PURE Study, Diet, heart disease, health, Scott Lear

Eat more fat, less carbohydrates and a moderate amount of fruits, vegetables and legumes, results from our global study say

September 03, 2017
Image credit: Holly, CC BY-NC-SA 2.0
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Vancouver, B.C.  –  Our research group contributed to two papers published in The Lancet this week that question conventional wisdom around the health benefits of a low-fat diet.

Results from the Prospective Urban Rural Epidemiologic (PURE) Study show that a diet which includes a moderate intake of fat, fruits and vegetables, and avoidance of high amounts of carbohydrates, confers the lowest risk of premature death.

In the first paper, people with the highest carbohydrate intake (>67% of daily caloric intake) had higher rates of premature death compared to those with the lowest intake (approximately 46%). In contrast, the highest intake of total fat (approximately 35%) was associated with the lowest risk for premature death. Analyses by fat type indicated that people with the highest intakes of saturated (13%), mono- (13%) and polyunsaturated (8%) fats had the lowest risk. These findings are in contrast to current dietary recommendations that fat make up less than 30% of daily caloric intake.

The second paper looked at the benefits of fruits and vegetables. Compared to only one serving per day, increasing fruit and vegetable intake was associated with a reduction in premature death. The lowest risk was at 3 to 4 servings per day, with no additional benefit when eating up to 8 servings daily. Of note, eating raw vegetable was more strongly associated with a lower risk of premature death compared to cooked vegetables.

The PURE Study followed more than 135,000 people across five continents for seven years. A unique aspect of the study is its inclusion of low- and middle-income countries. These are often excluded from studies, yet they comprise the bulk of the world’s population. The lifestyle and access to foods is quite different in these countries compared to high-income ones, allowing for more robust analyses.

For a long time, a diet low in fat has been recommended to prevent and treat heart disease and stroke. However, this has led to many people consuming diets high in carbohydrates, and particularly processed carbohydrates.

Together, these two robust papers from the largest study of its kind highlight that higher fat and lower fruit and vegetable intakes than prescribed by current guidelines are associated with lower risk of premature death. The inclusion of low and middle income countries will help to inform guidelines in these parts of the world that have generally been based on data from high income countries.

The PURE study was funded from more than 50 sources, including the Population Health Research Institute, the Heart and Stroke Foundation of Ontario and Canada and the Canadian Institutes of Health Research.


Publications

Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study

Fruit, vegetable, and legume intake, and cardiovascular disease and deaths in 18 countries (PURE): a prospective cohort study