The relationship between saturated fat and type 2 diabetes may be more complex than previously thought, according to the results of a large international study. It found that saturated fatty acids can be associated with both an increased and decreased risk of developing the disease, depending on the type of fatty acids in the blood.
The results add to the growing debate around the health consequences of fat and could partially explain evidence from recent studies that suggest some foods high in saturated fats, such as dairy products, could actually lower the risk of type 2 diabetes.
Saturated fatty acids have long been considered detrimental to health, and current recommendations suggest they should makeup no more than 10% of the calories we eat. However, the evidence of a link between saturated fat and type 2 diabetes is unclear.
In the EPIC-InterAct Study, which was funded mainly by the European Commission under its Framework 6 programme, a team of researchers set out to examine the relationship between blood levels of nine different saturated fatty acids and the risk of developing type 2 diabetes in later life.
They looked at 12,403 people who developed type 2 diabetes from among a group of 340,234 adults across eight European countries. They determined the proportion of each of the nine fatty acids in blood samples from the study participants and related this with later incidence of type 2 diabetes.
They found that saturated fatty acids with an even number of carbon atoms in their chain were associated with a higher risk of type 2 diabetes, while the odd-chain saturated fatty acids, were associated with a lower risk.
Lead scientist, Dr Nita Forouhi, from the MRC Epidemiology Unit at the University of Cambridge, 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 trigger new directions in experimental studies and basic research so we can better understand the biology.
“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 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 authors therefore conclude that it is too early to make any direct dietary recommendations on the basis of this work. The results of the EPIC-InterAct study have been published in The Lancet Diabetes and Endocrinology.
