Omega-6s in Vegetable Oil Linked to Lower Diabetes Danger

Contrary to some advice to limit the omega-6 fats found in vegetable oil, a new Finnish study finds that high blood levels are associated with a significantly reduced risk of type 2 diabetes, at least in men. The study looked primarily at linoleic acid, an essential omega-6 fat not formed by the body, which must be obtained from the diet. It’s the primary fatty acid found in oils high in polyunsaturated fats (see box) as well as nuts and seeds.

“Diets rich in omega-6 fatty acids have been consistently associated with optimal health outcomes, and this study further reinforces those findings,” says Alice H. Lichtenstein, DSc, director of Tufts’ HNRCA Cardiovascular Nutrition Laboratory. “Fortunately, it is relatively easy to incorporate vegetable oils high in omega-6 fatty acids, such as soybean and corn oils, into the diet.”

LENGTHY FOLLOW-UP: The study, published in the American Journal of Clinical Nutrition, used data on 2,189 men, ages 42 to 60 at the start, participating in the Kuopio Ischemic Heart Disease Risk Factor Study. After an average follow-up of 19 years, those in the highest one-quarter of total omega-6 levels were 60% less likely to have developed type 2 diabetes than those in the lowest group.

Those who reported consuming the highest amount of omega-6 fatty acids had the highest level of education, smoked less, consumed less alcohol, were more active and were leaner than the group that consumed the least. Nevertheless, the associations largely remained even after adjusting for these potential confounding factors. But, as an observational study, the research can’t prove cause and effect.

OMEGA-6 BENEFITS: Some studies – and innumerable Internet posts – have suggested omega-6 fatty acids increase inflammation or advocate maintaining a low ratio of omega-6 to the omega-3 fats found in fish. But replacing saturated fats with polyunsaturated fats such as those in liquid vegetable oil – and specifically linoleic acid – has been shown effective in reducing cardiovascular risk. (See the February 2015 newsletter.) Polyunsaturated-fat levels have also been linked to lower mortality risk. (See the December 2015 newsletter.)

While more research is needed, the prospect of a link between linoleic acid intake and sharply lower diabetes risk adds to the evidence to encourage – not discourage – substitution with polyunsaturated fats, as part of a healthy lifestyle and eating pattern.

TO LEARN MORE: American Journal of Clinical Nutrition, May 2016 –

http://ajcn.nutrition.org/content/103/5/1337.abstract?etoc