The Mediterranean diet is known to have many beneficial effects on health, from lowering peripheral arterial disease risk to reducing sleep apnea to increasing life expectancy. Now, according to a small new study from Sapienza University in Rome, extra virgin olive oil as part of a Mediterranean diet appears to have healthier effects on cholesterol and blood sugar after meals than other types of fat.
The Mediterranean diet is an eating style typical of countries such as Greece, Italy, Morocco and Spain, that emphasizes whole grains, vegetables, fish, fruits, low-fat dairy, nuts, legumes, and extra virgin olive oil (oil that has been produced by simply pressing the olives). Previous research has indicated that extra virgin olive oil may help protect against cardiovascular disease, but it has not been clear what accounts for this effect. To determine how the oil benefits heart and blood vessel health, researchers evaluated the effects of adding either no oil, 10 grams (approximately 2 tablespoons) of extra virgin olive oil, or 10 grams of corn oil to a standard Mediterranean lunch in 25 subjects without diabetes. In the first phase of the study, the participants were randomly assigned to eat the meal either with or without the additional extra virgin olive oil. A month later, the participants were randomly assigned to eat the meal either with the addition of extra virgin olive oil or the addition of corn oil.
Blood tests taken two hours before and two hours after the meals indicated that blood sugar levels rose much less after the meal with extra virgin olive oil (26.2 mg/dl, on average) compared to the meal with corn oil (40.7 mg/dl, on average) or the meal with no additional oil (53.6 mg/dl, on average). Lower levels of LDL, or “bad” cholesterol, were also found after the meal with supplemental extra virgin olive oil compared to the meals with corn oil or no oil.
Although the study is small, the researchers note that it is one of the first to link lower cholesterol and blood sugar after meals to a Mediterranean diet with extra virgin olive oil.
“Lowering (after-meal) blood glucose and cholesterol may be useful to reduce the negative effects of glucose and cholesterol on the cardiovascular system,” said lead study author Francesco Violi, MD.
Those who wish to incorporate this oil into their diet should “use extra virgin olive oil instead of other fats,” said Arrigo Cicero, MD, PhD, who was not involved in the research, in an e-mail to Reuters. “The assumption is it has to be included as a source of energy in the context of a balanced diet.”
For more information, read the article “Extra virgin olive oil linked to lower blood sugar and cholesterol” or see the study in the journal Nutrition & Diabetes. And to learn more about reducing blood sugar after meals, see the piece “Strike the Spike II,” by 2014 Diabetes Educator of the Year Gary Scheiner.