Turmeric may be an effective analgesic in treating chronic knee pain, according to a randomized, clinical study published on September 15 in the Annals of Internal Medicine. Turmeric is already well known for its anti-inflammatory properties and is a common spice traditionally and widely used in India. Turmeric contains the phytochemical curcumin, which not only gives curry and mustard that unmistakable golden color but also has caused turmeric to score as the most anti-inflammatory food on the Dietary Inflammatory Index. Available as a dietary supplement, turmeric's antioxidant and anti-inflammatory properties may address numerous health conditions, including arthritis. Turmeric's therapeutic potential originates from curcumin's mediation of inflammatory enzyme expression. Curcumin regulates numerous signaling molecules, including pro-inflammatory cytokines, apoptotic proteins, NF–κB, cyclooxygenase-2, 5-LOX, STAT3, C-reactive protein, prostaglandin E2, prostate-specific antigen, adhesion molecules, phosphorylase kinase, transforming growth factor-β, triglyceride, ET-1, creatinine, HO-1, AST, and ALT in human participants. Curcumin also downregulates cyclin D1, cyclin E, and MDM2. According to the National Institutes of Health, turmeric and curcumin have a variety of interesting biological activities, but they’re challenging to study because curcumin is unstable and has low bioavailability when it's taken orally. In addition, curcumin products may differ in composition or contain more substances than expected, which makes the results of research on these products difficult to understand and compare. The most common type of arthritis, osteoarthritis (OA), has no cure, and treatments such as exercise, weight loss, and pain relievers are not always effective. Often, patients with OA look for dietary or natural alternatives to anti-inflammatory drugs. Several studies have evaluated turmeric (Curcuma longa) and curcumin for treatment of arthritis. In one recent study, the researchers randomly assigned 70 patients with painful knee OA and knee effusion or synovitis to receive placebo or 1,000 mg of C. longa capsules daily for 12 weeks. Primary outcomes of knee pain changes were measured on a visual analogue scale, and effusion–synovitis volume was measured by MRI. While the C. longa group showed a statistically significant, but modest, reduction in pain over the placebo group, there was no significant difference between groups for change in effusion–synovitis volume or cartilage composition on MRI. In addition, no differences were reported in the incidence of adverse events. This study indicates that while C. longa may not impact joint effusion, it may help reduce knee pain. While these results are promising, limitations to the study include small sample size and short duration. The authors noted that larger, longer-term studies are needed to assess clinical significance of C. longa in inflammatory knee OA. Clinical trials have established the safety and tolerability of turmeric at high doses and indicate that 500 mg to 2,000 mg per day may be effective. The average Indian diet provides around 2,000 mg of turmeric per day, and WHO recommends an acceptable daily intake of 1.4 mg per pound of body weight. Turmeric can be added to the diet as a supplement, as tea, or in meals. NIH warns that turmeric supplements have low bioavailability and need fat or heat to enhance absorption. Combining turmeric with black pepper or ginger, or coconut milk or other fats, enhances bioavailability. Most turmeric supplements contain 1,000 mg of the spice along with 5 mg of black pepper. Advise patients that turmeric and curcumin are safe in recommended amounts when taken orally or applied to the skin. While there are no reported adverse effects and many potential health benefits, turmeric should not replace conventional therapy for OA. Caution pregnant or breastfeeding women as well as patients who have gallstones or are susceptible to kidney stones to moderate their turmeric consumption and not to exceed amounts commonly found in food.
Read full abstract
Apr 1, 2021
M.-F Hsueh + 5
Open Access
