Can Just One Drink Shrink Your Brain?

Whether you drink regularly or just enjoy the odd glass of wine on a special occasion, you have probably wondered how alcohol impacts your health.

Many studies¹ have historically reported improved brain function with moderate alcohol consumption. Red wine, in particular, has often been touted for its supposed health benefits. However, new research is now calling that thinking into question.

Drinking, even in small amounts, may be causing more harm than good.

A study² found that significant brain aging can occur with even light to moderate alcohol consumption. Just one drink a day could be affecting you more than you think.

How alcohol impacts your body and health

It’s no secret that heavy alcohol consumption harms the human body.

Despite research in the 1990s that suggested alcohol benefits health, the WHO’s International Agency for Research on Cancer classified alcohol as a level-one carcinogen³ as far back as 1988. This means alcohol is likely to cause cancer.

According to the WHO, there are three million alcohol-related deaths worldwide every year.⁴ In the US alone, roughly 95,000 people die annually from alcohol-linked causes,⁵ making it one of the most common preventable deaths.

Heavy alcohol consumption can cause a range of long-term health effects, including:

• High blood pressure, heart disease, and strokes

• Cancer of the liver, breast, colon, and more

• Memory impairment

• Immune system problems

• Mental health issues⁶ including depression and anxiety

How alcohol affects your brain

When it comes to brain health, heavy alcohol consumption can cause your brain volume to decrease, brain atrophy (a loss of brain neurons), and poorer white matter fiber integrity (associated with cognitive decline).

Are light drinkers also at risk of brain shrinkage?

A new study² of participants from the UK Biobank has found that even moderate or light alcohol consumption is associated with reduced brain volume.

Researchers accessed the brains of 36,678 healthy middle-aged and older adults. Participants were grouped by average daily alcohol intake.

The researchers found brain changes were more pronounced in participants who consumed more alcohol. They discovered alcohol consumption is negatively associated with global brain volume (brain size), regional gray matter volume, and white matter microstructure. These things are all linked to critical bodily functions and cognition.

It’s important to note that our brains naturally shrink as we age. For example, older adults⁷ may be slower at finding words and recalling names, experience mild decreases in the ability to pay attention, and find multitasking more challenging.

Alcohol can speed up this process, leading to accelerated brain shrinkage. This could cause memory, decision-making, and other important brain functions to decline faster.

Researchers in the UK Biobank study discovered that alcohol-associated brain shrinkage is equivalent to aging two years when a person in their 50s increases their drinking from a half-serving of alcohol to a full serving. A full serving is a pint of beer or a glass of wine.

There are thought to be more negative effects when more alcohol is consumed. Compared with not drinking at all, drinking four drinks a day is associated with more than ten years of brain aging.

Are you a heavy drinker?

It might come as a surprise, but heavy drinking is associated with alcohol consumption you might consider normal.

Three drinks per day for women (or more than seven drinks per week) and four drinks for men per day (or more than 14 drinks per week) are considered limits of heavy drinking as defined by the National Institute on Alcohol Abuse and Alcoholism (NIAAA).⁸

The US dietary guidelines recommend women should consume no more than one drink per day. Men should consume no more than two drinks per day.

One serving size is classified as a standard drink: a 12-ounce beer, a 5-ounce glass of 12% alcohol, or a 1.5-ounce serving of 40% alcohol.

Can a little alcohol be good for you?

In the 1990s, researchers thought moderate amounts of alcohol could benefit your heart and brain. 

Various studies fueled this thinking. Long-term observational studies compared drinkers to non-drinkers. In these studies, light to moderate drinkers consuming around one to two drinks per day frequently showed better health outcomes than non-drinkers and heavier drinkers.

For example, in a study⁹ of British doctors, light to moderate drinkers were found to have lower rates of heart disease and diabetes. They were also found to live longer. 

However, studies like this have limitations.

Many of the studies compared drinkers to non-drinkers instead of comparing lighter drinkers to heavier drinkers specifically. They also did not consider religious, social, and cultural factors for not drinking.

Importantly, researchers did not exclude past drinkers from the non-drinker category. They did not consider that abstainers (known as “sick quitters”) may have quit drinking because they were dependent in the past or had underlying health issues. This led to skewed results.

The alcohol industry was also involved in these studies, aiming to promote alcohol sales. This made the studies unreliable. Research¹⁰ found the alcohol industry has been both persuasive and biased when creating studies about moderate alcohol consumption.

Now that researchers are comparing lighter drinkers with heavier drinkers specifically, the benefits of modest alcohol consumption are no longer relevant.

Simple tips for cutting back on alcohol

Even light alcohol consumption can cause serious health effects, so cutting back or stopping your alcohol intake altogether is beneficial for your health.

Some tips for cutting back include:

Keep a diary

Do you know exactly how much you drink each week? It can be easy to lose track, particularly if you drink regularly or drink while socializing with friends.

Keeping a diary for a few weeks can help you understand exactly how much alcohol you consume. You might find you drink more than you realized. A drink or two on weekdays, and more on the weekends, can add up quickly.

Getting real about how much alcohol you drink will help you start cutting back.

Know your “why”

It’s much easier to cut back or give up alcohol if you have a strong reason for doing so. Keeping your “why” in mind could help when you feel tempted to have a drink.

Make a list of reasons that are specific to you. Some examples might include enjoying long-term health benefits, waking up with a clear mind, improved sleep, and reduced anxiety.

It’s also helpful to identify other impacts, like the opportunity to save money and adopt healthier habits.

Find other ways to have fun

Relying on alcohol for fun could mean you get less enjoyment from other activities or that you don’t dedicate any time to them.

23%¹¹ of the people in a survey reported they gave up or cut back on activities so they could drink. These other activities either gave them pleasure or were interesting to them.

Embracing healthy habits can lead to genuine fulfillment and fun instead of letting alcohol take over your life.

For example, you might meet friends for walking dates rather than after-work drinks. Making a plan to get up early on weekends for hikes, watersports, or similar activities can be a good reason not to drink the night before.

Getting into hobbies that don’t revolve around alcohol can become part of an improved positive routine.

Save alcohol for special occasions

If going cold turkey on alcohol (complete abstinence) seems too intimidating, you could try saving alcohol for special occasions.

Out of sight really can be out of mind. Try keeping alcohol out of your home so you’re not tempted to have the odd drink. Instead, buy alcohol only when there is a special occasion, like a birthday.

Get help for addiction

Have trouble cutting back? You might have alcohol dependency if you struggle to reduce your alcohol consumption or you find it has a significant impact on your activities and daily life.

If this is the case, it’s time to seek help from a professional. Get in touch with a counselor, psychologist, or doctor to discuss strategies that may work for you.

Be persistent

Don’t stop trying if you fall back into old habits. It’s natural for people, particularly those experiencing addiction, to attempt quitting drinking multiple times. Doing so takes persistence and dedication.

If you start consuming alcohol again after giving up, seek help, stay focused, and repeat the above steps. Failing a few times doesn’t mean you will never make the changes you want to make.

The lowdown

Further research is needed, but many studies now show any kind of alcohol consumption is unhealthy. Drinking just a little can still damage your health.

Finding simple ways to reduce your consumption can be good for your long-term and short-term health, both mental and physical.

Keep the following points in mind:

• One drink a day can reduce the size of your brain and lead to early cognitive decline.

• Alcohol consumption is associated with cardiovascular disease, diabetes, and strokes. It has a negative effect on your overall health.

• Alcohol is classified by the WHO as a level one carcinogen, leading to an increased risk of cancer-related illness and death.

• While more research is needed, many studies are now finding there is no safe limit to alcohol consumption. Cutting back on, or eliminating alcohol, is likely the healthiest choice.

• Finding other ways to have fun and socialize that don’t revolve around drinking can help reduce your intake.

• Be kind to yourself. If you slip up or drink more than you planned, be persistent and keep trying to make long-term changes.

• If you are struggling to cut back or believe you are dependent on alcohol, speak to a health professional such as your doctor. They can give you advice, strategies, and a referral to a dependency expert.

Sources:

1. Association of low to moderate alcohol drinking with cognitive functions from middle to older age among US adults (2020)

2. Associations between alcohol consumption and gray and white matter volumes in the UK biobank (2020)

3. Alcohol | Australian Government Cancer Australia

4. Alcohol | World Health Organization

5. Alcohol facts and statistics | National Institute of Health: National Institute on Alcohol Abuse and Alcoholism

6. A review of the effects of moderate alcohol intake on the treatment of anxiety and mood disorders (1996)

7. How the aging brain affects thinking | NIH: National Institute on Aging

8. Drinking patterns and their definitions (2018)

9. Mortality in relation to consumption of alcohol: 13 years' observations on male British doctors. (1994)

10. Alcohol industry involvement in the moderate alcohol and cardiovascular health trial (2020)

11. New survey provides insights into drinking behaviors during the pandemic | Alkermes

Other sources:

• Global status report on alcohol and health 2018 | World Health Organization

• The relation between different dimensions of alcohol consumption and burden of disease: An overview (2010)

• Alcohol dependence during COVID-19 lockdowns (2021)

• Changes in adult alcohol use and consequences during the COVID-19 pandemic in the US (2020)

• Alcohol's effects on the risk for coronary heart disease | NIH: National Institute on Alcohol Abuse and Alcoholism

Chloe Garnham is a writer exploring a broad range of topics, including healthcare, education, and technology.