London - Some types of saturated fat may protect against diabetes – contrary to the belief they all increase the risk, say researchers.
They found the kind of saturated fat in dairy products such as yoghurt is likely to cut the risk of type 2 diabetes. But other kinds, found in red meat and fried food, or generated after eating carbohydrates or drinking alcohol, may be harmful.
The difference depends on the number of carbon atoms the molecules of saturated fatty acid contain, according to a study.
Those with an even number were associated with a higher risk of type 2 diabetes, the most common form of the disease, affecting almost three million Britons.
Molecules with odd numbers of carbon atoms led to a protective effect, The Lancet Diabetes and Endocrinology journal reports. Saturated fat, found in products such as butter, cheese and red meat, has been linked to high cholesterol, heart disease and type 2 diabetes.
Lead researcher Dr Nita Forouhi, from the Medical Research Council Epidemiology Unit at Cambridge University, said “Our findings provide strong evidence that individual saturated fatty acids are not all the same. The challenge we face now is to work out how the levels of these fatty acids in our blood correspond to the different foods we eat.
“Our research could help trigger new directions in experimental studies and basic research so we can better understand the biology.”
She added “These odd-chain saturated fatty acids are well-established markers of eating dairy fats, which is consistent with several recent studies, including our own, that have indicated a protective effect against type 2 diabetes from eating yoghurt and other dairy products.
“In contrast, the situation for even-chain saturated fatty acids, such as 16:0 and 18:0, is more complex. As well as being consumed in fatty diets, these blood fatty acids can also be made within the body through a process which is stimulated by the intake of carbohydrates and alcohol.”
The Epic-InterAct study funded by the European Commission investigated the relationship between blood levels of nine different saturated fatty acids and type 2 diabetes risk.
Researchers looked at 12 403 people who developed the disease from a population of more than 340 000 from eight European countries.
Levels of each of the nine fatty acids in participants’ blood streams were compared with type 2 diabetes incidence.
Experts said the presence of different kinds of fatty acids in the blood stream did not necessarily represent a direct link to the diet.
Professor Tom Sanders, the Head of Diabetes and Nutritional Sciences Division, School of Medicine, King’s College London, said “Generally, the size effects of these fatty acids on risk of type 2 diabetes is minuscule compared to the effects associated with being overweight.
“This is an observational study, not a trial of modification of diet. However, the findings are in line with some other reports that suggest the consumption of dairy products is associated with a lower risk of type 2 diabetes.”
Professor Keith Frayn, Emeritus Professor of Human Metabolism, University of Oxford, said the saturated fatty acids measured in the study are in the bloodstream and not in the diet.
He said “These results do not say that it would therefore be beneficial to ingest these particular fatty acids: it is quite possible, indeed probable, that these are simply markers of a particular dietary pattern that may involve other factors protecting against diabetes.” - Daily Mail