Summary: A new study has found a correlation between diets high in ultra-processed foods and a heightened risk of depression.
The study revealed the risk of depression significantly increased among individuals consuming over 30% of their daily diet as ultra-processed food.
While the study does not confirm ultra-processed food as a causal factor for depression, it underscores an association with a higher risk.
- The study is the first to link diets high in ultra-processed foods with an increased risk of depression in Australians.
- People who consume more than 30% of their daily diet as ultra-processed food show a marked increase in depression risk.
- The research suggests an association between high consumption of ultra-processed food and a higher risk of depression, even after accounting for factors like smoking, lower education, income, and physical activity.
Source: Deakin University
Australian research has for the first time established a link between diets high in ultra-processed foods and an increased risk of depression.
The recently published findings in the Journal of Affective Disorders show the risk of depression jumps markedly among people whose daily diet includes more than 30% ultra-processed food.
Dr. Melissa Lane, who completed the research as part of her Ph.D. studies at Deakin University’s Food and Mood Center, said the results provide further evidence of the wide-ranging harms of diets loaded with cheap, well-marketed but often nutrient poor convenience foods.
“While Australians eat a lot of ultra-processed foods, the link with depression has never been assessed in a group of Australians until now,” Dr. Lane said.
Ultra-processed foods are not limited to typical junk and fast foods. They also include mass-produced and highly refined products that might be considered relatively “neutral” or even “healthy” like diet soft drinks, some fruit juices and flavored yogurts, margarine, packet preparations of foods like scrambled egg and mashed potato and many ready-to-heat-and-eat pasta dishes.
Working with Dr. Priscila Machado from Deakin’s Institute for Physical Activity and Nutrition (IPAN) and Associate Professor Allison Hodge from the Cancer Council Victoria, Dr. Lane looked at associations between ultra-processed food consumption and depression in more than 23,000 Australians from the Melbourne Collaborative Cohort Study.
“Australians who ate the most ultra-processed food had about a 23% higher risk of depression compared to those who ate the least amount,” Dr. Lane said.
“Our study comprised people who were initially not taking any medication for depression and anxiety and followed them over 15 years,” Dr. Lane said.
“Even after accounting for factors like smoking and lower education, income and physical activity, which are linked to poor health outcomes, the findings show greater consumption of ultra-processed food is associated with a higher risk of depression.”
Dr. Lane said that while the study was not proof the ultra-processed food necessarily caused depression, it showed that eating more ultra-processed food was associated with an increased risk of depression.
“Depression is one of the most common mental disorders across the globe and it is a major health problem because it negatively affects daily living and well-being through lasting low energy, changes in appetite and sleep, loss of interest or pleasure, sadness, and sometimes thoughts of suicide,” Dr. Lane said.
“Identifying a critical level of consumption that may increase the risk of depression will help consumers, healthcare professionals and policymakers make more informed decisions around dietary choices, interventions and public health strategies.
“We hope this study will contribute to the promotion of mental well-being and guide efforts to prevent or reduce the prevalence, development and symptom severity of depression within the community.”
About this diet and depression research news
Original Research: Open access.
“High ultra-processed food consumption is associated with elevated psychological distress as an indicator of depression in adults from the Melbourne Collaborative Cohort Study” by Melissa M. Lane et al. Journal of Affective Disorders
High ultra-processed food consumption is associated with elevated psychological distress as an indicator of depression in adults from the Melbourne Collaborative Cohort Study
Few studies have tested longitudinal associations between ultra-processed food consumption and depressive outcomes. As such, further investigation and replication are necessary. The aim of this study is to examine associations of ultra-processed food intake with elevated psychological distress as an indicator of depression after 15 years.
Data from the Melbourne Collaborative Cohort Study (MCCS) were analysed (n = 23,299). We applied the NOVA food classification system to a food frequency questionnaire (FFQ) to determine ultra-processed food intake at baseline. We categorised energy-adjusted ultra-processed food consumption into quartiles by using the distribution of the dataset. Psychological distress was measured by the ten-item Kessler Psychological Distress Scale (K10). We fitted unadjusted and adjusted logistic regression models to assess the association of ultra-processed food consumption (exposure) with elevated psychological distress (outcome and defined as K10 ≥ 20). We fitted additional logistic regression models to determine whether these associations were modified by sex, age and body mass index.
After adjusting for sociodemographic characteristics and lifestyle and health-related behaviours, participants with the highest relative intake of ultra-processed food were at increased odds of elevated psychological distress compared to participants with the lowest intake (aOR: 1.23; 95%CI: 1.10, 1.38, p for trend = 0.001). We found no evidence for an interaction of sex, age and body mass index with ultra-processed food intake.
Higher ultra-processed food intake at baseline was associated with subsequent elevated psychological distress as an indicator of depression at follow-up. Further prospective and intervention studies are necessary to identify possible underlying pathways, specify the precise attributes of ultra-processed food that confer harm, and optimise nutrition-related and public health strategies for common mental disorders.