India has a low incidence and prevalance of Alzheimer’s, which may be related to genetics or a particular intake of specific foods. Some people attribute the low incidence of Alzheimer’s to a high intake of turmeric in Asia. As turmeric contains an average of 5-10% curcumin, the daily intake of curcumin is approximated in India is thought be about 125 mg. Curcumin is an anti-inflammatory molecule in the turmeric root.
In cooking curries, curcumin is often dissolved and extracted into fat, eg. ghee, which may increase its bioavailability. Animal studies have demonstrated that the way it is administered affects its distribution in the body. Unformulated curcumin, such as purified and dried curcumin in a capsule, is absorbed easily but the liver and GI tract tag it in a way that make it not very bioavailable to the brain.
There is confusion about curcumin bioavailability versus absorption. Curcumin is absorbed, but not necessarily bioavailable. Further GI and liver glucuronidation or sulfation “tagged curcumin” which interfere with bioavailability it some tissues also leadds to its rapid removal by the kidneys. Unliked tagged curcumin, free curcumin readily crossed the blood brain barrier and is relatively stable.
According to researchers at UCLA: “Our group has tested curcumin in several models and found that it not only reduces oxidative damage and inflammation (as expected), but also reduces amyloid accumulation and synaptic marker loss while promoting both amyloid phagocytosis and clearance. In in vitro studies, we found curcumin worked to prevent synaptic marker and cognitive deficits caused by amyloid peptide infusion and abeta oligomer toxicity.”
“Curcumin has demonstrated ability to enter the brain, bind and destroy the beta-amyloid plaques present in Alzheimer’s with reduced toxicity,” reported Wellington Pham, Ph.D., assistant professor of Radiology and Radiological Sciences and Biomedical Engineering at Vanderbilt and senior author of a study published in the Journal of Alzheimer’s Disease.
Scientists at the Shiga University of Medical Science in Otsu, Japan, have developed a new strategy to deliver a molecule similar to curcumin more effectively to the brain, an atomizer to generate a curcumin aerosol. “In this way the drug can be breathed in and delivered to the brain,” said Pham.
A new year-long trial, published in the British Journal of Nutrition, also found evidence that curcumin blocks rogue proteins called beta amyloid which clumps together and destroys neurons.
In the study 96 participants aged between 40 and 90 were given either a daily placebo or 1,500 mg of curcumin for 12 months. In tests of verbal and memory skills, those taking the dummy pill suffered a decline in mental function after just six months that was not observed in those having the curcumin.
Dr Stephanie Rainey-Smith, of Edith Cowan University, Perth, Australia, said: ‘Curcumin therapy in animals has produced positive cognitive and behavioral outcomes; results of human trials, however, have been inconsistent.”