Contrary to most dietary advice handed out for decades, consuming moderate amounts of fat appears to reduce the risk of premature death, a major global study has found.

Research involving more than 135,000 people across five continents has shown that fat consumption representing about 35 per cent of daily caloric intake was associated with a lower risk of death, compared to lower fat intakes.

Researchers also found that dietary fats, including saturated, polyunsaturated and monounsaturated fats, are not associated with major cardiovascular diseases or increased risk of heart attacks.

However, a diet high in carbohydrates, in which carbs represent more than 60 per cent of caloric intake, was linked to higher mortality rates.

Overall, the study showed that avoiding a high-carb diet and consuming a moderate amount of fat, along with fruits and vegetables, can lower the risk of premature death.

The Prospective Urban Rural Epidemiology (PURE) study was led by researchers at the Population Health Research Institute (PHRI) at McMaster University and Hamilton Health Sciences in Hamilton, Ont.

For an average of seven-and-a-half years, the study followed more than 135,000 people from 18 countries and various economic and cultural backgrounds. The collected data produced two reports, published Tuesday in The Lancet.

While the PURE study’s findings about dietary fats may seem surprising, Canadian researchers say the latest results are consistent with several other studies conducted in western countries over the last 20 years.

Mahshid Dehghan, the lead author of the PURE study and an investigator at PHRI, said that for decades, dietary guidelines have focused on reducing total fat consumption to below 30 per cent of daily caloric intake.

She said those guidelines were developed about 40 years ago using data from some western countries that showed average fat consumption represented more than 40 per cent of daily caloric intake.

But overall fat consumption is significantly lower today in North America and Europe, at 31 per cent, she said. Dehghan added that in some countries, reducing fat intake actually led to other dietary problems.

“A decrease in fat intake automatically led to an increase in carbohydrate consumption and our findings may explain why certain populations such as South Asians, who do not consume much fat but consume a lot of carbohydrates, have higher mortality rates,” Dehghan said in a news release.

Richard Bazinet, a professor at the University of Toronto’s department of nutritional sciences, said that in the past decade, researchers have been getting “some really conflicting evidence” on how fat consumption impacts our health.

The PURE study is a “very large piece of evidence” that shows saturated fat is not as bad for us as previously thought, he told CTV News Channel on Tuesday.

“A lot of people around the world haven’t been able to reproduce the findings that saturated fats are a major culprit (for disease),” he said.

The PURE study also found that:

  • People who ate three to four servings (between 375 and 500 grams) of fruits, vegetables and legumes per day had the lowest risk of premature death.
  • Although most dietary guidelines recommend a minimum of five daily servings of fruits and veggies, researchers say higher intakes did not result in many additional health benefits.

“Most people in the world consume three to four servings of fruits, vegetables and legumes a day,” Andrew Mente, a PHRI investigator and McMaster University professor, said in a news release.

“This target is likely more affordable and achievable, especially in low and middle income countries where the costs of fruits and vegetables are relatively high.”

Researchers say the PURE study further demonstrates the importance of dietary moderation, and provides “robust, globally applicable” evidence that can be used to inform nutrition policies.