In a new paper just published we describe the results of our double blind randomized controlled human clinical trial to determine if piperine increases the absorption of resveratrol, the compound from red wine.
A popular formulation strategy for dietary supplement companies is to add a compound from black pepper (Piper nigrum) known as piperine to increase the absorption of dietary phytochemicals.
One of the the most popular examples of this combination is curcumin with piperine.
The main reason for this combination is because curcumin has been shown to have low absorption even when given gram quantities.
For that reason there is always an interest in trying to increase the absorption of curcumin including combining with piperine.
The interest in this strategy goes back to a paper published in Planta Medica in 1998 suggesting the concentration of piperine when given with curcumin can increase the blood concentrations by 2,000% compared to curcumin alone.
Our Previous Research
In 2011 we used a mouse model to test if piperine with another popular dietary supplement resveratrol, the compound from red wine, can increase the blood levels of resveratrol.
Interestingly, we did find in this animal model that piperine increased the peak blood concentration of resveratrol by 1,544% compared to resveratrol alone.
Our clinical trial with resveratrol and piperine
Study design: This was a randomized double blind controlled clinical trail with human subjects receiving either 1) resveratrol 2.5 grams 2) resveratrol 2.5 grams with 5 mg piperine or 3) 2.5 grams with 25 mg of piperine.
These results were recently published the European Journal of Cancer Prevention and can be found here.
The main result of study found that when piperine at either 5 or 25 mg had no effect on increasing the absorption of resveratrol in a human clinical trial.
Final thoughts:
There could be several reasons for our results that suggest piperine does not increase the blood levels of resveratrol that include:
- Piperine has no effect on resveratrol absorption in humans
- The dose of resveratrol was too high to see an effect with resveratrol
- It could be possible that multiple days of piperine are needed to increase the absorption of resveratrol.
- Or there is another unknown reason.
I think what is most important from this strategy is that piperine does not appear to increase the concentration of every phytochemical it is added to.
It is also clear from this study that more research is needed to show that piperine when given in combination with other polyphenols and phytochemicals can actually increase their absorption.
