In wake of policy change, heart attack and stroke incidence dropped, study shows
Taking artificial trans fats off the menu reduces hospitalizations for heart attack and stroke, suggests a study that examined what happened after several areas in New York restricted the fats’ use. The findings portend larger scale public health benefits after a nationwide ban on artificial trans fats begins in the United States in 2018.
Hospital admission rates for heart attacks declined 7.8 percent more in New York counties that restricted trans fats than in those counties that had not, researchers report online April 12 in JAMA Cardiology.
“This is the first study that links a trans fats ban to a reduction in heart disease and stroke in large populations,” says nutritional epidemiologist Frank Hu of the Harvard T.H. Chan School of Public Health. “The evidence from this study indicates that implementation of a nationwide ban on trans fats will reduce heart disease and save many lives in the United States.”
Heart disease causes one in every four deaths in the United States. Coronary heart disease, the most common kind, kills more than 370,000 people each year. Past research finds that eating foods containing artificial trans fats, also called trans-fatty acids, increases the risk of coronary heart disease. Among other effects, consuming these fats leads to higher levels of low-density lipoprotein cholesterol, or “bad” cholesterol, a component of artery-clogging plaque. Artificial, or industrial, trans fats occur in vegetable oils that are partially hydrogenated. Foods typically made with these oils include deep-fried fast foods, baked goods, crackers and margarine.
Beginning in 2007, New York City restricted artificial trans fats in food bought at restaurants, cafeterias, bakeries and other eateries. A number of New York counties followed suit over the next several years. The restrictions provided a good opportunity to examine changes in cardiovascular health after implementation, says coauthor Eric Brandt, a Yale University internist.
Brandt and colleagues included in the analysis 11 counties that had restrictions on artificial trans fats and 25 counties that did not. The researchers looked at hospital admission rates for heart attack or stroke from 2002 to 2013. Heart attack and stroke admissions already were trending down in the counties prior to the first restrictions, says Brandt, due to improvements in medication and treatment.
At least three years after the artificial trans fats restrictions took effect, admission rates for heart attacks and strokes combined dropped an additional 6.2 percent among residents of restricted counties versus non-restricted counties. That means for every 100,000 people, there were 43 fewer heart attacks and strokes. This drop is beyond what would have been expected by population trends alone, says Brandt.
The team also separated out hospitalizations for each diagnosis. In restricted counties, hospital admission rates for heart attacks also declined more than in non-restricted counties. It is highly likely that the reduction in admission rates for heart attacks and stroke together, and heart attacks alone, is due to the artificial trans fats restrictions, says Brandt. While stroke admission rates alone also dropped in restricted counties, this result may not have been primarily related to the policy.
Taken together with previous work tying the consumption of these fats to coronary heart disease, “it’s a very powerful nail in the coffin for industrial trans fats,” says cardiologist Dariush Mozaffarian of Tufts University in Boston.
The Food and Drug Administration, which in 2015 determined that partially hydrogenated oils were no longer “generally recognized as safe,” has ordered that food manufacturers ensure their products are free of these oils by June 2018. This will effectively eliminate artificial trans fats from the entire U.S. food supply, notes Mozaffarian. The study “very strongly supports” the upcoming FDA action, he says. “If we reduce heart disease across the whole country” by the amount suggested by the study, Mozaffarian says, “that reduction would be incredible.”
E. Brandt et al. Hospital admissions for myocardial infarction and stroke before and after the trans-fatty acid restrictions in New York. JAMA Cardiology. Published online April 12, 2017. doi:10.1001/jamacardio.2017.0491