Omega-3s also improved genetic and blood-fat profiles in small clinical study
by Craig Weatherby
Evidence that omega-3s and vitamin D may play helpful roles in type 2 (adult onset) diabetes continues to mount. For more on these topics, See the “Omega-3s & Metabolic Health” section of our news archive.
Evidence also continues to accumulate that the shortage of omega-3s—and excess of omega-6s—in Western diets exacerbates the growing epidemic of metabolic syndrome and its twin spawn: heart disease and diabetes.
(Those excess omega-6s come from vegetable oils, the prepared and packaged foods made with those oils, and meats and poultry raised on grains instead of grass.)
- Omega-3 fish oil produced beneficial changes to diabetic women’s bodies.
- Fish oil reduced fat mass, the size of abdominal fat cells, and expression of pro-inflammatory genes in abdominal fat.
- Results add to prior findings of anti-diabetic effects from omega-3s.
The results of a small clinical trial from France lend weight to the hypothesis that diets high in omega-3s may help deter or ameliorate diabetes and cardiovascular disease.
Belly fat and diabetes risk: A case of apples versus pears
Compared with pear-shaped people—whose fat is centered on the hips and thighs— apple-shaped people with body fat centered on the abdomen are at greater risk of metabolic syndrome, heart disease and diabetes.
This appears to be a function of the fact that fat cells (adipocytes) in the abdomen possess properties different from adipocytes found in the lower body.
For one thing, abdominal adipocytes generate pro-inflammatory chemicals associated with increased risk of metabolic syndrome, heart disease and diabetes.
In addition to anti-inflammatory impacts, omega-3s exert some of the same effects produced by the leading diabetes drugs, called PPAR agents: see “FDA Drug Cops Fumble in Diabetes Fiasco: Omega-3s Seen as Credible Natural Contenders”.
The results of a clinical trial from France add to the good news, and are most welcome, given the need for nutritional tactics to deter metabolic syndrome, diabetes, and heart disease.
French trial shows belly fat loss from fish oil
Last month, researchers from INSERM—France’s counterpart to the US National Institutes of Health—published the results of a small, controlled clinical trial designed to test the effects of fish oil (Kabir M et al. 2007).
They recruited 27 women with diabetes and randomly assigned them to receive either fish oil (providing 1.8 grams of omega-3s per day) or a placebo (paraffin oil) for two months.
At the end of the study, the women in the omega-3 showed significant reductions in their total fat mass and the diameter of the fat cells beneath the surface of their abdominal skin.
No such benefits were detected in the placebo group.
In addition, the omega-3 group showed reduced blood fat (triglyceride) levels and a lower ratio of triglycerides to HDL (“good”) cholesterol: changes that reduce the risk that plaque will form in arteries.
Finally, the omega-3 group enjoyed reductions in a subset of inflammation-related genes in their belly fat.
The fish oil group showed no improvements in measures of insulin sensitivity, but omega-3s have never been associated with such changes, per se.
Omega-3s appear able to stabilize blood sugar levels, but they do it by means other than insulin sensitization, which remain unclear.
NOTE: Fish oil supplements can temporarily worsen blood sugar control in diabetics. Diabetics who take fish oil for the first time should consult their physician, and monitor their blood sugar more closely for a few weeks.
- Delarue J, LeFoll C, Corporeau C, Lucas D. N-3 long chain polyunsaturated fatty acids: a nutritional tool to prevent insulin resistance associated to type 2 diabetes and obesity? Reprod Nutr Dev. 2004 May-Jun;44(3):289-99. Review.
- Kabir M, Skurnik G, Naour N, Pechtner V, Meugnier E, Rome S, Quignard-Boulangé A, Vidal H, Slama G, Clément K, Guerre-Millo M, Rizkalla SW. Treatment for 2 mo with n 3 polyunsaturated fatty acids reduces adiposity and some atherogenic factors but does not improve insulin sensitivity in women with type 2 diabetes: a randomized controlled study. Am J Clin Nutr. 2007 Dec;86(6):1670-9.
- Luo J, Rizkalla SW, Vidal H, Oppert JM, Colas C, Boussairi A, Guerre-Millo M, Chapuis AS, Chevalier A, Durand G, Slama G. Moderate intake of n-3 fatty acids for 2 months has no detrimental effect on glucose metabolism and could ameliorate the lipid profile in type 2 diabetic men. Results of a controlled study. Diabetes Care. 1998 May;21(5):717-24.
- Mostad IL, Bjerve KS, Bjorgaas MR, Lydersen S, Grill V. Effects of n-3 fatty acids in subjects with type 2 diabetes: reduction of insulin sensitivity and time-dependent alteration from carbohydrate to fat oxidation. Am J Clin Nutr. 2006 Sep;84(3):540-50. Erratum in: Am J Clin Nutr. 2007 Jun;85(6):1668.
- Rivellese AA, Maffettone A, Iovine C, Di Marino L, Annuzzi G, Mancini M, Riccardi G. Long-term effects of fish oil on insulin resistance and plasma lipoproteins in NIDDM patients with hypertriglyceridemia. Diabetes Care. 1996 Nov;19(11):1207-13.
- Rodriguez-Cruz M, Tovar AR, del Prado M, Torres N. [Molecular mechanisms of action and health benefits of polyunsaturated fatty acids]. Rev Invest Clin. 2005 May-Jun;57(3):457-72. Review. Spanish.
- Yamamoto K, Itoh T, Abe D, Shimizu M, Kanda T, Koyama T, Nishikawa M, Tamai T, Ooizumi H, Yamada S. Identification of putative metabolites of docosahexaenoic acid as potent PPARgamma agonists and antidiabetic agents. Bioorg Med Chem Lett. 2005 Feb 1;15(3):517-22.