GAINESVILLE, Fla. — Older adults who consume a few alcoholic drinks a week are more likely to ward off heart disease and live longer, a new multicenter study led by University of Florida researchers shows, but not for the reasons many might think. In a surprising twist, alcohol’s anti-inflammatory properties alone do not explain the reduced risk of heart attack or death associated with light to moderate drinking, the researchers report.
Published in the Archives of Internal Medicine, the current study suggests the cardiovascular benefits of imbibing even one drink a week could instead be tied to not yet fully understood cellular and molecular effects and genetic interactions.
“Actually we expected to see that the protective effect of alcohol intake was mediated by its anti-inflammatory properties, but we didn’t find this, and this is interesting,” said Dr. Cinzia Maraldi, the study’s lead author and a lecturer in the College of Medicine’s department of aging and geriatric research. “Those other mechanisms that could explain that association should be investigated.”
Chronic inflammation within the circulatory system has been linked to an increased risk of cardiovascular disease and death. Previous studies have documented alcohol’s anti-inflammatory properties, which limit the overproduction of damaging inflammatory molecules such as interleukin-6, or IL-6, and C-reactive protein, or CRP.
UF Institute on Aging researchers, who collaborated with scientists from the University of Pittsburgh, the University of Tennessee, the University of Ferrara in Italy and several other academic institutions, studied 2,487 men and women between the ages of 70 to 79 who had no history of heart disease. At the beginning of the study, funded by the National Institute on Aging, they gathered reports of alcohol consumption and measured blood levels of IL-6 and CRP. Researchers then tracked the participants’ health for an average of five-and-a-half years, during which time 397 died and 383 had heart problems.
Compared with the group of people who either never drank or were occasional drinkers, the group of people who reported being moderate drinkers — consuming one to seven drinks a week — were 26 percent less likely to die and almost 30 percent less likely to experience a heart attack or heart disease.
“This is very important because cardiovascular disease is among the main causes of hospitalization and death in the United States and Europe, so a 30 percent reduction may have important clinical and public health implications,” Maraldi said.
Researchers also discovered moderate consumption of alcohol was good for the heart regardless of study participants’ CRP and IL-6 levels, indicating its benefits were independent of its effects on inflammation.
Men at highest risk of developing heart disease benefited most, Maraldi said.
“We observed that the main protective effect of alcohol intake was observed in men with high levels of IL-6, which is a strong predictor of cardiovascular disease,” Maraldi said. “This may suggest that the beneficial effects of alcohol consumption may depend on the background of cardiovascular risk, because subjects with high levels of Il-6 are subject to increased risk of cardiovascular disease.”
Researchers cautioned that alcohol consumption may not help everyone and also can substantially increase the incidence of severe chronic diseases, such as liver disease. In fact, they found alcohol’s beneficial effects disappeared for heavy drinkers who reported regularly consuming eight or more drinks a week.
“Consumption should be based on strict calculation and consideration of individual patients’ risks and benefits,” Maraldi said.
Eric Rimm, an associate professor of epidemiology and nutrition at the Harvard School of Public Health’s departments of epidemiology and nutrition, said the study is unique because of its large number of participants over the age of 70.
“This study shows the beneficial effects of moderate drinking on the heart continue as people age into their 70s and 80s, and as the population ages in the United States that becomes important for a growing number of people,” Rimm said. “We are also in the early stages of looking at inflammation’s association with alcohol, and given that inflammation is difficult to measure, this study adds weight to the argument that inflammation doesn’t look like it fully explains the association between alcohol and a reduced risk of heart disease.”