The scientific community has long credited wine with benefits for cardiovascular health. Because cardiovascular disease shares many risk factors with chronic kidney disease (CKD), a team of researchers decided to investigate whether wine might have beneficial effects for the kidney, too. Their research found that moderate wine consumption is associated with a decreased risk for CKD, and that among those who already suffer from CKD, moderate wine consumption is linked to a healthier cardiovascular system.
According to the National Kidney Foundation, CKD affects 26 million Americans. It's “defined by either decreased kidney function or abnormal protein in the urine,” said Dr. Tapan Mehta, renal fellow at the University of Colorado at Denver, and an author of the study. Its risk factors include high blood pressure, diabetes, smoking, obesity and high cholesterol. Sound familiar? “The risk factors are the same as cardiovascular disease,” he told Wine Spectator.
“Apparently, nobody has looked at this before,” said Mehta. “But in the general population, the common risk factors were so similar that we were led to hypothesize that wine intake would also lower cardiovascular disease risk in patients who have kidney disease.” Currently awaiting his paper’s publication, Mehta presented his team’s findings at recent conferences in San Diego and Las Vegas.
Mehta and his colleagues analyzed data from a three-year period of the National Health and Nutrition Examination Survey, an annual study by the National Center for Health Statistics. This chunk of data came from 5,852 Americans. Of those, 1,031 suffered from CKD.
Compared with nondrinkers, subjects with healthy kidneys who drank an average of less than a glass of wine per day (for the study, a glass of wine was defined as 4 ounces) were 37 percent less likely to develop CKD. Subjects who already had CKD and drank less than one glass of wine per day, meanwhile, had a 29 percent lower chance of developing cardiovascular disease, in comparison with abstainers.
It’s important to remember that these results prove only association, not causation. “We can’t say moderate wine consumption lowers the risk of chronic kidney disease,” said Mehta. “We didn’t follow patients over a period of time, measuring kidney function and then analyzing that with the wine intake. But we did find that there was a lower likelihood of having chronic kidney disease by drinking less than one glass a day versus not drinking wine at all.”
Mehta’s team will next conduct experimental studies, both in vitro and in vivo, to investigate whether wine does indeed mitigate kidney problems and accompanying cardiovascular problems, and if so, why. “We have generated a hypothesis based on this association,” Mehta said, “and we will use this to do more randomized studies.”