In the rush to post headlines on the latest studies, some writers or editors miss or confuse key facts. Sometimes, it’s the studies’ authors who get it wrong. Here’s a look behind a few recent headlines.
French fries linked to death?
“People have long known French fries aren’t great for your health—but now a study has linked eating fried potatoes at least twice a week with an increased risk of death,” reported TIME in June.
The risk of dying was twice as high for people who ate fried potatoes at least twice a week than for those who ate them no more than once a month, said the study, which tracked 4,440 people aged 45 to 79 for eight years.1
In contrast, “eating unfried potatoes, such as potato salad and boiled, baked and mashed potatoes, was not linked to an increased risk of death,” said TIME.
“Unfried white potatoes are a relatively healthy food because they contain a good amount of fiber, vitamins and micronutrients, the study authors write,” noted TIME, “which ‘could have counterbalanced the detrimental effects of their high glycemic index.’”
Yes, the authors wrote that, but they should have noted that frying lowers a food’s glycemic index—that is, fried potatoes cause less of a spike in blood sugar than unfried potatoes.
“Fried potatoes, however, typically have lots of fat and added salt,” explained TIME, paraphrasing the authors.
News flash: mashed potatoes and potato salad also typically have plenty of salt. And the unsaturated fat used for frying isn’t harmful, except that it boosts calories.
At least TIME didn’t repeat the authors’ claim that fries are high in trans fat. The trans that was in fries during the early part of the study (2004 to around 2008) could have raised the death rate, but most restaurant chains no longer fry in trans fat.
Bottom Line: Do french fries raise your risk of dying? It’s unclear. Longer, larger, better studies do find a higher risk of type 2 diabetes in people who eat more potatoes, fried or unfried. But this study only made headlines because fries + death = clickbait.
The Mediterranean diet cures depression?
“Following a modified Mediterranean diet helped some patients being treated for depression in a study,” reported the Wall Street Journal in January. The article noted that the study was “the first randomized controlled one.”
“A third of patients assigned to a group that followed a modified Mediterranean diet met the criteria for remission in 12 weeks, compared with just 8 percent in a control group,” said the Journal.
True, but the study was small, and it enrolled people whose diets were heavy on sweets and chips, not fruits and vegetables.2
What’s more, it didn’t compare the diet it told people to follow to any other diet. (The control group got “social support”—visits discussing sports, news, music, or other topics of interest.)
And for many people, the study’s “Mediterranean diet” would have meant a major overhaul. As the Journal noted, it “included a lot of fruits, vegetables, beans, fish, whole grains, lean red meat, olive oil and nuts, and cut back on sweets, processed foods, soft drinks and other unhealthy items.” Which of those changes mattered is unclear.
Too bad the article ended by quoting a psychiatrist who “gives his patients brain-food prescriptions that include increasing the consumption of certain categories of food—such as leafy greens and bivalves—as well as certain nutrients, such as vitamin B12, long-chain omega-3 fatty acids, and magnesium.”
The Journal neglected to say whether there are randomized controlled studies to back all of that advice.
Bottom Line: A heart-healthy “Mediterranean diet” is a good bet whether you’re depressed or not.
Artisanal bread no better than processed white?
“Artisanal bread, like these French baguettes, is not necessarily healthier than processed white bread, a new study says,” noted the photo caption in Newsweek in June.
The study pitted a Wonder-like white bread against an artisanal (traditionally made) whole wheat sourdough, not a white baguette like those in the photo.
The results: 20 people who ate the white bread for a week had no higher blood sugar levels than after they ate the whole wheat sourdough for a week.3
That’s not a huge surprise. In earlier studies, both whole wheat and white bread caused a similar rise in blood sugar (though white sourdough might cause a slightly smaller jump).
The surprise: “The researchers found that which bread was best for each person could be predicted based on the bacteria present in their gut,” explained Newsweek.
As one study author explained, “these findings could lead to a more rational approach for telling people which foods are a better fit for them, based on their microbiomes.”
Hmm. That would have been a good time to note, as did a CNN report on the same study, that two of the authors “are paid consultants for a company that offers personalized nutrition recommendations based on DNA sequencing of your microbiome.”
CNN also pointed out that blood sugar isn’t the whole ballgame. “The health benefits of whole grains may be much longer term than a one-week study can show, especially in relation to gut health and prevention of conditions like bowel cancer,” Elizabeth Lund, a former researcher at the Institute of Food Research in the UK, told CNN.
“This study does not imply that people should give up eating whole-grain foods based on these results.”
Bottom Line: Why eat grains that are stripped of their fiber, vitamins, and minerals? Whole grains may also lower your risk of heart disease. What’s more, how much any food raises your blood sugar depends on how it’s cooked, the rest of the meal, your gut microbes, and more.