The Anatomy of a DUI – Alcohol in Men vs. Women

 Alcohol in Men vs. Women

As I discussed in a previous article, alcohol has an affinity for water.   This means that alcohol is attracted to body tissues and organs that have a high water content. Once the alcohol moves from the stomach into the blood, it will be distributed throughout the various body tissues and organs by the blood in proportion to their water contents, and deposited in those tissues and organs by the blood. Brain tissue and muscle have a high water content, so the brain and muscle receive a substantial share of the distributed alcohol. On the other hand, fat tissue contains very little water so very little alcohol will be deposited in the drinker’s body fat.

The affinity of alcohol for water, and its lack of affinity for fat, helps explain an important difference in the way alcohol affects women and men. Pound for pound,

the typical female’s body contains less water than does the typical male’s. This is because males generally have more muscle mass than do females. Also, females generally have more fatty tissue, designed in part to protect a child in the womb. The typical male body is about 68% water, and the typical female only about 55%. Thus, when a woman drinks alcohol, she has less water — pound for pound — in which to distribute the alcohol. Thus, if a woman and a man who weighed exactly the same drank exactly the same amount of alcohol under the same circumstances, the woman’s blood alcohol concentration (BAC) would climb higher than his. This is because more of the alcohol will remain in the woman’s blood stream than in the man’s blood stream, because more of the alcohol would leave the man’s blood stream and be deposited in the muscle tissues.

When we couple this to the fact that the average woman is smaller than the average man, it becomes apparent that a given amount of alcohol will cause a higher BAC in a woman than it usually will in a man.  This explains why the average female will usually become intoxicated sooner than the average male, assuming they drink the same amount of alcohol (remember these are averages). This is because since more of the alcohol remain in the blood stream, more alcohol gets to the brain. In the man, alcohol leaves the blood stream and is deposited in muscle mass, thus less alcohol gets to the brain.

Thus from a practical perspective, when consuming alcohol, women should consider the fact that they will achieve a higher BAC than will a man, drinking the same alcohol beverages.

For example, consider “Jack,” who weighs 170 lbs., drinking five Corona beers (4.84 alcohol concentration) on an empty stomach. He starts drinking at 9:00 p.m. and takes his last drink at 12:00 midnight, thus consuming the beers over three hours. Jack’s BAC would peak at around 12:30 a.m. at 0.069% (+/- 0.027%). Now consider Jill, also weighs 170 lbs., drinking the same five Corona beers on an empty stomach. She also starts drinking at 9:00 p.m. and takes her last drink at 12:00 midnight, consuming the beers over three hours. Jill’s BAC would peak at about 12:30 p.m. at 0.081% (+/- 0.033%).

In this example, the amount of alcohol consumed was the same – five Corona beers. The circumstances surrounding the drinking were also the same – both Jack and Jill each weighed170 lbs, both drank on empty stomachs (no food), and both consumed the five beers spread over the same three hour period.   Yet at 12:30 a.m., Jack’s blood alcohol concentration (BAC) would peak at .069% and Jill’s BAC would peak at about .081%.   (The above conclusions are based on average absorption and elimination rates). Keep in mind that every human being, male and female, may have different absorption and elimination rates at any given time.

In this specific situation, it would be unlawful for Jill to drive a motor vehicle at 12:30 a.m. because her BAC at that time is “0.080% or more at the time of driving.”   Considering that Jack’s BAC peaked at 0.069% at 12:30 a.m., he would never have reached 0.080% under this specific scenario and could drive legally assuming he is not impaired by the alcohol (under the influence).

In the next part of this article, I will discuss how alcohol is eliminated from the body. Stay tuned… and until then, be safe.