I recently had dinner with colleagues and two of us ordered wine with our meal. The waiter asked our third dinner companion, a well-known and respected researcher who works on the cellular effects of alcohol, if he would like anything to drink and he replied, “No thanks. I don’t enjoy drinking alcohol knowing that every sip is basically putting poison into your body.” Ouch.

He’s not wrong. Alcohol is broken down by enzymes in our body into a chemical called acetaldehyde. Acetaldehyde is a carcinogen, a toxin, described as a “clear liquid that burns easily”. It’s used to make other chemicals like disinfectants and perfumes. It can make breathing difficult. It’s what causes a hangover and makes it hard to remember things after drinking alcohol; that’s the result of acetaldehyde poisoning damaging your liver, your brain, and getting into your blood to harm membranes throughout your body. So, yeah, alcohol’s not good for you.

But…really? If you don’t drink heavily, is it really that bad? Is there a level that is “safe” to drink?

The answer to that question is, it depends.

Some people carry a genetic variant that doesn’t allow them to break down acetaldehyde, so it builds up in their bodies when they drink. This means that even a small amount of alcohol causes facial flushing, elevated heartrate, headaches, and nausea. It also leads to higher rates of esophageal cancer. The genetic variant is primarily found in individuals of East Asian ancestry and is sometimes referred to as the “Asian Flush”. It turns out that when alcohol makes you sick every time you drink it’s highly protective against developing alcohol problems.

But for the rest of us, who don’t experience such extreme adverse reactions to alcohol, is it really so bad to have the occasional glass of wine with dinner?

A new huge global study set out to answer that question. And it turns out that the answer there is complicated too.

It’s hard to figure out how much alcohol affects your health because to answer that question, you’d want a version of you that drinks and a version of you that doesn’t drink to test how your health is affected. That’s why scientists study identical twins to learn about the effects of environmental exposures on health outcomes. But most of us don’t have a genetic copy of ourselves, so instead scientists estimate overall alcohol consumption rates in a population, using a combination of alcohol sales and self-report data, and look at the association between how much alcohol is consumed and how prevalent alcohol-related diseases are in the population.

Some of the best data we have on alcohol consumption patterns and health consequences comes from the Global Burden of Diseases, Injuries, and Risk Factors Study, which collected data from 204 countries and territories, for individuals aged 15–95 years old, from 1990 to 2020. It’s the most comprehensive study of health outcomes in the world.

This is because how much alcohol affects your health is related to how good your health would be if you didn’t drink. Based on the base rates of overall health for a particular age group in a particular area, we can calculate the consumption level where your health risks are no worse than for people who don’t drink, which is called the “non-drinker equivalence”.

Young people are generally healthy, so drinking alcohol has more obvious effects on health. For individuals ages 15–39, the non-drinker equivalence is essentially zero, meaning that any amount of alcohol consumed affects one’s health for the worse. In young people who drink, most of the harm comes from injuries related to alcohol consumption.

For individuals aged 40–65 years, because overall health starts to decline, it’s only when people are drinking more than 1–2 drinks per day that you see adverse effects on health directly attributable to alcohol consumption. There’s also a shift in that alcohol having its greatest adverse effect by impacting chronic health conditions, including cardiovascular disease and cancer.

In individuals over 65, the major causes of disease associated with alcohol were cardiovascular diseases, though it becomes difficult to estimate what level of alcohol is associated with significantly worse health since overall health is declining more rapidly at this stage of life.

A couple other key take-aways from the study: among individuals consuming harmful levels of alcohol, 59% were young people 15–39 years of age, and 77% were male.

So, is it safe to drink in moderation? If you’re young, the answer is no; alcohol consumption is clearly associated with worse health related outcomes. If you’re over 40, and as you age from there, the answer appears to be, probably. If you’re not having more than a drink or so a day, your health probably isn’t drastically worse than what would be expected if you didn’t drink. That said, the healthiest choice is surely a non-alcohol beverage. Mocktails anyone?

I recently had dinner with colleagues and two of us ordered wine with our meal. The waiter asked our third dinner companion, a well-known and respected researcher who works on the cellular effects of alcohol, if he would like anything to drink and he replied, “No thanks. I don’t enjoy drinking alcohol knowing that every sip is basically putting poison into your body.” Ouch.

He’s not wrong. Alcohol is broken down by enzymes in our body into a chemical called acetaldehyde. Acetaldehyde is a carcinogen, a toxin, described as a “clear liquid that burns easily”. It’s used to make other chemicals like disinfectants and perfumes. It can make breathing difficult. It’s what causes a hangover and makes it hard to remember things after drinking alcohol; that’s the result of acetaldehyde poisoning damaging your liver, your brain, and getting into your blood to harm membranes throughout your body. So, yeah, alcohol’s not good for you.

But…really? If you don’t drink heavily, is it really that bad? Is there a level that is “safe” to drink?

The answer to that question is, it depends.

Some people carry a genetic variant that doesn’t allow them to break down acetaldehyde, so it builds up in their bodies when they drink. This means that even a small amount of alcohol causes facial flushing, elevated heartrate, headaches, and nausea. It also leads to higher rates of esophageal cancer. The genetic variant is primarily found in individuals of East Asian ancestry and is sometimes referred to as the “Asian Flush”. It turns out that when alcohol makes you sick every time you drink it’s highly protective against developing alcohol problems.

But for the rest of us, who don’t experience such extreme adverse reactions to alcohol, is it really so bad to have the occasional glass of wine with dinner?

A new huge global study set out to answer that question. And it turns out that the answer there is complicated too.

It’s hard to figure out how much alcohol affects your health because to answer that question, you’d want a version of you that drinks and a version of you that doesn’t drink to test how your health is affected. That’s why scientists study identical twins to learn about the effects of environmental exposures on health outcomes. But most of us don’t have a genetic copy of ourselves, so instead scientists estimate overall alcohol consumption rates in a population, using a combination of alcohol sales and self-report data, and look at the association between how much alcohol is consumed and how prevalent alcohol-related diseases are in the population.

Some of the best data we have on alcohol consumption patterns and health consequences comes from the Global Burden of Diseases, Injuries, and Risk Factors Study, which collected data from 204 countries and territories, for individuals aged 15–95 years old, from 1990 to 2020. It’s the most comprehensive study of health outcomes in the world.

This is because how much alcohol affects your health is related to how good your health would be if you didn’t drink. Based on the base rates of overall health for a particular age group in a particular area, we can calculate the consumption level where your health risks are no worse than for people who don’t drink, which is called the “non-drinker equivalence”.

Young people are generally healthy, so drinking alcohol has more obvious effects on health. For individuals ages 15–39, the non-drinker equivalence is essentially zero, meaning that any amount of alcohol consumed affects one’s health for the worse. In young people who drink, most of the harm comes from injuries related to alcohol consumption.

For individuals aged 40–65 years, because overall health starts to decline, it’s only when people are drinking more than 1–2 drinks per day that you see adverse effects on health directly attributable to alcohol consumption. There’s also a shift in that alcohol having its greatest adverse effect by impacting chronic health conditions, including cardiovascular disease and cancer.

In individuals over 65, the major causes of disease associated with alcohol were cardiovascular diseases, though it becomes difficult to estimate what level of alcohol is associated with significantly worse health since overall health is declining more rapidly at this stage of life.

A couple other key take-aways from the study: among individuals consuming harmful levels of alcohol, 59% were young people 15–39 years of age, and 77% were male.

So, is it safe to drink in moderation? If you’re young, the answer is no; alcohol consumption is clearly associated with worse health related outcomes. If you’re over 40, and as you age from there, the answer appears to be, probably. If you’re not having more than a drink or so a day, your health probably isn’t drastically worse than what would be expected if you didn’t drink. That said, the healthiest choice is surely a non-alcohol beverage. Mocktails anyone?