Quick answer: Research suggests intermittent fasting may lower inflammation, a driver of many chronic diseases. Proposed mechanisms include reduced oxidative stress, fewer pro-inflammatory cytokines, more regulatory T cells that calm the immune system, and changes in the gut microbiome and barrier. Much of this evidence is from animal and small human studies.
Key takeaways
Chronic inflammation contributes to many long-term health problems, which is why researchers are interested in fasting as one possible lever.
Fasting may lower oxidative stress and inflammatory signaling, though much of this research comes from animal studies and human results vary.
A simple blood test called hs-CRP can help you and your provider track inflammation over time.
Why inflammation matters
Chronic inflammation contributes to many chronic diseases. See inflammaging.
How fasting may reduce inflammation
Much of this research comes from animal studies, and results in people vary.
Lower oxidative stress
Fasting may reduce reactive oxygen species and increase antioxidant defenses.
Calmer immune signaling
Fasting may reduce cytokines such as IL-6 and TNF-alpha.
Regulatory T cells
These immune cells release anti-inflammatory signals such as IL-10 and help keep the immune system balanced.
Gut health
Fasting periods may support beneficial gut bacteria. See the gut microbiome.
Measuring inflammation
hs-CRP is a simple blood marker of inflammation. See hs-CRP.
Healthy aging lens
Lowering chronic inflammation is one of the most important levers for healthy aging. Fasting is one tool among many, alongside diet quality, movement and sleep.
What the research shows
Human studies of fasting and inflammation measure blood markers such as CRP and IL-6.
Ramadan fasting and inflammation markers (Faris 2012, observational study). 50 healthy adults who fasted from dawn to sunset during Ramadan had blood drawn before, during and after the month. The inflammatory signals IL-1β, IL-6 and TNF-α, along with blood pressure, weight and body fat, were lower during Ramadan than before or after. A limitation is that there was no control group, and weight loss may explain part of the change.
Two low-calorie days a week (Harvie 2011, randomized trial). 107 premenopausal women with overweight or obesity followed either a 5:2-style plan (about 650 kcal a day on 2 days a week) or a daily 25% calorie cut for 6 months. Weight loss was similar (6.4 kg vs. 5.6 kg), and both groups saw comparable drops in high-sensitivity CRP, LDL cholesterol, triglycerides and blood pressure. Fasting insulin and insulin resistance fell slightly more with the 5:2 approach. A limitation is that only women were studied, for 6 months.
Alternate-day fasting vs. daily calorie cutting (Trepanowski 2017, randomized trial). Researchers in Chicago assigned 100 adults with obesity to alternate-day fasting (25% of energy needs on fast days and 125% on feast days), daily calorie restriction (75% of needs every day) or no change for one year. Weight loss was the same in both diet groups at 6 months (6.8% each) and similar at 12 months (6.0% vs. 5.3%). Dropout was highest with alternate-day fasting (38%, vs. 29% with daily restriction), and LDL cholesterol was 11.5 mg/dL higher in the fasting group by month 12. A limitation is that 86 of the 100 participants were women, so the results may not apply equally to men.
Strength of the evidence: Results are mixed: some studies show lower inflammation markers, often alongside weight loss, while a year-long trial found no difference in CRP compared with daily calorie restriction.
When to see a naturopathic doctor
It may be time to see a naturopathic doctor if you have diabetes, take blood sugar or blood pressure medication, or have a chronic condition, or if you are pregnant, breastfeeding, underweight, or have a history of disordered eating. The same is true if fasting leaves you dizzy, shaky or exhausted, or if you want a fasting approach tailored to your health goals.
See a medical provider promptly for fainting, confusion, chest pain, a racing heartbeat, or very low blood sugar symptoms such as shaking, sweating and confusion.
Want a fasting plan that fits your health?
A free 15-minute consultation with Dr. Kneessi. No cost, no obligation. In-office in Odenton, MD or by telehealth.
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
Would checking my hs-CRP help us see whether inflammation is a concern for me?
Could intermittent fasting help with inflammation in my case?
Would an inflammation lab help us see whether fasting is making a difference?
Are there signs that fasting is adding stress to my body instead?
Frequently asked questions
Does intermittent fasting reduce inflammation?
Some studies suggest it may, but results vary.
How can I measure inflammation?
hs-CRP is a common blood test.
Is fasting better than diet for inflammation?
Diet quality matters as much as timing.
Can fasting help gut health?
Fasting periods may support the gut microbiome.
Sources
- Furman D, et al. Chronic inflammation in the etiology of disease across the life span. Nat Med 2019. PMID: 31806905. https://pmc.ncbi.nlm.nih.gov/articles/PMC7147972/
- Faris MA, et al. Intermittent fasting during Ramadan attenuates proinflammatory cytokines and immune cells in healthy subjects. Nutr Res 2012. PMID: 23244540. https://pubmed.ncbi.nlm.nih.gov/23244540/
- Josefowicz SZ, Lu LF, Rudensky AY. Regulatory T cells: mechanisms of differentiation and function. Annu Rev Immunol 2012. PMID: 22224781. https://pmc.ncbi.nlm.nih.gov/articles/PMC6066374/
- Cignarella F, et al. Intermittent Fasting Confers Protection in CNS Autoimmunity by Altering the Gut Microbiota. Cell Metab 2018. PMID: 29874567. https://pmc.ncbi.nlm.nih.gov/articles/PMC6460288/
- Pepys MB, Hirschfield GM. C-reactive protein: a critical update. J Clin Invest 2003. PMID: 12813013. https://pmc.ncbi.nlm.nih.gov/articles/PMC161431/
- National Institute on Aging: Research on intermittent fasting shows health benefits
- MedlinePlus: C-Reactive Protein (CRP) Test
- Harvie MN, et al. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women. Int J Obes (Lond) 2011. PMID: 20921964. https://pubmed.ncbi.nlm.nih.gov/20921964/
- Trepanowski JF, et al. Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults: A Randomized Clinical Trial. JAMA Intern Med 2017. PMID: 28459931. https://pubmed.ncbi.nlm.nih.gov/28459931/
This article is for educational purposes only and is not medical advice. It does not replace an individual evaluation. Talk with your healthcare provider before starting supplements or changing medications, especially if you are pregnant, nursing, or managing a health condition.
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