Replacing animal fats with vegetable oils, a mainstay of modern health advice, may lead to an increased risk of death among people with heart disease
, according to an analysis of data gathered 40 years ago.
In a study of 458 men, those who had experienced a heart attack or other coronary event and replaced saturated fats with omega-6 polyunsaturated fats found in corn, sunflower, and safflower oil had a 16 percent rate of death from heart disease, compared with 10 percent for those who didn’t get dietary advice, researchers found.
“These findings argue against the ‘saturated fat bad, omega 6 polyunsaturated fat good’ dogma,” said Philip Calder, professor of nutritional immunology at the University of Southampton, in an editorial accompanying the study publication. The American Heart Association
’s advisory “may be misguided.”
of research in Australia
recovered data from the Sydney Diet Heart Study conducted from 1966 to 1973, which didn’t report deaths due to cardiovascular disease and coronary heart disease. It was published Tuesday in the British Medical Journal.
The association’s scientific advisories “are based on careful analysis of peer-reviewed studies” reviewed by a team of experts who reach conclusions based on the full body of scientific evidence, the American Heart Association says on its website. The current guideline recommends that most people consume at least five percent of their total daily calories from omega-6 fatty acids.
The analysis published Tuesday may not invalidate switching to fats found in some of the most common vegetable oils, according to some researchers.
“Should we be concerned about our current intake of omega-6 polyunsaturates, linoleic acid in particular? As a dietician, I think not,” said Catherine Collins, principal dietician at St. George’s Hospital London
. “Our diet is now naturally higher in mono-unsaturates, which is protective against omega-6 fats.”
Almost 70 percent of the study subjects were smokers, much higher than the current population, Collins said. Smoking damages arteries, enhancing the risk of damage from the combination of smoking with linoleic acid, she said.
“These are typically 50-year-old men, mainly smokers, who have had a heart attack already, and there were only 63 deaths altogether,” said David Spiegelhalter, Winton Professor of the Public Understanding of Risk at the University of Cambridge.“So I would not want to get very excited about this study on its own.”
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