On Jan. 17, nutrition and preventive medicine experts from around the world gathered at the UC Davis Olive Center at the Robert Mondavi Institute in Davis, California, to present the latest scientific findings on the health benefits of olive oil consumption and the role of olive oil in the prevention of chronic disease.
“Olive oil, a mainstay in the Mediterranean diet, offers a host of health benefits – and new research continues to reveal new benefits,” said Jaime Lillo, deputy executive director of the International Olive Council. The International Conference on Olive Oil and Prevention of Chronic Disease focused on findings from seven experts in the field who have been studying the role of the Mediterranean diet and olive oil on cardiovascular disease, diabetes, cancers and cognitive health.
The conference presented numerous developments on the positive association of olive oil on good health:
Evidence of Cancer Prevention
Estefania Toledo, M.D., M.P.H., Ph.D., from the University of Navarra and lead author of a 2015 JAMA Internal Medicine paper, reported evidence of the beneficial effects of extra-virgin olive oil consumption on breast cancer prevention. She noted that other studies have shown potential beneficial effects on colorectal cancer, bladder cancer, upper aero-digestive tract cancer and ovarian cancer. The potential beneficial effects have been attributed mainly to certain components of olive oil that are present in higher concentrations in extra-virgin varieties.
Improved Cognitive Health, Reduced Risk of Depression
José A. Luchsinger, M.D., M.P.H., from Presbyterian Hospital and Columbia University Medical Center, referenced a growing body of data from large epidemiological studies that suggests better adherence to the Mediterranean diet is associated with a lower risk of cognitive decline and dementia. The PREDIMED-Navarra trial, for example, found that a Mediterranean diet supplemented with extra-virgin olive oil was associated with better cognitive function in comparison with a control diet.
Additionally, Luchsinger reported an association between dietary habits and depression risk. A systematic review of available data indicates that a dietary pattern defined by a high consumption of olive oil, fruit, vegetables, whole grains, fish, low-fat dairy and antioxidants (but low consumption of animal foods) has been associated with a decreased risk of depression.
Reduced Diabetes Risk
Frank Hu, M.D., M.P.H., Ph.D., from the Harvard T.H. Chan School of Public Health and Harvard Medical School, has seen substantial scientific evidence that diets high in olive oil improve cardiometabolic risk factors and reduce Type 2 diabetes risk, potentially due to the monounsaturated fatty acid content and high amounts of polyphenols in olive oil.
One intervention study showed that individuals assigned to a Mediterranean diet supplemented with extra-virgin olive oil had significantly reduced risk of Type 2 diabetes compared with a control diet. A separate study on U.S. women showed that total olive oil consumption, as well as using olive oil in place of other fats, was inversely associated with Type 2 diabetes risk.
Impacts on Cardiovascular Disease
The impacts of olive oil on heart health commands significant attention from researchers. Manuel Franco, M.D., Ph.D., from the University of Alcalá and Johns Hopkins Bloomberg School of Public Health, has been involved in the Heart Healthy Hoods project, funded by the European Research Council. The project studies associations between Mediterranean food environments (a diversity of small food stores and public markets), adherence to the Mediterranean diet (including olive oil) and related chronic diseases. He reports Mediterranean food environments may help improve population diets and thus reduce the risk factors for heart disease, including hypertension, diabetes and obesity.
Miguel A. Martínez-González, M.D., M.P.H., Ph.D., from the University of Navarra and Harvard T.H. Chan School of Public Health, coordinated the PREDIMED Research Network. It conducted the first primary prevention trial of heart disease through a dietary intervention based on the Mediterranean diet supplemented with either extra-virgin olive oil or tree nuts versus a control (low-fat) group.
- Initial results in 2013 indicated both intervention diets showed a roughly 30 percent reduction in heart attacks, strokes or cardiovascular deaths after five years of follow-up.
- Newer analysis shows the risk of developing atrial fibrillation was about 40 percent lower with the Mediterranean diet supplemented with extra-virgin olive oil.
- A similar approximate 40 percent reduction was observed in risk of developing diabetes.
Walter Willett, M.D., Dr.P.H., from Harvard T.H. Chan School of Public Health and Harvard Medical School, has conducted extensive investigations into the relationship between dietary fat and cardiovascular disease. Studies indicate:
- Trans fatty acids are most strongly predictive of heart disease, and saturated fat and typical forms of carbohydrate are similarly related to risk.
- Monounsaturated and polyunsaturated fatty acids are related to lower risk of heart disease.
- Support for eliminating partially hydrogenated fats and replacing animal fats and highly saturated plant oils with primarily unsaturated plant oils: omega-3 (in walnuts), omega-6 polyunsaturated fatty acids (seed oils) and monounsaturated fatty acids (in olive oil).
Finally, Francesco Visioli, Ph.D., from the University of Padua and the Madrid Institute for Advanced Studies, reports new evidence of the beneficial cardiovascular effects of olive oil polyphenols has come from techniques of nutrigenomics and proteomics. Scientific advances introduce the possibility of incorporating these beneficial molecules into novel foods and functional foods.