Eating olive oil once a week may be associated with making blood less likely to clot in obese people

In a group of healthy, but obese adults, eating olive oil at least once a week was associated with less platelet activity in the blood, which may reduce the tendency of blood to clot and block blood flow, according to preliminary research presented at the American Heart Association's Epidemiology and Prevention | Lifestyle and Cardiometabolic Health Scientific Sessions 2019, a premier global exchange of the latest advances in population-based cardiovascular science for researchers and clinicians.

Platelets are blood cell fragments that stick together and form clumps and clots when they are activated. They contribute to the buildup of artery-clogging plaque, known as atherosclerosis, the condition which underlies most heart attacks and strokes, according to lead study author Sean P. Heffron, M.D., M.S., M.Sc., assistant professor at NYU School of Medicine and the NYU Center for the Prevention of Cardiovascular Disease in New York, New York.

Using food frequency surveys, researchers determined how often 63 obese, nonsmoking, non-diabetic study participants ate olive oil. The participants' average age was 32.2 years and their average body mass index (BMI) was 44.1. Obesity is defined as having a body mass index—a measure of body weight—over 30.

Researchers found that those who ate olive oil at least once a week had lower platelet activation than participants whose ate it oil less often, and that the lowest levels of platelet aggregation were observed among those who ate olive oil more frequently.

"People who are obese are at increased risk of having a heart attack, stroke or other cardiovascular event, even if they don't have diabetes or other obesity-associated conditions. Our study suggests that choosing to eat olive oil may have the potential to help modify that risk, potentially lowering an obese person's threat of having a heart attack or stroke," Heffron said. "To our knowledge, this is the first study to assess the effects of dietary composition, olive oil specifically, on platelet function in obese patients," said co-author Ruina Zhang, B.S., an NYU medical student.

Some limitations of the study are that it relied on questionnaires completed by the participants; it measured how often they ate olive oil, but not how much olive oil they ate; and because it was observational the study could not prove that eating olive oil will reduce platelet activation in obese adults.