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Diet and mental health: the Asian perspective

March 12, 2025

The connection between nutrition and mental health is a rapidly growing field, with increasing evidence highlighting the critical role of diet in psychological well-being. While Western studies have dominated the conversation, research from Asia offers unique perspectives on traditional diets, the gut-brain axis, and the potential of psychobiotics. This article builds on the foundational work presented in Nutrition and Mental Health: Current Insights and Future Directions, integrating findings from Asian studies to provide a comprehensive understanding of the nutrition-mental health relationship.

Table of Contents

1. Traditional diets and mental Health in Asia

1.1. Chinese diets and mental health

Traditional Chinese diets are rich in vegetables, whole grains, legumes, and fish, providing high levels of fibre, omega-3 fatty acids, and antioxidants. Research has shown that these dietary patterns may protect against mental health issues. For example:

A cross-sectional study found that higher fruit and vegetable consumption was linked to lower rates of depressive symptoms in Chinese adults (Blanchflower et al., 2013). The anti-inflammatory properties of these foods are thought to play a key role (see also Hepsomali et al. study, 2021, on 502,494 middle-aged adults in the UK Biobank dataset).
Omega-3 fatty acids from fish and antioxidants from green tea, staples in Chinese diets, have been associated with reduced anxiety and depression risk (Wang et al., 2020).
Fermented foods like pickled vegetables and tofu, rich in probiotics, support gut health and mental well-being by influencing the gut-brain axis (Zhang et al., 2019; Ouwehand et al., 2002).

1.2. Japanese diets and mental health

The traditional Japanese diet, rich in fish, soy products, vegetables, and fermented foods like miso and natto, has been linked to mental health benefits. Key findings include:

Higher fish and soy intake is associated with lower rates of depressive symptoms, likely due to the anti-inflammatory and neuroprotective effects of omega-3s and isoflavones (Jacka et al., 2010).
Fermented foods like miso and natto contain probiotics that modulate the gut-brain axis, reducing anxiety and improving mood (Messaoudi et al., 2011).
Green tea, a staple in Japan, is rich in L-theanine, an amino acid linked to reduced depression risk, particularly in elderly populations (Niu et al., 2009).

1.3. Korean diets and mental health

Korean diets, particularly the consumption of kimchi (fermented vegetables), are rich in probiotics, vitamins, and bioactive compounds. Studies suggest:

Higher kimchi intake is associated with lower levels of social anxiety, likely due to its probiotic content and its impact on the gut-brain axis (Logan & Katzman, 2005).
The Korean diet’s emphasis on vegetables, legumes, and fish provides nutrients like fibre, omega-3s, and antioxidants, which are linked to improved mental health outcomes (Ng et al., 2018).

1.4. The impact of contaminants and dietary compounds on mental health

A scientific review (Xiong et al., 2023) analysing five years of high-quality literature from Web of Science and PubMed highlights the link between diet and mental health:

Certain contaminants, including heavy metals, organic pollutants, antibiotics, pesticides, and food additives, have been associated with anxiety, depression, schizophrenia, and ADHD.
Conversely, dietary bioactive compounds such as probiotics, fruits, vegetables, and spices demonstrate protective effects. Thus supporting the potential of natural dietary products in preventing mental disorders.

2. The gut-brain axis in Asian populations

2.1. Gut microbiota and mental health

The gut-brain axis is a key area of interest in nutritional psychiatry. Asian research highlights:

A diverse gut microbiota, supported by traditional diets rich in fibre and fermented foods, is associated with lower rates of depression and anxiety (Zhang et al., 2019).
Psychobiotics, such as Lactobacillus and Bifidobacterium strains found in fermented foods, have been shown to reduce symptoms of depression and anxiety (Sato & Yamagishi, 2020).

2.2. Dysbiosis and mental health

Dysbiosis (microbial imbalance) has been linked to mental health disorders. For example:

A South Korean study found that individuals with depression had lower levels of beneficial bacteria like Bifidobacterium and Lactobacillus. Dietary interventions, such as increasing prebiotic and probiotic intake, may help restore gut health and improve mental well-being (Kim et al., 2021);
A gut metagenomic study of stool samples from 921 volunteers within the large-scale CMEC Microbiome Project in Southwestern China revealed novel associations between microbiome composition, host factors, and metabolic disorders, offering insights for clinical applications (Qu et al., 2025).

2.3. Positive mood-related gut microbiota in a long-term: the Lunar Palace 365 mission

A Chinese study by Hao et al. (2023) on Microbiome, conducted during the year-long Lunar Palace 365 mission, a closed Bioregenerative Life Support System isolation experiment, explored the relationship between gut microbiota and psychological health in long-term closed environments.

Using metagenomic, metaproteomic, and metabolomic analyses, four potential psychobiotics (Bacteroides uniformis, Roseburia inulinivorans, Eubacterium rectale, and Faecalibacterium prausnitzii) were identified.

These psychobiotics were found to improve mood through three mechanisms: short-chain fatty acid production, regulation of amino acid metabolism (e.g., serotonin and GABA), and modulation of stress-related pathways like taurine and cortisol metabolism. The findings provide crucial insights into gut microbiota’s impact on mental health in space exploration, suggesting potential microbiota-based countermeasures for future missions.

3. Omega-3 fatty acids and mental health

Omega-3 fatty acids, found in fatty fish and microalgae, are widely studied for their mental health benefits. Key insights include:

A meta-analysis in China found that omega-3 supplementation significantly reduced depressive symptoms, with EPA and DHA playing critical roles in neuronal integrity and inflammation reduction (Li et al., 2016).
Traditional diets in Japan and China, rich in omega-3s from fish, are associated with lower rates of depression and anxiety.

3.1. Practical recommendations

Increase intake of fatty fish (e.g., salmon, mackerel) and/or microalgae, and plant-based sources (e.g., flaxseeds, hemp, walnuts).
Consider omega-3 supplements with high EPA content (≥ 60%) for individuals with depression or at risk of mental health disorders.
Promote omega-3-rich diets in public health policies to support mental health at the population level.

4. Probiotics and psychobiotics

Probiotics, particularly Lactobacillus and Bifidobacterium strains, have shown promise in improving mental health. Key findings include:

Lactobacillus plantarum PS128. A Taiwanese study found that this strain reduced depressive symptoms and improved sleep quality in individuals with insomnia (Ho et al., 2021).
Lactobacillus rhamnosus HN001. A Japanese study demonstrated its effectiveness in reducing postpartum depression and anxiety in new mothers (Slykerman et al., 2017).

4.1. Mechanisms of action

Probiotics modulate the gut-brain axis, influencing neurotransmitter production (e.g., serotonin, GABA).
They reduce systemic inflammation and strengthen the gut barrier, preventing ‘leaky gut’ and its associated mental health risks.

5. Future directions for research

While the evidence is promising, further research is needed to:

Identify the most effective probiotic strains and dosages for psychological well-being and depression, anxiety prevention.
Explore the long-term safety and efficacy of probiotic interventions.
Investigate the potential of synbiotics (combinations of probiotics and prebiotics) to enhance gut-brain communication.

Interim conclusions

Asian nutritional research powerfully demonstrates the critical link between diet and mental health, with traditional diets, the gut-brain axis, and psychobiotics playing pivotal roles. Diets abundant in omega-3 fatty acids and probiotics, prevalent in Chinese, Japanese, and Korean culinary traditions, reveal significant potential for enhancing mental well-being.

To fully realize these benefits, further research is essential, particularly in optimizing probiotic strains, dosages, and exploring synbiotics.

By integrating Asian insights with Western scientific advancements through international cooperation and scientific diplomacy, researchers can develop more effective, globally applicable strategies for preventing and treating mental health disorders. Ultimately, this collaborative approach to nutritional psychiatry holds immense promise for improving psychological well-being and quality of life worldwide.

Dario Dongo

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