CANADA, Hamilton, Ont. Saturated fats were not associated with all-cause mortality, cardiovascular disease, coronary heart disease, ischemic stroke or type 2 diabetes in a systematic review funded by the World Health Organization. Any health effects associated with replacing saturated fats in products may depend on what ingredients replace them, according to a review, which appeared on-line in the BMJ (formerly the British Medical Journal).
Trans fats, on the other hand, were associated with all-cause mortality, coronary heart disease and coronary heart disease mortality in the review. Few observational studies have modeled the effect of replacing saturated fat or trans fat with other nutrients, the authors of the review said.
Dietary advice tends to recommend limiting intake of both saturated fat and trans fat. The American Heart Association recommends that healthy Americans over age 2 limit their saturated fat intake to less than 7% of total daily calories and their trans fat intake to less than 1%. The 2015 Dietary Guidelines Advisory Committee recommended people limit daily saturated fat intake to less than 10% of total calories. The WHO said lowering saturated fat intake to less than 10% of total energy intake and trans fats to less than 1% reduces the risk of developing non-communicable diseases.
The study appearing in the BMJ involved researchers from McMaster University and Hamilton Health Sciences in Hamilton, Ont., as well as from the University of Toronto and the Hospital for Sick Children in Toronto. They examined 41 primary reports of associations between saturated fats and health outcomes in prospective cohort studies published between 1981 and 2014.
Risks were associated with what ingredients replaced saturated fat. A pooled analysis of 11 prospective cohort studies found replacement of saturated fat with polyunsaturated fat reduced coronary risk by 13%.
Researchers said foods high in saturated fat, particularly processed and red meat, have been associated with increased mortality and risk of cancer, but dairy foods were not consistently associated with cancers.