Herbs and Spices

Tumeric has long been described as a miracle spice and it’s been recommended by many people as a potential way to reduce your Alzheimer risk.  Turmeric has long been used by Ayurvedic medicine to treat many different diseases, but it is not recognized by the US FDA as being effective against any disease.  Turmeric is the powered rhizome of a plant called Curcuma longa which belongs in the ginger family.  Turmeric power is mostly carbohydrates but contains between 1 and 6% curcuminoids which is a polyphenol.18   

There is a lot of in vitro and in vivo data to back up some of the claims that turmeric can help fight Alzheimer’s.  Studies have shown that curcumin prevents amyloid beta aggregation, decreases the hyperphosphorylation of tau and enhances its clearance, prevents cognitive decline in Alzheimer’s mouse models and improves synaptic functions.  However randomized clinical trials have not shown any positive results.18,19,20,21      

Some scientists have blamed the poor clinical results on curcumin’s low bioavailability which, as we discussed previously, means that curcumin doesn’t enter into the bloodstream effectively.  If it can’t enter the bloodstream, it can’t do any good.  Other scientists have cast doubt on the in vivo and in vitro results because of curcumin’s unique chemical structure which can interfere with many assays causing false positive results.18,21,22  

There is some evidence that adding black pepper or fat increases bioavailability of curcumin.  However, there is still no randomized trial that I am aware of that has shown curcumin in any formulation, including adding black pepper or fat, to be effective against cognitive decline or Alzheimer’s. In fact, there was a randomized clinical trial using curcumin and Bioperine, a marketed product designed to increase bioavailability of natural products that appears to be derived, at least in part, from black pepper.  The study used 10 patients with mild cognitive impairment and was supposed to last 24 months.  Unfortunately two of the 10 patients had adverse effects (incongestion) and dropped out of the study. It was a physician’s decision to stop the trial in five patients.  One patient was lost to follow up which means they have become unreachable.  The remaining two patients left the study when the principal investigator of the study decided not to continue the study and terminated it.  Maybe in the future, someone will perform a clinical trial with curcumin that is effective but as it stands right now, randomized clinical trials have not shown curcumin or turmeric to be effective against Alzheimer’s.  If you want to take or continue taking curcumin or turmeric based on in vitro and in vivo data, that is a personal decision you will have to make.  There is little risk in taking turmeric or curcumin, but one should be aware that the in vitro and in vivo data does not prove that curcumin or turmeric is effective in a human being.  Pretty much every drug that is tested in clinical trials has in vitro and in vivo evidence that it is effective, but the vast majority of drugs do make it to market because it is either ineffective or unsafe.23