A whole-fat diet is not unhealthy and may help avert cardiovascular disease (CVD) and premature death, according to a global study conducted in 80 countries, challenging the recommendation to limit high-fat dairy foods.

The study, published in the European Heart Journal Global study, showed that fruit, vegetables, dairy (mainly whole-fat), nuts, legumes and fish were linked with a lower risk of CVD and premature death in all world regions. The addition of unprocessed red meat or whole grains had little impact on health outcomes.

"Low-fat foods have taken centre stage with the public, food industry and policymakers, with nutrition labels focused on reducing fat and saturated fat," said Dr Andrew Mente of the Population Health Research Institute, McMaster University in Canada.

Our findings suggest that the priority should be increasing protective foods such as nuts (often avoided as too energy-dense), fish and dairy, rather than restricting dairy (especially whole-fat) to very low amounts.

"Our results show that up to two servings a day of dairy, mainly whole-fat, can be included in a healthy diet. This is in keeping with modern nutrition science showing that dairy, particularly whole-fat, may protect against high blood pressure and metabolic syndrome," Mente said.

About 147,642 people from the general population in 21 countries were tested on a "healthy and longevity" diet including 2-3 servings of fruit per day, 2-3 servings of vegetables per day, 3-4 servings of legumes per week, 7 servings of nuts per week, 2-3 servings of fish per week, and 14 servings of dairy products (mainly whole fat but not including butter or whipped cream) per week.

The results showed that diet was linked with a 30 per cent lower risk of death, 18 per cent lower likelihood of CVD, 14 per cent lower risk of myocardial infarction and 19 per cent lower risk of stroke.

Associations between the healthy diet score and outcomes were confirmed in five independent studies including a total of 96,955 patients with CVD in 70 countries.

"The associations were strongest in areas with the poorest quality diet, including South Asia, China and Africa, where calorie intake was low and dominated by refined carbohydrates. This suggests that a large proportion of deaths and CVD in adults around the world may be due to undernutrition, that is, low intakes of energy and protective foods, rather than overnutrition. This challenges current beliefs," said Professor Salim Yusuf, senior author and principal investigator.