DALLAS, Jan. 20, 2015 -- Eating healthier fats could save more than a million people internationally from dying from heart disease, and the types of diet changes needed differ greatly between countries, according to new research in Journal of the American Heart Association.
"Worldwide, policymakers are focused on reducing saturated fats. Yet, we found there would be a much bigger impact on heart disease deaths if the priority was to increase the consumption of polyunsaturated fats as a replacement for saturated fats and refined carbohydrates, as well as to reduce trans fats," said Dariush Mozaffarian, M.D., Dr.P.H., senior study author and dean of the Tufts Friedman School of Nutrition Science & Policy in Boston. Refined carbohydrates are found in sugary foods or beverages and are generally high in rapidly digested starch or sugar and low in nutrition.
He said this study provides, for the first time, a rigorous comparison of global heart disease burdens estimated to be attributable to insufficient intake of polyunsaturated fats versus higher intake to saturated fats.
Polyunsaturated fats can help reduce bad cholesterol levels in the blood which can lower the risk of heart disease and stroke. Oils rich in polyunsaturated fats also provide essential fats that your body needs - such as some long chain fatty acids. Foods that contain polyunsaturated fats include soybean, corn and sunflower oils, tofu, nuts and seeds, and fatty fish such as salmon, mackerel, herring and trout.
To estimate the number of annual deaths related to various patterns of fat consumption, researchers used diet and food availability information from 186 countries, and research from previous longitudinal studies- which study people over long periods of time - on how eating specific fats influences heart disease risk. Using 2010 data, they estimate worldwide:
711,800 heart disease deaths worldwide were estimated to be due to eating too little healthy omega-6 polyunsaturated fats, such as healthy vegetable oils, as a replacement for both saturated fats and refined carbohydrates. That accounted for 10.3 percent of total global heart disease deaths. In comparison, only about 1/3 of this - 250,900 heart disease deaths -- resulted from excess consumption of saturated fats instead of healthier vegetable oils; accounting for 3.6 percent of global heart disease deaths. Saturated fats are found in meat, cheeses and -fat dairy products, as well as palm and coconut oils. The authors suggest that the difference is due to the additional benefits of increasing omega-6 polyunsaturated fats as a replacement for carbohydrates.
In addition, 537,200 deaths, which represent 7.7 percent of global heart disease deaths - resulted from excess consumption of trans fats, such as those in processed, baked, and fried goods as well as cooking fats used in certain countries.
Comparing 1990 to 2010, the investigators found that the proportion of heart disease deaths due to insufficient omega-6 polyunsaturated fat declined 9 percent and that due to high saturated fats declined by 21 percent. In contrast, deaths due to high consumption of trans fats rose 4 percent.
"People think of trans fats as being only a rich country problem due to packaged and fast-food products. But, in middle and low income nations such as India and in the Middle East, there is wide use of inexpensive, partially hydrogenated cooking fats in the home and by street vendors. Because of strong policies, trans fat-related deaths are going down in Western nations (although still remaining important in the United States and Canada), but in many low- and middle-income countries, trans fat-related deaths appear to be going up, making this a global problem," Mozaffarian said.
In the study, nations in the former Soviet Union, particularly Ukraine, had the highest rates of heart-disease deaths related to low consumption of heart-protective omega-6 polyunsaturated fat. Tropical nations, such as Kiribati, the Solomon Islands, the Philippines and Malaysia, had the highest rates of heart-disease deaths related to excess saturated fat consumption.
"We should be a cautious in interpreting the results for saturated fat from tropical nations that consume lots of palm oil. Our model assumes that the saturated fats in palm oil have the same heart-disease risk as animal fats. Many of the blood cholesterol effects are similar, but long-term studies have not specifically looked at the heart disease risk of tropical oils," said Mozaffarian.
"These findings should be of great interest to both the public and policy makers around the world, helping countries to set their nutrition priorities to combat the global epidemic of heart disease," Mozaffarian concluded.
Co-authors are Qianyi Wang, Sc.D.; Ashkan Afshin, Sc.D., M.D.; Mohammad Yawar Yakoob, Sc.D., M.D.; Gitanjali M. Singh, Ph.D.; Colin D. Rehm, Ph.D., M.P.H.; Shahab Khatibzadeh, M.D.; Renata Micha, Ph.D. and Peilin Shi, Ph.D., on behalf of the Global Burden of Diseases Nutrition and Chronic Diseases Expert Group. Author disclosures are on the manuscript.
The research was undertaken as part of the 2010 Global Burden of Diseases, Injuries, and Risk Factors Study which is supported in part by the Bill and Melinda Gates Foundation and by the National Heart, Lung and Blood Institute of the National Institutes of Health (award number R01HL115189).
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