Could Inflammation be the Cause of Myriad Chronic Conditions?
In 2007, associate professor of medicine Samia Mora and colleagues published a study of exercise that sought to understand why physical activity is salutary. They already knew that exercise reduces the risk of cardiovascular disease as much as cholesterol-lowering statin drugs do. By analyzing biomarkers in the blood of 27,055 women participating in a long-term study, and other objective measures, they hoped to tease out the source of this effect. How much of the benefit was attributable to improved blood pressure? To lower body weight? Or to something else? The women had donated blood in the 1990s when they entered the study. Eleven years later, the researchers analyzed this frozen blood to see if they could find anything that correlated with long-term cardiovascular outcomes such as heart attack and stroke. “We were actually surprised that reduced inflammation was the biggest explainer, the biggest contributor to the benefit of activity,” says Mora, “because we hadn’t hypothesized that. We knew that regular exercise does reduce inflammation over the long term, but we also knew that acute exercise transiently increases inflammatory biomarkers during and immediately after exertion.” About a third of the benefit of regular exercise, they found, is attributable to reduced inflammation.