In the past decade there have been many studies on the effects of curcumin on the brain. Observation studies from India where curcumin is regularly ingested in the diet show that the incidence and prevalence of AD is much lower than in the US. These studies show that people regular who eat high concentrations of curry with curcumin have better cognitive performance than those who eat curry sparingly.

So how does curcumin protect against Alzheimer disease?

There are several mechanisms by which curcumin may be protective against AD. One study from California observed that curcumin could enhance the function of macrophages. Macrophages pretreated with curcumin were found to be more efficient at taking up protein plaques.

Another study revealed that curcumin because of its lipid properties was able to cross into the brain and prevented the glial cells from proliferating.  It is known that glial cells play a key role in the formation of the beta amyloid, a protein plaque seen in patients with Alzheimer disease.

There are also several studies suggesting that curcumin because of its anti-inflammatory properties could be protecting the brain tissue from damage cause by the abnormal amyloid proteins. A similar anti-inflammatory effect has been seen by non-steroidal anti-inflammatory drugs like Motrin. However, NSAIDS are not safe for long term use and perhaps curcumin may be a better alternative.

In addition, curcumin has also been found to be a potent inhibitor of interleukin 12, which is a pro-inflammatory cytokine.

Studies from China suggest that curcumin may be protective in the brain because of is antioxidant properties. In laboratory rats pretreated with curcumin, there was less brain damage compared to untreated rats.

In addition, studies show that curcumin can reduce lipid peroxidation and scavenge the free radicals. In fact there are reports that curcumin can preserve or increase levels of glutathione, which is an important water based antioxidant.

The most prominent feature of AD is presence of amyloid plaques. Now studies show that rats pretreated with curcumin have markedly lower levels of beta amyloid and consequently have a marked decrease in degeneration of brain tissue.

Another mechanism that may explain the benefits of curcumin include its ability to lower blood cholesterol. This action further reduces the development of amyloid plaques, which are made of cholesterol ester. By inhibiting cholesterol formation and serum peroxide, curcumin may be preventing the progression of AD.