By Dr. Mark Atkinson
Why immune health matters
Do you find yourself catching every cold that goes around? Wondering why some people rarely get sick while others seem to be constantly unwell? The immune system plays a central role in our health and resilience. This blog outlines evidence-based strategies to support immune function, incorporating insights from functional medicine and personalised health optimisation.
What is the immune system?
The immune system is an adaptive network of cells, tissues, and organs that protects the body from pathogens and regulates inflammation. It also supports tissue repair, detoxification, and the elimination of abnormal cells, including potentially cancerous ones. It is divided into two main branches:
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Innate immunity, which acts as a first-line defence through physical barriers (like the skin and mucous membranes) and rapid response cells such as macrophages.
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Adaptive immunity, a more specific response involving B cells and T cells that develops memory of pathogens for quicker responses upon re-exposure.
When functioning optimally, the immune system defends without overreacting. Dysregulation, however, can result in immune deficiency or autoimmunity.
Signs your immune system may be compromised
It’s not always obvious when the immune system is underperforming. Persistent fatigue, slow wound healing, frequent infections, digestive disturbances, and poor stress recovery can all be signs of reduced immune function. Autoimmune-related symptoms such as joint pain, prolonged inflammation, or food sensitivities may also indicate imbalance. Recognising these early warning signs is essential to restore balance and prevent progression.
Nutrition: foundational support for immunity
A nutrient-dense, anti-inflammatory diet provides the foundation for immune resilience. Key nutrients include vitamins C, D, A, E, B6, B12, folate, zinc, selenium, iron, and omega-3 fatty acids—all essential for immune cell development and communication.
Some foods go beyond basic nutrition to offer functional immune support:
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Garlic and onions contain allicin and other sulphur compounds with antimicrobial properties.
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Bone broth provides collagen, glycine, and glutamine to support gut lining integrity.
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Medicinal mushrooms like reishi, shiitake, and maitake are adaptogenic and modulate immune activity.
Because around 70% of the immune system resides in the gut, fermented foods (e.g., kefir, sauerkraut) and prebiotics (from fibres like inulin and resistant starch) are crucial for maintaining a balanced microbiome.
Functional practitioners often recommend laboratory testing to identify micronutrient deficiencies and tailor supplementation. Advanced strategies may include nutrigenomic testing to personalise dietary interventions based on your genetic profile.
Sleep: an immune regulator
Sleep plays a critical role in restoring and regulating the immune system. During deep non-REM (slow-wave) sleep, the body increases production of certain cytokines that help orchestrate immune responses and promote recovery. This is also when immune memory is consolidated, helping your body “learn” from past infections.
Chronic sleep deprivation disrupts this process—reducing protective immune molecules, impairing antibody response, and increasing inflammation.
To optimise sleep:
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Establish a consistent bedtime routine.
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Get 10–20 minutes of morning light exposure to reset your circadian rhythm.
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Reduce blue light exposure in the evening.
Magnesium glycinate, GABA, L-theanine, or 5-HTP may help promote relaxation and deeper rest. Sleep-tracking wearables like the Oura Ring or WHOOP strap offer personalised feedback on sleep stages, HRV (heart rate variability), and recovery—making it easier to track how lifestyle changes affect your resilience.
Exercise and movement
Physical activity improves lymphatic flow, immune surveillance, and stress modulation. Regular moderate-intensity exercise enhances immune readiness, while overtraining without recovery may lead to elevated cortisol and inflammation.
Functional medicine promotes movement diversity, including:
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Low-impact activities: yoga, walking, tai chi.
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Resistance training: supports mitochondrial health and metabolic function.
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HIIT (in moderation): stimulates metabolic flexibility and immune resilience.
Tracking HRV can help determine when to rest or push further. Recovery-focused strategies like stretching, foam rolling, and active rest days also support immune balance.
Stress management as immune medicine
Chronic stress suppresses immune function through elevated cortisol, reducing lymphocyte count and increasing susceptibility to infections. A functional medicine approach addresses both physical and psychological stressors.
Supportive tools include:
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Adaptogens: herbs like ashwagandha, Rhodiola, and holy basil help modulate cortisol levels.
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Breathwork and mindfulness: practices like box breathing or guided meditation reduce sympathetic nervous system dominance.
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Biofeedback and neurofeedback: tools like HeartMath and Muse train you to improve HRV and emotional regulation.
High perceived stress correlates with low immune activity, so addressing mindset is not just helpful—it’s essential.
Hydration and detoxification
Proper hydration supports cellular metabolism, lymphatic circulation, and detoxification. It also helps flush pathogens and toxins from the body. Aim for clean, filtered water and consider enhancing it with electrolytes (e.g., magnesium, sodium, potassium) or trace minerals.
Advanced options include:
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Hydrogen-rich water, which may reduce oxidative stress.
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Deuterium-depleted water, studied for its potential to support mitochondrial and immune function.
Biohacking tools and immune modulation
Modern biohacking offers tools that can enhance traditional strategies:
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Cold exposure (ice baths, cold showers, cryotherapy) boosts noradrenaline and immune cell mobilisation.
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Infrared saunas stimulate heat-shock proteins and detoxification.
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Intermittent fasting (e.g. 16:8) supports autophagy—your body’s natural clean-up process.
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Red light therapy (photobiomodulation) enhances mitochondrial function and cellular repair.
These interventions are best layered over strong foundational practices in nutrition, sleep, and stress management.
Emotions, neuroimmunology, and mindset
Your thoughts and emotions are biochemically active. Positive emotional states like joy, connection, and gratitude increase vagal tone, improve immune response, and lower systemic inflammation. This field—psychoneuroimmunology (PNI)—explores how psychological health directly affects immune regulation.
Recommended practices:
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Gratitude journalling: track 3 things you’re grateful for each day.
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Mindfulness and self-compassion exercises: reduce reactivity and support emotional regulation.
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Heart coherence training: improve HRV and reduce cortisol.
Tools such as neurofeedback headsets (e.g. Sens.ai, Muse) and visualisation techniques are also helpful for cultivating mental resilience and immune strength.
Identifying and addressing root causes
If you're dealing with recurrent illness, fatigue, or inflammation, it’s worth exploring underlying dysfunctions. Functional testing can uncover hidden stressors such as:
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Gut dysbiosis and leaky gut
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Nutrient deficiencies
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Hormonal imbalances (e.g. cortisol, thyroid, sex hormones)
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Chronic stealth infections (e.g. Epstein-Barr virus, Lyme)
Protocols often include:
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Gut repair (L-glutamine, probiotics, digestive enzymes)
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Detox support (glutathione, NAC, milk thistle)
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Hormone balancing (based on laboratory results)
For complex cases, collaboration with a functional medicine practitioner allows for precision-targeted interventions, including IV therapy, peptides, or mitochondrial support.
A systems approach to resilient immunity
The immune system doesn’t operate in isolation. It reflects the health of your entire body—and your lifestyle. By addressing nutrition, movement, sleep, stress, emotional wellbeing, and environmental exposures, you can build a resilient immune foundation.
Functional medicine gives us the framework. Biohacking gives us tools. Together, they help us not only prevent illness but also enhance vitality, performance, and longevity.
