How much alcohol a day?

Dear Boundaries, 

What's "too much" alcohol will vary for each person, based on several variables such as physiology, risk factors, and how it impacts your daily life. Some may choose to drink in moderation while others may opt to refrain completely. Often, drinking thresholds are separated based on sex assigned at birth due to the typical body composition for each group, which impacts the rates at which alcohol is processed (more on this in a bit). Guidelines for light to moderate drinking include limiting alcohol intake to one drink or less a day for people assigned female at birth and two drinks or less a day for people assigned male at birth. The standard for one drink is 1.5 ounces of liquor (40 percent alcohol content), 5 ounces of wine (12 percent alcohol content), or 12 ounces of beer (5 percent alcohol content). While recommended drinking guidelines may offer a helpful starting point, ultimately only you can evaluate your relationship with alcohol and decide what works best for you. 

If you’re thinking about the immediate effects of alcohol consumption, the degree to which alcohol impacts health and behavior is directly related to blood alcohol concentration (BAC). A person's BAC depends on the amount of alcohol consumed and how quickly it's metabolized. Metabolism may be affected by such factors as body weight, relative amounts of body fat and lean body mass, and sex assigned at birth. People assigned female at birth tend to have more body fat and less lean body mass than those assigned male at birth. Since lean body mass contains water and ethanol (alcohol) is soluble in water, those with greater lean body mass will have a lower BAC after consuming a given amount of alcohol, all else being equal. Also, people assigned female at birth typically have less of the alcohol dehydrogenase (ADH) enzyme necessary for alcohol to be broken down in the stomach, which causes more alcohol to go directly into the bloodstream before it is processed. When alcohol is consumed, it passes from the stomach and intestines into the blood, a process called absorption. While all ingested alcohol is eventually absorbed, the rate of absorption is determined by a variety of factors, including the amount of food in the stomach, the rate at which alcohol is consumed, and other medications or drugs in your system. Over-intoxication occurs when the body absorbs more alcohol than it metabolizes. For most people, the liver metabolizes approximately one standard drink per hour.  

All that said, the vast majority of alcohol research is conducted with cisgender research participants, and there is very little research on recommended alcohol consumption guidelines for transgender or intersex people. In the absence of hormone replacement therapy (HRT), transgender people may be able to follow the guidelines for their sex assigned at birth; transgender people on HRT may wish to consult with a health care provider about what levels of alcohol consumption are recommended based on their individual history. Similarly, intersex people may also wish to seek medical guidance. 

While many promote the health benefits of moderate alcohol consumption (such as reducing the risk of heart disease or stroke), the evidence tends to be limited, and it’s not recommended that non-drinkers start drinking to obtain these promoted health benefits. What’s a bit clearer is that the health risks are more likely to increase as more alcohol is consumed. According to National Institute on Alcohol Abuse and Alcoholism (NIAAA), heavy drinking is considered four or more drinks a day or more than 14 drinks in a week for people assigned male at birth and three or more drinks a day or more than seven drinks a week for people assigned female at birth. Binge drinking is four or more drinks on one occasion for people assigned female at birth and five or more drinks on one occasion for people assigned male at birth. Drinking excessively is associated with several short- and long-term health consequences (and no health benefits), including: 

• Alcohol poisoning 
• Alcohol abuse or dependence  
• Certain cancers  
• Pancreatitis 
• Stroke 
• High blood pressure 
• Liver damage such as cirrhosis (liver scarring) 
• Miscarriage, stillbirths, or fetal brain damage among pregnant people 
• Alcohol withdrawal syndrome 
• Violence such as homicide or suicide 
• Accidental serious injury or death 
• Sudden death (if you already have cardiovascular disease) 
• Heart muscle damage, which could lead to heart failure 

While limited libations pose little risk for most, others are at a higher risk of adverse health outcomes. It’s advised to avoid alcohol entirely if you: 

• Are younger than 21 
• Are pregnant or trying to become pregnant 
• Have been diagnosed with alcoholism or alcohol addiction, or you have a strong family history of alcoholism 
• Are driving or planning to drive 
• Had a hemorrhagic stroke (when a blood vessel in your brain leaks or ruptures) 
• Have liver or pancreatic disease 
• Have heart failure or you've been told you have a weak heart 
• Take prescription or over-the-counter medications that can interact with alcohol 

Both lists are adapted from the Centers for Disease Control and Prevention (CDC) and Mayo Clinic. 

It’s worth mentioning again that only you can decide what type of relationship you have with alcohol. While alcohol consumption does have some risks to physical health, it may also provide benefits to emotional, social, or cultural well-being. Balancing those risks and benefits will be different for each person based on how alcohol consumption makes them feel, impacts their relationships, and contributes to their interests and life goals. If you'd like to explore your drinking behaviors, you might be interested in speaking with a health promotion specialist or mental health professional to learn more. The Go Ask Alice! Q&A Alcohol habit forming? might be of interest if you want to better understand unhealthy relationships with alcohol. In any case, it's never last call when it comes to a healthy pour of knowledge that informs decisions about substance use. Cheers to that!