Immunomodulation for Mental Health: A Focus on Positive Mood

People struggling with low mood experience variable ranges of psychological and physical symptoms. These can include pervasive feelings of sadness or hopelessness, a lack of interest in activities, fatigue and difficulty concentrating. These symptoms are often accompanied by physical manifestations such as changes in appetite, sleep disturbances and decreased energy levels.2 Importantly, underlying immunological processes have been found to play a critical role in regulating mood states, opening avenues for innovative therapeutic approaches.1

Immunological Basis of Mood and Mental Health

Immune System Activation and the Brain

An area of science called neuroimmunology has highlighted the deep, bidirectional connection and communication between the brain and immune system and its influence on mood regulation.3–5 Immune cells, including microglia, astrocytes and cytokines, interact directly with neurons, contributing to the modulation of mood and cognitive function.6,7

Studies suggest that systemic immune activation can affect the nervous system via production of cytokines, including interleukin-1 beta (IL-1b), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α), which can cross the blood-brain barrier.1 Alteration of the immune/brain interaction can affect neurotransmitter balance, affecting the production of serotonin, GABA, dopamine and norepinephrine, which are critical for mood stabilization.4

Cytokines and Neurotransmitter Balance

Cytokines can influence neurotransmitter balance by modulating key pathways responsible for serotonin, dopamine and glutamate/GABA synthesis and reuptake. For example, the cytokine interferon-gamma (IFN-g) can activate the enzyme indoleamine 2,3-dioxygenase (IDO), which degrades tryptophan, a precursor to serotonin, into kynurenine. This shift reduces serotonin availability, affecting mood regulation.8 However, some kynurenine metabolites have neuroprotective properties, reinforcing the importance of having a healthy cytokine balance within the body.8

Similarly, some cytokines (IL-1b, IL-6, IFN-g, and TNF-α) have been shown to decrease the transport of tyrosine (a non-essential amino acid produced from phenylalanine), which is needed for the synthesis of dopamine and catecholamines.9 Cytokines have also been implicated in increasing glutamate activity through quinolinic acid production.10

Lifestyle Components to Support Positive Mood Through Cytokine Modulation

• Nutrition: Diet plays a critical role in immune and mood regulation. A nutrient and polyphenol-dense Mediterranean diet is rich in vegetables, fruits, omega-3 fatty acids and fiber. It has been shown to modulate cytokine levels and promote mental well-being.11,12
• Exercise: Regular, moderate-intensity physical activity has been shown to promote cytokine balance. Exercise also helps to reduce stress and provides neuroprotection through the antioxidant system.13
• Sleep: Poor sleep quality is associated with elevated levels of IL-6, TNF-α, nuclear factor-kB (NF-kB), and CRP (C-reactive protein), important markers of the immune system.14 Prioritizing sleep hygiene and achieving 7 to 9 hours of restorative sleep can help restore immune balance and positively influence mood.
• Mind-Body Practices: Yoga, meditation and mindfulness practices can reduce stress, improve sleep and promote a balanced immune response, including the modulation of cytokines.15

Nutrient Solutions to Support a Positive Mood Through Cytokine Modulation

Polyphenols, including flavonoids, curcumin, epigallocatechin gallate (EGCG) and oligomeric proanthocyanidins (OPCs), are found in a variety of plant-based foods, such as vegetables, berries, green tea and dark chocolate.16

Curcumin, the active compound in turmeric, exerts its mood benefits by regulating cytokine activity, mainly by reducing levels of TNF-α and IL-6. By maintaining a healthy cytokine response, curcumin supports neurotransmitter balance, especially the monoamines, serotonin, norepinephrine and dopamine.17 Further, preclinical data suggest that curcumin may bind to NMDA receptors to balance glutamate/GABA signaling.18‡

Green tea extract contains a high concentration of EGCG, a compound known for its antioxidant and cytokine-modulating properties. The catechins in green tea also help boost dopamine levels, while theanine modulates glutamate, GABA, serotonin and dopamine levels, enhancing a sense of calm and providing cytokine balance.19,20 Green tea extract also supports neurogenesis and promotes the release of brain-derived neurotrophic factor (BDNF), which plays a critical role in mood regulation.19‡

Pycnogenol, derived from the bark of the French maritime pine tree, is another potent immunomodulator that shows promising cognitive-enhancing effects by reducing oxidative stress and enhancing neurotransmitter activity.21 Over 450 articles have been published highlighting the plethora of benefits of this compound in multiple areas of health.22‡

Conclusion

The intricate relationship between the immune system and mood highlights the importance of cytokine modulation in mental health. By targeting key cytokines involved in mood regulation, it is possible to influence neurotransmitter pathways and foster positive emotional states. Making lifestyle changes and using immune-modulating ingredients like pycnogenol and polyphenols offers a holistic approach to supporting mental well-being.