature, more people should do it, there is a wealth of information out there, educate yourself. I might suggest joining the library of a third level institution, if you’re interested in scientific journals, the world would be at your finger-tips. If you’re really interested in specific aspects of science why not turn up to some first year undergraduate lectures, Universities cram hundreds of students into them-they’re not going to notice one extra person, fuck them.
    I could be wrong on lots of things I said concerning metabolism, its not my area, i’m a synthetic organic chemist, but nothing you’ve said has convinced me otherwise.
    I’ll tell you and anyone else who will listen to me that detoxification in the human body does not exist. Its bullshit. Lets call a spade a spade-what your talking about is metabolism and excretion. Look it up in any decent text book, you’ll find lots on metabolism of said compounds and excretion but sweet fuck all on detox. Celebrities detox. Nothing annoys me more than decent people being mislead for profit, I couldn’t give a toss about celebrities (i’m currently working on my Beverly Hills River Lee colon irrigation product). The same goes for antioxidants (you heard it on Bock first). Im foaming at the mouth now. As for the papers you have listed, I haven’t read them, but if they’re talking about detox in the context that we have been then they should make appropriate corrections. People should be very aware of the amount of shit thats published these days, even in a medical journal as prestigious as the Lancet.
    As for your second post, I was trying to answer Bocks question as to why we have the ability to process alcohol off the top of my head, referring to the specific bacteria in our gut that ferment sugars to produce ethanol. I am more than aware of our relationship with prokaryotes, its leaving-cert biology isn’t it? Could you clarify something?

    “For every “Scotlyn” gene I carry, there are 100X that number of bacterial genes working away within those bacteria..”

    Are you saying that for every gene that we have a bacteria has 100X that number of genes? Noting that our genome (library of genes) is huge compared to a bacteria genome. Its a race to the bottom for bacteria, the smaller genome the better.

    “99.99999……% of those bacteria are friendly to me..”

    You are aware that the bacteria on your skin (billions per square inch) are in fact deadly to humans, Staphylococcus Aureus for example. The reason they do not kill us is due to a number of things, our immune system and that they are in a constant battle for survival with the other bacteria they share our body with. They keep each other in check, within certain population limits. In some instances, when one colony is temporarily eradicated (maybe specifically targeted by a particular antibiotic), the other organisms flourish and they make their presence felt-like thrush.

    “Without their presence in my gut, I would not be able to digest my food ..”

    I don’t know what to say here but would you like to reconsider this? Are you serious? Its a wonder why we have our own complex digestive system. Are you getting the majority of your info from wikipedia? I noticed that the jist of the above post is very similar to a wikipedia gut flora entry, as was your earlier post concerning the thermodynamics of ethanol degradation (which is why I think you muddled it up). While it is an invaluable source of information you have to be wary, anyone can write on and edit a subject. While on one hand you can have the correct information using it correctly is another.

    “They can put their 100 fold genes to use to break down foods and liberate their nutrients in novel ways that I cannot…”

    Bacteria do possess a uniquely fascinating bag of enzymes that we do not, but in saying so, we are far more complex organisms, in so many ways, with thousands of more genes that they simply do not have.


    How do I make type in bold and italic? And quote like you do Scotlyn, in those white boxes? Tell me please or alternatively send me a dunce hat that I will most certainly wear while typing.


    I tried to put them in a comment but they wouldn’t show.

    Do you know about tags?

    For italic, put an “i” in the tags. For bold use “strong”. And for a quote use “blockquote”


    So is the answer, no, beer is not fattening? Christ if I had to listen to all that in a pub.. I’d get very drunk as quickly as possible. Sorry Irate Chemist.. :) I’d go with your theory though .. I did not know we had “bacteria genes’ to aid digestion/fight bacteria .. always thought it was white blood cells myself specifically Neutophils, which kill bacteria by digesting it with digestive enzymes.


    Personally, I wouldn’t be jumping into the middle of this unless I was sure of all my facts.


    I didn’t know about tags, thanks Bock. No offence taken FME, my own mother wouldn’t go for a drink with me. Scotlyn and I both think beer is fattening for more or less the same reasons. We have a lot of different bacteria in our gut as Scotlyn said, a lot.
    When you said this;

    I did not know we had “bacteria genes’ to aid digestion/fight bacteria

    We don’t, the bacteria inside us do. But I think you have raised a very important point, maybe during evolution we did pick up a bacteria gene, such a gene for breaking down alcohol?
    Some of these bacteria do very special things for us. One such bacteria feeds on the food we have digested and produces vitamin K, without which we most certainly would die (It is fundamentally involved in the blood clotting process), all this for a bit of B&B. Our immune system is a wondrous thing, white blood cells do indeed keep us safe against many things, invading bacteria included.

    When I said the bacteria keep each other in check, a loose analogy would be to imagine rival gangs living within one estate, fighting with each other for control of the estate. They’re number ratios remain pretty constant, one gang prevents the other from growing large enough to gain control of the estate (by means of gang size) and vice-versa. They end up living side by side, even though they’re enemies. Kind of like a West Side Story in the bacteria world. Theres where my analogy breaks down.


    Huzzah. It worked, thanks again Bock.


    Yes, that’s what I was thinking Irate chemist.. The bacteria have the genes, we don’t specifically have bacteria genes in our genome, but I could stand corrected on that. Not really sure what Scotlyn is referring to there. “For every “Scotlyn” gene I carry, there are 100X that number of bacterial genes working away”.
    In any event most bacteria is killed by acid in the stomach I thought also.
    And in terms of Hydrogen, comment 47, granted hydrogen H is not abundant on earth, except as a compound – most commonly H20, but we are in fact made up of two thirds Hydrogren compound. :)
    Oh and I’d go for a drink with you.. you’re a gentleman.. :) (I presume)


    This link might help the discussion.
    Happy Paddy’s Day all.


    I am a gentleman, i’m sound. I’m not too sure about most bacteria being killed by stomach acid, some bacteria actually thrive in low pH environments. In fact bacteria are very good at surviving in the most inhospitable environments on earth, I remember once reading that certain bacterial species have been found on the inside of nuclear reactors, this was not the paper I read but its close enough. They are also found living happily in space, on the surface of the moon for example.
    Hydrogen is the most important element, in so many subtle ways. All the elements of the periodic table, that we know of, are made from hydrogen gas.


    Hi Folks,
    Sorry I can only visit during short bursts now and again.

    First thing, Iratechemist is right, and, on reflection, I realise I am wrong on several things I said about the metabolism of ethanol. Apologies for leading you astray (or asleep). Also I would love to join an institutional library or attend talks, but access to both is somewhat limited in Donegal.

    However, I stand by what I say about bacteria – based on a lifetime of very diverse reading (although I admit some of it is eclectic).

    Staphylococcus Aureus and a handful (really, there are only a tiny number) of other bacterial species do cause us problems, sometimes to the death – we can call these our bacterial “nasties”. However, we are inhabited throughout our lives by hundreds, possibly thousands, of bacterial species (which jointly possess 100x the number of genes that I do, although individually their genomes are minute – see this fascinating talk for this number). Sometimes there is a wholly different bacterial ecosystem to be found on the left hand and the right hand of the same individual.

    The vast majority of these species cause us no problems, and actually are beneficial, as they help keep the few “nasties” at bay a great deal of the time. “Infections” of the “nasties” are quite often an overgrowth rather than a new acquisition. Such bacteria are there all the time, but only cause harm when their populations are able to initiate an unchecked growth curve and reach a critical mass – or when they are able to invade into the body tissues through a compromised gut wall or a cut in the skin. Many of the bacterial species in the gut (of every animal, not just ourselves) are essential for digestion. Although we do produce many of our own digestive enzymes, our gut bacteria also do a great deal of preliminary breakdown work as well, turning the bulk of our foods into smaller units that are more easily absorbed into the bloodstream and from there into the cells. People with a more diverse gut ecology can effectively process more types of foods.

    Of course, biologists became familiar with our “nasties” first, of course, and those few bacterial species have been intensively studied for over a hundred years. Thankfully for us, such study led to the discovery of anti-sepsis (Joseph Lister and others) and of anti-biotics (Alexander Fleming and others), without both of which modern medicine could not be practiced. Imagine any kind of surgery, immune suppressant therapies, organ transplants, or trauma medicine (burns/wounds) without antibiotics – almost impossible.

    But scientists are now beginning to pay attention to the fact that the world has never stopped belonging, first and foremost, to the bacteria. We exist at their pleasure. Biologists are now studying, and discovering at a phenomenal rate, the many species of neutral, beneficial and essential bacteria that inhabit us. Also, the ones that inhabit the soil, allowing us to grow foods, the ones that inhabit plants and insects and allow them to carry out many necessary processes. Quite simply, earth’s bacteria can do nicely without us (and no doubt will, in the fullness of time). No multi-celled organism could live a day without them.

    Ref your particular scepticism about the role of bacteria in the gut, one of many similarly worded abstracts on aspects of intestinal health reads as follows:

    The human gut is the natural habitat for a large and dynamic bacterial community, but a substantial part of these bacterial populations are still to be described. However, the relevance and effect of resident bacteria on a host’s physiology and pathology has been well documented. Major functions of the gut microflora include metabolic activities that result in salvage of energy and absorbable nutrients, important trophic effects on intestinal epithelia and on immune structure and function, and protection of the colonised host against invasion by alien microbes.

    We ourselves (and all multi-celled creatures) have bacterial ancestors, of course. All life on earth was bacterial for the first 2 billion years or so, and we didn’t somehow “join in” later! So, inasmuch as we have conserved some genes from our first 2 billion years on earth, then, yes, we have “bacterial” genes. Many of the genes that control the cell’s metabolic machinery are greatly conserved. We may also have acquired more recent “bacterial” genes, but these would have been inserted into our genomes (our human genomes, that is), by viruses (acting as vectors).

    Just one fascinating example includes the seven or so viral insertions now considered to have played a part in allowing mammals to develop the habit of hosting our babies in the womb. When you think about it, viruses are all about tricking live cells into allowing them to temporarily take over the living machinery for their own purposes. So perhaps, such habits allowed us to “trick” ourselves into hosting a “not-quite-us” stranger in our bodies for a period of time.

    FME, you are right about white blood cells – they are part of our immune system, and fight bacteria that land into our actual tissues, either through a break in our skin, or damage to our gut wall. But a large number of bacteria are able to live in our gut, which although it is “inside” us, is still technically outside us – it is essentially a tunnel that goes through us with two connections to the outside world. The bacterial/human interface therefore mainly takes place all over the surface of the body, if you take “surface” to include the length of the gut from mouth to rectum.

    Sorry, Bock, this is beginning to sound like a take-over bid on your post, so I’ll stop now.


    Feel free to keep talking. It’s the most detailed discussion I’ve ever had on any post. Ever.


    Ok, then – one more thing. It should be clarified that the bacteria on the surface of the moon that Irate chemist refers to, was a wholly “earthly” species of bacteria that apparently survived for a year or two inside a camera left on the moon’s surface between two of the Apollo moon missions. Bacteria can and do survive in every type of earth environment imaginable (that’s why bacteria do not figure on anyone’s “endangered” list). Possibly bacteria can survive non-earth-like conditions such as the vacuum of space and or the totally non-organic surface of the moon for as yet untested lengths of time. However, the growth or reproduction of bacteria in such off-world environments, in the absence of any earth-like nutrient or other support, has not yet been documented. Neither has the existence of any bacteria of a non-earthly origin. Although some people are still arguing about the possibility of “nano-bacteria” in Martian rocks. Scientific American ran an article last December debunking the idea of nanobacteria in the body, so the jury is still out on that one.


    Also, Bock, if you get the chance to view the TED talk in my first link – it is really quite something – a little bit spooky, too. What happens if all the bacteria inhabiting me get to talking….cue Twilight zone theme tune….


    Scotlyn, that was a good talk (TED). I’m well aware of the ball-park number of bacteria that live in/on us, I never contested that and my objection to your reasoning was not the total number of bacterial genes, my original objection was to the number of different genes present in bacteria versus human, do you know the number?

    By the way, after watching that video I decided to work the number of bacterial genes versus human genes out for myself, in the spirit of the great Richard Feynman. Okay, so one of the largest bacterial genome I could find was Solibacter usitatus, it has 9,970,000 base pairs in its genome. Homo sapiens have 3,200,000,000 base pairs in their/our genome. There are ~1 trillion human cells in the body and ~10 billion bacterial cells. When I do the multiplying I get the human genome coming out on top by an order of 10. Not the bacterial genome by a factor of 100. Am I doing something wrong?

    No multi-celled organism could live a day without them

    I disagree with this quote, it is simply false, on a most basic level.

    Ref your particular scepticism about the role of bacteria in the gut

    Are you reading into something that I haven’t said? I know that bacteria do many wonderful things in our gut, my objection was to your post saying that we could not digest food without them, which I stand by.
    Just on when friendly bacteria get to places they should not be, when an appendix becomes inflamed and ruptures releasing bacteria into our body cavity-what happens (if you don’t get to hospital in time for a surgeon to cut you open a give you a cavity wash!)?.

    Although we do produce many of our own digestive enzymes, our gut bacteria also do a great deal of preliminary breakdown work

    Give me specifics, I don’t believe you. I’ll start, carbohydrates-a morsel of bread for instance, when you put it on your tongue salivary amylase (enzyme in our saliva, produced by our cells) breaks some carbohydrates down to simple sugars. Don’t believe me-try it, can you taste a certain sweetness?

    We may also have acquired more recent “bacterial” genes, but these would have been inserted into our genomes (our human genomes, that is), by viruses (acting as vectors).

    So, are viruses inserting bacterial genes into our genome? Is this what you are saying here?

    Just one fascinating example includes the seven or so viral insertions now considered to have played a part in allowing mammals to develop the habit of hosting our babies in the womb.

    Mammals do have an awful habit of hosting babies in our womb. Are you talking about Homo sapiens (or earlier species)? Because we always had this habit, so I don’t think habit is at all appropriate. How did we host our babies before this?

    When you think about it, viruses are all about tricking live cells into allowing them to temporarily take over the living machinery for their own purposes. So perhaps, such habits allowed us to “trick” ourselves into hosting a “not-quite-us” stranger in our bodies for a period of time.

    Thats what viruses do, its the definition of what a virus is! They penetrate our cell then over-ride cell function, using our cell organelles and energy resources to produce more bits and pieces of itself, which are then assembled, they all then burst out of the cell and go on to repeat the process. Viruses can’t live without a host because they cant replicate themselves. If you think our bodies are tricking themselves into hosting viruses then AIDS is a bit of a wake-up call isn’t it?

    Ok, then – one more thing. It should be clarified that the bacteria on the surface of the moon that Irate chemist refers to, was a wholly “earthly” species of bacteria that apparently survived for a year or two inside a camera left on the moon’s surface between two of the Apollo moon missions.

    What are you clarifying from my post? I was giving an example of bacteria surviving in space, does it matter where they came from? As a matter of interest, bacteria has been found in the upper atmosphere that astro-biologists think may very well come from space. There has been talk for along time concerning bacteria on comets but I don’t know how credible they are. As for earth-like nutrients, bacteria can feed on iron and sulphur, among other things. They cannot survive without water though, thats fundamental. Amino acids have been found in moon samples also, strange.


    Hi Irate Chemist,
    The 100X figure is a collective figure. Individual bacterial genomes are tiny compared to ours, but the collective number of bacterial genes carried just by the bacteria inhabiting the many ecosystems on the furfaces and fissures of our bodies are very great. Another way of expressing these numbers is to say that my human cells make up 10% of the cells that walk around with me, while my human genes make up 1% of the genes that walk around with me.

    Re this quote:

    No multi-celled organism could live a day without [bacteria]

    The only possible thing wrong with this statement is the word “a day.” Possibly that specific length of time is an exaggeration. However, in the hypothetical (and HIGHLY UNLIKELY) situation in which every bacterium was somehow scoured from the face of the earth, everything else would soon die – and lie around mummified for all time, with no bacteria to begin the process of decay. Soil bacteria are essential to breakdown the remains of dead plants and animals and create the thin fertile layer in which new plants can grow. Gut bacteria in many insects (possibly all – although all is certainly a big word, and this is a relatively new subject of study) allow them to process the foods they eat, and provide essential plant-pollination services. Gut bacteria in animals, including ourselves provide essential nutritional and immune support. Taking a bigger view, bacteria world-wide are involved in the regulation and cycling of nutrients through our oceans and atmosphere. Some multi-cellular animals might survive longer than “a day” perhaps. But a bacteria-free earth is essentially a sterile and life-free earth.

    There are animals being raised in the rarified conditions of a lab which have extremely restricted gut bacterial colonies (they cannot be made completely sterile, but for all practical research purposes they are pretty close). They are being used to study the very subject we are discussing – what is the role of gut bacteria on animal health. These lab animals certainly cannot survive long in the wild. Just to give one example – a “normally” colonised animal will not be made sick by receiving a dose of Salmonella smaller than about 1,000,000 individuals. A dose of just 10 individual Salmonella bacteria is sufficient to sicken and kill a lab animal with a sterile gut.

    In humans, like most animals, we begin our digestion with enzymes we produce ourselves in mouth, stomach and small intestine. There are a lot of bacteria in the mouth, but only relatively small amounts in the stomach and small intestine. However, our food spends about 2-6 hours within these organs – during which time we will certainly have absorbed a goodly amount of the nutrients available in its more easily digested portion. But we then turn the process over to the huge ecosystem that is the colonic bacteria, and they get to work on what is left – which at this point still contains a huge amount of nutritional value. These bacteria, depending on the particular make-up of species and dietary components, produce short chain fatty acids which may be reabsorbed into the body and account for up to 30% of its caloric intake, produce essential vitamins, including vitamin K and many B vitamins, and improve the absorption of many other minerals. Infants are often supplemented with Vitamin K for that reason – their colons have not yet been “colonised.”

    The main point of this is the following – we are emerging from 100-200 years in which the focus of research on human/bacterial interactions was on those that cause disease. This was essential research, and it has produced measurable benefits for human health. However, it also skewed that research to a certain extent, and the more nuanced view that is now emerging is based on huge amounts of new data confirming beneficial, and sometimes essential, aspects of that interaction. Such data are only beginning to be accumulated, however, and no doubt another 10 or 20 years will see massive changes in our understanding of bacterial/human interdependencies.

    Some interesting links – if you can access them
    Intestinal flora and endogenous vitamin synthesis; Nutrition and Colonic Health: the critical role of the Microbiota; The Human Ecosystem

    Re Moon bacteria – I wasn’t correcting anything you said, Irate Chemist – what you said was essentially correct. However, your comment was phrased in such a way that it might be incorrectly assumed to refer to moon-native or space-native bacteria. The idea that bacterial spores are floating in space and may have “seeded” the earth is not, in and of itself is not easy to rule out completely. However, evidence in favour is so far completely lacking. All bacteria that have been found to date have clear links to the earthly kind. Simple amino acids, on the other hand, are certainly thought to be abundant on comets and other carbonaceous bodies in near space, at any rate – amino acids were also among the organic compounds famously produced in the Stanley Miller “prebiotic soup” experiments. However an amino acid is a very, very long way from a bacteria.

    Viruses as vectors of interspecies gene transfers is a fascinating subject, but too big to get into now, as I have to go cook the dinner. The subject I was addressing was whether we have “bacterial” genes in our own genomes – which we do – sourced in one of the two ways I mentioned:
    1) simple inheritance from long-ago bacterial ancestors
    2) intraspecies genetic transfer


    Sorry – getting back to the math – if there are 1 trillion cells in the human body (that belong to it), then there are 10x that number of bacterial cells – that is to say 10 trillion (not 10 billion as you say). Obviously the calculation is skewed by the fact that many bacterial genes will be widespread among many individuals. I trust the bacteriologists that have done the calculation have worked it out in all its detail, including such complications.

    Also, I will amend my statement re gut bacteria to the following “we cannot digest ALL of our food without them… and this with the proviso that I suspect more and more evidence of bacterial help in parts of the gut other than the colon will emerge in future. Such bacteria are still very hard to culture or study in vivo.”

    Would be easier to discuss the essentialness of bacteria to multicellular life if you could spell out the “basic” nature in which this is wrong.


    Ok, just one more thing –
    The first part of the paragraph on viral insertions into mammalian gene sequences that control the development of the placenta was based on evidence described in articles like this one.

    The second part of the paragraph was just me waxing all lyrical and speculative about this tantalising bit of information. (Having been called upon twice in this life to perform my own mammalian duty to carry a semi-stranger within me). Is that allowed?


    Scotlyn, either I misunderstood your original post or you’re changing the goal posts. If there were no bacteria on Earth I agree with you that life would probably cease, although I can’t say for sure. I also agree that bacteria in our gut are vital to us in a lot of ways, its hard to tell if we could survive without them at all(in our gut)-its a purely hypothetical situation, we would have to be completely sterile. We would also have to comsume the nutrients they give us, like in the case of vitamin K, which I discussed earlier, I can’t say whether we could or not, it would be a very complex balance-I could only speculate. I do however stand over what I have said about digestion-if you have a leaving cert biology book to hand, you can follow the pathways of food that we consume, how its dealt with by our digestion etc. I don’t think that we rely on bacteria exclusively for the digestion of our food, although they do have a very important input, I have never said the contrary. I suppose saying that we cannot digest all of our food without them is close enough.

    When you said you were clarifying my comment on bacteria being the moon I interpreted that as you correcting what I had said. I do apologise for using the word living and happily, they were neither dead nor alive (dormant) and they never sent me a post-card so I couldn’t say if they were happy. I do however think it is amazing that they survived without an atmosphere, to protect them from cosmic rays. I don’t know if they suffered any genetic damage, more than likely they did. But they survived and that was my point. Does it matter where they came from?

    In humans, like most animals, we begin our digestion with enzymes we produce ourselves in mouth, stomach and small intestine. There are a lot of bacteria in the mouth, but only relatively small amounts in the stomach and small intestine.

    I was referring to the post in which you said that bacteria do the preliminary breakdown. In our mouth?
    I gave the example of carbohydrates and amylase. The only bacteria I know of in our mouth is plaque, that feeds on sugars we consume and produce and acidic metabolite that degrades our teeth. There are doubtless more, but any that help digestion in our mouth? I thought the majority of our bacteria are in our large/small intestine, not relatively small amounts as you say above?

    When I was writing my last post I miss-spelled the word trillion as billion but my calculations were correct as far as I can see. Get a calculator and try it with the numbers I have above, I get orders of a billion trillion versus a hundered million trillion. The total human genetic material is ten orders more than the genetic material of bacteria in/on us. Not 100 fold as you reported. I also used the largest bacterial genome I could find in the calculation, this is a maximum figure.

    Just one fascinating example includes the seven or so viral insertions now considered to have played a part in allowing mammals to develop the habit of hosting our babies in the womb

    When you were talking about mammalian wombs, were you waxing all lyrical and speculative about this tantalising bit of information or were you extrapolating the evidence? The article you linked came to the conclusion that this gene insertion enhanced mammalian reproduction.

    My problem with your post on virus acting as vectors was not concerning said, thats established. Im not aware, as per my last post, of viruses as acting as vectors for bacteria. Maybe they do.


    It all turns to piss anyway


    Thats right Dean, its all piss. Disregard the above discussion.


    Dean is a straggler from the Gerry Ryan row. What do you expect?

    Pay no attention to him.


    Its good to see that he has interests beyond the death of Gerry Ryan.


    I think this is the funniest thread I’ve ever seen. Dean’s sense of comic timing is absolutely impeccable, and Irate Chemists withering response is perfect. I’m still laughing.

    Bravo to both.


    Very interesting and Informative, cheers bock and posters


    I don’t know whether beer is like a meal, but it’s definitely making ME gain weight.. especially the day after. The interesting thing is that usually two days after partying and drinking 5 – 7 pints (which is a lot for a girl) my weight goes back to normal — especially if I’ve done some moderate exercise the day after drinking.

    But I’m starting to wonder whether I shouldn’t switch to vodka, which is what my family drinks. We’re Polish. Beer is just such a great summer drink..


    Here is the other article which I would also like to comment upon for itself in which I take up your invitation to show you where you might be wrong.

    You cannot equate the static mass of alcohol simply with how much weight you would gain in a straight addition because it just does not work like that.

    The body has it own internal fat regulating mechanism which orders the metabolism of fat and alcohol in sufficient quantity, inhibits this ability to balance the set-up and those burgers that you mention become even more fattening that they would be otherwise. Fat is retained.
    Now, the beer itself contains other foodstuffs besides alcohol and this is retained.

    Yes, beer is very fattening.


    When the clergy withdraw from every aspect of Irish public life, their beliefs will no longer be any of my business, so let’s do a deal. You pull your priests out of the school boards, get their hands off the female reproductive system drop your god from the constitution. In return, I’ll promise to stop taking the piss out of transubstantiation.

    I can’t say fairer than that.


    Fantastic site. A llot of helpful information here.
    I’m sending it to several friebds ans also sharing in delicious.
    And naturally, thanks on your sweat!


    Fantastic site! What are you talking about, Balloonscm? A lot of helpful info? This site is full of misinformation and misleading.

    Example: Take a look at some of the entries further up especially the last two before your own. Here Mr. Bock was given a rational explanation of why beer might be fattening and his reply is just an irrelevant blast at Catholic priests to get out of public life and “get their hands off the female reproductive system”. Maybe he is finding that beer is more than possibly fattening, it is also very definitely intoxicating. Maybe he was a bit inebriated when he wrote this as indeed when he wrote some other trash.

    He does not know which way is up half the time.



    You’re arguing with a spambot now, fool. A new low in stupidity even for you.


    ‘I’m sending it to several friebds ans also sharing in delicious.’
    ‘This site is full of misinformation and misleading’

    I can’t tell which one is the bot.

Leave a Reply