Could Common Indian Spice Curcumin Really Help Prevent, Even Treat Alzheimer’s Disease?

A 2004 UCLA-Veterans Affairs study involving genetically altered mice suggests that curcumin, the active ingredient in the common East Indian spice tumeric, might well inhibit the accumulation of destructive beta-amyloid in the brains of Alzheimer’s disease patients — and may even break up existing plaques associated with the disease.

There is also circumstantial evidence that curcumin improves mental functions: A survey of 1,010 Asian people who ate yellow curry and were between the ages of 60 and 93 showed that those who ate the sauce “once every six months” or more had higher results on standardized tests of mental functioning than those who did not.

From a scientific standpoint, though, this does not show whether the curry caused it, or people who had healthy habits also tended to eat the curry, or some completely different relationship.

Numerous studies have demonstrated that curcumin, amongst only a few other things such as high impact exercise, learning, bright light, and antidepressant usage, has a positive affect on neurogenesis in the hippocampus and concentrations of brain-derived neurotrophic factor (BDNF), reductions in both of which are associated with stress, depression, and anxiety.

Little curcumin, when eaten, is absorbed : from 2 to 10 grams of curcumin eaten alone resulted in undetectable to very low serum levels. Curcumin is unstable in the gut, and the traces that pass through the GI tract rapidly degrades or is conjugated through glucuronidation. Co-supplementation with 20 mg of piperine (extracted from black pepper) significantly increased the absorption of curcumin by 2000% in a study funded by a prominent manufacturer of piperine. Further, due to its effects on drug metabolism, piperine should be taken cautiously (if at all) by individuals taking other medications. Some benefits of curcumin, such as the potential protection from colon cancer, may not require systemic absorption.

Alternatively, dissolving curcumin in hot water prior to ingestion, or in warm oily liquids, appears to increase bioavailability; however, no published studies to date have documented this. Cooking with curcumin and oil may increase absorption, however peer-reviewed scientific literature has not documented this, while the literature has documented concerns regarding the heat stability and degradation of curcumin in the gut.

In 2007, a polymeric nanoparticle encapsulated formulation of curcumin (”nanocurcumin”[20]) has been synthesized which has the potential to bypass many of the shortcomings associated with free curcumin, such as poor solubility and poor systemic bioavailability. Nanocurcumin particles have a size of less than 100 nanometers on average, and demonstrate comparable to superior efficacy compared to free curcumin in human cancer cell line models.[20] However, actual in vivo absorption has not been demonstrated with this nanoparticle.

In July 2008, researchers from the aforementioned team in UCLA’s Department of Neurology announced results on a form of “lipidated curcumin” that was noted to achieve more than 5 micromolar in the brain in vivo, 50 times that found in clinical studies.

Another method to increase the bioavailability of curcumin filed a patent in 2006 that involves a simple procedure creating a complex with soy phospholipids, however the plasma concentration of curcumin using this formulation only reached 0.033 micromolar.