For years we’ve been encouraged to cut back on saturated fat and to choose low-fat or fat-free dairy foods in place of full-fat dairy. Could that be about to change? Researchers have been looking at the effects on our health of whole foods rather than single nutrients such as saturated fat – and they’re finding some unexpected results.
You may think that low-fat dairy foods are healthier than full-fat options that are rich in saturated fat. But is it true? The results of well-designed studies over the past 10 years have challenged current dietary guidance which advises us to reduce our intake of saturated fat to lower the risks of heart disease and stroke. Full-fat dairy foods, particularly yogurt and cheese, may in fact be associated with protection against these diseases and against type 2 diabetes, say the authors in a report from the 6th Global Summit on the Health Effects of Yogurt.
The facts about saturated fat
Current dietary advice which tells us to curb our saturated fat intake is based largely on out-of-date nutrition studies from the 1960s and 1970s, many of which were not particularly well designed, say the authors.
Over the years, the quality of clinical studies has improved, and reviews of new and old studies are revealing a different picture to that suggested by the dietary guidance. The research has also failed to show consistent evidence that replacing saturated fat with polyunsaturated fats (mainly from plants) reduces the risk of heart disease, the authors point out.
A recent review of multiple studies, altogether involving nearly a million participants, found total dairy intake wasn’t associated with the risk of heart disease or stroke. Meanwhile, total fermented dairy intake – yogurt, sour milk products, cheese – was associated with a reduced risk of these chronic diseases.
‘Current evidence does not support a positive association between intake of dairy products and risk of cardiovascular disease (i.e. stroke and coronary heart disease) and type 2 diabetes’ [consensus of expert workshop in Gentofte, Denmark, 2016].– Astrup et al, 2019.
Fermented dairy foods are linked to health benefits
Fermented dairy foods such as cheese and yogurt are associated with lower body fat, healthier levels of fats in the blood, and reduced risks of heart disease, stroke and type 2 diabetes.
These effects may be partly due to bioactive compounds and structural changes in fats and proteins produced during the fermentation process. Probiotics (‘good bacteria’) found in some fermented dairy foods may also contribute by interacting with the microbes that live in our gut, say the authors.
Full-fat dairy products, especially cheese and yogurt, don’t increase blood pressure or levels of LDL-cholesterol (‘bad cholesterol’) in the blood, studies suggest, despite their salt and saturated fat content. Their high calcium content may be at least partly responsible, say the authors.
The effects of foods should therefore be considered in terms of the whole food, known as the food matrix, rather than single nutrients.
‘…different dairy structures and common processing methods may enhance interactions between nutrients in the dairy matrix, which may modify the metabolic effects of dairy consumption’ [consensus of expert workshop in Gentofte, Denmark, 2016]. – Astrup et al, 2019.
Lots more research is needed to unravel the effects of dairy products on our health. It’s becoming clear that advice to curb or cut out full-fat dairy products from our diet to reduce saturated fat intake and avoid disease is outdated, say the authors. They call for dietary guidelines to be re-evaluated in the light of the recent evidence.
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