Scientific Basis with measurable results

Clinical Study: Validation of Non-Invasive Raman Spectroscopy as an Indicator of Total Antioxidant Nutritional Status in Humans

October 2005

Measurement of blood antioxidants is widely accepted as the gold standard method to determine antioxidant nutritional status in human research studies. This method typically involves invasive blood sampling, extraction and analysis of carotenoids, vitamin E and/or vitamin C by high performance liquid chromatography (HPLC). Blood antioxidant analysis is not practical for use outside the clinic since it is invasive, time-consuming, expensive and the blood levels are affected by multiple factors, such as antioxidant consumption from recent meals.

Recent research strongly supports the concept of an “antioxidant network” in the body in which different antioxidant species work synergistically to preserve, support and regenerate one another in combating oxidative stress in the body.

To test this theory, Pharmanex® sponsored a study in collaboration with three major US universities to test skin carotenoid levels as an indicator of the overall health of the antioxidant network in over 300 healthy subjects. Specifically, the researchers investigated correlations between skin carotenoids—measured non-invasively by Raman spectroscopy (Pharmanex BioPhotonic Scanner)—and blood serum antioxidants (vitamins C, E, and carotenoids by HPLC), as well as urinary isoprostanes, which are widely regarded as the best measure of oxidative stress in the body.

The results of this study confirmed prior research showing strong correlations between skin and blood carotenoids. Most importantly, however, the present study showed highly significant correlations between skin carotenoids (BioPhotonic Scanner) and other blood antioxidants. In addition, a highly significant inverse correlation between skin carotenoids and oxidative stress (urinary isoprostanes) was observed. Together these results confirm that the BioPhotonic Scanner is the best non-invasive indicator of overall antioxidant status in the body, as well as a good indicator of overall oxidative stress.

In addition, the study demonstrated that skin carotenoids as measured by the Scanner, are a more accurate indicator of average fruit and vegetable consumption than blood carotenoids. Previously, blood carotenoids had been viewed as the gold standard indicator of fruit and vegetable intake.

This study will be submitted for publication at a major scientific meeting as well as in a peer-reviewed journal. Specific results and further information will be released in these publications.