Just 3 Drinks Per Week May Raise Dementia Risk

Though we’ve previously reported about alcohol’s potential health benefits, like improving mood or supporting heart health, more and more research suggests that drinking alcohol has far more negative consequences than benefits. 

In fact, evidence has surfaced questioning some of these previous findings and alcohol’s supposed benefits. For example, in January 2025, the U.S. Surgeon General issued an urgent warning about alcohol consumption and cancer risk. The advisory states that alcohol consumption increases the risk of at least seven types of cancer, including oral, breast, liver and colorectal. It also states that alcohol is now the third leading preventable cause of cancer, and is responsible for 100,000 new cancer cases and 200,000 deaths per year in the U.S. alone.

And what about the brain? If you’re someone who likes to unwind with a cocktail or use some “liquid courage” to relax and have fun while out with friends, it may seem like alcohol could be beneficial. But is it? There is older evidence that has suggested that light-to-moderate drinking may have protective benefits for the brain. That said, newer research is challenging those findings.

Researchers from the U.S. and the U.K. joined forces to examine the data from two large studies to try and clear up some of the confusion regarding alcohol consumption and brain health. Stating that this study is the largest combined observational and genetic study to date on this topic, they published their findings in BMJ Evidence-Based Medicine. Let’s break down what they found.

How Was This Study Conducted?

Researchers analyzed data from two large cohorts: the U.S. Million Veteran Program and the U.K. Biobank. A total of almost 560,000 people were included, aged 56 to 72 years at baseline. Those in the U.S. Million Veteran Program were followed for an average of four years, while the U.K. cohort had an average follow-up period of 12 years.

Both cohorts were observational studies that collected demographic information, health history, medical information, family history and bloodwork from each participant. Observational studies collect information and then group participants based on certain factors to observe specific outcomes; they’re basically a snapshot in time. 

In this case, researchers considered whether a relationship exists between alcohol consumption and people who did and did not develop dementia. Dementia is a general term for loss of memory, language, problem-solving and other abilities that are severe enough to interfere with everyday life. Alzheimer’s disease is the most common type of dementia.

The other part of this study used Mendelian randomization (MR), which considers genetic variables that mimic the randomization process. MR tends to be a more accurate process of linking relationships than observational studies, because it is less susceptible to confounding factors and bias in participants’ and researchers’ reporting. This genetic analysis included 2.4 million participants.

What Did This Study Find?

For the first part of this study, based on observational data, researchers found what many previous studies have found: Heavy drinkers (>40 drinks per week), non-drinkers and those with alcohol use disorder (AUD) had a higher risk of developing dementia compared to light drinkers (<7 drinks per week). Specifically, heavy drinkers and non-drinkers showed a 41% higher risk of dementia, and those who were alcohol-dependent had a 51% higher risk.

But the Mendelian randomization genetic analysis didn’t match up with the observational study results. Instead, these results suggest that as genetically-predicted alcohol consumption increases, so does the risk of dementia—which means that even light drinkers have an increased risk and non-drinkers have a lower risk. 

For example, for every extra one to three drinks per week, the risk of dementia increased by 15%. And a doubling in the genetic risk for AUD was associated with a 16% higher risk of dementia. These results suggest that there is no “safe” recommendation for alcohol intake as far as dementia goes. 

But why did the observational study suggest that non-drinkers have a higher risk of dementia, while light drinkers had a lower risk? Researchers note the limitations of observational studies, including bias and inaccurate reporting of data by participants. They also state that observational studies only measure temporary, fluctuating characteristics that are influenced by environmental and stage-of-life factors, whereas Mendelian randomization uses stable, long-term traits.

Researchers note that while Mendelian randomization may be more accurate in identifying relationships that suggest causation, it still has its limits. In this case, they state that the strongest associations were found in individuals of European descent, so these results may or may not apply to other races and ethnicities. They also note that MR relies on genetic assumptions that can’t always be verified.

How Does This Apply to Real Life?

If you struggle with the tug-of-war of wanting to enjoy a drink with friends, but also wanting to be healthy, it’s important to consider what we currently know about alcohol. Besides alcohol being linked to increased cancer risk, we know that it also influences the gut microbiome, creating an increase in endotoxin levels. These toxins increase inflammation in your body, which has been linked to pretty much every disease you can think of, from heart disease and cancer, to diabetes and autoimmune diseases. 

Regular alcohol consumption has also been linked to declining grey and white brain matter—in other words, smaller brains. And this decline in brain volume was even seen in people who drank as little as one drink per day, with brain mass loss increasing as the number of drinks increased. Another study suggests that heavier drinkers (eight or more drinks per week) had a higher risk of dementia than non-drinkers, including a whopping 133% higher risk of brain lesions. 

To drink or not to drink comes down to weighing the pros against the cons and deciding which is more important to you. It’s also wise to examine the reasons you choose to imbibe. For example, if you drink to relax, consider trying other ways to unwind, like going for a walk, practicing yoga or meditation, journaling, getting out into nature, cooking up a healthy meal (we might have a few ideas!) or calling a friend. 

Consider switching to mocktails if you drink because you like the taste of it.  We love our Mojito Mocktails, Tart Cherry Nighttime Mocktail or No-Added-Sugar Sangria Mocktail. And if you drink to try and fit in—and maybe even have difficulty getting your friends to stop pouring you a glass—it might be time to switch your friend group. 

Our Expert Take

Drinking is a highly personal choice, and it’s wise to consider the potential harm alcohol may inflict on your body and brain. This study suggests that any amount of drinking—including light and moderate—has negative consequences to brain health and increases the risk of dementia. 

If you feel like you can’t cope with life without alcohol, it may be time to reach out for help. If you or someone you know is struggling with alcohol dependence, misuse or addiction, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 800-662-4357 for information on support and treatment facilities in your area. It’s important to note that because your body can become physically dependent on alcohol, it can be dangerous to quit cold turkey; for this reason, alcohol detox under medical supervision is recommended.