Some healthy vegetable oils may actually boost the risk of heart disease, finds study.
Replacing saturated animal fats with polyunsaturated vegetable oils has become common practice because they can reduce serum cholesterol levels and help prevent heart disease.
"Careful evaluation of recent evidence, however, suggests that allowing a health claim for vegetable oils rich in omega-6 linoleic acid but relatively poor in omega-3 alpha-linolenic acid may not be warranted," Drs. Richard Bazinet, Department of Nutritional Sciences, University of Toronto and Michael Chu, Lawson Health Research Institute and Division of Cardiac Surgery, Western University, London, Ontario said.
Corn and safflower oil, which are rich in omega-6 linoleic acid but contain almost no omega-3 alpha-linolenic acid, are not associated with beneficial effects on heart health according to recent evidence.
In the study the intervention group replaced saturated fat with sources of safflower oil or safflower oil margarine (rich in omega-6 linoleic acid but low in omega-3 alpha-linoleic acid).
They found that the intervention group had serum cholesterol levels that were significantly decreased (by about 8percent-13percent) relative to baseline and the control group, which is consistent with the health claim.
However, rates of death from all causes of cardiovascular disease and coronary artery disease significantly increased in the treatment group.
The study is published in the Canadian Medical Association Journal.