It’s a no-brainer that binge drinking isn’t good for your brain—a pounding headache and day-long hangover after a night of drinking communicates that more effectively than any statistics. But could drinking too little also be bad for your brain? A new study shows that both drinking too much and drinking too little is associated with a higher risk of dementia later in life.
In a study published in the British Medical Journal, scientists tracked over 9,000 people for about 23 years during the middle of their lives, from ages 35 to 55. They saw that people with extreme drinking habits—either those who drank a lot, at more than 14 units of alcohol per week, and those that didn’t drink at all—had a higher risk than those who fell in the middle. Risk was raised by 40 percent for those who consumed more than 14 drinks per week. In that group, every seven unit increase after 14 raised the risk by another 17 percent.
Excessive alcohol use has shown up as a risk factor for dementia in previous studies from the past year. People with dementia are twice as likely to have an alcohol-use disorders than those without dementia. In one study of 57,000 people with early-onset dementia, classified as those with a diagnosis before the age of 65, researchers found that chronic alcohol use was associated with 57 percent of patients. In another study, scientists measured the reaction time of those who drank in excess compared to those who drank moderately. They found that people who reported drinking more than 10 grams per day—about one drink—had a slower response time than those who reported drinking less than 10 grams.
But is the answer to give up alcohol entirely? No, according to this study. Abstaining entirely from alcohol in middle age was associated with a 45 percent increase in risk for dementia in comparison to those who drank within recommended limits of below 14 units—about a bottle and a half of wine per week.
“We show that both long term alcohol abstinence and excessive alcohol consumption may increase the risk of dementia,” the authors of the study wrote. “Given the number of people living with dementia is expected to triple by 2050 and the absence of a cure, prevention is key.”
Research on alcohol and the brain can be contradicting, but other studies have shown that moderate amounts of alcohol might help the brain. One animal study showed that while high amounts of alcohol raise inflammation levels in the brain, small amounts might actually help the brain remove waste. The MIND diet, which has been shown to potentially lower the risk of Alzheimer’s by 53 percent, even recommends a glass of wine per day.
However, this was an observational study that simply noted a correlation between drinking and dementia risk—not a clinical trial that randomly assigned some people to drink certain amounts to measure the effects. There could be other lifestyle factors at play. People who completely abstain from alcohol in middle age could have a previous history of heavy drinking in their youth, for example.
“By finding evidence that drinking lots of alcohol, and also drinking no alcohol at all both increase dementia risk, this study supports other work that continues to question whether drinking up to the equivalent of six glasses of wine per week might have a protective effect against dementia,” said Doug Brown, Chief Policy and Research Officer at Alzheimer’s Society. “However, as this is an observational study we need longer trials to explore whether this is actually the case—particularly as we know people tend to underestimate their alcohol consumption,” he said.
Wondering what you should do about that bottle of wine chilling in your fridge for this summer weekend? It’s probably OK to indulge in a glass without worrying about your brain health, according to Brown.
“While this study does throw up questions about alcohol and dementia, there could be other risk factors at play,” he said. “What we do know is that excessive drinking is a proven cause of liver disease and cancers. We recommend that people enjoy a drink responsibly, but don’t overdo it.”