And, it's not just the things you should be avoiding - such as salt and trans fats - that are contributing to these deaths. The excess deaths may also be caused by what's missing in your diet - namely, nuts and seeds, vegetables and whole grains, the researchers said.
"Cardiovascular disease is the number one cause of death in the United States, killing more people in 2015 than any other cause," said lead researcher Dr. Ashkan Afshin of the University of Washington in Seattle.
He's an acting assistant professor of global health at the university's Institute for Health Metrics and Evaluation.
"Poor diet is the top risk factor for cardiovascular disease death and, therefore, deserves attention from decision-makers in the U.S. when setting health agendas," Afshin said.
The study results suggest that nearly half of heart disease and stroke (cardiovascular disease) deaths in the United States might be prevented with improved diets, he explained.
Debates on dietary policies in the United States tend to focus on cutting out unhealthy foods and nutrients, such as trans fats, salt and sugar-sweetened beverages. But this study shows that a large number of heart-related deaths may be due to a lack of healthy foods, Afshin reported.
"This study highlights the urgent need for implementation of policies targeting these unhealthy food groups as well healthy foods, such as nuts, whole grains and vegetables," he said.
The study data came from the U.S. National Health and Nutrition Examination Survey from 1990 to 2012. The researchers also used food availability data from the Food and Agriculture Organization of the United Nations and other sources.
Looking at deaths in the United States from heart and blood vessel diseases for 2015, the investigators found unhealthy diet choices and lack of eating healthier foods had a part in the deaths of more than 222,000 men and over 193,000 women. The study could not, however, prove a direct cause-and-effect relationship.
Low intake of nuts and seeds likely accounted for nearly 12 percent of deaths. Too few vegetables probably contributed to as many as 12 percent of the heart disease and stroke deaths.
And, low intake of whole grains may have been responsible for more than 10 percent of those deaths. Too much salt likely accounted for 9 percent of deaths, Afshin said.
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