Oils found that fight fat

Obese older women with type 2 diabetes who added safflower oil or conjugated linoleic acid (CLA) supplements to their diet either decreased their body mass index or boosted their muscle mass, researchers found.

“I don’t think it’s a magic bullet, but I think it could have enhancing effects,” said the study’s lead author, Martha A. Belury, the Carol S. Kennedy professor of human nutrition at Ohio State University in Columbus. The study appeared online in the American Journal of Clinical Nutrition.

Belury, who received no funding from the supplement industry, compared the effects of the two oils in 55 obese, postmenopausal women with type 2 diabetes. Their average age was 60. Each woman tried both oils, one at a time, during two 16-week periods separated by a four-week period when they took neither oil.

Participants took eight dietary oil capsules a day, two at each meal and another two at night, for a total of eight grams of added oil per day. In all, 35 women finished both study periods. They didn’t change their diet or exercise patterns, although they kept diet and exercise diaries so the researchers could account for any change in energy output and calorie consumption.

Safflower oil is a common cooking oil. CLA, an omega-6 fatty acid, is found in trace amounts in lamb, beef and milk, but researchers prefer to study the commercial CLA supplements, because the concentration in food is too small to have much fat-lowering ability, Belury wrote. Both oils are considered “good” fats when consumed in proper amounts.

The women who took the CLA had a significant decrease in their body mass index (BMI) — about half a point on average. Their total body fat declined by about 3.2 percent.

The safflower oil did not affect total body fat, but did decrease the trunk, or belly fat tissue, by 2.6 to 4.2 pounds. It also boosted muscle mass by 1.4 to three pounds.

The safflower oil also lowered fasting blood sugar levels by 11 to 19 points. Average levels after 16 weeks of safflower oil supplements were 129 to 148, still high but significantly improved.

While her study included only women, previous studies have found that CLA lowers fat in men, Belury said.

How the oils affect fat loss and muscle mass is still unclear. Belury said it may be related to changes in the functioning of adipose tissue, where fat is stored.