Having one or two drinks with friends is a fun way to socialize, but you don't want to overdo it and make a fool of yourself. If you know your level of tolerance to alcohol, you can pace yourself and avoid embarrassment and accidentally driving while over the limit.
Unfortunately, no alcohol tolerance quiz can accurately tell you how you're dealing with the alcohol you're putting into your system. But if you understand the effects alcohol has and how fast it's eliminated from the human body, you can learn how to drink sensibly.
How Alcohol Affects You
Your feelings of intoxication change as your blood alcohol level rises. At a BAC (blood alcohol concentration) of 0.01 to 0.05, you probably don't feel very different from normal, though in fact you're less inhibited, more sociable, talkative and self-confident, and generally happier. If you continue to drink and your BAC rises to 0.03 to 0.12, you begin to lose judgment and control and find it harder to pay attention; your fine motor skills become less efficient. At a BAC of 0.09 to 0.25, your reaction times increase, your balance is impaired and you feel drowsy, disoriented, confused and dizzy.
The human body eliminates alcohol at a roughly constant rate, so if you drink alcohol faster than this rate, your blood alcohol concentration rises. For most people the rate of elimination is 1/2 ounce of alcohol, or one average drink per hour. Obviously, certain drinks, like potent cocktails, contain more alcohol than the average drink and so your body takes longer to metabolize it. Chronic alcohol users eliminate alcohol faster than average drinkers, and their internal organs develop resistance to alcohol's effects – but they still suffer from impaired functioning at BACs that exceed safety limits for driving and job performance.
How to Know Your Alcohol Limit
Your sex, muscle mass, medications you're taking and how recently you ate all affect how quickly alcohol builds up in your blood. Alcohol dissolves into the water in your body but not the fat, so women feel its effects faster than men because their bodies carry proportionally more fat. Conversely, alcohol levels rise more slowly in the blood of heavily muscled individuals because their body mass contains more water. Also, birth control pills and certain other medications slow down the metabolization of alcohol, causing it to become more concentrated in the blood.
The absence or presence of food in your stomach affects how quickly your body absorbs alcohol. If you drink on an empty stomach, the alcohol passes quickly into the small intestine, which is where your body absorbs the most alcohol. A full stomach prevents alcohol from reaching the small intestine quickly, slowing its absorption and reducing its buildup in the blood. What's more, your body is more efficient at eliminating alcohol when it's at a low concentration, so drinking after eating means a lower overall BAC, on average.
How to Drink Responsibly
Whatever your tolerance level, it makes sense to place limits on alcohol when you're out socializing or even enjoying a quiet beer at home. One of alcohol's effects is to impair your judgment and self-control, so to help yourself drink moderately and avoid binge drinking, set some parameters before you begin to indulge. Aim to drink only one drink per hour, or fewer if you're drinking spirits, cocktails or other potent drinks. Eat before you drink; don't play drinking games; drink water between drinks, and set a limit on the number of drinks you'll drink.
Jenny Green has a Masters in English literature and has been a freelance writer since 2008.