Virgin Olive Oil May
Reduce Cholesterol Damage
NEW YORK (Reuters Health) - Just a spoonful of extra
virgin olive oil helps the cholesterol go down, results of a small study
indicate.
According to the report, adults who consumed 25 milliliters (mL) or nearly 2 tablespoons
of virgin olive oil daily for one week showed less oxidation of LDL ("bad") cholesterol
and higher levels of antioxidant compounds, particularly phenols, in the blood.
Antioxidants can help prevent oxidative damage, which is caused by free radicals,
byproducts of the body's normal processes that can damage body tissues. Studies
have shown that the oxidation of LDL cholesterol is associated with the hardening
of arteries that can lead to heart disease.
The findings may help to explain the heart healthy benefits of the Mediterranean
diet, which is rich in olive oil, fruits, vegetables and grains and low in saturated
fat from meat. Studies have documented lower rates of heart disease in countries
such as Italy and Spain, where people consume more than one third of their daily
calories from fats high in monounsaturated fatty acids. These fats may help
to lower total cholesterol and LDL cholesterol, the researchers explain in the
April issue of the European Journal of Clinical Nutrition.
But while all types of olive oil are sources of monounsaturated fat, virgin
olive oil also contains higher levels of antioxidants, particularly phenols
and vitamin E, because it is less processed.
"Our results support the idea that daily ingestion of virgin olive oil could
protect LDL from oxidation," Dr. M. C. Lopez-Sabater from the University of
Barcelona in Spain and colleagues report.
Phenols from other sources, such as red wine and onions, have been shown to
help control cholesterol but there is little information about the effect of
antioxidants from olive oil on cholesterol.
To investigate, the researchers instructed 16 healthy adults to avoid phenol-containing
foods such as coffee, tea, wine and vegetables for 4 days. On the fifth day
adults consumed 50 mL of virgin olive oil--about 3.3 tablespoons--alone or with
bread.
The participants avoided all other foods with phenols for the next 24 hours
and then ate their regular diet, supplemented by 25 mL of olive oil daily, for
a week. Study volunteers were also told to avoid high-fat foods such as butter,
margarine, cooking oil, nuts, baked foods and eggs.
Blood samples taken before and during the study revealed higher levels antioxidant
compounds, including vitamin E and phenols, after one week. Similarly, levels
of oleic acid, the predominant type of fat in olive oil, as well as monounsaturated
fatty acids, were higher. These changes were associated with a slower LDL oxidation
rate.
"In addition to the LDL-lowering effect of virgin olive oil, our results suggest
that an intake of 25 mL/day could increase the resistance of LDL to oxidation
because it becomes richer in oleic acid and antioxidants," the study concludes.
"These benefits could be achieved by including virgin
olive oil daily in our diet."
