BARCELONA, Spain – A major tenant of 20th century health guidelines has been called into question at one of the world’s largest cardiology conferences.
In light of emerging data, researchers at this week’s European Society of Cardiology conference have suggested a reconsideration of global dietary fat recommendations. In a study of some 135,000 people from 18 countries, high carbohydrate intake has been linked to more deaths than high fat diets.
“Our findings do not support the current recommendation to limit total fat intake to less than 30% of energy and saturated fat intake to less than 10% of energy,” says study investigator Dr. Mahshid Dehghan of McMaster University in a news release. “Limiting total fat consumption is unlikely to improve health in populations, and a total fat intake of about 35% of energy with concomitant lowering of carbohydrate intake may lower risk of total mortality. In fact, individuals with high carbohydrate intake, above 60% of energy, may benefit from a reduction in carbohydrate intake and increase in the consumption of fats.”
The Prospective Urban-Rural Epidemiology (PURE) study looked at individuals aged 35 to 70 years, from low, middle, and high-income countries all around the world, with an average 7.4 year period of following up on participants.
What the researchers found called into question the conventional wisdom about nutrition.
The study showed those with the highest carbohydrate intake had a nearly 30% increased risk of death, though this was not linked to cardiovascular disease by the study. On the other hand, those with the highest fat intake had a 23% lower total mortality risk, 18% lower risk of stroke, and a 30% lower risk of non-CVD mortality.
The researchers also found more of a benefit in diets high in “good” fats. Mortality risks were shown to be “14% lower for diets high in saturated fat, 19% lower for mono-unsaturated fat, and 20% for polyunsaturated fat. Higher saturated fat intake was also associated with a 21% decrease in stroke risk.”
Researchers said much of the evidence behind conventional fat recommendations have been from studies of Western countries “where nutritional excess is a reality.” They said this latest study still takes into account such Western diets, but also populations where under nutrition is a bigger problem.
The PURE research comes on the heels of recent attention to historical sugar lobby efforts to cast attention on fats rather than sugars in heart disease and other health concerns.
Last year, researchers unearthed documents showing that in the 1960s a major sugar lobby paid Harvard scientists to publish hand-picked studies that minimized connections between sugar and cardiovascular disease. Instead, these studies put the blame on saturated fat.
According to the New York Times article How the Sugar Industry Shifted Blame to Fat, “…five decades of research into the role of nutrition and heart disease, including many of today’s dietary recommendations, may have been largely shaped by the sugar industry.”
While the PURE study doesn’t indict sugar specifically in higher mortality, the American Diabetes Association does note that sugar is one of the three main types of carbohydrates. The other two are fiber and starches.
A Heart Foundation information page notes that “many people think of rice, potatoes and pasta as ‘carbs’ but that’s only a few of the huge range of foods that contain carbohydrates.”
Though they say that there is not scientific consensus on the relationship of sugar to heart disease, the Heart Foundation does draw the link to a diet high in sugar and obesity, which does carry an increased risk of cardiovascular disease.
While the results of the PURE study have yet to impact policy changes, the American Heart Association is already updating some of its recommendations based on other research.
In an advisory issued earlier this summer, the AHA said that lowered intakes of saturated fats were not beneficial in reducing heart disease if the fats were replaced with mostly refined carbohydrates and sugars. Instead, they “conclude strongly that lowering intake of saturated fat and replacing it with unsaturated fats, especially polyunsaturated fats, will lower the incidence of CVD.”
The findings of the PURE study were presented at this weeks ESC conference and published in an article in the Lancet.