Carbs are worse for you and fat is better for you than current guidelines suggest, according to results from a large new study released today. And researchers say it’s time to rework recommendations that government agencies, doctors and other clinicians make to patients on healthy eating.
Said study investigator Mahshid Dehghan from Canada’s McMaster University: “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…. 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 findings come from more than 135,000 people in 18 countries across the economic spectrum. PURE participants were aged 35 to 70 and came from countries in North America, South America, the Middle East, Africa, Europe, South Asia, South East Asia and China. The dats from these people indicates that eating a high percentage of carbohydrates is tied to worse health outcomes. Nearly 5,800 deaths and 4,800 major cardiovascular events were recorded. Researchers found carb consumption in the highest versus lowest quintile was associated with a nealry 30% increased risk of total mortality. On the other hand, people who were at the high end of fat consumption fat intake saw a 23% reduction in total mortality risk, an 18% reduced risk of stroke, and a 30% reduced risk of non-CVD mortality. All fat types were associated with significantly reduced mortality risk: 14% lower for saturated fat, 19% for mono-unsaturated fat, and 20% for polyunsaturated fat.
The researchers also looked at the effects that fats and carbs had on blood lipids. They found that while LDL (so-called “bad” cholesterol) goes up with higher intakes of saturated fat, HDL (“good” cholesterol) also increases. They further found that LDL cholesterol is a poor predictor of the effects that saturated fat will have on future cardiovascular events. Instead, ApoB/ApoA1 was the best risk indicator among the markers tested.
Said Dehghan: “Focusing on a single lipid marker such as LDL-C alone does not capture the net clinical impact of nutrients on cardiovascular risk…. For decades, dietary guidelines have focused on reducing total fat and saturated fatty acid (SFA) intake based on the presumption that replacing SFA with carbohydrate and unsaturated fats will lower LDL-C and should therefore reduce CVD events.” But, she explained, evidence behind this has largely come from Western populations where nutritional excess is a reality. “PURE provides a unique opportunity to study the impact of diet on total mortality and CVD in diverse settings, some settings where over-nutrition is common and others where under nutrition is of greater concern.”
