Alcohol Education

Standard Serving

A standard serving of alcohol, or "one drink" contains 14 grams (0.5 oz) of pure alcohol (ethanol). 

The amount of alcohol in the drink is more important than the volume of liquid. Different types of drinks contain different concentrations of alcohol. You might see the concentration of alcohol in the drink expressed as a percent (e.g. 40% alcohol by volume), or as a proof. Proof is simply the percentage multiplied x2, so a drink with 40% alcohol by volume is 80 proof. 

Blood Alcohol Content

Blood Alcohol Content (BAC) is a measure of alcohol in the blood as a percentage. It is calculated in grams per 100 mL of blood, so a BAC of 0.08 means your blood is 0.08% alcohol by volume.

Using a breathalyzer, BAC is measured as grams per 210 Liters of breath (since the ratio of breath alcohol to blood alcohol is 2,100:1). All the calculations are done inside the device, so the number on the display represents the percentage of alcohol in your blood rather than on your breath.

Calorie Source

Alcohol itself is a source of calories. The number of calories in a drink is primarily determined by the alcohol content, rather than the amount of sugar that is added to the drink. That's because alcohol is more calorie dense than carbohydrates. 

Alcohol is a source of "empty calories," which means it is calorie dense but does not provide other nutrients, like vitamin and minerals. 

This table shows the relative number of calories (calories per gram) coming from each macro-nutrient group. 

Dehydration

Alcohol in the bloodstream causes the pituitary gland in the brain to block the creation of vasopressin. This causes the kidneys to send water directly to the bladder rather than reabsorbing filtered water into the bloodstream. This diuretic effect increases as the blood alcohol content increases, and can lead to dehydration - a contributing factor to hangovers. 

Studies have shown that drinking 250 mL of alcoholic beverage causes the body to expel between 800-1000 mL. This means that the body is releasing more than just the liquid being consumed. One way to decrease the effect is to keep your BAC low, and alternate between alcoholic and non-alcoholic drinks (preferably water).

Potential Health Benefits

There is no "one size fits all" approach to potential health benefits from alcohol. As little as one drink a day for women has been linked to increased risk for cancer of the breast, liver, rectum, throat, mouth, and esophagus. However, numerous studies dating back decades have shown a positive relationship between moderate alcohol consumption and heart health. 

The benefits for heart health are more prominent in men over 40 and women over 50, and only when consumption is limited to no more than 1 drink a day for women, or 2 drinks a day for men

Factors like individual genetics, family history of cancer, family history of heart disease, high blood pressure, cholesterol, and stress level need to be considered to determine if drinking a small amount will end up being harmful or helpful. Experts agree that for people who don't already drink, they should not begin drinking just to gain a small possible benefit. There is no universally "safe" level of drinking other than abstaining (WebMD: Alcohol and Your Health).

Alcohol is a toxin that must be neutralized or eliminated from the body. Ten percent of alcohol is eliminated through sweat, breath, and urine. Alcohol is volatile (will evaporate in air), so when alcohol in the blood comes in contact with air in the alveoli of the lungs, it can be transferred out of the body through breath.

The liver is the primary organ responsible for the detoxification of alcohol. Liver cells produce the enzyme alcohol dehydrogenase which breaks alcohol into ketones at a rate of about 0.015 g/100mL/hour (reduces BAC by 0.015 per hour). Nothing will speed up the rate of detoxification, but the effective metabolism of alcohol can be limited by medications and liver damage.

When the rate of consumption exceeds the rate of detoxification, BAC will continue to rise.

How Fast Can You Sober Up?

Alcohol leaves the body at an average rate of 0.015 g/100mL/hour, which is the same as reducing your BAC level by 0.015 per hour. For men, this is usually a rate of about one standard drink per hour. However, there are other factors that affect intoxication level (gender, some medications, illness) that will cause BAC to rise more quickly, and fall more slowly. 

Example: At an average rate of -0.015/hr, how long would it take someone with a BAC of 0.20 to sober up?

Can You Speed Up This Process?

Once alcohol is in the bloodstream, it can only be eliminated by the enzyme alcohol dehydrogenase, sweat, urine, and breath. Drinking water and sleeping will not speed up the process. Coffee, energy drinks, and a cold shower will not sober you up faster. These might make you feel more awake, but caffeine and cold showers will not pull alcohol out of the blood - and thus will not lower your BAC level.

Tolerance means that after continued drinking, consumption of a constant amount of alcohol produces a lesser effect or increasing amounts of alcohol are necessary to produce the same effect.

Humans develop tolerance when their brain functions adapt to compensate for the disruption caused by alcohol. "Chronic heavy drinkers display functional tolerance when they show few obvious signs of intoxication even at high blood alcohol concentrations (BAC's), which in others would be incapacitating or even fatal"(Chesher & Greeley, 1992).

What's the Difference?

Imagine two people with different levels of tolerance, but the exact same BAC level. How are they different?

Notice anything? The things that don't improve with tolerance are pretty important for things like driving a car! That's why the legal BAC limit to drive is a set number, and does not depend on whether or not the person has a high tolerance. 

Problems Resulting from High Tolerance

• Physical damage and impairment are occurring without your knowledge.  With tolerance, you feel less drunk, so you’re less able to accurately judge your ability to function.
• Your body no longer protects you the way it is meant to – since you’re less likely to vomit or pass out, you may reach even higher, more toxic BAC levels.
• When you develop tolerance, you can no longer experience the “buzz” – you don’t get the same euphoric effects at low doses.
• It’s expensive – since you don’t feel the effects as quickly, you end up buying more drinks.
• Tolerance and withdrawal are the two things that distinguish alcohol abuse from alcohol dependence – if you’re building your tolerance, you’re moving toward physical addiction.

Alcohol poisoning is a condition caused by high concentrations of alcohol in the blood. Blood alcohol concentration rises as alcohol is consumed in large quantities and over short periods of time. 

Symptoms

• Person cannot be awakened
• Person has cold, clammy, pale, or bluish skin
• Person has slow, shallow, or irregular breathing
• Person is vomiting while passed out and does not wake up

These symptoms are typical of a BAC level in the vicinity of .25-.40.  At that level, the depressant effects of alcohol can simply slow the breathing and heart rate down to a point where a person enters a coma and may die.

However, alcohol can kill before a deadly BAC level is reached. If someone vomits while asleep or passed out, and they are unable to clear their mouth (or if they are asleep on their back), death may occur from asphyxiation. In other words, there is a risk the person could drown on their vomit. This is a risk if the person is drunk enough to vomit, even if they do not have other symptoms of alcohol poisoning.

If You Suspect Alcohol Poisoning...

• Call 911 if someone shows symptoms of alcohol poisoning
• Do not leave them alone
• Do not put them in bed to sleep it off
• If they pass out, put them on their side to prevent choking on vomit
• If breathing stops, perform CPR or find someone who knows how

Prevent Alcohol Poisoning in the First Place

It's better to avoid a crisis altogether. Here are some tips to prevent alcohol poisoning in the first place:

• If you go out with friends, stay together as a group
• Let someone else know what you are doing and who you are with
• Set a limit. Before you go out, decide how many drinks you will have.
• Know the alcohol content and serving size of what you plan to drink.
• Follow other risk reduction techniques.