Eating lots of fried foods is already linked with obesity and heart disease, but could the habit impact your mental health as well?
A new study suggests that may be the case. Frequent fried food consumption—“especially fried potato consumption” like french fries—was strongly associated with a 12% higher risk of anxiety and a 7% higher risk of depression, researchers reported in the Proceedings of the National Academy of Sciences on Monday.
Men and younger people seemed to be particularly affected.
The authors of the paper blamed acrylamide—a contaminant produced in starchy foods when they are fried, baked, roasted, or otherwise cooked at high temperatures—as a potential culprit for the mental health changes.
Acrylamide forms mainly in potato products, grains, or coffee, the U.S. Food and Drug Administration noted.
The findings are based on data from more than 140,000 people in the U.K. who shared their health information and dietary habits for a large medical database and were followed for an average of 11 years.
For the new study, researchers in China looked for people in that database who regularly ate fried food and then checked whether they experienced more anxiety or depression symptoms than people who didn’t eat that much fried food.
Dr. Uma Naidoo, a Harvard University-trained nutritional psychiatrist and author of “This is Your Brain on Food,” was not involved in the study, but says the results match both her research and clinical findings.
“It’s not about eating a potato, as it’s a healthy food in moderation and there are healthy ways to cook potatoes. But it is about the method of deep frying,” Naidoo, the director of nutritional and lifestyle psychiatry at Massachusetts General Hospital in Boston, told.
“In general, deep-fried foods are unhealthy for both our physical and mental health and should be a less frequent food in our diet.”
Fast food, which is part of the standard American diet, is usually fried in pro-inflammatory and cheaper vegetable oils, Naidoo says.
This leads to more inflammation in the gut, leading to inflammation in the brain over time, she adds. In research, such neuroinflammation has been associated with conditions like depression and anxiety, she says.
When it comes to acrylamide, the human health effects from low levels of it are unknown; but in animals, long-term exposure can cause reproductive problems, nerve damage, and cancer, according to the Centers for Disease Control and Prevention.
In the new study, zebrafish who were exposed to acrylamide for 180 days were less social and showed “anxiety- and depressive-like behaviors,” the authors wrote, though they acknowledged fish activity can’t be directly compared to human anxiety and depression.
Still, global health experts have called acrylamide “a human health concern,” according to the FDA. It can cause inflammation throughout the body, including the nervous system, Naidoo says.
To avoid exposure to acrylamide, she advises using gentle heat when cooking, like boiling potatoes instead of frying them. If you’re still craving french fries, air frying potatoes produces less acrylamide, studies have shown.
To protect your mental health in general, Naidoo recommends eating whole, natural foods that are minimally processed. Skip foods with added sugars, preservatives, and chemicals, and cut back on fried foods.
The relationship between nutrition and poor mental health tends to be a two-way street, Naidoo says.
“Unhealthy foods are detrimental to the microbiome and can exacerbate depressive symptoms, but at the same time those experiencing low mood tend to be more inclined to reach for ‘comfort’ foods such as fried foods and desserts,” she says.
“However, we see that once individuals consciously choose healthy whole foods, they begin to feel better emotionally and are more likely to continue to make healthy food choices.”
