Is There a Link Between Ultra-Processed Foods and Depression?
Source: The Messenger /image: Getty Images /Author: Hannah Murphy
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Long-term consumption of ultra-processed foods might increase a person’s risk of psychological distress in the future.
That’s according to new research published in the Journal of Affective Disorders that analyzed more than a decade’s worth of data from more than 23,000 study participants.
Ultra-processed foods include additives and preservatives; they also include the addition of ingredients like sugar, starch, fats and hydrogenated oils to enhance their taste, appearance and shelf life.
Ultra-processed products are everywhere and many of them, like chicken nuggets, potato chips and soft drinks, are fan favorites due to their taste and convenience.
In the study, researchers with Deakin University in Geelong, Australia found that those who consumed the highest amount of ultra-processed food — around 650 grams, or approximately 23 ounces, per day on average — were the most likely to experience depressive symptoms in comparison to those who routinely ingested more moderate amounts. Compared to those who reported eating the least amount of processed foods — less than 283 grams, or around 10 ounces, per day — people in the highest category of consumption were 1.14 times more likely to develop depression.
The observational study, which took place in Australia, looked at self-reported data from questionnaires related to dietary habits and psychological distress. Participants who were not taking medication for depression and anxiety at the start of the study were eligible to participate in the research. Participants followed up periodically throughout a span of 15 years, completing the questionnaires at each visit.
The researchers categorized the food participants reported consuming into two categories: ultra-processed or non-ultra-processed foods. That data was compared alongside the psychologic distress assessments to identify any links between the participants’ dietary habits and psychological state.
The same participants who consumed the largest amounts of highly processed foods were also more likely to consume less forms of protein and fiber and partake in less physical activity, the researchers noted.
The authors explained that this could be due to the “nutrient-poor profiles” that many ultra-processed foods have, meaning that although these products may contribute to overall caloric intake, they offer fewer benefits with regard to energy and nutrition than other less-processed foods.
Many of the additives contained in processed foods have been linked to health issues like inflammation when consumed in excess — something that was observed in this latest research.
Additionally, prior studies have suggested that several of the artificial additive ingredients included in these foods have been linked to the development of gut and metabolic disease, both of which are known to have ties with mental disorders, the authors noted.
That explanation is in line with some of the researchers’ findings — those who consistently ate the highest amounts of ultra-processed foods displayed increased risks of psychological distress.
“This reinforces the importance of using the weight of ultra-processed food (i.e. grams per day) to better account for ultra-processed foods that provide little to no energy,” the authors wrote.
The authors noted that future nutrition-related interventions targeted at public and mental health should consider not just the quality of the food people consume, but the weighted amount of nutrient-poor products they are ingesting as well.
It should be noted that the researchers relied on self-reported data from study participants, rather than full physical analyses of them. And although the researchers accounted for factors like socioeconomic status, race and history of depression and anxiety, the study was conducted in an observational manner — meaning that the researchers simply observed a potential relationship between excess consumption of highly processed foods and depressive symptoms, rather than definitively determining that there was a direct link between the participants’ diet and mental health.