Many health experts will tell you to replace unhealthy saturated fat (found in meat, butter, and lard) with healthy polyunsaturated fat (from vegetable oils). The idea goes that if you eat more of these oils and less saturated fat from animal sources, your cholesterol levels would decrease, lowering your risk of heart disease.
However, several Canadian scientists have recently criticized food manufacturers for labeling plant oils like sunflower, safflower, and corn oils (which are rich in omega-6 fatty acids but contain little or no omega-3 fatty acids) as heart-healthy.
According to Dr. R. Bazinet, a faculty member of nutritional sciences at the University of Toronto, Health Canada should not allow the manufactures of vegetable oils rich in omega-6 fats to make heart-healthy claims.
Recent research published in the Canadian Medical Association journal by Dr. Bazinet found that the consumption of omega-6 fatty acids typically found in vegetable oils not only fail to prevent heart disease—but the consumption of these oils can actually increase the risk of a heart attack!
Another expert, Dr. S. Cunnane from the University of Quebec, an expert on brain aging, is in full agreement with Dr. Bazinet.
Oils derived from safflower, sunflower and corn oils contain high amounts of the omega-6 fatty acid (linoleic acid) and little or no omega-3 fatty acids. Although consuming these oils can lower total cholesterol, they lower the good HDL cholesterol and not the bad LDL cholesterol to the same degree. They also increase the inflammatory reaction inside your blood vessels which can cause damage to the inner-most surface of the artery lining. This situation is not particularly good if you want to lower your risk of heart disease or stroke!
In contrast, oils like canola, soybean and olive oil contain fewer omega-6 fats and much more omega-3 and the omega-9 family of fats which can lower blood pressure, decrease inflammation and blood clotting, and lower the risk of heart attack and stroke.
Based upon the scientific evidence that I have seen so far, oils containing a high concentration of the omega-6 family of fats should not come with heart-healthy labels.
In my opinion, these oils (sunflower, safflower and corn) should not even be used for cooking as they also do not tolerate heat that well and tend to go rancid quickly.
My advice is to stick to oils like canola and extra-virgin olive oils. Other oils like hempseed, walnut, and, at times, palm or coconut oil may also be much better choices.
“Corn, sunflower, safflower oil health benefits challenged,” CBC web site, November 11, 2013;http://www.cbc.ca/news/health/corn-sunflower-safflower-oil-health-benefits-challenged-1.2422522,last accessed Nov.11, 2013.
Bezinet, R.,et al., “Omega-6 polyunsaturated fatty acids: Is a broad cholesterol-lowering health claim appropriate?”CMAJ, published ahead of print November 11, 2013.