For years, experts have preached the gospel of eating "healthy" fats and limiting "unhealthy" fats. Now, a new study contends that if people worldwide began to eat healthier fats, there might be more than a million fewer deaths from heart disease every year.
Although a great deal of attention has been focused on reducing saturated fats from the diet, the researchers said the focus should be two-fold: reducing unhealthy fats such as saturated fat and trans fats, and replacing them with healthy fats, such as polyunsaturated fats.
Read: Understanding the different kinds of fat in out diet
"Our findings highlight the importance of ending America's fear of all fat. We estimate that nearly 50,000 Americans die of heart disease each year due to low intake of vegetable oils," said Dr Dariush Mozaffarian, senior study author and dean of the Tufts Friedman School of Nutrition Science and Policy in Boston.
However, while the study found an association between risk of death from heart disease and the types of fats consumed, it didn't prove cause-and-effect.
The study was published online in the Journal of the American Heart Association.
Read: Saturated vs. unsaturated fats
Polyunsaturated fats are found in fatty fish (such as salmon, herring, mackerel and trout), soybeans, tofu, soybean oil, corn oil, sunflower oils and seeds, and walnuts. These fats help lower bad cholesterol, and have been linked to a lower risk of heart disease and stroke, according to the American Heart Association (AHA).
Saturated fats are found in meat and dairy products. Trans fats are found in processed, baked and fried foods, according to the AHA.
To estimate the number of deaths linked to various patterns of fat consumption, Mozaffarian and his team used diet information from 186 countries. They looked at research from previous studies that followed people over long periods of time to see how eating certain fats affects heart disease risk. Death rate information was gathered from a 2010 study.
Read: What happens to the fat we eat?
Using all of that information, the researchers estimated that more than 700,000 deaths worldwide each year, or about 10 percent of heart disease deaths, were due to eating too little healthy omega-6 polyunsaturated fats, as opposed to saturated fats and refined carbohydrates.
Eating too much saturated fat instead of healthier fats accounted for roughly 4 percent of heart disease deaths about 250,000 deaths that might be prevented with decreased saturated fat intake.
And, about 8 percent of heart disease deaths were estimated to be due to an excess of trans fats, the researchers said.
That means decreased trans fat intake could result in about 537,000 fewer heart disease deaths, the study estimated.
Read: Fat is good for you
Residents of different countries reported different patterns of fat consumption. For instance, deaths from trans fats are declining in Western nations as the unhealthy fat is garnering more attention.
However, the United States and Canada were still in the top four nations for heart disease deaths attributed to trans fat intake, the study showed.
Residents of Russia, Germany and Egypt had the highest rates of heart disease death due to low intake of healthy polyunsaturated fats.
Residents of the Philippines, Malaysia and tropical nations had the highest heart disease death rate due to eating too much saturated fat, the researchers said.
Read: Natural trans fats are good for your heart
The new study comes out at an ideal time – January, said Dr Suzanne Steinbaum, a cardiologist and director of Women's Heart Health at Lenox Hill Hospital in New York City. She reviewed the findings. "Diet is on everyone's mind," she said.
The new study shows that "reducing saturated fats actually makes a difference", Steinbaum said. And, she added, "it provides an understanding of the huge impact that food has on heart disease".
Steinbaum plans to cite the study with her patients who come in saying this is the year they will lose their excess weight. "What I am going to use this for is to say, 'Check this out, this is around the world,' " she said, pointing to the saving of 1 million lives a year by eating healthier fats.
"I will use it as a power tool to change behaviour," she said.
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