Foods with a high proportion of animal fat - such as butter, cheese, red meat and fried foods - typically contain saturated fat.
Foods with a high proportion of animal fat - such as butter, cheese, red meat and fried foods - typically contain saturated fat, which has long been considered unhealthy.
Currently, recommendations suggest that no more than 10% of our calorie intake should be made up of saturated fats.
Although some scientists have suggested there may be a link between consumption of saturated fats and increased risk of type 2 diabetes, the association and mechanisms behind it have not been clear.
The new study - called the EPIC-InterAct Study - was funded by the European Commission to investigate the relationship between nine different types of saturated fatty acids and the risk of developing type 2 diabetes. The study was conducted by researchers from the UK's Medical Research Council (MRC) and the University of Cambridge.
High-speed blood analysis used to calculate type 2 diabetes risk
The study analyzed blood samples taken from 12,403 people - out of a group of 340,234 European adults - who developed type 2 diabetes. Using a new kind of high-speed blood analysis, which was developed especially for the project, the researchers were able to determine the proportions of each of the nine fatty acids in the participants' blood samples and relate them to type 2 diabetes risk.
The researchers found that saturated fatty acids containing an even number of carbon atoms in their molecular chain - for example, 14:0, 16:0 and 18:0 - were associated with a higher risk of type 2 diabetes, compared with saturated fatty acids containing an odd number of carbon atoms, such as 15:0 or 17:0.
"These odd-chain saturated fatty acids are well-established markers of eating dairy fats," explains lead scientist Dr. Nita Forouhi, from the MRC Epidemiology Unit at the University of Cambridge, "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."
Dr. Forouhi says the results show that individual saturated fatty acids "are not all the same." Next, the team will investigate how blood levels of these fatty acids correspond to different foods. "Our research," adds Forouhi, "could help trigger new directions in experimental studies and basic research so we can better understand the biology."
As rates of type 2 diabetes are rising around the world, Prof. David Lomas, chair of the MRC's Population and Systems Medicine Board, says that identifying new ways to treat and prevent the condition is vital.
Commenting on the new study, he says:
"This research [...] is an example of the power of international collaboration to generate larger and more reliable studies. By combining large-scale population data with advanced laboratory analysis, this research has delivered a compelling case to look more closely at the contribution of individual components of fat to health and disease."
In March, Medical News Today reported on a University of Cambridge study published in the Annals of Internal Medicine article that questioned the link between saturated fats and heart disease.
In that study, the researchers found no evidence to support guidelines recommending that people should restrict consumption of saturated fats to lower their risk of heart disease.