Turmeric and Alzheimer’s Disease
Q How does turmeric work for someone with Alzheimer’s disease? Also, can the person take it in a capsule form?
PAT, Brooklyn, NY
A Alzheimer’s disease, the devastating, progressive brain-wasting disease that is approaching epidemic proportions among the elderly in the United States and other Western nations, strikes four times fewer people in rural India. The reason(s) for this remarkable differential are being vigorously investigated, but a prime suspect at this point is turmeric (Curcuma longa), the spice that is ubiquitous in Indian and other South Asian cooking, but which rarely makes it out of the local Indian restaurant in the US—except perhaps among people of South Asian origin. According to South Asian folklore and Indian Ayurvedic medical tradition, turmeric powder, among its other qualities, has the ability to preserve memory and clear thinking long into old age. New scientific research is confirming what many South Asians have known since antiquity.
The recent scientific findings to support turmeric’s cognition-sparing benefits include:
- A study from Singapore showing that regular curry (containing turmeric) consumption helps preserve cognitive function in mentally competent Asians aged 60 to 93 years.
- A study from UCLA School of Medicine researchers showing that an active ingredient in turmeric (the principle ingredient in curry) may boost Alzheimer’s patients’ immune system function, thus facilitating the clearance of amyloid plaques from the brain. Amyloid plaques are the primary cause of the most common brain pathology in Alzheimer’s patients.
- Finally, new research indicating that amyloid plaques, very similar to those known to cause Alzheimer’s disease, may also be a principal factor in the loss of vision in glaucoma. Does that mean turmeric could benefit people with glaucoma, as well? It’s certainly an area ripe for investigation.
Also, turmeric has long been used in Ayurvedic medicine, principally as a treatment for inflammatory conditions. Turmeric’s primary constituents include the three curcuminoids—curcumin, demethoxycurcumin, and bisdemethoxycurcumin—as well as volatile oils (tumerone, atlantone, and zingiberone), resins, sugars, and proteins. The most celebrated constituent is curcumin, which comprises 2–8% of turmeric, and is typically extracted from turmeric, to its potency’s detriment. However, altogether there are at least 10 bioactive components found in turmeric, which produce a wide array of biomedical benefits. Curcumin’s activity is the most touted, especially for its anti-inflammatory effect, especially for those effects on cancer.
Research has shown curcumin to be a highly pleiotropic (possessing multiple effects) molecule. Accordingly, it is capable of interacting with a great many molecular targets involved in inflammation. But the repeated problem, as “authoritatively” presented, is low bioavailability.
Branching out from early cell culture and animal research, clinical trials have found curcumin to possess powerful therapeutic agencies in diseases such as inflammatory bowel disease, arthritis, pancreatitis, and chronic anterior uveitis, not to mention certain types of cancer. It may well be true that curcumin’s rapid plasma clearance and conjugation renders its therapeutic use less than desirable, leading researchers to investigate the benefits of complexing curcumin with other substances to increase systemic bioavailability.
While clinical trials have provided a deeper understanding of the mechanisms and therapeutic potential of curcumin, overhanging the published research is the specter of “low bioavailabilty.” Could this notion be a chimeric fantasy, fostered by those looking for a new profit avenue?
It is interesting to note that one of the leading “enhanced bioavailability” curcumin formulations makes significant use of the essential oils that are removed by the extraction process. Could turmeric contain its own delivery system? As we have previously reported, when you cut a piece of fresh turmeric, you will notice that your hands turn yellow, an indication that there is good bioavailability, because skin has evolved to be highly resistant to penetration by foreign substances. Also, if you’re taking whole turmeric, your stool does not turn yellow. Turmeric, containing curcumin, is certainly quite bioavailable.
Yes, you may take it in capsule form.
- Ng TP, Chiam PC, Lee T, Chua HC, Lim L, Kua EH. Curry consumption and cognitive function in the elderly. Am J Epidemiol 2006;164:898-906.
- Fiala M, Liu PT, Espinosa-Jeffrey A, et al. Innate immunity and transcription of MGAT-III and Toll-like receptors in Alzheimer’s disease patients are improved by bisdemethoxycurcumin. Proc Natl Acad Sci USA 2007;104:12849-12854.
- Guo L, Salt TE, Luong V, et al. Targeting amyloid-β in glaucoma treatment. Proc Natl Acad Sci USA 2007 Aug 14;104(33):13444-9.