- People think “superfoods” have unique nutritional qualities and health benefits.
- But in her new book “Unsavoury Truth,” nutrition expert Dr. Marion Nestle wrote that the term is a just a marketing concept.
- Healthy diets are about our overall eating pattern, not just a handful of so-called “superfoods.”
- Plus, studies that claim to find special health benefits in single foods can be influenced by food industry funding, as Nestle explored in the book.
“Superfoods” are a nice idea. It’s comforting to think that kale or wild blueberries possess unsurpassed nutritional qualities that will improve your health and protect you from disease whenever you eat them. But beneath that comforting concept lies a disappointing reality: The term “superfood” is merely a marketing concept, Dr. Marion Nestle, nutrition and public health professor emerita at New York University, wrote in her latest book, “Unsavoury Truth.”
The book, published in October, explores the ways that the food industry sponsors research into its own products, from dairy to sugary soda. In it, Nestle also zeroed in on a specific phenomenon: Industry-funded research of healthy, unprocessed foods, like walnuts, pears, or avocados.
This type of research aims to discover special health benefits that can later be touted in advertising, Nestle argued in the book.
“When marketing imperatives are at work, sellers want research to claim that their products are ‘superfoods,’ a nutritionally meaningless term,” she wrote.
In reality, the idea that singular foods can have outsized, dramatic effects on your health doesn’t make scientific sense. INSIDER spoke with Nestle to learn why.
Industry-funded nutrition studies can make it seem like single foods have unique health benefits
Nestle began to notice an uptick in industry-funded nutrition studies back in 2015. So she started to collect examples of these studies and post about them on her blog, Food Politics. (This information isn’t necessarily secret, by the way: Most scientific journals require study authors to disclose who paid for the research and any financial ties they have with funders, Nestle wrote in the book.)
At the end of a year, she’d collected 168 industry-funded studies, 156 of which had a result that favoured the funders’ interests, she told INSIDER.
She also said she was surprised to discover many industry groups that market healthy foods were also funding this kind of research.
“One of the things I noticed was that there were [studies on] all these foods that are demonstrably healthy. Why would you need to do research to prove that blueberries or raspberries or pomegranates or grapes are healthy?” Nestle said. “Of course they’re healthy. So they only reason they were doing it is because they’re trying to increase market share.”
The idea that “one food has special health benefits defies common sense”
In “Unsavoury Truth,” Nestle wrote that guidelines for healthy eating universally recommend diets rich in plant foods like fruits, veggies, beans, grains, and nuts. But no single food makes or breaks a healthy diet – it’s our overall eating pattern that matters.
The most recent Dietary Guidelines for Americans, for example, don’t recommend focusing on any single foods for better health: They call for a “healthy eating pattern,” which includes a “variety of vegetables,” fruits, grains, and more.
“To ask whether one food has special health benefits defies common sense,” Nestle wrote in the book. “We do not eat just one food. We eat many different foods in combinations that differ from day to day.”
Read more: 15 ‘health foods’ you’re better off avoiding
Plus, truly teasing out the potential health effects of a single food would require wildly expensive, long-lasting, and difficult research studies.
For example: If you wanted to figure out whether one type of nut is better at protecting against heart disease than another, you’d have to a run a study for years, since heart disease symptoms can start to show up in an individual’s 40s, 50s, or 60s, Nestle explained to INSIDER.
“You would also have to lock people up and feed them defined diets … because otherwise people might go off and eat other things and that would mess up your results – and you’re looking at one food in the context of many, many, many different kinds of foods,” Nestle said. “It’s unlikely that one food is going to make much difference except to somebody who’s allergic to it. [For] average healthy people, it’s hard to imagine that it would make any difference.”
Studies may be designed to make foods look good
Nestle also explained that some industry-funded nutrition studies may be designed to make foods look beneficial. For instance, a study might examine one food’s effects but neglect to compare it to a placebo, a different food, or nothing at all. If that food isn’t tested against something, it’s impossible to put any uncovered “benefits” in a larger context.
Nestle cited research on pomegranate juice as one example. Some industry-funded research has shown that pomegranate juice has antioxidant activity, but all fruits and vegetables contain antioxidants, she wrote in the book – they’re not unique to particular fruits. (Plus, more antioxidants aren’t necessarily better: Scientists still don’t know if antioxidants are actually what makes fruits and vegetables so good for us – despite all the buzz they have accrued.)
This doesn’t mean every scientist who conducts industry-funded nutrition research is trying to deceive consumers.
“In general the influence of food industry funding occurs at a subconscious level,” Nestle said. “I think people who are doing this kind of research believe sincerely that the funding has no influence on their science.”
Instead, she said, industry influence occurs mainly at the level of the research question, or how the study is set up from the start.
“It’s one thing [to say,] ‘Let’s show the benefits of pomegranate juice,'” she said. “And it’s another to ask, ‘What is the effect of pomegranate juice in otherwise healthy diets?'”
Research on “superfoods” may have other weaknesses besides potential bias from industry funding
Potential industry influence aside, the science used to bolster superfood claims may be still lacking.
When studies of so-called superfoods are conducted in humans, they are often tested at high doses over short periods of time, which doesn’t reflect the way humans really eat, University of Newcastle nutrition researchers Emma Beckett and Zoe Yates wrote in a post for The Conversation in 2013.
And many studies on so-called superfoods aren’t conducted in humans at all, but in animals or isolated cells, according to the non-profit European Food Information Council. The results of animal or cell studies aren’t necessarily true for humans.
“It is unrealistic to expect a narrow range of ‘superfoods’ to significantly improve our well-being,” the organisation wrote in 2012.
Beneath flashy health claims, nutrition advice remains the same
Nestle acknowledged that health claims tied to specific foods can be alluring.
“I think we’re hard-wired to find those kinds of things appealing,” she said. “If you thought about it, for one second, you would immediately realise that blueberries are unlikely to solve problems of erectile dysfunction. I just read one [study] on beer reducing symptoms of Alzheimer’s disease. This is very unlikely if you think about it. But you’re not supposed to think about it. It’s supposed to hit you on some emotional level that you’re not even conscious of.”
In “Unsavoury Truth,” Nestle recommended that consumers be sceptical of any report that says a single food, drink, supplement, ingredient, or food product either causes or reduces the risk of obesity or major diseases like cancer.
She also offered a reminder: Beneath hyped-up health claims, expert nutrition advice hasn’t changed much.
“The basic principles of eating healthfully have remained remarkably consistent over the years,” she wrote in the book. “Eat a wide variety of relatively unprocessed foods in reasonable amounts.”