People who replace saturated fat (mainly found in meats and dairy foods) in their diets with unsaturated fats (found in vegetable oils and nuts) or carbohydrates from whole grains lower their risk of coronary heart disease (CHD), according to a new study from researchers at Harvard Chan School of Public Health (US). Replacing saturated fats with refined carbohydrates (found in white bread) does not lower CHD risk.
The association between dietary saturated fats and the CHD risk was recently challenged. This study sought to investigate associations of replacing saturated fats with unsaturated fats and different sources of carbohydrates in relation to CHD risk.
This is the first prospective cohort study to directly compare saturated fat with other types of fats and different types of carbohydrates in relation to heart disease risk. Data from the Nurses’s Health Study (N=84,628 women) and the Health Professionals Follow-up Study (N=42,908 men) were used. During 24 to 30 years of follow-up, 7,667 incident cases of CHD were documented.
Replacing 5% of energy intake from saturated fats with equivalent energy intake from either polyunsaturated fats, monounsaturated fats, or carbohydrates from whole grains was associated with 25%, 15%, and 9% lower risk of CHD, respectively.
In contrast, replacing saturated fats with carbohydrates from refined starches/added sugars was not significantly associated with CHD risk.
In conclusion: dietary recommendations to reduce saturated fats remains valid but should specify their replacement with preferentially poly-unsaturated fats or carbohydrates from whole grains.
Reference: Li Y, Hruby A, Bernstein AM et al. Saturated Fats Compared With Unsaturated Fats and Sources of Carbohydrates in Relation to Risk of Coronary Heart Disease: A Prospective Cohort Study. J Am Coll Cardiol 2015;66:1538-48.