Diets Rich In Beta-Carotene A Potential Health Risk

Diets Rich In Beta-Carotene A Potential Health Risk

Researchers at Ohio State University have found that diets rich in beta-carotene can have negative effects. Beta-carotene is actually a red-orange antioxidant pigment that is found in abundance in fruits and vegetables. This antioxidant is called provitamin A because it is converted in the body into vitamin A,  which has many roles, such as in vision, skin integrity, immunity etc. After its absorbtion in the gut, beta-carotene is clived into two molecules of vitamin A. However, when the body has enough vitamin A, the formation of new molecules is inhibited. So there are mechanisms that prevent hypervitaminosis A. In addition, excess carotene is stored in fatty tissues of the body. It should be noted that excess beta-carotene also cause orange discoloration of the skin which is reversible. Beta-carotene is cleaved in two modes, symmetric and asymmetric. When cleaved symmetrically it forms two molecules of retinal that are then converted into retinol (vitamin A) and retinoic acid. Asymmetric cleavage of beta-carotene  leads to the formation of two asymmetric products, apocarotenal. Asymmetric cleavage causes a decrease in retinoic acid.

Scientists believe that too much beta-carotene can lead to negative health effects. This finding may explain the result of an earlier trial in which patients with supplementation of beta-carotene developed lung cancer. Then it was found that beta-carotene supplementation in smokers increases the risk of lung cancer.
Even if final research conclusions are not yet available scientists recommend moderate consumption of beta -carotene. What researchers now aim to see is if these substances that act as antivitamin A are determined by environmental factors. It seems that these drugs block the action of vitamin A  and disrupt the whole metabolism.

Harrison and colleagues, Robert Curley, professor of medicinal chemistry and pharmacognosy, and Steven Schwartz, professor of food science and technology, Both at Ohio State, have created synthetic molecules that mimic derivatives of beta-carotene. Of the 11 synthetic molecules created, 5 functioned as inhibitors of vitamin A. They found that these molecules do not activate retinoic acid receptors, as does vitamin A, but rather inhibit them. Therefore, these molecules act as antagonists of vitamin A. Previous studies have suggested that pollution and smoking can lead to increased production of these compounds. Earl Harrison, Dean’s Distinguished Professor of Human Nutrition at Ohio State and lead author of the study, said that these components are found in food and can represent the negative side of beta-carotene. He added that more studies are needed to certify the clear origin of these substances.