Is Fasting Good to Help Inflammation? What Science Says

October 18, 2025 •

4 min read

According to a 2022 review of 18 studies, intermittent fasting can significantly reduce markers of inflammation, such as C-reactive protein. This growing body of research suggests that a strategically timed break from eating, known as fasting, may indeed be a powerful tool to help combat inflammation.

Quick Summary

Fasting and caloric restriction have shown promising anti-inflammatory effects by triggering cellular repair mechanisms and modulating immune responses. Key metabolic shifts, such as increased ketone body production and autophagy, help to suppress inflammatory pathways. Research indicates that various fasting methods can reduce inflammatory markers, especially in conditions linked to chronic inflammation.

Key Points

Autophagy Activation: Fasting promotes cellular repair and the removal of damaged cells, a process called autophagy, which helps reduce inflammatory triggers.
Ketone Body Production: During fasting, the body produces ketone bodies like BHB, which actively suppress the NLRP3 inflammasome, a key inflammatory pathway.
Immune Cell Modulation: Research shows intermittent fasting reduces the circulation of inflammatory monocytes in the blood, effectively putting them in a 'sleep mode'.
Reduction in Inflammatory Markers: Various fasting methods have been shown to lower systemic inflammatory markers such as C-reactive protein and interleukin-6.
Enhanced Gut Microbiota: Fasting can improve gut health by increasing the diversity of beneficial bacteria, which in turn boosts anti-inflammatory responses.
Reduced Oxidative Stress: Fasting enhances the body's resistance to oxidative stress, a factor that contributes to aging and many chronic inflammatory diseases.

The Scientific Mechanisms Behind Fasting and Inflammation

Research has increasingly focused on the link between fasting and its anti-inflammatory effects. The underlying mechanisms involve a series of metabolic and cellular changes that occur when the body is in a fasted state. Chronic, low-grade inflammation is often associated with modern high-calorie, processed Western diets and contributes to conditions like obesity, type 2 diabetes, and heart disease. Fasting helps to reverse this by promoting systemic and cellular-level shifts.

Cellular Housekeeping Through Autophagy

One of the primary benefits of fasting is the activation of autophagy. This is a natural, regulated mechanism in which the body cleans out damaged or malfunctioning cells, recycling the non-essential components for repair and rebuilding. By taking a break from constant digestion, the body can redirect its resources towards this vital cellular 'spring clean.' Activating autophagy helps reduce cellular stress and clear out factors that trigger inflammation. Studies have shown that fasting activates AMP-activated protein kinase (AMPK) and inhibits the mammalian target of rapamycin (mTOR), a signaling pathway that suppresses autophagy. This metabolic switch allows the body to turn inward and focus on cellular maintenance.

The Role of Ketone Bodies

When the body is deprived of glucose from food for a period, it switches to using stored fat for energy, producing molecules called ketone bodies. A significant ketone body, β-hydroxybutyrate (BHB), has been shown to have a potent anti-inflammatory effect. Research from Yale has identified that BHB directly inhibits the NLRP3 inflammasome, a multi-protein complex that triggers the inflammatory response. This discovery provides a strong molecular explanation for how fasting can combat inflammation, particularly in conditions driven by NLRP3 activation, such as autoimmune diseases, type 2 diabetes, and Alzheimer's.

Modulating Inflammatory Cells and Signaling

In addition to its metabolic effects, fasting directly impacts the immune system. Mount Sinai researchers found that intermittent fasting reduces the release of highly inflammatory immune cells called 'monocytes' into the bloodstream. These circulating monocytes enter a 'sleep mode' during fasting and are less inflammatory than those found in continuously fed individuals. Fasting also reduces levels of pro-inflammatory cytokines like C-reactive protein (CRP) and interleukin-6 (IL-6), while modulating the balance of T-cells that regulate the immune response.

Enhancing Gut Health and Microbiota

The gut microbiota plays a crucial role in regulating inflammation throughout the body. Fasting has been shown to enhance the abundance and diversity of the gut microbiome, specifically promoting the growth of beneficial, anti-inflammatory bacteria. This modulation can increase the production of short-chain fatty acids (SCFAs), which have powerful anti-inflammatory effects and help enhance gut barrier function. Improving the health of the gut lining is critical for reducing systemic inflammation, as a leaky gut can allow inflammatory compounds to enter the bloodstream.

Fasting Protocols and Anti-Inflammatory Effects

Different fasting protocols can be used to achieve anti-inflammatory benefits. Choosing the right method often depends on individual health goals and lifestyle.

Comparison of Fasting Methods for Inflammation


Fasting Type	Regimen Description	Anti-Inflammatory Benefits	Suitability for Beginners
Time-Restricted Eating (TRE)	Confines eating to a specific window, e.g., 16:8 (fasting for 16 hours, eating for 8).	Reduces blood sugar, oxidative stress, and inflammatory markers like CRP. Improves gut health.	High; easier to follow consistently than longer fasts.
Alternate-Day Fasting (ADF)	Alternates days of normal eating with days of fasting (typically 0-500 calories).	Potent effects on weight loss and inflammatory markers. Strong improvements in metabolic syndrome features.	Moderate; requires greater discipline than TRE.
5:2 Diet	Normal eating for 5 days of the week, with two non-consecutive days of very low-calorie intake (500-600 calories).	Effective for weight loss and reducing inflammatory markers.	Moderate; requires careful planning for low-calorie days.
Prolonged Fasting	Fasting for 24 hours or longer (up to 21 days), often water-only, under supervision.	Triggers deeper cellular repair mechanisms and significant reduction in systemic inflammation.	Low; should only be undertaken with medical supervision due to risks.

Lifestyle Factors to Maximize Anti-Inflammatory Effects

While fasting is a powerful tool, it is most effective when combined with other healthy habits.

Eat Anti-Inflammatory Foods: Focus on a diet rich in whole foods, fruits, vegetables, nuts, seeds, and oily fish. These foods are packed with anti-inflammatory compounds like polyphenols and omega-3s. Conversely, avoid highly processed foods, sugary drinks, and refined carbohydrates, which can fuel inflammation.
Prioritize Sleep: Adequate sleep is essential for managing inflammation, as poor sleep can increase stress hormones and inflammatory signals. Aim for 7–9 hours of quality sleep per night.
Manage Stress: Chronic stress keeps the body in a state of alert, worsening inflammation. Practices like yoga, meditation, and spending time outdoors can help mitigate stress levels.
Stay Hydrated: Drinking plenty of water is crucial for flushing toxins from the body and supporting overall cellular function.

Conclusion: Fasting as a Tool for Inflammation Control

The scientific evidence strongly suggests that fasting is good to help inflammation, acting through multiple interconnected pathways. By triggering autophagy, promoting ketone production, modulating immune cells, and improving gut health, fasting provides a comprehensive approach to reducing chronic inflammation. While the anti-inflammatory effects appear promising, especially with consistent practice, it is crucial to approach fasting responsibly. Before beginning any fasting protocol, consult a healthcare professional, particularly if you have underlying health conditions. Combining fasting with a healthy diet and lifestyle can maximize its benefits and contribute to long-term well-being.

This article is for informational purposes only and is not medical advice. Consult a healthcare provider before starting any new diet or treatment.

Fasting-induced FOXO4 blunts human CD4+ T helper cell responsiveness

Frequently Asked Questions

Studies show that even short periods of intermittent fasting, such as time-restricted eating within a 12-hour window, can begin to lower inflammatory markers. More prolonged fasts, like a 24-hour water fast, can have more significant effects on cellular repair mechanisms like autophagy.

Initial research is promising, especially in animal models of autoimmune conditions like rheumatoid arthritis, where fasting has reduced disease severity and inflammation. The anti-inflammatory mechanisms, including BHB production and immune cell modulation, may be beneficial, but more human research is needed.

During a fast, the immune system undergoes a reset. Circulating pro-inflammatory immune cells, such as monocytes, are reduced and become less inflammatory. This does not compromise the immune system's ability to respond to acute infections.

No, fasting is not safe for everyone. Individuals who are pregnant, breastfeeding, underweight, have a history of eating disorders, or certain medical conditions like diabetes should not fast without medical supervision. It is essential to consult a doctor before starting any fasting regimen.

Yes, research suggests fasting may be particularly effective against chronic, low-grade inflammation associated with metabolic syndrome, obesity, and Western diets. Its effects on acute inflammatory responses from infection are less clear and require further research.

The gut plays a significant role, as fasting can positively modulate the gut microbiome, promoting the growth of beneficial bacteria. These bacteria produce short-chain fatty acids that help strengthen the gut barrier and reduce systemic inflammation.

Yes, combining fasting with an anti-inflammatory diet is a highly effective strategy. Focusing on whole, unprocessed foods rich in omega-3s and polyphenols during eating windows can complement the cellular and metabolic benefits of fasting.