Olive Oil Could Protect Heart from Smog

The study included 42 healthy people, whose average age was 58. They consumed three grams of olive or fish oil, or no oil, daily for four weeks. The researchers looked at the functioning of the cells lining the subjects' blood vessels after the patients were exposed to the artificially created pollution in a lab for two hours.

Air pollution "can lead to endothelial dysfunction, a condition in which the endothelium (inner lining) of blood vessels does not function normally," study author Dr. Haiyan Tong, a research biologist with the United States Environmental Protection Agency, said in a statement. Such dysfunction is a risk factor for atherosclerosis, or the buildup of plaque inside the arteries.

"As olive oil and fish oil are known to have beneficial effects on endothelial dysfunction, we examined whether use of these supplements would counteract the adverse cardiovascular effects of exposure to concentrated ambient particulate matter in a controlled setting," Tong said. [6 Foods That Are Good For Your Brain]

But other experts said that the scope of the research was too limited to draw any conclusions about the possible beneficial effect of olive oil supplements on pollution-induced dysfunction in the lining of blood vessels.

"The bottom line is that it is an extremely small study, done in a laboratory environment," Dr. Pieter Cohen, an assistant professor of medicine at Cambridge Health Alliance in Somerville, Massachusetts, told Live Science.

The researchers also didn't report whether they used supplements or if they instead used olive oil and fish oil in the form of food, Cohen said. And if the study authors were indeed using only supplements, they should have specified what kind of supplements these were, he said.

The researchers also did not look at people who are exposed to pollution in a real-life environment, he said.

Still, in general, adding olive oil to the diet is a healthy choice, Cohen said. "We should be doing that already," he said. "There is no need to change the plan."

The researchers did not include information in their statement about how their research was funded, and could not be reached for comment.

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