Turmeric and curcumin for inflammation: what the evidence says and safety

Turmeric (Curcuma longa) is a golden-yellow spice used in cooking and in traditional medicine. Arthritis UK explains that it belongs to the ginger family and is grown in South Asia, and that curcumin is the active ingredient, which has been described as having anti-inflammatory and antioxidant effects. The Welsh Medicines Advice Service, a UK NHS medicines information service, notes that curcumin is the main active ingredient of turmeric and that turmeric has been used orally for many conditions, including rheumatoid arthritis, ulcerative colitis, dyspepsia, cancer, depression and diabetes.

It is important to separate three things: the turmeric used in a curry, which is low in curcumin; turmeric or curcumin supplements, which are concentrated; and prescribed medicines for inflammatory conditions, which have undergone formal testing. The first is food, the second is sold as a food supplement and the third is regulated medicine.

Arthritis UK describes one study in which people were randomised to 2 g of turmeric or 0.8 g of ibuprofen a day for six weeks; pain improved in both groups and more in the turmeric group, but it highlights several limitations: the doses were taken a different number of times a day, the sample was small and uneven, the ibuprofen dose was too low to be expected to have its full effect, and the study was single-blinded. A later double-blind trial by the same group using 1.5 g of curcumin extract and 1.2 g of ibuprofen a day concluded that curcumin extracts worked as well as ibuprofen for pain and movement.

Against these, the same article notes a 2017 review of 13 studies combining 1,101 participants that suggested effectiveness is still uncertain, because of small samples, badly designed studies and different pain scores. It concludes that the effects are statistically significant but all the studies have flaws and that better research is needed. The British Dietetic Association is firmer for osteoarthritis, stating that there is no good trial evidence for turmeric helping symptoms, and recommends that the most important diet measure is maintaining a healthy weight.

Arthritis UK says curcumin is not well absorbed, so its benefits are limited, and that black pepper can improve absorption; cooking does not affect how curcumin works. The Welsh Medicines Advice Service says only high doses of curcumin are absorbed into the blood and can have an effect throughout the body, that giving curcumin with piperine, a constituent of pepper, enhances absorption, and that a common medicinal dose is 400 to 600 mg three times a day, equivalent to 15 g of turmeric powder. Products combining curcumin with piperine therefore carry more absorption, and with it more potential for effects and interactions.

The Welsh Medicines Advice Service advises buying supplements from a trusted source, warning that contamination of turmeric and curcumin supplements with another active ingredient cannot always be ruled out. It says children, adolescents and pregnant women should avoid medicinal doses until there is more evidence of safety. Its series also covers adverse effects and interactions, which is a reason for anyone who takes prescribed medicines or has a long-term condition to check with a pharmacist or doctor before using supplements.

Do not use turmeric to replace prescribed treatment for an inflammatory condition such as rheumatoid arthritis or inflammatory bowel disease. These conditions can cause permanent damage if untreated. Persistent joint pain, swelling or morning stiffness should be assessed by a GP rather than managed with supplements alone.

The British Dietetic Association says the most important relationship between diet and osteoarthritis is weight. It says there is strong evidence that losing weight can reduce pain and improve function, with losing at least ten per cent of body weight giving most benefit in people with overweight or obesity, and that exercise alongside dietary changes helps maintain muscle. It also notes that long-chain omega-3 fatty acids in oily fish may be of benefit, and suggests two portions of fish a week, one of them oily. These are measures with more supporting evidence than turmeric.

Turmeric supplements are not prescribed on the NHS and are bought over the counter or online. A pharmacist can advise on interactions at no charge. Private practitioners who sell supplements should be able to tell you what the evidence is for your condition and what the product contains; if they cannot, treat claims with caution.