"Mayonnaise helps protect women from strokes."
"Eating 2 servings of raisins a day may help lower the risk of colon cancer."
"…scientists are studying links between honey consumption and athletic performance."
"…compounds present in…sunflower seeds…have been shown to offer…protection against heart disease and cancer, as well as a role in memory and cognitive function."
These are just a few examples of the claims that certain foods can improve health. However, if you ate a single serving of mayonnaise, raisins, honey, and sunflower seeds on a daily basis, you'd be downing 550 calories from those foods alone.
"It quickly gets very silly, this message of, 'this much on a daily basis will do whatever,'" says Jeanne Goldberg, PhD, director of the Center on Nutrition Communication at Tufts University.
But does it work? Do people buy x food because of the message that it can prevent y disease? It appears they do—at least to some degree.
"The primary determinant of food selection is taste," says Dr. Goldberg. Typically, cost is second, followed by convenience. However, people respond erratically. They'll add new products to their diet based on health claims. But, if they don't like them, then they won't buy them again.
Regardless, Dr. Goldberg says that the health benefit angle has at least pushed them to give it a shot, especially if they are worried about getting cancer or some other disease.
Brian Wansink, PhD, director of the Food & Brand Lab at the University of Illinois, agrees that people who are particularly concerned about their health make an easy target.
"Most people don't make lifestyle changes unless there's a critical event, a heart attack, or someone you went to high school with 30 years ago looks great, while you look like hell." says Wansink.
Even then, he says, the change in eating behavior is often "very, very temporary. So the difference in sales from these [promotional efforts] is just a really short-term blip, if at all."
However, a short-term blip is just fine for industry, says Marion Nestle, PhD, chair of the Department of Nutrition and Food Studies at New York University and an expert in food marketing and promotion.
"The pressure…is all for immediate results," she explains. Ad agencies and public relations agencies "have to demonstrate blips in sales.." She adds that selling foods for their perceived disease-prevention benefits "works really well" in that regard.
Just how do these food and disease messages about the power of single foods make their way to the public? How can a company get away with "mayonnaise helps protect women from strokes" or "raisins...lower the risk of colon cancer"?
It happens all the time, Dr. Wansink says. A researcher will get a call from someone [in the food industry] asking, "Do you suppose you can do a study that shows blah, blah, blah?" In other words, he notes, "they're saying in advance, 'here's what we want the results to be.'" They're not really testing any hypothesis.
"The industry will start with people who have a certain amount of credibility," he explains. "Those people say, 'No.' Then the industry keeps dropping down until they find someone who'll do it. Maybe that person is low in research grants. So industry will say, 'We'll give you more money to do more of your own research if you get the result we want.'"
What happens next, whether industry actually pays for a study or not, is that the research results get exaggerated and sent to the press where they then get dispensed to the public.
So the next time you're presented with the amazing benefits of a food product, take it with a grain of salt.
Academy of Nutrition and Dietetics
The Nutrition Source—Harvard School of Public Health
Dietitians of Canada
Connors M, Bisogni CA, Sobal J, Devine CM. Managing values in personal food systems. Appetite. 2001;36:189-200.
Williams P. Consumer understanding and use of health claims for foods. Nutr Rev. 2005;63:256-264.
Last reviewed March 2017 by Michael Woods, MD, FAAP