Chronic systemic inflammation is a hallmark of long COVID. Multiple large studies using high-sensitivity C-reactive protein, interleukin-6, tumour necrosis factor-alpha, and other inflammatory markers have found elevated levels in long COVID patients compared to both healthy controls and COVID-recovered individuals without persistent symptoms. This inflammation is not incidental. It is thought to be a primary driver of fatigue, cognitive impairment, pain, and cardiovascular symptoms. Addressing it through diet is not a marginal intervention; it is potentially one of the most important actions a person with long COVID can take.
The Mediterranean Diet as the Evidence Base
The Mediterranean dietary pattern is the most extensively studied anti-inflammatory diet. A large prospective study published in eBioMedicine in 2021, led by researchers at King's College London and the ZOE project, found that greater adherence to a predominantly plant-based Mediterranean-style dietary pattern was associated with a 41 percent lower risk of developing long COVID after acute infection. Those with the highest dietary quality also had significantly lower inflammatory marker levels at follow-up.
The anti-inflammatory mechanisms of a Mediterranean-style plant-rich diet are well characterised. Extra-virgin olive oil contains oleocanthal, a phenolic compound that inhibits COX-1 and COX-2 enzymes through the same mechanism as ibuprofen but without gastrointestinal side effects at dietary doses. Omega-3 fatty acids from oily fish or algae supplements are converted to resolvins and protectins, signalling molecules that actively resolve inflammation rather than simply suppressing it.
Top Anti-Inflammatory Plant Foods for Long COVID
- Extra-virgin olive oil: two to four tablespoons daily; choose cold-pressed, peppery oil for highest phenolic content; the stronger the peppery sensation in the throat, the higher the oleocanthal content
- Fatty fish or algae-derived omega-3: EPA and DHA at 2 to 3 grams daily reduce pro-inflammatory eicosanoid production and support the resolution phase of inflammation; for plant-based individuals, algae-derived omega-3 is the direct source of EPA and DHA without the conversion step from ALA
- Turmeric with black pepper: curcumin inhibits NF-kB and reduces interleukin-1 beta and interleukin-6; a dose of 500 mg curcumin twice daily with piperine is used in clinical trials; incorporate daily in cooking or supplement if unable to achieve dietary doses
- Ginger: gingerols and shogaols inhibit prostaglandin synthesis and have demonstrated anti-inflammatory effects comparable to some NSAIDs in preclinical studies; add fresh or dried ginger to cooking, smoothies, and teas
- Berries: anthocyanins reduce NF-kB activation and circulating interleukin-6; a meta-analysis in Nutrients in 2021 found that blueberry supplementation significantly reduced CRP and interleukin-6 in adults across multiple trials
- Green tea: epigallocatechin-3-gallate inhibits multiple pro-inflammatory pathways and has antiviral properties against respiratory viruses in cell culture; two to four cups daily is associated with lower inflammatory markers in population studies
- Walnuts: the only tree nut with meaningful ALA content plus ellagitannins and polyphenols with anti-inflammatory activity; a 2020 randomised trial in Journal of the American College of Cardiology found walnut consumption significantly reduced interleukin-6 compared to control diets
- Dark leafy greens: magnesium in greens supports resolution of inflammation; vitamin K1 modulates inflammatory cytokine production; aim for at least 2 large portions daily
Foods That Drive Inflammation and Should Be Minimised
Ultra-processed foods, refined sugars, and trans fats are the primary dietary drivers of systemic inflammation. Ultra-processed food consumption is associated with higher circulating CRP, interleukin-6, and TNF-alpha independently of total caloric intake. Refined sugar promotes the glycation of proteins, including haemoglobin and collagen, producing advanced glycation end-products that bind to RAGE receptors and directly activate inflammatory signalling. A long COVID recovery diet should aim to largely replace ultra-processed foods and refined carbohydrates with whole plant foods.
Sources
- Merino, J., et al. (2021). Diet quality and risk and severity of COVID-19. Gut, 70(11), 2096-2104.
- Calder, P.C. (2020). Nutrition, immunity and COVID-19. BMJ Nutrition, Prevention and Health, 3(1), 74-92.
- Bayes, J., et al. (2022). Effects of polyphenols in a Mediterranean diet on symptoms and progression of COVID-19. Frontiers in Nutrition, 9, 889734.
- Rossi, M.A., et al. (2021). Blueberry supplementation and metabolic syndrome: a systematic review. Nutrients, 13(5), 1458.
- Schwingshackl, L., & Hoffmann, G. (2014). Mediterranean dietary pattern, inflammation and endothelial function: a systematic review. European Journal of Nutrition, 53(5), 1197-1208.