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  #1  
Old 08-01-2006, 01:31 PM
Renee Renee is offline
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Why the difference in blood alcohol content between men and women?

In this link, they say that a woman and a man of the same weight will have different blood alcohol contents after drinking the same amount of alcohol. Is this true? If it is, why would that be?
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  #2  
Old 08-01-2006, 01:37 PM
groman groman is offline
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My WAG is that a man and a woman of the same weight will, on average, have different % body composition when it comes to skeleton, lean body mass and fat. Implication being of course that it somehow affects BAC.
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  #3  
Old 08-01-2006, 02:26 PM
Squink Squink is offline
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Quote:
Younger women naturally produce less of the gastric enzyme alcohol dehydrogenase, which breaks down ethanol in the stomach. As a result, after consuming comparable amounts of alcohol, women under 50 have higher blood alcohol content than men of the same age, even with allowance for size differences.
Sex Differences in Response to Pharmaceuticals, Tobacco, Alcohol and Illicit Drugs
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Old 08-02-2006, 01:46 AM
Renee Renee is offline
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Hm. I wonder if this is true across the board. Do people who can "hold their liquor" metabolize it faster/better, or do they just handle the higher BAC better? IOW, if two women (or two men) of the same weight/build had the same number of drinks under the same circumstances (eating the same, etc.) and one seemed significantly less drunk than the other, would that be because her BAC was lower or because her brain just handles the effects of alcohol better?
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  #5  
Old 08-02-2006, 02:22 AM
Blake Blake is offline
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I'd just like to point out that while the information in Squink's link is accurate it also makes a trivial contribution to the differences in BAL between the sexes. The whole page seems to be like that, ie accurate but poorly presented and with glaring omissions. I suspect it was prepared by someone with limited medical/physiology knowledge from scouring journal articles.

In reality the primary reason why men can handle more alcohol seems to be simply because men have more muscle and less fat. Most muscle mass is water, most fat and bone is not. Alcohol is water soluble, it isn't fat or bone soluble. As a result the more muscle a person has the more their body dilutes the alcohol. A man will normally have around twice the muscle mass of a woman the same size, and as a result effectively dilutes any alcohol by a factor of two. Not surprisingly the amount of alcohol in the bloodstream is lower. If men and women with comparable muscle mass as well as comparable weight are studied the differences are far less pronounced.


Factors such as the production and activity levels of various enzymes have also been implicated in the differences, but have yet to be clearly demonstrated AFAIK. Doing so is difficult because the body learns to adapt to high alcohol content by altering enzyme production. Since men have traditionally drunk more, especially while young, it is difficult to separate out innate differences from conditioned responses. When men and women with similar drinking history are included in studies the differences in enzyme production or activity seems to vanish in many cases.

Quote:
Originally Posted by Renee
f two women (or two men) of the same weight/build had the same number of drinks under the same circumstances (eating the same, etc.) and one seemed significantly less drunk than the other, would that be because her BAL was lower or because her brain just handles the effects of alcohol better?
A little from column A, a little from column B.

The human body certainly learns how to process alcohol, and the liver of a regular drinker will produce more of the appropriate enzymes, will produce those enzymes faster, and the enzymes produced will be of a more active form. As a result a regular drinker will require more drinks to reach a specified BAL. In fact most regular drinkers will never reach an illegal driving limit if they drink at a steady pace of one drink/hour, which is about the pace that the liver processes alcohol. In contrast a novice drinker will be unable to process alcohol fast enough to stop the blood alcohol levels steadily rising. As a result a novice drinker can be unable to walk straight after drinking steadily all night whereas an experienced drinker will easily pass a blood test and quite safe to drive.

However the brain also learns to cope with alcohol impairment, just as it does with any other impairment. It learns to deal with the suppression of various brain centres and either ramps up their activity or bypasses them using other centres. Most of use will have noticed this ourselves in that we acted stupid the first few times we drank but after a while we learned how to deal with the fact that we have lowered inhibitions and we watch ourselves very carefully.

So if two people are at different apparent levels of intoxication despite the same rate of drinking it is probably a combination of differing BALs and ability to disguise the effects.
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Old 08-02-2006, 03:03 AM
I Love Me, Vol. I I Love Me, Vol. I is offline
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Perhaps men and women of the same weight have different amounts of blood. So when you add the same amount of alcohol to each person, the BA levels are different.
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Old 08-02-2006, 03:10 AM
gabriela gabriela is offline
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Originally Posted by I Love Me, Vol. I
Perhaps men and women of the same weight have different amounts of blood. So when you add the same amount of alcohol to each person, the BA levels are different.
Sorry, nope.

Blood volumes are calculated on the order of 70 mg/kg in the adult. Male or female.

The only time some women have different volumes of blood from men and other women is when those some women are pregnant. Slight increase. Not enough to change anesthesia amounts (which we'll use for an example instead of seeing her drink herself snockered with a baby on board).
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  #8  
Old 08-02-2006, 03:43 AM
Blake Blake is offline
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Quote:
Originally Posted by I Love Me, Vol. I
Perhaps men and women of the same weight have different amounts of blood. So when you add the same amount of alcohol to each person, the BA levels are different.

And just to expand on what gabriela said, blood volume is determined almost entirely by how far nutrients and oxygen can diffuse. The body needs enough blood vessels to ensure that all cells are within that diffusion difference of a blood vessel, and all blood vessels need to be filled with blood within a narrow pressure range. As a result blood volume is going to be determined by body volume and not much else. Although women have a slightly lower density, and hence higher volume/mass, than men the difference isn't going make much difference to blood volume.

The total volume of water in the body is important in diluting alcohol and thus reducing BAL, but that water difference is due primarily to muscle volume, not blood.
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