A recent longitudinal, cohort study consisting of more than 100,000 men and women (taken from data from the Health Professionals Follow-up Study and the Nurses’ Health Study) who were followed for over 20 years showed that replacing 1% of energy consumed in the form of saturated fats with polyunsaturated fats, monounsaturated fats, whole-grain carbohydrates or plant proteins, led to a 5 to 8% decreased risk of coronary heart disease. Results of the study also showed an association between increased intake of individual saturated fats and an increased risk of coronary heart disease.
Whether saturated fat consumption is a definitive link to coronary heart disease has been the subject of much debate in recent years, with some reports indicating there is no link.
Although the researchers of the study did try to control for confounding factors, some factors that may also have an impact on coronary heart disease risk, such as stress, cannot be measured. Strengths of the study, however, include the large sample size, the length of follow-up, and repeated examination of diet, lifestyle, and health outcomes. In addition to not being able to measure for certain confounding factors such as stress, other limitations of the study include the analysis being based on self-reported dietary intake (which may be subject to recall bias) and the subjects consisting of health professionals, who may not be representative of other populations. Further, because subjects did not eat just one type of saturated fat it is difficult to determine which saturated fats have a greater association with coronary heart disease.