- A new study has found a link between ultra-processed foods and increased depression risk.
- In particular, artificial sweeteners were associated with depression.
- It isn’t clear why this link exists, but artificial sweeteners might trigger purinergic transmission in the brain.
- Factors like a disrupted gut microbiome or nutrient deficiencies might also play a more general role.
- Taking control of your food preparation and reading labels can help reduce your intake of these foods.
We’ve all heard the saying “You are what you eat,” meaning that good nutrition is vital to our physical health. However,
Researchers at Harvard University have found that eating ultra-processed foods — which they say are “energy-dense, palatable, and ready-to-eat” — is linked to an increased risk for depression.
In particular, they found an association between depression and consuming artificial sweeteners and artificially sweetened drinks.
The study authors note that there is increasing evidence linking diet to depression. However, little work has been done examining the relationship between ultra-processed foods and mood disorders.
Additionally, no study has looked at specific ultra-processed foods or ingredients or the timing of eating these foods in relation to the development of depression. The authors’ goal with the current study was to take a closer look at this question.
The study participants were middle-aged women who took part in the Nurses’ Health Study II, a large study looking into the risk factors for major chronic diseases in women. Nearly 32,000 individuals were included. These women did not have depression at the outset of the study.
The women filled out food frequency questionnaires every 4 years from 2003 to 2017.
To estimate how much ultra-processed food they were eating, the researchers used the
Ultra-processed foods, according to the NOVA system, are ready-to-eat foods made mostly or entirely from foods and food additives that have little, if any, intact whole foods.
These ultra-processed foods were then further divided into categories, such as fats and sauces, processed meats, or beverages.
Those who had been diagnosed with depression and/or who were using antidepressants for their symptoms were considered to have depression.
The team then analyzed the data looking for any changes in the consumption of ultra-processed foods and whether people subsequently were diagnosed with depression.
The researchers identified 4,840 cases of depression, although this figure dropped to 2,122 when they used a stricter definition requiring women to have both a diagnosis of depression as well as being prescribed an antidepressant.
It was additionally found that those with the highest consumption of ultra-processed foods had an increased risk of developing depression when compared to those with the lowest consumption.
Artificially sweetened beverages and artificial sweeteners, in particular, were found to be associated with depression risk.
It was also determined that reducing the intake of ultra-processed foods was linked to a lowered risk of depression.
When asked for his thoughts on why ultra-processed foods might be associated with increased depression risk, Dr. Daniel Atkinson, GP Clinical Lead at Treated, who was not involved in the study, responded, “The truth is, we don’t know.”
Atkinson went on to explain that it can be difficult to develop a clear picture of what the link is. “This is because ‘ultra-processed’ is, scientifically speaking, quite a vague and broad term,” he said, “which encompasses a wide range of foods and ingredients.”
Atkinson added that there are also external factors as well as the fact that just because there is a statistical association, that doesn’t necessarily mean that one thing caused the other. For example, people who are stressed tend to reach for what’s easiest, which is processed foods. So, it might not be the food itself, but instead the fact that these people are already prone to depression.
“The study, however, did seem to account well for many of these concerns, so the suggestion of causality in this case does seem to be quite credible,” he said.
One speculative reason that ultra-processed foods are linked to depression, according to Atkinson, is that ultra-processed foods disrupt the gut’s microbiome. Gut health plays an important role in healthy
Atkinson said that it is also worth noting that diets high in ultra-processed foods are more deficient in nutrients than those that are less processed, such as the Mediterranean diet.
“The Mediterranean diet has long been associated with better health outcomes overall, including lower levels of
stress,” he said. “So it could be that higher levels of depression can be linked to certain dietary deficiencies that have been brought about by less nutrient-rich foods.”
“Interestingly, though,” said Atkinson, “the study found the primary correlation to be due to artificial
sweeteners specifically, rather than UPFs [ultra-processed foods] more broadly. This might help us to narrow down
specific ingredients or processes that are most likely to have an effect … .”
While Atkinson didn’t speak further on why artificial sweeteners might be to blame, the study authors state that there is data suggesting that these chemicals might trigger purinergic transmission in the brain, which has previously been
Catherine Gervacio, a Registered Nutritionist-Dietitian and Certified Exercise Nutrition Coach, says there are some simple and practical steps you can take to make healthier choices and reduce the amount of processed foods that you are consuming.
“One of which is to always check out the ingredients list of products,” she said. “Before buying packaged foods, carefully read the ingredients list and choose those that have a smaller number of ingredients. Limit or avoid those that contain preservatives, additives, and artificial sweeteners.”
Gervacio also suggests making your own meals at home so you can control the ingredients that are going into them.
“It also minimizes the chances of using processed sugars and seasonings which are often used in convenience foods,” she explained.
Finally, she advises the importance of consuming everything in moderation.
“Processed foods are everywhere and it is inevitable to take them once in a while,” she said. “The key here is to consume them occasionally and aim to still prepare a healthy diet prepared from natural ingredients.”
A new study has found a link between ultra-processed foods and increased depression risk.
In particular, artificial sweeteners were associated with depression.
It isn’t clear why this link exists, but artificial sweeteners might trigger purinergic transmission in the brain.
Factors like a disrupted gut microbiome or nutrient deficiencies might also play a more general role.
Taking control of your food preparation and reading labels can help reduce your intake of these foods.