A group of researchers took advantage of a “natural” field study by examining records of hospitalization for heart attacks or stroke among New York residents living in counties that had implemented restrictions on the use of trans fats in restaurant meals; the team collected hospitalization data both before and after the restrictions and then compared those data with hospitalization rates in counties that took no action to restrict the use of trans fats. The comparison found a modest decline in individuals hospitalized for heart attacks in the trans fat-restricted counties.
However, the study design could not establish causality, so the research could only conclude that it had found a link. Although the headline admirably opted for the term “linked,” the story lede translates that into a causal statement–the ban “led to fewer heart attacks and strokes.” Another story we reviewed, by Reuters Health, was more cautious.
But otherwise, this story hit a lot of high notes, especially when it came to discussing the benefits measured by the study.
According to the CDC, some 610,000 people die of heart disease annually in the United States; it is the leading cause of death for both men and women. The FDA plans a nationwide restriction of trans fats beginning in 2018, so understanding the impact of such a dietary shift is important.
While there may be costs associated with different food ingredients (i.e., different types of fats), that does not seem relevant here.
The story employs both absolute numbers and percentages, so that we know how great a magnitude the change was (e.g., 43 fewer heart attacks and strokes per 100,000 people).
The concept of harm/side effects does not seem relevant here.
However, we did want to note: When trans fats were first introduced, they were supposed to be a healthy alternative to tropical oils with lots of saturated fat. Now that they are being removed, it’s worth discussing what they will be replaced with and whether that change could have negative health consequences, too.
The story states the study compared “before-and-after data” and “examined hospital admissions data from 2002 to 2013 in 11 New York counties that adopted bans and in 25 counties that did not.”
But it should have let readers know that the findings couldn’t provide a definitive cause-and-effect relationship between a trans fat ban and fewer hospitalizations–just an association between the two. It’s inappropriate to state that the ban “led to fewer heart attacks and strokes” as claimed in the lede.
Heart disease is a major killer; the story did a good job explaining what trans fats are, and why they’re unhealthy.
Trans fats, also called partially hydrogenated oils, enhance food texture and structure. They were once commonly used to make restaurant fried chicken, French fries, doughnuts and other foods and found in grocery items including cookies, crackers and margarine.
These fats can boost blood levels of unhealthy cholesterol, increasing risks for heart problems.
The story included two independent sources; we did not detect any undisclosed conflicts of interest.
The story mentioned smoking bans and mandatory calorie counts on menus, which could be considered alternative public health measures to reduce heart disease.
The story lets readers know that soon a trans fat ban will apply to the entire country:
The study hints at the potential for widespread health benefits from an upcoming nationwide ban, the authors and other experts say. The U.S. Food and Drug Administration in 2015 gave the food industry until next year to eliminate artificial trans fats from American products
The story implied that this study’s finding is not novel, with this quote:
Dr. Mark Creager, former American Heart Association president, said the results echo previous studies “and are consistent with the thinking of most scientists” on potential benefits of these bans.
But, we wish the story would have explained this a little more specifically, as Reuters Health did. They mentioned that previous studies looked at mortality from heart disease, and that until this one was published, “no study looked at non-fatal cardiovascular issues like hospitalizations due to heart attacks and strokes, however.”
Although Yale University did issue a news release, this story contains details not available in that text.