Provitamin
A biofortification, the provision of provitamin A carotenoids
through agriculture, is regarded as an effective and sustainable intervention
to defeat vitamin A deficiency, representing a global health problem.
This food-based intervention has been questioned in conjunction with
negative outcomes for smokers and asbestos-exposed populations of
the CARET and ATBC trials in which very high doses of β-carotene
were supplemented. The current notion that β-carotene cleavage
products (apocarotenoids) represented the harmful agents is the basis
of the here-presented research. We quantitatively analyzed numerous
plant food items and concluded that neither the amounts of apocarotenoids
nor β-carotene provided by plant tissues, be they conventional
or provitamin A-biofortified, pose an increased risk. We also investigated
β-carotene degradation pathways over time. This reveals a substantial
nonenzymatic proportion of carotene decay and corroborates the quantitative
relevance of highly oxidized β-carotene polymers that form in
all plant tissues investigated
