A recent study provides a simple and effective way of reducing the risk of coronary heart disease — replace saturated fats such as those found in red meat and dairy products with high-quality carbohydrates and unsaturated fats such as olive oil, other vegetable oils, nuts and seeds.
Researchers from the Harvard School of Public Health reached this conclusion based on analysis of data from two large studies in the US that spanned a period of 24 to 30 years.
Although saturated fats increase the risk of heart disease, recent studies failed to find any association between intake of saturated fats and risk of coronary heart disease. Such results created a controversy and led to the TIME magazine cover story “Eat Butter.”
Replacing saturated fats and refined carbohydrates with unsaturated fats such as olive oil and whole grain carbohydrates may help lower risk of heart disease.
But the real reason, according to the authors of the present study, could very well be that the type of fat and carbohydrates used to replace the saturated fats affects the risk of coronary heart disease differently.
In an attempt to address this question, the present study, the first of its kind, set out to compare the risk of heart disease with intake of saturated fat, unsaturated fats and different types of carbohydrates.
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The investigation included 84,628 healthy women enrolled in the Nurses’ Health Study and 42,908 healthy men enrolled in the Health Professionals Follow-up Study, who had no history of heart disease, diabetes and cancer.
Food frequency questionnaires, completed at the start of the study and every 2 to 4 years thereafter by the subjects provided dietary, medical and lifestyle information for the duration of the study. There were 7,667 cases of coronary heart disease over the course of the study.
The results of the study, reported on September 28, 2015 in the Journal of the American College of Cardiology, found that when subjects reduced their intake of saturated fats, they replaced calories from saturated fats with calories from low-quality carbohydrate foods such as white bread, rice or potatoes rather than whole grain carbohydrates or unsaturated fats.
The premise that removal of saturated fats from the diet would suffice in lowering risk of coronary heart disease was proved wrong when analysis of data revealed that risk of heart disease was higher when consumption of refined carbohydrates and added sugars was increased. Refined carbohydrates appear to be as unhealthy for the heart as saturated fats, according to the paper.
On the other hand, higher intake of whole grain carbohydrates was associated with a lower risk of heart disease. Similarly, higher intakes of polyunsaturated fats and monounsaturated fats were also associated with a lower risk of heart disease.
The authors estimated that replacing five percent of the energy from saturated fats with five percent energy from polyunsaturated fats lowered heart disease risk by 25 percent. Likewise, replacing five percent of the energy from saturated fats with a similar amount of energy from monounsaturated fats reduced CHD risk by 15 percent and by nine percent when replaced with energy from whole grain carbohydrates.
According to the study, replacing saturated fats with refined carbohydrates is not beneficial in preventing heart disease.
Findings of this large and long-term study indicate that replacing saturated fats and refined carbohydrates that are part of the Western diet with unsaturated fats such as olive oil and whole grain carbohydrates typical of the Mediterranean diet may help lower risk of heart disease.