ScienceDaily (July 9, 2008) — Trans-fatty acids have been the topic of a lot of negative health news, but a new dietary study in rats suggests that trans-fats do not increase the risk of insulin resistance and diabetes, which may ease at least one area of concern.

Epidemiological studies indicate that chronic consumption of trans-fats may alter muscle insulin sensitivity, as their unusual molecular shapes can reduce muscle's ability to burn energy; in turn, reduced fat oxidation may promote insulin resistance.

The data in this area has been conflicting, so Beatrice Morio and colleagues undertook a detailed study in rats. They gave rats an eight-week diet enriched in either industrial trans-fats (processed oils), natural trans-fats (dairy fat), or regular unsaturated fats.

In none of the cases did the diet alter the rat's insulin or glucose responses, nor did it significantly affect their muscle capacity. The researchers confirmed their rat studies in cell culture studies by incubating muscle cells with either trans-fatty acids or oleic acid (olive oil); as in the rats, there were no noticeable difference in the insulin sensitivity of the cells.

So while trans-fatty acids are still relatively unhealthy, these findings do show that muscles can utilize them, whether natural or industrial, much like regular fats; thus, trans-fat metabolites won't accumulate in muscles and increase the risk of insulin resistance and diabetes.

Journal reference:

1. Tardy et al. Effects of trans MUFA from dairy and industrial sources on muscle mitochondrial function and insulin sensitivity. The Journal of Lipid Research, 2008; 49 (7): 1445 DOI: 10.1194/jlr.M700561-JLR200

Related Stories

Pregnant Mothers' Diet Linked To Baby's Obesity, Study Suggests (Apr. 7, 2008) — Rats eating trans-fatty acid while pregnant or breastfeeding have fatter babies. The unhealthy diet has deleterious consequences even after the fats were removed from the diet and has links to ...  > read more

Trans Fat Leads To Weight Gain Even On Same Total Calories, Animal Study Shows (June 19, 2006) — The "apple" body shape that increases the risk of diabetes and heart disease may be accelerated by eating trans fat such as partially hydrogenated vegetable oil, according to new animal research at ...  > read more

Palm Oil Not A Healthy Substitute For Trans Fats, Study Finds (May 11, 2009) — Manufacturers are now required to state on food labels the amount of trans fatty acids, also called hydrogenated fats, in packaged foods. Both trans fatty acids and saturated fatty acids are ...  > read more

Facts On Fats Could Prompt Healthier Eating (Mar. 25, 2008) — The 2005 Dietary Guidelines for Americans included --- for the first time --- recommendations that U.S. consumers keep their intake of trans fatty acids as low as possible. The dietary guidelines now ...  > read more

Search ScienceDaily

Insulin Independence