Oral curcumin shows no benefit in reducing inflammation following vascular surgery

A study of oral curcumin, the active medicinal ingredient in turmeric, showed no benefit in preventing inflammation and complications in patients undergoing elective surgery for aortic aneurysm repair, according to a large randomized controlled trial in CMAJ (Canadian Medical Association Journal).

"Turmeric has been used for thousands of years in Indian and Chinese medicine, and curcumin continues to gain popularity today as a natural health supplement," writes Dr. Amit Garg, Lawson Health Research Institute and Department of Medicine, Western University, in London, Ontario, with coauthors. "In this randomized trial, the largest to date, perioperative oral curcumin did not ameliorate the complications of elective abdominal aortic aneurysm repair." 

Despite the increasing popularity of curcumin, and many animal studies showing benefit, few rigorous clinical trials have looked at its effects in humans. One single-centre study found that curcumin was associated with lower biomarkers for inflammation after coronary bypass surgery. In contrast, this study enrolled five times the number of patients at 10 hospitals for a different type of procedure to test the hypothesis that curcumin reduces inflammation and improves outcomes of surgery. 

Researchers included 606 patients scheduled for elective surgery for abdominal aortic aneurysm repair at 10 Canadian hospitals. Participants were randomized to receive high-dose oral curcumin (2000 mg twice a day over four days) or placebo before surgery. Study results showed no positive effect of curcumin on inflammation compared with placebo, and, in secondary analyses, there was an increased risk of post-surgical kidney damage in patients in the curcumin group.

"Our findings emphasize the importance of testing turmeric and curcumin in rigorous human clinical trials before espousing any health benefits, as is currently done in the popular media," caution the authors.

To hear more about the study from Dr. Amit Garg, listen to the CMAJ podcast.  

The study was funded by the Canadian Institutes of Health Research (CIHR). 

"Oral curcumin in elective abdominal aortic aneurysm repair: a multicentre randomized controlled trial" is published in CMAJ.