As scientists discover growing levels of microplastics in the brain, new proof suggests that your favorite convenience food can quietly influence your mental health – sparking urgent calls for research and dietary change.
Study: Microplastics and mental health: the role of ultra -processed foods. Image Credit: Sivstock Studio / Shutterstock
A new point of view article published in the magazine Brain medicine Emphasizes a possible role of microplastics in influencing the association between ultra-processed food intake and setbacks in mental health care.
Ultra-processed foods and mental health
Ultra-processed foods, such as instant noodles, carbonated drinks and packaged foods, industrial formulations are made of substances that are derived from entire foods. These food products contain large amounts of industrial additives and include advanced packaging.
The consumption of ultra-processed foods is increasing rapidly worldwide, especially in countries with a high income. In the United States, these foods are associated with more than 50% of energy intake. Convenience, affordability, accessibility, aggressive marketing and lifestyle changes are the most important factors that stimulate the global food shift from Whole Foods to ultra-processed food.
According to an umbrella assessment published in the BMJ and to which reference is made, people who consume ultra-processed food have a 22% higher risk of depression, a 48% higher risk of anxiety and a 41% higher risk of poor sleep results compared to those with a lower intake.
Recent observation studies indicate that excessive consumption of ultra-processed food is associated with poor sleep quality, physical health against setbacks, depression and anxiety. This evidence is further supported by studies that report that a higher consumption of food -rich, unprocessed foods may reduce the risk of psychological disorders. Small randomized controlled studies, in particular those those Mediterranean diet interventions in people with depression, have demonstrated moderate improvements in depressive symptoms. The findings of recent interventional studies also clearly indicate a link between the intake of food and mental health.
Microplastics as a contributing factor
Mental health against setbacks associated with ultra-processed food intake can be attributed to their poor nutrients, energy density and physical or chemical properties with regard to industrial processing and packaging methods, which introduce bisphenols and microplastics as contamination.
Similar to ultra-processed food, it is known that microplastics oxidative stress, inflammation, immunis function, changed metabolism, reduced cell growth and organ development and carcinogenicity.
Microplastics and nanoplastics can increase the risk of neuropsychiatric disorders by inducing oxidative stress in the brain, causing damage to nerve cells and influencing the functionality of neurotransmitters, such as acetylcholine, γ-aminobutter acid and glutamate. However, it is important to note that much of mechanistic evidence on microplastics and neurological effects comes from research into animals and cell culture, with limited direct human data.
Sources of microplastics in diet
Due to the processing and packaging methods, ultra-processed foods contain large amounts of microplastics. These foods are often stored and heated in plastic containers, an important source of microplastics. For example, chicken nuggets can contain 30 times more microplastics per gram than chicken fillet, and in the microwave some plastic containers can release millions of microplastic and nanoplastic particles within minutes. In addition to microplastics, bisphenol A that is used in plastic production can be released and mixed with ultra-processed food when plastics break down. Bisphenol A is specifically associated with autism and depression in some human studies. These observations clearly indicate that excessive consumption of ultra-processed foods can collect microplastics and bisphenol A in the body.
Microplastics in the human brain
Up to evidence emphasizes the presence of microplastics in the human brain. These microplastics, mainly polyethylene, are smaller in diameter (less than 200 nanometers) and are 7 to 30 times higher than those in other organs, such as the liver or kidney. A recent study also found an increase of 50% in the microplastic concentration of the brain from 2016 to 2024, parallel to the continuous rise of ultra-processed food. A recent study showed that people with dementia had three to five times higher levels of brain microplastics, but the authors emphasize that this correlation does not imply a causal connection.
Although some human studies have shown a connection between Bisphenol, exposure and the risk of autism, depression and anxiety, no evidence is currently available that microplastic exposure to psychological health is linking setbacks. This gap in knowledge is partly due to the difficulty in quantifying microplastic exposures in the human brain from an observational perspective and the ethical limitations on microplastic exposure in interventional studies.
Implications for intervention in food
Identifying microplastics in the brain and throughout the body evokes significant health problems. Various studies have emphasized the potential negative impact of microplastics on immune functions, genetic stability and endocrine functions.
The Smiles study is the first randomized controlled study to investigate the effectiveness of additional nutritional intervention in the treatment of moderate to severe depression. The main purpose of the dietary intervention was to replace nutrient-deficient, ultra-processed foods with nutrient-rich, unprocessed foods. The test findings indicated a significant improvement of depression among participants who consumed the intervention diet for 12 weeks. In comparison with the participants of the 8% control group, remission was reached for 32% of the participants in the intervention group. This means that for almost every four people who have adopted the nutritional changes, one extra person has experienced remission of depression compared to the control group (a measure known as the “number needed to treat”, which was 4.1).
Although the study does not immediately measure the microplastic accumulation in the bodies of the participants, it is necessary to assume that the improvement of depression is associated with a reduction in microplastic exposure due to food substitutions. However, this remains a hypothesis that requires further research, because microplastic exposure was not immediately measured.
The point of view notes that it would be valuable to carry out post-hoc analyzes in such nutritional investigations, so that changes in microplastic content afterwards estimate as a result of dietary interventions and their potential effect on the results of mental health, as more information about microplastic content in foods becomes available.
Need for a new food risk index
Although the paper notes that research that the microplastic content of various ultra-processed food products is increasingly available, it is not stated that methods are already well established for all foods. It would be of the most important importance to evaluate the changes in microplastic content as a result of dietary interventions and their subsequent effect on different results of mental health care.
Various diet-based risk indices have been developed to assess the long-term impact of exposure to nutrients on physical and mental health. The inflammatory index in the diet has been developed to assess the inflammatory potential of the diet of a person based on the food they consume. Similarly, the Nova Food Classification System has been developed to categorize food based on the size and purpose of industrial processing.
Given the significant usefulness of these indices, the authors of this article to design a microplastic index in the diet to assess the microplastic content and the risk of accumulation based on the food consumed.
Currently, no nutritional population surveys and follow the microplastic intake through a diet, which excludes a robust analysis of long -term microplastic exposure and adverse results of mental health.
The global increase in the intake of microplastic enriched ultra-processed foods, together with the simultaneous induction of setbacks in mental health care, emphasizes the need for more research to investigate this association in people.