An apple a day may keep the doctor away, but what about a glass of wine?
Previous studies have shown that low levels of wine consumption may have some benefits, including protection against cardiovascular disease and all-cause mortality. But health experts have cautioned that several issues must be taken into consideration.
Here’s what the most current research tells us about the benefits and risks of wine—the alcoholic beverage many assume to be the healthiest.
The science behind alcohol and health benefits
While the potential benefits of red wine are promising, authors of the Scientific Report of the 2020 Dietary Guidelines Advisory Committee have further limited alcohol consumption guidelines based on new evidence. The old guidelines suggested a limit of two or fewer drinks for men and one drink daily for women. Now, the guidelines suggest that men and women stick to one drink daily in order to mitigate overall health risks.
What prompted the revision?
For years, studies have shown connections between red wine and better health. French epidemiologists observed that lower rates of heart disease among French people, even with diets rich in cheese and other fatty foods, may be due in part to red wine consumption. This notion came to be known as the “French paradox” in the 1980s. But a key finding in the research pointed to a group of plant chemicals present in grapes—specifically a high level of micronutrients called polyphenols in the skin and seeds of grapes. They’re rich in antioxidants, including those that protect the heart.
Research has also shown that a glass or two of wine a day may improve cognitive health. The study, which appeared in the journal Scientific Reports and was performed on mice, showed that low levels of alcohol consumption reduced brain inflammation and helped facilitate clearance of metabolic waste and potentially toxic proteins from interstitial fluid, including those associated with Alzheimer disease. Researchers at the University of Rochester Medical Center pointed to a potential link to alcohol’s ability to activate the glymphatic system, the brain’s “cleaning process” in which cerebrospinal fluid clears waste from the brain.
“Prolonged intake of excessive amounts of ethanol is known to have adverse effects on the central nervous system,” observed Maiken Nedergaard, MD, DMSc, lead author of the study. However, this study showed that low doses of alcohol may offer potential benefits for brain health.
When mice received high levels of alcohol over time, their brain cells showed impaired cognitive abilities and more inflammation. But when mice received low levels of alcohol—the equivalent of about 2.5 drinks per day in humans—their brains showed less inflammation, and their glymphatic systems were more effective at removing waste.
The study supports other research that links moderate alcohol intake with health benefits, but it is the first to show how low doses of alcohol appear to improve brain health, including reducing the risk of dementia and Alzheimer disease.
New science behind alcohol and health harms
However, alcohol consumption, even in small amounts, has been shown in other studies to have negative health effects. There’s evidence that has linked even low consumption of alcohol to increased cancer risk—specifically, breast cancer. The study, reported by the World Cancer Research Fund and the American Institute for Cancer Research, examined data on 260,000 cases of breast cancer from 119 studies involving 12 million women in an expansive look at how certain factors, including alcohol consumption, can increase breast cancer risk. A small glass of wine or beer a day (about 10 g of alcohol) can increase the risk of premenopausal breast cancer by 5% and postmenopausal breast cancer by 9%, according to the report.
As a nationwide uptick in alcohol consumption continues amid the coronavirus pandemic, doctors and scientists on the Dietary Guidelines Advisory Committee have pushed for updates to the US Department of Health and Human Services dietary guidelines. A recent report from the committee noted that earlier research that associated moderate alcohol consumption with lowered risk of cardiovascular disease often included people with “otherwise healthy dietary patterns”—pointing to the Mediterranean diet—and advised no more than one standard drink per day for men and women.
But newer evidence has supplanted those findings, the committee noted. “The observational evidence base with respect to alcohol consumption is insufficient to recommend drinking at any level, particularly for a substance that is intoxicating, potentially addictive, and a leading preventable cause of death and other harms,” they wrote.
It’s comforting to believe that a glass of wine falls into the precious category of food and drinks that not only taste good but are good for you. But the heart health benefits of wine are not outweighed by the broader assessment and, as the new recommendations note, some people might experience adverse effects from alcohol, including an increased risk of breast cancer, even if they drink at relatively low levels.
The latest update backpedals from previous guidelines, but it maintains that those who consume alcohol at low levels are at lower risk for health complications that stem from drinking. Still, drinking is no longer considered to be a preventative health measure, so it seems increasingly unlikely that you can drink your way to better health.
If you choose to drink, drink low amounts of wine—and be mindful of the risks.