The Combined Effects of an Anti-Inflammatory Diet and Curcumin Supplementation on Thyroid Function and Lipid Profile in Patients With Hashimoto's Thyroiditis: A Double Blind Randomised Clinical Trial.

The short version

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.

Key findings

• In this double-blind trial, 57 adults with Hashimoto's thyroiditis (an autoimmune disease in which the immune system attacks the thyroid) all followed an anti-inflammatory diet, and half also took 1,320 mg of curcumin, the main active compound of turmeric, daily for 12 weeks.
• Antibodies against the thyroid (anti-TPO) fell significantly more with curcumin than with placebo (adjusted p = 0.006), the only measure that differed significantly between groups.
• Waist size fell 4.2 cm and TSH (the pituitary signal that drives the thyroid) fell 2.38 mIU/L within the curcumin group, but these changes were not significantly different from placebo after adjustment, and T3 fell in both groups, which suggests the diet contributed.
• Cholesterol, triglycerides and T4 did not differ between groups, and HDL-C (the so-called good cholesterol) only approached significance (p = 0.053).
• The authors call the findings preliminary because of the small sample, short 12-week duration and shared diet, and recommend larger, longer studies.

Common questions