Neuroinflammation

 When Your Brain's Defence System Won't Switch Off

We often associate inflammation with swollen joints, painful muscles or digestive discomfort. But inflammation can also occur within your brain.

Known as neuroinflammation, this process is attracting increasing attention in research into cognitive decline, neurological health and neurodegenerative conditions.

Inflammation isn't always harmful. Your brain relies on carefully regulated immune responses to protect itself, remove damaged cells and support repair. Problems can arise when these responses become prolonged or poorly controlled.

Let's explore what happens when your brain's defence system struggles to switch off, what might contribute to this process and how we can support a healthier neurological environment.

Meet Your Brain's Immune Cells: Microglia

Your brain contains specialised immune cells called microglia.

Think of them as your brain's maintenance and security team. They constantly monitor their surroundings, remove cellular debris and respond to potential threats.

When microglia detect infection, injury or cellular damage, they change their activity to help protect surrounding tissue.

However, when inflammatory signals persist, microglia may remain in a heightened state of activity, contributing to oxidative stress, disrupted communication between neurons and potential cellular damage.

Other supporting cells, particularly astrocytes, also participate in inflammatory signalling and help maintain the brain's protective environment.

The goal isn't to switch off your brain's immune system. It's to help it respond appropriately and return to balance.

What Can Trigger Neuroinflammation?

Your brain doesn't operate independently from the rest of your body. It constantly responds to signals from your immune system, metabolism, gut and environment.

Several factors may contribute to neuroinflammatory activity:

• Chronic systemic inflammation: Ongoing inflammatory conditions and infections can influence immune signalling within the brain.

• Blood sugar instability: Insulin resistance and elevated glucose can contribute to oxidative stress and vascular dysfunction.

• Poor sleep: Chronic sleep disruption can interfere with immune regulation and normal brain maintenance.

• Environmental exposures: Air pollution, certain pesticides and heavy metals may influence neurological inflammatory pathways.

• Gut microbiome disruption: Changes in gut bacteria and their metabolites can influence immune communication along the gut–brain axis.

• Persistent stress: Prolonged stress can alter cortisol regulation and immune activity.

These factors often overlap, which is why identifying underlying contributors can be more useful than focusing on inflammation alone.

The Blood–Brain Barrier: Your Brain's Protective Gatekeeper

Your brain has an extraordinary protective structure called the blood–brain barrier (BBB).

This highly selective gateway regulates what moves from your bloodstream into your brain, protecting delicate neurons from potentially harmful substances while allowing essential nutrients to enter.

The BBB relies on healthy blood vessel cells, specialised tight junction proteins and supporting cells called astrocytes and pericytes.

Chronic inflammation, oxidative stress, insulin resistance and vascular dysfunction can interfere with its integrity, potentially contributing to further neuroinflammation.

How Can We Support the Blood–Brain Barrier?

Alongside maintaining healthy blood pressure, blood glucose, sleep and physical activity, three areas of nutritional and herbal research are particularly interesting:

• Butyrate – Gut–brain connection: This short-chain fatty acid is produced when beneficial gut bacteria ferment certain dietary fibres. Experimental research suggests butyrate may support tight junction proteins and help regulate inflammatory signalling.

• Phospholipids – Cell membrane health: These specialised fats, including phosphatidylcholine, are essential components of cellular membranes and support their structure and signalling. Whether supplementation improves BBB integrity in humans remains uncertain.

• Ginkgo biloba – Vascular protection: Traditionally used to support circulation and cognitive health, Ginkgo contains compounds being investigated for their effects on cerebral blood vessels, oxidative stress and endothelial function. Some experimental studies suggest protective effects on BBB integrity.

Although these approaches are promising, they haven't been conclusively demonstrated to restore BBB integrity in humans.

The blood–brain barrier isn't simply a wall. It's a living, responsive system that depends on healthy blood vessels, functioning cell membranes and carefully regulated immune activity.

What Does Neuroinflammation Feel Like?

Neuroinflammation is being investigated in connection with symptoms such as brain fog, memory difficulties, mental fatigue, mood changes, disrupted sleep and slower cognitive processing.

However, these symptoms don't necessarily indicate neuroinflammation. Hormonal changes, nutritional deficiencies, thyroid dysfunction, medications and sleep disorders can produce similar experiences.

Neuroinflammation is also being studied in Alzheimer's disease, Parkinson's disease and multiple sclerosis, although its contribution differs between conditions.

Can You Test for Neuroinflammation?

There isn't one routine test that definitively diagnoses neuroinflammation. However, several investigations can provide useful insights into neurological health and contributing factors.

1. BrainScan™ – Blood Biomarkers of Brain Health

BrainScan™ combines three biomarkers associated with different aspects of neurological health:

• p-Tau 217: Associated with Alzheimer's-related tau pathology.

• Neurofilament Light Chain (NfL): A marker of nerve-cell injury.

• Glial Fibrillary Acidic Protein (GFAP): Associated with astrocyte activation or injury, which may occur during neuroinflammatory processes.

These biomarkers offer emerging insights into neurological health but don't independently diagnose neuroinflammation.

2. General Blood Tests

Blood tests such as hs-CRP, ESR, homocysteine, HbA1c, vitamin B12, folate and thyroid function can help identify systemic inflammation, metabolic dysfunction and nutritional deficiencies that may influence cognitive health.

3. Organic Acids Testing (OAT) – Exploring Inflammatory Pathways

The kynurenine pathway connects immune activity, inflammation and brain health through the metabolism of tryptophan.

Some comprehensive Organic Acids Tests measure metabolites including kynurenic acid, quinolinic acid, picolinic acid and xanthurenic acid, alongside ratios that explore relationships between these pathways.

These compounds are involved in neurotransmitter signalling, NAD+ production, oxidative stress and immune regulation.

Although altered results may provide clues about metabolic activity, urinary measurements cannot directly diagnose neuroinflammation.

No single test tells the whole story. A thorough clinical history, appropriate neurological assessment and carefully selected investigations can help identify potentially modifiable factors affecting brain health.

Everyday Strategies to Support a Healthier Brain

Supporting healthy inflammatory regulation begins with reducing the demands placed on your cells.

A nutrient-dense, Paleo-inspired diet rich in colourful vegetables, quality proteins, healthy fats and antioxidant-rich foods provides important building blocks for cellular function.

Regular movement supports circulation and metabolic health, while restorative sleep allows the brain to carry out essential maintenance processes.

Managing chronic stress, maintaining healthy blood glucose and reducing unnecessary environmental exposures also help create a healthier environment for neurological function.

Small, consistent changes can make a meaningful difference to your overall brain health.

Final Thoughts: Calm the Environment, Support the Cells

Your brain's immune system is designed to protect you. But like any defence system, it needs to know when to respond and when to stand down.

Rather than focusing solely on suppressing inflammation, I encourage looking at the bigger picture: metabolic health, sleep, nutrition, environmental exposures, vascular function and the health of the cells themselves.

Because supporting your brain isn't just about protecting neurons. It's about creating an environment in which all your brain cells can function effectively.

And that's an important part of recharging your brain.

Continue the Recharge Your Brain Series

Missed Part 1?

In the first article, The Brain Needs Energy, we explored five important nutrients involved in mitochondrial function, cellular communication and neurological health.