Consuming more than 7 grams of olive oil per day is associated with lower risk of cardiovascular disease mortality, cancer mortality, neurodegenerative disease mortality and respiratory disease mortality, according to a study of over 92,000 U.S. adults.
“Olive oil consumption has been shown to lower cardiovascular disease risk, but its associations with total and cause-specific mortality are unclear,” said Dr. Marta Guasch-Ferré, a senior research scientist in the Department of Nutrition at Harvard T.H. Chan School of Public Health, and her colleagues.
“The purpose of our study was to evaluate whether olive oil intake is associated with total and cause-specific mortality in two prospective cohorts of U.S. men and women.”
The researchers analyzed 60,582 women (Nurses’ Health Study) and 31,801 men (Health Professionals Follow-up Study, 1990-2018) who were free of cardiovascular disease or cancer at baseline.
During 28 years of follow-up, diet was assessed by a semiquantitative food frequency questionnaire every 4 years.
Olive oil consumption was calculated from the sum of three items in the questionnaire: olive oil used for salad dressings, olive oil added to food or bread, and olive oil used for baking and frying at home. One tablespoon was equivalent to 13.5 grams of olive oil.
The consumption of other vegetable oils was calculated based on the participants reported oil brand and type of fat used for cooking at home.
Margarine and butter consumption was based on the reported frequency of stick, tub or soft margarine consumption, and the amount of margarine or butter added from baking and frying at home. Intakes of dairy and other fats and nutrients were also calculated.
The scientists found olive oil consumption increased from 1.6 grams/day in 1990 to about 4 grams/day in 2010, while margarine consumption decreased from about 12 grams/day in 1990 to about 4 grams/day in 2010. The intake of other fats remained stable.
Participants with higher olive oil consumption were often more physically active, had Southern European or Mediterranean ancestry, were less likely to smoke and had a greater consumption of fruits and vegetables compared to those with lower olive oil consumption.
The average consumption of total olive oil in the highest category was about 9 grams/day at baseline and included 5% of the study participants.
When the authors compared those who rarely or never consumed olive oil, those in the highest consumption category had 19% lower risk of cardiovascular mortality, 17% lower risk of cancer mortality, 29% lower risk of neurodegenerative mortality and 18% lower risk of respiratory mortality.
They also found substituting 10 grams/day of other fats, such as margarine, butter, mayonnaise and dairy fat, with olive oil was associated with 8-34% lower risk of total and cause-specific mortality.
They found no significant associations when substituting olive oil for other vegetable oils.
“It’s possible that higher olive oil consumption is a marker of an overall healthier diet and higher socioeconomic status,” Dr. Guasch-Ferré said.
“However, even after adjusting for these and other social economic status factors, our results remained largely the same.”
The findings were published in the Journal of the American College of Cardiology.