Connie Capone for MDLinx
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May 12, 2020
For many, a glass of red wine with dinner is as habitual as brushing one’s teeth. Wine has been a staple of human culture since about 6,000 BCE. And for just as long, the drink has inspired anecdotal claims touting its benefits, ranging from the probable to the downright mythical. Medical studies, indeed, have linked the consumption of red wine to numerous health benefits, but debate remains over whether these advantages outweigh the risks.
The detrimental impacts of long-term alcohol abuse have been well documented, and red wine is not necessarily an exception. For this reason, the US Department of Health and Human Services’ dietary guidelines recommend alcohol abstinence. However, for those who choose to imbibe, the guidelines advise moderate levels of consumption—no more than one standard alcoholic drink per day for women and two standard drinks per day for men.
Decades of trial-based study has found consistent evidence that moderate alcohol consumption results in increased cognitive function, decreased rates of cardiovascular disease, and decreased risk of death. Red wine, in particular, has yielded promising research and plenty of hope. But, should physicians advise their patients to consume it?
The case for red wine
Red wine is made by crushing grapes and then fermenting the extracted juice by adding yeast. The fermenting process plays an important role in wine’s resulting antioxidant content and capacity. For example, unlike red wine, white wine is usually fermented without skin and seeds, and because of this, is usually missing many of the antioxidants found in these parts of the grape. Thus, red wine generally contains a greater body of rich antioxidants, referred to as polyphenols, which are the source of red wine’s positive press.
Regular and moderate consumption of red wine has been linked to a decreased incidences of cardiovascular disease, hypertension, diabetes, and certain types of cancer. These health benefits have all been attributed to the polyphenols in wine, specifically resveratrol, quercetin, catechin, and tannin.
“Epidemiological studies have shown that five to seven portions of fresh fruit and vegetables and two glasses of wine a day can lead to a longer and healthier life,” wrote researchers in a review on red wine’s contributions to human health. “The beneficial effect of wine is attributed mainly to its antioxidant properties of the large number and amount of polyphenolic compounds present in red wine.”
Perhaps most notably, the regular consumption of red wine has been targeted as an explanation for the French Paradox, which describes a low incidence of cardiovascular disease mortality in France despite the high prevalence of saturated fats in the country’s standard diet.
The chemical composition of wine and its polyphenolic compounds have cardioprotective effects, researchers have found. Consider the Copenhagen City Heart Study, a cardiovascular population study that monitored over 13,000 men and women for up to 12 years. Researchers concluded that individuals who drank low to moderate levels of wine had half the risk of dying from coronary heart disease or stroke compared with those who never drank wine. More interestingly, individuals who drank beer or spirits did not have the same advantage. The polyphenols in wine have also been linked to limiting the onset and progression of atherosclerosis, a hardening of the arteries.
There is also evidence that red wine improves digestive health. A team of scientists from King’s College London studied the effects of beer, cider, red wine, white wine, and spirits on the gut microbiomes of 916 women. Their research, published in Gastroenterology, found that red wine had the greatest positive impact on gut health. Those who drank red wine had a greater diversity of bacteria in their digestive tracts than those who consumed other kinds of alcohol.
Red wine has been found to positively impact brain function. While long-term alcohol abuse has been linked to damage in areas of the brain involved in cognition and learning, moderate consumption of red wine has been associated with a lower risk for dementia. What’s more, a study following over 5,000 men and women found that wine consumption in the range of two to seven drinks a week was associated with lower rates of depression.
Findings also support that the antioxidant properties in wine defend against diseases in aging and inflammation. During a trial led by researchers at Harvard Medical School, mice were fed resveratrol, one of the primary polyphenols in wine. Compared with those that didn’t receive the compound, mice with resveratrol in their diets had clearer arteries, stronger bones, and better longevity overall.
The case against red wine
The medical community agrees that excessive alcohol consumption can take a serious toll on a person’s health. In fact, some studies have found that even limited consumption of alcohol poses health risks. Consequently, institutions such as MD Anderson Cancer Center have urged that abstaining from drinking alcohol is the safest choice for minimizing health risks.
The WHO cites alcohol consumption as a major causal factor in more than 200 diseases and injuries. Alcohol is directly attributed to several disease conditions such as alcoholic liver disease and alcohol-induced pancreatitis. Research has also found alcohol to be a component cause of several infectious diseases—including tuberculosis, HIV, and pneumonia—as well as diabetes and cancer. In fact, the US Department of Health and Human Services classifies consumption of alcoholic beverages as a human carcinogen.
But, red wine’s specific health risks are less clear. In a 2012 review of red wine’s association with cardiovascular health, researchers in Germany concluded that the medical and scientific communities must continue to study the drink and its health effects, a sentiment that researchers echo today.
“[N]umerous issues need to be resolved to clearly assess the preventive or therapeutic potential of red wine constituents,” wrote the researchers. “Specific chemical entities responsible for the beneficial effects have to be identified.”
The health effects of red wine might depend on the type of wine and its associated grape and growing region, they noted.
Does red wine help patients?
The bottom line is that when it comes to red wine, as with any alcoholic beverage, moderation is key. The research may bend in favor of moderate consumption, but experts have cautioned that the benefits aren’t compelling enough for a patient who does not drink alcohol or red wine to start.
By drinking a glass of red wine a day, patients might not keep the doctor away. But there’s a strong body of research that suggests it doesn’t hurt.