Study Finds Just One Drink Per Day Can Shrink Your Brain

Puzzled man in a van

A long-standing viewpoint has been that one alcoholic beverage per day will not cause significant harm. In fact, the Centers for Disease Control and Prevention still cite two drinks or less per day as being “moderate drinking” for men and one drink or less per day as “moderate drinking” for women.

Despite the known harms of alcohol consumption, there is still a widely believed notion that moderate alcohol consumption is perfectly okay. However, new research published in the journal Nature suggests that even just one alcoholic beverage per day can reduce brain size over time.

Hopefully, these findings will serve as a wake-up call that the only safe alcohol consumption is NO alcohol consumption.

Study Findings: Alcohol Consumption and Brain Gray and White Matter

It has been known for some time that excessive alcohol consumption is harmful to one’s health. Despite that knowledge, millions of Americans still consume alcohol in what they believe to be “moderate” levels of drinking.

Recently, researchers compiled evidence suggesting that even consuming just one alcoholic beverage per day prematurely ages the brain by reducing white and gray matter within the brain. The conclusion of the research was that Americans who drank alcohol frequently, even if they only had one or two drinks per day, still experienced advanced “aging” of their brains due to loss of white and gray matter.

brain x-ray

The study arrived at the following key findings:

  • People aged 50 who drank a pint of beer or a 6-ounce glass of wine (each the equivalent of two alcohol units) every day in the month leading up to the study had brains that appeared to be two years older than those 50-year-olds who only drank half a beer (one alcohol unit). The relative “age" of the brain was determined by the amount of gray and white matter in the brain, compared to what is considered normal in gray and white matter for healthy, non-drinking adults of the same age.
  • The brains of people aged 50 who drank three alcohol units per day in the month leading up to the study had reductions in gray and white matter that looked as if their brains had aged 3.5 years beyond the participants’ actual age.
  • The brains of people who did not drink at all prior to the study but who began having one unit of alcohol every day for the month leading up to the study showed the equivalent of one-half-year of brain aging.
  • Finally, study participants who drank the equivalent of four units of alcohol per day had brains that measured loss of gray/white matter to the tune of an additional ten years of aging (beyond the individual’s actual age).

For the study, a "unit of alcohol" was clarified as just 8 grams of pure alcohol, making a standard beer or a glass of wine two units of alcohol. From the data, even individuals who had just one alcoholic beverage per day still manifested a slight loss in gray and white brain matter.

And as one can imagine, those individuals who drank more alcohol per day experienced exponentially higher losses in brain matter, equivalent to the volume of alcohol they drank per day.

A Breaking Revelation

The study cited above drew on a dataset of 36,000 people living in the UK, giving the researchers a large study group to work with. The researchers were able to account for variables such as age, sex, smoking status, socioeconomic status, genetic ancestry, and overall head size.

“The fact that we have such a large sample size allows us to find subtle patterns, even between drinking the equivalent of half a beer and one beer a day.”

Though the study does not account for all potential variables, the researchers felt confident in the conclusion. Quoting coauthor Gideon Nave, “The fact that we have such a large sample size allows us to find subtle patterns, even between drinking the equivalent of half a beer and one beer a day. Having this dataset is like having a microscope or a telescope with a more powerful lens. You get a better resolution and start seeing patterns and associations you couldn’t before.” The findings put forth a powerful claim, suggesting that Americans should not consume alcohol at all, certainly not with any frequency.

alcoholic thinks

No Amount of Alcohol Consumption Is Healthy

Recent studies like the one discussed here and others have led to a profound change in how the medical community views alcohol. It led to the World Heart Foundation publishing a report firmly stating that no amount of alcohol is good for the heart. Beatriz Champagne, chair of the advocacy committee that produced the report, stated, “At the World Heart Federation, we decided that it was imperative that we speak up about alcohol and the damages to health, as well as the social and economic harms because there is an impression in the population in general, and even among health care professionals, that it is good for the heart. It is not, and the evidence has increasingly shown that there is no level of alcohol consumption that is safe for health.”

Any Amount of Alcohol Consumption Poses Risk

The recent study only complements a considerable wealth of existing data on the harms and dangers of consuming alcohol. According to the National Institute on Alcohol Abuse and Addiction:

Teenagers are drinking
  • Approximately 14.5 million Americans are now addicted to alcohol, meaning that 5% of Americans over the age of 12 cannot control their alcohol consumption.
  • An estimated 414,000 Americans between the ages of 12 and 17, almost 2% of that age group, also meet the criteria for alcohol addiction.
  • Approximately 95,000 Americans die from alcohol-related causes each year.
  • Alcohol-related emergency department visits are rising, marking a 47% increase between 2006 and 2014 (translating to an annual average increase of 210,000 alcohol-related emergency department visits).
  • In 2019, alcohol-impaired driving fatalities accounted for 10,142 deaths, almost one-third of driving fatalities.
  • The economic burden of alcohol abuse in America is also quite high, accounting for a $249 billion cost on the American people.
  • The family burden of alcohol abuse in America is also quite significant, with more than 10% of American children growing up in a family with at least one parent who is addicted to alcohol.

These data items point to one truth: Those who misuse alcohol must seek treatment. Further, those who consume alcohol, even in "moderation,” harm their neurological health and put themselves at risk for alcohol misuse.

Alcohol should be avoided. And those who do consume it and become addicted to it should receive help at qualified drug and alcohol rehab centers. If someone you care about is using alcohol and cannot stop using it, make sure they get help today.


Reviewed by Claire Pinelli, ICAADC, CCS, LADC, RAS, MCAP, LCDC



After working in addiction treatment for several years, Ren now travels the country, studying drug trends and writing about addiction in our society. Ren is focused on using his skill as an author and counselor to promote recovery and effective solutions to the drug crisis. Connect with Ren on LinkedIn.