It probably won’t surprise anyone to learn that ultra-processed food is linked to poorer health.
But a new study shows that it’s not only bad for your physical health but can also impact your mental well-being.
Scientists say that consuming large amounts of ultra-processed food could be associated with a higher risk of depression.
A link between artificial sweeteners and depression
The team of researchers from Harvard’s School of Public Health collaborated with the Brigham and Women’s Hospital and published the results in the JAMA Network Open journal. They monitored the diets of 30,000 women over 14 years.
But how do you define ultra-processed food in the first place?
"Processed foods may still retain many of their original nutritional qualities and can include minimally processed items like frozen vegetables, canned beans, and peanut butter," Clarissa Lenherr, a London-based nutritionist, told Euronews Next.
"On the other hand, ultra-processed foods go through much more extensive processing, often with the addition of numerous additives and artificial ingredients. They are typically very different from their natural source and are designed to be convenient and hyper-palatable," she added.
Harvard researchers defined sweet snacks, ready-to-eat meals, fats and sauces, processed meat, sodas, and artificial sweeteners as ultra-processed foods.
Artificial sweeteners and artificially sweetened beverages were in particular associated with an increased risk of depression.
This risk remained even after accounting for other factors that could contribute to depression, like age, exercise, and smoking.
But more research is needed. One limitation was that the study looked at white women over the age of 40, so the findings may not apply to everyone.
Some experts also underlined the limitations of the study’s methodology which was based on a self-reported questionnaire.
"At this stage, we cannot say how big an effect diet has on depression risk compared to other risk factors, like family history of depression, stress levels, and having a supportive social network," said Dr Paul Keedwell, Consultant Psychiatrist and Fellow of the Royal College of Psychiatrists, in a statement.
"An important consideration is that a diet based on ready meals and artificially sweetened drinks might indicate a hectic lifestyle or one with shift work. In other words, a fast food diet could be an indirect marker of chronic stress," Keedwell added, stating that prolonged stress “probably remains the main risk factor for depression".
It is not the first time researchers have investigated the link between diet and mental health. Previous studies have looked at how diet changes our microbiome and influences our stress levels.
The authors point out in the study that "increasing evidence suggests that diet may influence risk of depression".
So, how can your diet be improved?
For Lenherr, it's crucial to plan, batch cook, read labels, and choose wisely.
Spending some time each week planning your meals ensures that you’ll “make better choices and reduce reliance on convenience foods".
"On days when you have more time, consider batch cooking so you have healthy, home-cooked meals in the freezer or fridge," Lenherr added.
And if this option is not possible for you, read the labels.
"Look for products with fewer additives, lower sugar content, and recognisable ingredients," she said.
Finally, go for the safest options.
"Look for minimally processed convenience options such as canned beans, frozen veg, stir fry mixes etc - that can save time without being highly processed," she added.