Standard drink size and alcohol intake recommendations differ between countries.

In the United States, a standard drink contains approximately 14 grams of pure alcohol, which is the amount typically found in 12 ounces (355 mL) of regular beer, 5 ounces (150 mL) of wine, or 1.5 ounces (45 mL) of spirit.

Keep in mind that while there are standard drink sizes, drinks can vary in alcohol content, for instance when drinking an India pale ale (IPA) beer or higher proof liquor.

According to the Dietary Guidelines for Americans, U.S. Department of Agriculture, and U.S. Department of Health and Human Services, moderate drinking involves up to one drink per day for women and up to two drinks per day for men.

Research suggests that only about 2% of those who drink within these limits have an alcohol use disorder (3).

Problematic drinking can relate to binge drinking, heavy drinking, alcoholism, or alcohol dependence.

The Substance Abuse and Mental Health Services Administration (SAMHSA) defines binge drinking as four or more drinks for women or five or more drinks for men on the same occasion, meaning at the same time or within a couple of hours.

Heavy drinking or heavy alcohol use is defined as binge drinking on five or more days of the past month.

Meanwhile, alcoholism is when you have impaired control over alcohol, are preoccupied with its use, and continue to use it despite adverse consequences.

SUMMARY

Moderate alcohol consumption is one drink per day for women and two drinks per day for men. Alcohol use disorders include binge drinking, heavy drinking, and alcoholism.

Excessive drinking affects your health and almost every part of your body. It can not only damage vital organs but also affect your mood and behavior.

Brain

Consuming too much alcohol can have devastating effects on your central nervous system.

Several factors affect how and to what extent it affects your brain, including how much and how often you drink, the age you started drinking, your sex, and more.

The initial effects of alcohol on your central nervous system include slurred speech, memory impairment, and compromised hand-eye coordination.

Many studies have associated heavy chronic alcohol use with memory deficits.

Alcohol dependence is a major risk factor for developing Alzheimer’s disease, especially in women.

Furthermore, it’s estimated that alcohol-related brain damage may account for 10% of early-onset dementia cases.

Although brain damage appears to be partially reversible after a longer period of sobriety, chronic and excessive drinking can permanently impair brain function.

Liver

Liver damage is another consequence of chronic binge drinking.

Most of the alcohol you drink is metabolized in your liver. This produces potentially harmful byproducts that can damage your liver cells. As you continue drinking over time, your liver health declines.

Alcoholic fatty liver disease is the earliest stage of alcohol-induced liver damage. This condition can occur over time when too much alcohol leads to a buildup of fat in your body’s liver cells, which can hinder liver function.

This is the most common bodily response to chronic alcohol use and may develop in as many as 90% of people who chronically drink more than 5 drinks per day.

As heavy drinking continues, fatty liver disease can eventually advance to liver inflammation, cirrhosis, and even liver failure, which is a life threatening condition.

Dependency

The effects of alcohol can be mentally and physically addicting.

Feeling a compulsive urge to drink, worrying about where or when you’ll have your next drink, and finding it hard to enjoy yourself without drinking are all common signs of alcohol dependence.

The cause of this dependence can be complex. It may be caused in part by genetics and family history, but your environment can also play a large role.

Other effects

There are many other side effects of chronic alcohol use. While health effects vary between individuals, drinking is often linked to depression and anxiety.

Some people may use alcohol as a quick fix to improve their mood and reduce anxiety, but this typically only provides short-term relief. In the long term, it can worsen your overall mental and physical health.

Drinking may also affect your weight and body composition.

Though research on alcohol’s effects on weight is mixed, both moderate and heavy use has been linked to weight gain.

SUMMARY

While drinking in moderation is safe for most individuals, excessive alcohol intake and abuse can have detrimental effects on your physical and mental health.

Your sex and genetics can affect the rate at which your body metabolizes alcohol.

The primary enzymes involved in alcohol metabolism are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH).

Women often have lower ADH activity than men. Therefore, women may metabolize alcohol at a slower rate, making them more vulnerable to its effects. That said, some men have low ADH activity as well.

Alcohol’s effects on your body can also vary based on your body composition.

For instance, women’s bodies have more fat and less water than men’s bodies, on average. This may result in higher blood alcohol levels in women, even if they drink the same amount as men.

SUMMARY

Your sex, genetics, and body composition affect how your body metabolizes alcohol. Women may be more vulnerable to its effects than men.

For most people, having an occasional alcoholic beverage typically doesn’t cause harm. However, in certain situations and among specific populations, alcohol should be avoided.

Pregnancy and breastfeeding

Research has shown that there’s no safe level of alcohol use during pregnancy.

Many studies have concluded that alcohol use during pregnancy increases the risk of miscarriage, birth defects, and cognitive and developmental problems.

One study found that birth defects are four times more likely if the mother has been drinking heavily in the first trimester.

According to the Centers for Disease Control and Prevention (CDC), alcohol use during pregnancy is the leading cause of preventable birth defects, developmental disabilities, and intellectual disability in the United States.

It’s important to note that alcohol can also pass into breast milk if consumed by the nursing mother.

Breastfeeding mothers should wait for the complete elimination of alcohol from breast milk after drinking. This takes about 2–2.5 hours per drink, depending on your body size.

Other precautions

Additional reasons to abstain from alcohol include:

• Medical conditions. Alcohol may worsen preexisting health conditions like liver disease, diabetes, and kidney disease .
• Medications. Alcohol can interact with over-the-counter herbal and prescription medications, including antidepressants, antibiotics, and opioids .
• Underage drinking. Underage drinking, especially heavy and frequent intake, has been associated with immediate and chronic consequences.
• Current and recovering alcoholics. Recovering from an alcohol use disorder can be difficult. Recovering alcoholics should stop drinking completely and avoid their triggers for abuse .

SUMMARY

Alcohol use during pregnancy increases the risk of birth defects. It’s recommended to abstain from drinking if you have certain preexisting medical conditions, are underage, or take certain medications.

While drinking in moderation is safe for most individuals, heavy and chronic alcohol use can have devastating consequences for your mental and physical health.

Many factors play a role in alcohol metabolism, and the effects of alcohol vary by individual, making it tricky to set intake recommendations.

American Dietary Guidelines recommend limiting your alcohol intake to one drink per day for women and two drinks per day for men.

However, some people, such as those with certain medical conditions and pregnant women, should avoid alcohol completely.