Читать книгу Textbook of Lifestyle Medicine - Labros S. Sidossis - Страница 45

It is now generally accepted that the effects of SFA on CVD depend mainly on what replaces them in the diet.

In populations following Western dietary habits, it has been shown that when 5% of the energy derived from SFAs is replaced by PUFAs, LDL cholesterol concentrations decrease. In turn, this change can generate a decrease in CHD occurrence and deaths. Males from the Health Professionals Follow‐up Study and females from the Nurses' Health Study (NHS) were followed prospectively for 24–30 years; people with the highest consumption of PUFAs had 20% lower CHD risk compared to those who consumed a diet low in PUFAs. Notably, for every 5% decrease of energy coming from SFAs, the CHD risk decreased by 25% when an equal amount of energy was replaced by PUFAs. Similarly, combined scientific data from randomized controlled trials (RCTs) have demonstrated that individuals with increased PUFA intake, instead of SFAs, were 20% less likely to develop CHD, compared with those following a higher SFA diet. The protective effect against CHD incidence was 10% for every 5% of energy replacement by PUFAs, and the magnitude of this beneficial effect was contingent on the duration of the intervention.

Mixed results have been reported when total carbohydrates replace SFA, showing either no overall benefit, reduction, or even increased CVD risk. However, when separating whole grains from refined carbohydrates, isocaloric substitution of whole grains for SFA is associated with a decreased risk of CHD; CHD risk does not change in the case of isocaloric substitution of refined starches/added sugars for SFA.

Current guidelines recommend decreasing saturated fat intake to improve blood lipids and reduce cardiovascular risk. Dairy products have been thought to increase the risk of CVD, due to their high SFA, cholesterol, and calorie content. Indeed, most of the existing dietary guidelines for the prevention and management of cardiometabolic risk recommend low‐fat or nonfat dairy consumption. However, robust evidence from prospective studies shows no increase or even a small benefit in CVD risk from high dairy consumption (e.g., yogurt and cheese). The potential mechanisms of the attenuating effects of dairy foods remain to be fully elaborated but seem to involve food matrix effects on fat bioavailability, changes in the gut microbiome, and glucose, insulin, and other hormonal responses.