A study of people over 90 linked drinking with a long life — but there's a sizable catch when it comes to your brain health

Drinking has been linked with several negative health outcomes, including cancer, heart disease, and aggression.
Some studies, however, have suggested that moderate drinking could be connected to a longer life.
These benefits are unclear at best, as studies focusing on drinking and the brain have found more ties to negative impacts than positive ones.

Drinking isn't an overwhelmingly healthy habit.

Alcohol is a known carcinogen — a problem that led some of the nation's top cancer doctors to release an unprecedented warning last year asking Americans to drink less. Drinking has also been tied to as many as 30,000 deaths each year. And a recent study suggested a strong link between alcohol and aggression.

But some studies have suggested that drinking regularly in moderate amounts — defined as no more than one or two drinks per day — could be beneficial as we age. One study, cited prominently by multiple news outlets over the weekend, appears to be linked to a paper published in 2007 in the British journal Age and Aging which found that people who drank two or more drinks a day were less likely to die of any cause than those who did not.

Instead of focusing only on years lived, however, it's important to also look at the impacts of drinking on the brain. And the bulk of research suggests that when it comes to our aging minds, drinking is likely not very good for us — even in moderate amounts.

Binging is bad for the brain

Scientists have known for years that binge drinking, or indulging in as many as 4-5 drinks in two hours, is bad for the brain. The practice has been tied with a lower volume of gray matter, the nerve-cell-rich tissue on the brain's surface; a lower density of white matter, the part of the brain that houses the nerve fibers that send signals from one area to another; and severe memory and learning problems.

Unfortunately, binging is also the way most Americans drink, regardless of age. According to the CDC, one in six US adults binge drinks roughly four times a month, consuming about eight drinks per binge.

There are some people who classify as "heavy drinkers" and do not binge, nor have they been diagnosed with alcoholism — but it's unclear just how many people actually manage to qualify for this label.

A recent national survey suggested that as many as one in five people may drink "excessively" without binging or developing alcoholism, but experts say many of these folks may be negatively affected by their drinking, despite being largely unaware of it. Clinical psychologist Joseph Nowinski calls some of these people "almost alcoholics."

”There are many people in the almost alcoholic zone who are having alcohol-related problems with their health, their relationships and social lives, and even their work, but who don’t connect the dots between these problems and their drinking,” Nowinski told Harvard Health. “These people dismiss the possibility of being an alcoholic — and they truly don’t qualify under current definitions — but may need to take a step back to look at how drinking is affecting their lives.”

If youre truly a moderate drinker, your habit may be neutral

There may be people who drink moderate-to-heavy amounts of booze without binging or developing other problems. Some studies have suggested that among these people, there could be a slight benefit in keeping the mind sharp into old age. But more recent research, including one large study whose researchers made a big effort to control for"confounding variables" — factors like education and physical activity that could muddle a study's findings — has cast doubt on those conclusions.

Two studies that suggested a benefit to heavy drinking include a paper published last year in the Journal of Alzheimer's Disease which looked at more than 1,300 adults over age 65 in California, and a review of 74 studies published in 2011 in the journal Neuropsychiatric Disease and Treatment.

The California study found that adults over 65 who drank up to three drinks a day on as many as seven days a week were significantly more likely to reach their 85th birthday without ever showing signs of cognitive decline compared with their peers who never drank. The review concluded that moderate drinkers — those who had no more than one to two drinks per day — had a lower risk of cognitive decline than non-drinkers (although the opposite held true for excessive drinkers, who had a higher risk of cognitive decline).

"These studies overwhelmingly found that moderate drinking either reduced or had no effect on the risk of dementia or cognitive impairment," the authors of the California paper wrote in their study.

But another review — this one published just a month before the California paper in the British Medical Journal — came to the opposite conclusion about moderate drinking and brain health. Instead of benefiting the brain, the authors of that study found, moderate drinking was tied to cognitive decline.

For their study, the authors followed 550 healthy British men and women between 1985 and 2015 with no diagnosis of alcohol use disorder. On average, the participants were in their early 40s when the study began and in their 70s when it ended.

Compared against the non-drinkers in the study, those who drank moderately or heavily were significantly more likely to display an early marker of Alzheimer’s disease. They also displayed a more significant loss of language fluency, a key measure of executive functioning, compared with those who didn't drink.

"How should this paper inform discussions with patients? It certainly strengthens the view that if alcohol does confer beneficial effects on health, the link is probably confined to low intakes of no more than a unit a day," the researchers wrote in their study. "Even this level of consumption carries risk relative to abstinence for conditions such as breast cancer, and the evidence of benefit is certainly not strong enough to justify advising abstainers to drink."

Taken together, these studies seem to suggest that if you're a lifelong heavy drinker whose drinking doesn't get in the way of your daily life, your habit may be safe. But if you tend to drink more than you initially plan to drink, or if the practice has started to affect your relationships or your work, it may be time to reconsider whether drinking is a positive part of your life.