The alcohol research has been a bit maddening in recent years—one study seems to tell us that moderate drinking is beneficial for health, and the next that it will kill us.
A new study making the rounds appears to suggest that both heavy drinking and abstinence are linked to dementia over the years, while moderate drinking is linked to reduced risk.
There are a couple of reasons why we shouldn’t rejoice just yet: one is that the study may appear to show a trend that doesn’t totally exist. The second is to keep in mind that alcohol has been shown to cause a host of other health problems that are nothing to sneeze at. So moderate drinking may not be so "healthy" after all.
The study, published in the journal The British Medical Journal, used data the decades-long Whitehall II study of thousands of British civil servants.
The team looked at people who entered the study in 1985, when they were between the ages of 35 and 55. They periodically reported on their drinking habits, along with other health and lifestyle variables. The outcome of interest was the development of dementia over the next two to three decades.
About 9,000 participants made up the final group, and of these, 400 developed dementia. The researchers were particularly interested in correlating long-term abstinence as well as decreased consumption over time with dementia risk.
It turned out that long term heavy consumption was linked to increased dementia risk.
And for every seven units/week increase in consumption, there was an associated 17% increase in dementia. This is not so surprising.
But the researchers also found that long term abstinence was linked to increased risk of dementia—47% higher than those who drank moderately.
Even reducing consumption over the years was linked to increased risk.
These are the trends that have been interesting people.
There are some mechanisms that might explain why alcohol could theoretically help the brain. Its role in reducing inflammation and supporting blood vessel function and blood fats might explain it. Additionally, a study earlier this year found that moderate alcohol benefitted the brain’s glymphatic system, which clears out brain “gunk,” including Alzheimer’s-related proteins, during sleep.
The problem with the current study, as with virtually all studies on the topic, is that it’s not clear why people abstained.
Many likely abstain not because they’re health conscious, but because they have existing health problems, abstain for personal reasons/beliefs, or were previously heavy drinkers.
In the current study, the team looked at factors that covaried with abstinence: they found that people who abstained were also more likely to be obese, be physical inactive, have less education, and have higher overall risk of heart disease.
All of these are linked strongly to dementia, and in fact explained a chunk of the connection between abstinence and higher dementia risk in the current study.
So don’t celebrate just yet—it may be that moderate drinking doesn’t protect against dementia as much as it appears to, but it looks more dramatic next to abstinence, with all its dementia-related risk factors, and next to heavy drinking.
An ideal study would be to look at abstainers who also keep healthy weights and exercise—but that’s a little harder to do.
It’s also important to keep in mind that alcohol is linked to a host of other problems, not the least of which is seven types of cancer. It’s also known to cause liver problems, high blood pressure, stroke, and mental health issues, among others.
If you drink lightly already, it may be OK to keep doing it; but moderate drinkers may still want to think about risks vs. benefits. And if you don’t currently drink, don’t start drinking, hoping to capture the health benefits—because it’s too early to say whether they really outweigh the risks.
“The present findings on alcohol abstinence,” the authors conclude, “should therefore not motivate people who do not drink to start drinking given the known detrimental effects of alcohol consumption for all cause mortality and diseases such as neuropsychiatric disorders, cirrhosis of the liver, and cancer.”