Fat Loss and Glycemic Control With Omega 6 Fatty Acids in Post Menopausal Diabetic Women
In an effort to address these issues, Norris et al in their study on obese post menopausal women with Type 2 Diabetes Mellitus analyzed the effects of dietary conjugated linoleic acid (CLA) and safflower oil (SFA) on body composition.
Safflower oil is a commonly used cooking oil and conjugated linoleic acid is a compound naturally found in meat and dairy foods. CLA has been found to reduce weight and adipose tissue in various clinical trials and has been extensively promoted as a weight loss supplement.
Both the dietary oils and dairy products are composed of polyunsaturated fatty acids, which are considered as "good fats" and are associated with various health benefits. They are rich in the essential omega - 6 fatty acids (linoleic acid). A commercial mixture of CLA oil is used in most studies as the naturally occurring CLA from ruminant meats and dairy products is low in its adipose-lowering isomer. Safflower oil is a very popular cooking medium in the west.
For the study, fifty-five postmenopausal women less than 70 years with Type 2 Diabetes Mellitus were recruited. The goal of the study was to compare the effects of CLA and SAF on body weight, body composition, and adipose tissue distribution.
Subjects were randomly assigned to 2 groups in order to determine which supplement they would be taking first (CLA or SAF). The initial diet period was of 16 wk, followed by a 4-wk washout period and a second 16-wk diet period.
Subjects consumed 8 dietary oil capsules daily. Each CLA capsule contained 1.0 g CLA-80 oil and each SAF capsule contained 1.0 g SAF oil. A total of 8g dietary oil was consumed daily by all subjects.
They continued with their hypoglycemic drugs throughout the study. Women were asked to fast and abstain from taking the diabetes medications and treatment capsules the morning of each study visit. Dual-energy X-ray absorptiometry was used to assess the body composition.
With CLA supplementation a significant decrease in BMI was observed during the last half of each diet period. Total adipose mass was seen to significantly decrease with no effect on fasting glucose.
On the other hand SAF significantly reduced trunk adipose mass and increased lean tissue.. SAF also significantly decreased the fasting glucose.
Weight gain, increase in the body fat levels and abdominal fat accumulation are common post menopause. These changes increase the risk of developing heart ailments and metabolic syndrome. This particular study remains the first to show that even a modest amount (1-2/3 teaspoon or 8 mL) of linoleic acid-rich oil can have a significant effect on body composition. Postmenopausal women are at risk of losing lean tissue mass. But supplementation with CLA and safflower oil on the contrary did not cause a loss of the same. Rather SAF was seen to increase the total lean tissue.
Postmenopausal women are at a risk of developing central obesity and insulin resistance. However with SAF supplementation the study reported decreased trunk adipose mass and lowered glycemia.
Keeping aside the study limitations and the unfavorable events, the findings clearly suggest that dietary supplementation with oils rich in n−6 linoleic acid helps to positively affect body composition and improve glycemic control significantly. The study thus brings forth various important findings that could help manage the debilitating lifestyle related health threats. Discovering and implementing dietary methods to reduce the risk of heart disease, diabetes and its comorbidities can be a boon to the community.
The study suggests that even a modest dose of 6.4 g/d, CLA can have a significant effect on body weight and fat mass.
Use of lower doses of CLA over a period of time can actually prove to be an effective weight-loss aid.
In the study, CLA did not appear to affect the fat burning hormones, whereas SAF increased the hormone called as adiponectin which might have been responsible for burning dietary fats. Previously conducted work on animals suggests that in the case of CLA, the fatty acid allows the body to burn calories in a heat producing way.
Experts add that long term use of any supplements that lower body fat brings forth various safety issues and questions. They suggest, that if the fat that leaves fat tissues is not utilized, then it deposits in the liver or muscles leading to insulin resistance and diabetes. Therefore the exact mechanism behind the fat burning and channelizing further needs to be understood.
CLA and the linoleic acid in safflower oil cannot be produced by the human body and must be obtained from food, or dietary supplements.
Acronyms used -
CLA - Conjugated Linoleic Acid
SFA - Safflower oil
Norris LE et al. Comparison of dietary conjugated linoleic acid with safflower oil on body composition in obese postmenopausal women with type 2 diabetes mellitus. The American Journal of Clinical Nutrition, 2009.