New research links ultra-processed food and drink consumption to risk of depression in women

Consuming high amounts of ultra-processed food and drinks could increase the risk of developing depression in women, new research suggests.

The findings indicate this is especially true with the consumption of artificial sweeteners and artificially sweetened beverages, according to the study published Wednesday in the journal JAMA Network Open.

The study examined the diets of nearly 32,000 middle-aged female nurses as part of the Nurses’ Health Study II, a longitudinal study on various aspects of women’s health. Those who consumed over nine portions a day had about a 50% higher risk for developing depression than those consuming four portions or less.

The link between ultra-processed foods and depression remains unknown, according to the study. However, recent experimental data implies that artificial sweeteners evoke purinergic transmission in the brain, possibly leading to the development of depression.

"Participants with high UPF intake had greater BMI, higher smoking rates, and increased prevalence of comorbidities like diabetes, hypertension, and dyslipidemia and were less likely to exercise regularly," the study said.

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Coauthor Dr. Andrew T Chan, an immunology and infectious diseases professor at the Harvard School of Public Health in Boston, said ultra processed foods have long been linked to chronic inflammation, which has been linked to depression. He added that changes in the gut microbiome caused by consuming ultra processed foods may link to depression.

"Ultra-processed food [and] the kinds of foods that people eat may tend to promote certain bacteria or other microorganisms in the gut to be dominant, and some of those microorganisms may be associated with chronic inflammation or other factors that could lead to depression or other mood disturbances," Chan told USA TODAY.

Is the study applicable to men?

The study did not include men preserving the results most relevant for women.

Chan said he believes it's crucial to continue examining this link in other populations, including populations of men.

"It would be surprising to me though, that there would be a different result given that the mechanisms by which we think ultra-processed food are linked to depression don't seem to be sex specific," Chan said. "They're probably something that would be generalizable to men as well."

What are ultra-processed foods?

Ultra-processed foods are foods that contain little to no energy-dense whole foods. They are low in fiber, high in sugar, fat and salt and "liable to overcompensation," according to a 2019 article published in the National Center for Biotechnology Information.

These meals include prepackaged soups, frozen pizza, ready-to-eat meals, sauces and pleasure foods like cheeseburgers, hot dogs, French fries, sodas and desserts such as cakes, candies, doughnuts, ice cream and store-bought cookies. Many of these foods and drinks contain artificial sweeteners.

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Other harms of consuming ultra-processed foods

Ultra-processed foods have long been associated with an increased risk of developing diabetes and cardiovascular disease, and cancer, according to a 2022 study published in the American Journal of Preventive Medicine. That research found consuming ready-to-eat foods like hot dogs, frozen pizzas, and doughnuts may lead to premature death.

Consuming ultra-processed foods has also been linked to a higher cancer risk. A study published earlier this year in eClinicalMedicine said the consumption "may be linked to an increased burden and mortality for overall and certain site-specific cancers especially ovarian cancer in women."

Eating ultra-processed foods has also been linked to dementia, according to a 2022 study published in JAMA Neurology. The study found that if over 20% of a person’s daily calorie intake comes from ultra-processed foods, their risk of cognitive decline raises by around 28%.

How to avoid ultra-processed foods

One of the best ways to avoid ultra-processed foods is to look at nutrition panels and ingredient lists when purchasing food at the grocery store.

Samantha Cassetty, a registered dietitian nutritionist, told USA TODAY that looking at nutrition panels is not enough, that people need to look at the ingredients to better understand the degree of processing.

"Think about a potato (versus) a French fry or potato chip," Cassetty, said. "Or a rotisserie chicken compared to a slice of chicken deli meat. A 100% whole grain cereal is going to be less processed than a sugary cereal made from refined flour."

Contributing: Saleen Martin and Morgan Hines

This article originally appeared on USA TODAY: Study links consumption of ultra-processed foods to depression in women