Optical detection of carotenoids in living tissue as a measure of fruit and vegetable intake.

Circulating blood carotenoids have long been accepted as the most accurate biomarker of total fruit and vegetable intake. Recent technological developments have led to a novel optical detection method of carotenoids in living human tissue, allowing for a non-invasive and rapid method to assess fruit and vegetable intake. Future technological advances to increase sensitivity and molecular specificity, reduce cost, and detect other biomedically important compounds would expand use of this methodology.