Does Fasting Reduce Inflammation in the Brain? Exploring the Science

January 4, 2026 •

2 min read

According to extensive research, intermittent fasting can significantly reduce inflammation in the brain by promoting cellular repair and modulating inflammatory pathways. So, does fasting reduce inflammation in the brain, and what exactly are the underlying mechanisms that make this happen?

Quick Summary

Fasting reduces neuroinflammation by triggering cellular repair, boosting key proteins like BDNF, and shifting the body's energy source to ketones, but the effectiveness depends on the fasting type and diet.

Key Points

Cellular Repair: Fasting triggers autophagy, a process where the brain's cells clean up and recycle damaged components, directly reducing inflammatory stressors.
Boosts BDNF: Fasting significantly increases brain-derived neurotrophic factor (BDNF), a protein that enhances neuron growth and protects against inflammation.
Shifts Energy Source: The metabolic switch from glucose to ketones during fasting provides an inherently anti-inflammatory fuel source for the brain.
Suppresses Inflammasomes: Fasting increases arachidonic acid, which helps to inhibit the NLRP3 inflammasome, a major trigger for chronic inflammation.
Dietary Context is Key: The anti-inflammatory benefits of fasting are amplified by a whole-foods diet and can be undermined by a diet high in processed foods and sugar.
Intermittent vs. Prolonged Fasting: While intermittent fasting has shown consistent anti-inflammatory effects, research suggests prolonged fasting (48+ hours) may have temporary inflammatory consequences before refeeding.

What is Neuroinflammation?

Neuroinflammation is the inflammatory response within the brain or spinal cord. While acute inflammation is protective, chronic neuroinflammation is a persistent, low-grade state that can damage neurons and contribute to neurological and neurodegenerative disorders such as Alzheimer's, Parkinson's, and multiple sclerosis. Factors like poor diet, chronic stress, sleep deprivation, and environmental toxins can trigger it.

The Cellular Mechanisms of Fasting's Anti-Inflammatory Effects

Fasting initiates a metabolic shift that profoundly impacts brain inflammation. As glucose stores deplete, the body produces ketones from fat, a process central to fasting's anti-inflammatory benefits.

Key mechanisms include:

Autophagy: This cellular process recycles damaged components, reducing stress and inflammation. Fasting activates autophagy in neurons.
Brain-Derived Neurotrophic Factor (BDNF): Fasting increases BDNF, a protein that supports neuron growth and resilience against stress and inflammation.
Inhibition of Inflammasomes: Fasting increases arachidonic acid, which inhibits the NLRP3 inflammasome, a key driver of inflammation.
Ketone Production: Ketones themselves have anti-inflammatory effects, inhibiting the release of pro-inflammatory cytokines.

How Different Fasting Methods Compare

The impact of fasting on brain inflammation can vary by method.


Feature	Intermittent Fasting (e.g., 16/8, 5:2)	Prolonged Fasting (48+ hours)
Inflammation Effect	Generally reduces inflammation.	Mixed results, may temporarily increase inflammatory markers before refeeding.
Ketone Production	Moderate ketone production, typically after 10-14 hours.	High levels of ketone production, more pronounced metabolic switch.
Safety & Risks	Relatively low risk for most healthy individuals.	Higher risk of side effects like malnutrition, muscle loss, and mood dips; requires supervision.
Sustainability	Easier to sustain long-term as a lifestyle change.	Not sustainable for most people; typically used for short-term, specific goals.
Study Findings	Strong evidence for reducing neuroinflammation in animal models and human trials.	Emerging and inconsistent evidence, with some research showing temporary increases in inflammation.

The Interplay of Fasting, Diet, and Brain Health

The diet accompanying fasting significantly impacts its anti-inflammatory effects. Diets high in processed foods, sugar, and omega-6 fatty acids can counteract the benefits. Conversely, a diet rich in anti-inflammatory foods complements fasting. These include:

Flavonoids: Found in berries.
Omega-3 Fatty Acids: Present in fatty fish.
Curcumin and Resveratrol: Found in turmeric and grapes.

Practical Tips for Using Fasting to Support Brain Health

Start Slowly: Try less restrictive intermittent fasting methods like 16/8.
Prioritize Nutrient-Dense Foods: Focus on whole foods during eating windows and limit processed items.
Stay Hydrated: Drink plenty of water during fasting periods.
Monitor Your Body: Pay attention to how you feel.
Incorporate Exercise: Physical activity enhances anti-inflammatory effects and boosts BDNF.

Conclusion

Evidence suggests fasting, particularly intermittent fasting, can reduce brain inflammation through autophagy, increased BDNF, and inflammasome suppression. The metabolic shift to ketones also contributes to neuroprotection. However, the benefits are influenced by diet; a nutrient-dense diet amplifies the positive effects. Combining sustainable intermittent fasting with a whole-food diet is a promising strategy for reducing neuroinflammation.

NIH Study on Fasting and Inflammation

Frequently Asked Questions

Fasting helps to regulate the brain's immune cells, or microglia, by shifting them from a pro-inflammatory state to a more protective, anti-inflammatory one. This helps to minimize nerve damage and promote healing.

Both intermittent fasting and regular caloric restriction have demonstrated anti-inflammatory benefits in animal studies. However, intermittent fasting's cyclical nature and metabolic switching to ketosis offer unique neuroprotective advantages, including increased BDNF and autophagy.

Animal studies have shown that intermittent fasting can improve cognitive function and reduce markers associated with Alzheimer's disease, such as amyloid plaques. While more human research is needed, the anti-inflammatory and neuroprotective effects are promising.

Ketones, produced during fasting, are not only a brain fuel but also act as signaling molecules that suppress inflammatory pathways. They directly inhibit the release of pro-inflammatory cytokines, helping to create a less inflammatory environment in the brain.

Intermittent fasting protocols, such as the 16/8 method or the 5:2 diet, are often recommended for their effectiveness and manageability. These patterns allow for the metabolic shift necessary to trigger anti-inflammatory processes without the risks of more prolonged fasting.

Yes. Chronic neuroinflammation is linked to mental health disorders like depression and anxiety. By reducing brain inflammation, fasting can help lower cortisol levels and boost mood-lifting neurotransmitters like serotonin and dopamine, leading to improved mental clarity and mood.

A healthy diet is critical. A high intake of processed foods, sugar, and unhealthy fats can promote inflammation and counteract the benefits of fasting. Combining fasting with a diet rich in anti-inflammatory foods like berries, omega-3s, and leafy greens can amplify the positive effects.