Bananas might prevent blindness

Researchers recently published a study, which demonstrates new insights on how bananas make and store carotenoides[1]. Carotenoids which are found at various levels in different banana cultivars, are a important precursors for Vitamin A, which in turn promotes eye health. Their findings could someday help in the development of banana varieties with enhanced health benefits.

Vitamin A deficiency is widespread in Africa and Southeast Asia, causing an estimated 250,000 to 500,000 children to become permanently blind each year, the researchers note. Even worse, half of those children die within a year of losing their sight[2].

To combat vitamin A deficiency, other researchers have been investigating methods to boost carotenoids in bananas, because these compounds—which turn fruits and vegetables red, orange or yellow—are converted into vitamin A in the liver. However, this approach has been hindered by a lack of understanding of how bananas produce and store carotenoids.

The researchers studied two banana varieties to find out why they make very different amounts of carotenoids. They found that the pale yellow, low-carotenoid Cavendish variety produces more of an enzyme, carotenoid cleavage dioxygenase 4 (CCD4), that breaks down carotenoids.

In addition, the orange Fe'i group Musa cultivar Asupina stashes its carotenoids in microscopic sacs during ripening, shifting the chemical equilibrium in the fruit so it can make even higher levels of these substances. The researchers say their work will provide insights for future developments in the biofortification and breeding of bananas that contain higher levels of carotenoids.

[1] Buah et al: The Quest for Golden Bananas: Investigating Carotenoid Regulation in a Fe'i Group Musa Cultivar in Journal of Agricultural and Food Chemistry – 2016 
[2] Nutritional Anemia: Edited by Klaus Krämer, Michael B. Zimmermann – 2007