Curcumin is a component of the spice turmeric and a common traditional medicine in China and India. It's often promoted for its anti-inflammatory and anti-bacterial properties and for its benefits to cancer and Alzheimer's patients. However, a new study in The Journal of Medicinal Chemistry questions these therapeutic claims.
Curcumin has shown promise in thousands of preclinical studies. But over 100 clinical trials have failed to find health benefits in humans. Why? It turns out curcumin is a pan-assay interference (PAIN) compound, which affects screening tests commonly used in drug discovery research. In other words, it can give false-positive results and appear far more promising than it actually is. The study claims that many researchers may not have properly confirmed the true biological activity of cur cumin.
Even without the false positive issues, curcumin isn't likely to provide much therapeutic benefit. In order to be effective, an oral drug has to get through the digestive tract and be absorbed. Curcumin does not make it out. In one study, when patients took up to 12 grams of curcumin per day, almost none could be detected in the blood stream. A drug also has to reach its target in order to be effective. Curcumin is unstable and rapidly degrades in the body. So, it is very unlikely to reach the brain or other parts of the body and provide benefits. The lack of benefit in Alzheimer's patients was confirmed in a clinical trial supported years ago by the Alzheimer's Drug Discovery Foundation (formerly the Institute for the Study of Aging).
Curcumin is just one of many natural products that claims to prevent Alzheimer's disease and promote cognitive health. But many of these claims have not held up when tested in human clinical trials. Some natural products and supplements, such as fish and fish oil (DHA) or vitamin B, have some (albeit mixed) evidence that they can help some patients and additional clinical trials are underway. As always, our bottom line is to exercise caution when claims are based only on preclinical tests—results should always be confirmed in humans.
Nick McKeehan is a member of the ADDF's Aging and Alzheimer's Prevention program. He evaluates the scientific evidence for and against therapies to promote brain health and/or prevent Alzheimer's disease at our website CognitiveVitality.org and contributes regularly to the site's blog. Mr. McKeehan previously served as Chief Intern at Mid Atlantic Bio Angels (MABA) and was a research technician at Albert Einstein College of Medicine investigating repair capabilities of the brain. Mr. McKeehan received a bachelor of science degree in biology from Purdue University, where he was awarded a Howard Hughes Scholarship. He also writes about the biotechnology industry for 1st Pitch Life Science.
Get the latest brain health news: