Autoimmune Disease

Fatemeh Bourbour et al. (2026) · Endocrinology, diabetes & metabolism

This double-blind randomised trial with 57 adults who have Hashimoto's thyroiditis explored whether curcumin, the yellow polyphenol in turmeric (Curcuma longa), adds benefit to an anti-inflammatory diet. Hashimoto's thyroiditis is an autoimmune condition in which the immune system attacks the thyroid gland, shown in blood tests by anti-thyroid peroxidase antibodies (anti-TPO) and treated in many patients with lifelong levothyroxine. Because many people with the condition carry extra weight and chronic inflammation, the researchers asked whether an anti-inflammatory eating pattern plus curcumin could shift thyroid markers, body measurements and cholesterol. Researchers in Tehran, Iran, enrolled adults aged 20 to 70 with a confirmed diagnosis. Every participant ate the same structured anti-inflammatory diet of whole grains, olive oil, berries, nuts, legumes, vegetables and fatty fish. For 12 weeks, half also took 1,320 mg of curcumin daily as three capsules with meals, and half took look-alike rice-flour placebo capsules. Blood tests measured anti-TPO, thyroid-stimulating hormone (TSH), T3, T4 and lipids, and tape measures tracked waist and hips. Anti-TPO antibodies fell significantly more with curcumin than with placebo (p = 0.006), where antibodies rose numerically (within-group change not significant), which points to a possible effect on thyroid autoimmunity. Within the curcumin group waist circumference dropped 4.2 cm (p = 0.042) and TSH dropped 2.38 mIU/L (p = 0.014), but neither difference was significant against placebo after adjustment, so these changes may come partly from the diet. T3 fell in both groups, which supports that interpretation. Cholesterol, triglycerides and T4 did not differ between groups, and HDL-C moved only toward significance (p = 0.053). The curcumin group's gains held when men were excluded (anti-TPO p = 0.010). The authors call the results preliminary and note the small sample, the short 12-week window, and reliance on self-reported food recalls. Because both groups changed their diets, the trial cannot fully separate curcumin from the diet itself. Lower antibody levels may also fluctuate over time and do not prove long-term disease change. Larger, longer studies with designs that separate diet from supplement are needed before any treatment role for curcumin in Hashimoto's thyroiditis can be judged.

Zhiyong Long et al. (2023) · Frontiers in immunology

Whether the plant compounds often discussed for rheumatoid arthritis — turmeric, green tea, pomegranate, garlic — actually do anything is the question this meta-analysis set out to answer. This review gathered every randomized trial it could find on the question: 47 trials, nearly 3,900 people, fifteen different plant polyphenols, from Iran, China, Korea, Egypt, Japan, Brazil, India and the United States. The clearest picture came from two of them. The first is total glucosides of paeony, an extract of Chinese peony root that is a licensed prescription medicine in China. Twenty-three trials tested it — always added to standard RA drugs like methotrexate, never instead of them. Disease activity scores came down, and so did CRP, ESR and rheumatoid factor, the blood markers doctors track. The most interesting result: people taking it reported *fewer* side effects than people on the standard drugs alone. That fits how it is used clinically — it appears to soften the toll the conventional drugs take on the liver and stomach. The second is curcumin, the yellow compound in turmeric. Five trials, and the same direction: lower disease activity, lower inflammatory markers, no extra side effects. Green tea polyphenols looked promising across two trials. Saffron did not show a clear effect. Everything else — pomegranate, garlic, resveratrol, sesame, cinnamon, ginger, kudzu, cranberry, olive oil, quercetin — rests on one or two small trials apiece, which is encouraging but not yet evidence that bears weight. The honest caveat, which the authors state plainly themselves: the trials disagreed with each other a great deal, most were small, and when the researchers sliced the data by dose and duration some of the headline benefits faded. Nearly all of these were add-on studies. Nobody tested a polyphenol against methotrexate, so the evidence says nothing about replacing a prescribed medication. What it does support is turmeric and peony extract as the best-evidenced candidates, studied as additions to existing treatment rather than replacements for it.