Depression risk spikes for those who eat these unhealthy foods, study finds: ‘Not a coincidence’

That bag of chips or slice of frozen pizza might make you happy while you’re eating it — but it could make you more susceptible to sadness long after the last bite.

A new study published in the journal JAMA Open Network found that eating “ultra-processed” foods can contribute to a higher risk of depression.

Researchers from Brigham and Women’s Hospital and the Harvard T.H. Chan School of Public Health analyzed the dietary choices and mental health of more than 31,000 women between 42 and 62 years of age, according to the journal article.

The data came from the Nurses’ Health Study II, conducted between 2003 and 2017.

All participants filled out a food questionnaire every four years, disclosing whether they consumed ultra-processed foods (UPFs) or not.

UPFs were grouped into nine categories: ultra-processed grain foods, sweet snacks, ready-to-eat meals, fats and sauces, ultra-processed dairy products, savory snacks, processed meat, beverages, and artificial sweeteners.

“Ultra-processed foods are those that include many preservatives, stabilizers, bulking or gelling agents, as well as artificial colors and flavors,” said Tanya Freirich, a registered dietitian nutritionist in Charlotte, North Carolina, who practices as The Lupus Dietitian. (She was not involved in the study.)

“They are generally the types of foods that are shelf-stable for years to come,” she went on.

“Ultra-processed foods include things like chips, candies, frozen ‘TV dinners,’ chicken nuggets, sodas, sugar-filled breakfast cereals and packaged soups (the ‘just-add-hot-water’ type).”

“Our brain is just as vulnerable, if not more vulnerable than, other parts of our body to the negative effects of non-nutritive food additives.”

To gauge the participants’ mental health status, the researchers used two definitions: one, a strict definition requiring self-reported, clinician-diagnosed depression and regular antidepressant use; and two, a broad definition requiring clinical diagnosis and/or antidepressant use, as the journal article stated.

The researchers adjusted for other factors that could influence depression risk — such as age, body mass index, physical activity, smoking status, sleep health, chronic pain, alcohol consumption, income, and any existing medical conditions.

After analyzing the results, the researchers found that people who ate higher amounts of ultra-processed foods — in particular, artificial sweeteners and artificially sweetened beverages — were more prone to depression.

One possible reason is that artificial sweeteners cause chemical changes in the brain that can trigger the development of depression, they hypothesized.

“It is known that artificial sweeteners affect the brain through a different pathway than natural sweeteners like sugar or honey,” Frierich pointed out, noting that more research is needed in this area.

Those who had the highest intake of UPFs had a 34% to 49% increased risk of depression, the study found.

Frierich said she was not surprised by the findings overall.

“Many studies have documented associations between some food additives and cancer, hormonal changes, weight gain, and our mental health,” she told Fox News Digital.

“With that in mind, it is not surprising to me that there may be a link between ultra-processed foods and depression.”

She also said, “Our brain is just as vulnerable, if not more vulnerable than, other parts of our body to the negative effects of non-nutritive food additives.”

The study’s limitations

While the study had a large sample size, high follow-up rate, and advanced dietary assessment tools, it did have some limitations, the researchers pointed out.

The participants were primarily non-Hispanic White females.

Also, the study was observational — with no structured clinical interviews.

“More diversity in the sample size may find differences among races and ethnicities in the association between UPF consumption and depression,” Frierich said.

“The high intake of UPFs was associated with greater BMI, high smoking rates, decreased likelihood of exercising regularly, as well as increased disease incidence of diabetes, HTN, and dyslipidemia.”

Also, because this was an observational study and not a controlled one, it’s not a certainty that ultra-processed foods were the determining factor in the depression, she noted.

“A prospective study like this one only examines the association between the UPF and mental state,” Frierich said.

“Were people feeling more depressed and then turning to UPF as a form of comfort or convenience? Depressed people may not have the energy to grocery shop, meal-prep their lunches, or cook meals from scratch.”

“Depressed people may not have the energy to grocery shop, meal-prep their lunches or cook meals from scratch.”

“While we cannot figure out what came first, the depression or the UPF, is it vital to note that when people reduced their intake of UPF, there was a consequential reduction in depression,” she added.

“The association is not a coincidence.”

Lauren Harris-Pincus, a registered dietitian nutritionist who has been practicing for over 25 years in the New York/New Jersey area, told Fox News Digital that it’s important to take into account social determinants of health and access.

“Perhaps someone who eats most of their diet as UPF doesn’t have access to fresh foods in their neighborhood. Maybe they work several jobs and don’t have time to cook, or are caring for loved ones and sacrificing their own self-care,” said Harris-Pincus, who was not involved in the study.

Tips for improving diet for better mental health

When treating clients, Frierich recommends that they consider their diets as an important piece of the puzzle for mental health.

“Dietary changes do not need to be dramatic or expensive,” she said. “Start small by swapping out one processed snack for a piece of fruit, nuts, seeds, or a raw vegetable. An apple, baby carrots, or handful of nuts can be just as quick as a processed snack, but [this] reduces your intake of UPF by at least one serving.”

With small changes like these throughout the week, she said people may notice improvements in energy, digestion, and other areas.

As artificial sweeteners were noted to be associated with depression, Frierich suggests choosing honey, sugar, or agave nectar instead.

For beverages, she recommends opting for lightly sweetened or unsweetened tea, coffee, or seltzer water instead of diet sodas.

Frierich also suggests using maple syrup, fruit juice-based popsicles, and 100% fruit juice in place of sugar-free options.

“Artificial sweeteners can cause another problem — as we perceive them to be hundreds to thousands of times sweeter-tasting than natural sugars. If you use them often, you may have become accustomed to this ultra-sweet flavor,” she warned.

“Making the switch to natural sugars may taste less sweet at first, but your taste buds can and will adjust over time.”

All types of sugar should be consumed in moderation, the dietitian added.

The World Health Organization recommends limiting added sugars to 25 grams or less (six teaspoons) per day for adults.

Added Friedrich, “Decreasing your intake of both artificially and naturally sweetened beverages and foods is a great idea for your physical and mental health.”

Another important consideration is that not all UPFs are the same, Harris-Pincus said.

“When we message about limiting ultra-processed foods, there is nuance — they are not all created equal.”

Simply peeling a vegetable, for example, is a form of processing, she noted — and while soy milk might be classified as an ultra-processed food in a database, it is essentially a nutrient-dense whole food.

“Ultimately, we want to strive for a diet rich in fruits, veggies, nuts, beans, seeds, whole grains, and lean proteins,” Harris-Pincus said.