By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

The Mediterranean Diet, which uses olive oil as its principal source of fat, is known to be associated with a low risk of heart disease. Olive oil is one of the 'monounsaturated fats' or MUFA, and sunflower oil is another that is now widely available. A Spanish study compared the effects of olive oil and sunflower oil, each for a period of four weeks, in the regular diet of 16 hypertensive women, of whom half had high blood cholesterol levels, and half had normal levels. The oils were used for cooking and salads.

Total cholesterol and triglycerides were unaffected by either diet, but HDL cholesterol increased by about the same amount with both olive oil and sunflower oil. The changes were bigger in the women with high cholesterols (0.35 mmol/l or13 mg/dl) than in the women with normal cholesterols ( 0.15 mmol/l, or 6 mg/dl). The cholesterol-to-HDL ratio was improved by both diets.

Blood pressure was not affected by the sunflower oil diet, but both the systolic and diastolic pressures fell by about 8 mm Hg during the olive oil diet.

Doctor's comments

This study provides further evidence that if you have high blood pressure, using olive oil as your principal source of fat makes good sense, and that it may be better for your blood pressure than sunflower oil (although the number of women in the study was too small to be absolutely sure about this).

Where it was published