Fighting Diabetes a Glass at a Time

Diabetes is a rapidly growing health concern in the United States. Cases of Type 2 diabetes have increased by more than 60 percent since 1991, and health experts estimate it will affect 40 million Americans by 2050. But a new study suggests that moderate alcohol consumption, including wine, can reduce the odds of developing diabetes, particularly in women. Scientists found that moderate drinking lowered the risk by 19 percent among men and 37 percent among women aged 50 to 71.

The study, published in the Sept. 6 issue of the Annals of Internal Medicine, was conducted by scientists from the National Heart, Lung, and Blood Institute (NHLBI) and the National Cancer Institute, both of which are part of the National Institutes of Health (NIH), the federal medical research agency. They studied both Type 1 and Type 2 variations of diabetes, though the authors estimate that 95 percent of adult cases are Type 2, once known as adult-onset diabetes. Both manifestations of the disease are identified by elevated blood glucose levels and often lead to serious health disorders and premature death.

The NIH team analyzed a large health survey of over half a million AARP members, ages 50 to 71. After developing a set of five low-risk lifestyle factors, the scientists assigned 207,479 survey participants a score based on how many behaviors they followed. (The other participants were excluded because of missing data or preexisting conditions.) The researchers then tracked the occurrence of diabetes after nearly 10 years.

Along with moderate alcohol consumption (defined as half a glass to one drink daily for women and up to two drinks daily for men), the researchers included optimal body mass index, not smoking, adequate physical activity and a healthy diet as the low-risk lifestyle factors. Among the adults who followed all five low-risk behaviors, about 4 percent of men and 2 percent of women, the results were staggering—a reduced risk for diabetes of 72 percent for men and 84 percent for women.

Of the five behaviors studied, maintaining optimal body mass index had the largest effect, though every factor made a contribution. Moderate drinking independently offered a risk reduction of 19 percent for men and 37 percent for women. Jared P. Reis, a doctor with the division of Cardiovascular Sciences at the NHLBI and lead author of the study, told Wine Spectator that scientists are "currently unable to explain why moderate alcohol consumption was slightly more strongly associated with a lower risk for diabetes among women."

The NIH study is not the only research showing a link between women's health and moderate alcohol use. A recent Harvard study found moderate alcohol use during midlife was associated with healthier aging in women. And a recent Centers for Disease Control study using similar methodology also defined moderate alcohol consumption as a healthy lifestyle behavior.

Too much alcohol is detrimental for a variety of health reasons, but the scientists in all three of the recent studies found that abstaining from alcohol was a high-risk behavior. Dr. Reis noted that the NIH results were "consistent with the majority of the observational scientific evidence which suggests that modest consumption of alcohol is associated with a lower risk of developing diabetes." But he failed to offer any indication for why that is. "I think we need additional research to uncover the mechanisms whereby alcohol may influence diabetes risk."

Early experiments suggest a relationship between alcohol and insulin, the hormone that assists cells in obtaining glucose from the blood. "Insulin resistance is an important factor in the development of diabetes, and light to moderate alcohol consumption has been associated with enhanced insulin sensitivity," the authors wrote in the NIH study. The researchers also mention alcohol's anti-inflammatory properties and its ability to increase triglyceride concentration as possible links to diabetes risk reduction.

Despite mounting evidence, Dr. Reis does not see a public health recommendation on the horizon. "I do not think we are moving toward the use of alcohol as a treatment for those who may be at a higher risk for diabetes," he said. "We have a wealth of evidence from observational studies such as ours and clinical trials that increased physical activity, improvements in diet and weight loss strongly reduce the risk of developing diabetes as well as a number of other chronic conditions. We should focus our attention on those factors."