Called the 'karat' because of its bright orange flesh, the fat banana has been used for centuries in Micronesia to wean infants onto solid food but today imported foods have swamped its use.
According to an article in the New Scientist this week, a screening programme sponsored by the agriculture ministry of Pohnpei, a Micronesian island, has established that the karat is unusually rich in beta-carotene, which the body converts into vitamin A.
The hope is that the fruit could now be routinely given to children deficient in this vitamin, to help them avoid developing certain kinds of blindness and to lower childhood mortality.
Vitamin A is essential to health and is generally acquired by humans in a healthy diet. Deficiency of the vitamin is a major contributor to childhood mortality but the provision of high dose vitamin A supplementation every 4-6 months not only protects against blindness but also has a significant impact on the health of children 6-59 months of age, reducing the risk of dying from all causes by 23 per cent, according to the World Health Organisation.
Notwithstanding the high beta-carotene levels, the 'karat', like other bananas, is packed with potassium, a range of B vitamins - thiamine, riboflavin and niacin and folic acid - as well as calcium and magnesium.
The New Scientist reports that Lois Englberger of the Island Food Community of Pohnpei and Adelino Lorens of the Pohnpei ministry of agriculture screened 21 cultivars of native banana all selected for their deeply hued yellow, orange or red flesh, a result of high levels of carotenoids.
They found that 15 of them contained enough carotenoids to supply half of the recommended daily intake of vitamin A, if consumed as part of a typical diet. The karat was the most promising cultivar studied, and had more than 25 times as much beta-carotene as the traditional Cavendish banana.
According to the scientists, steam-boiling karats makes more carotenoids available to the body but they can also be eaten ripe and raw, said Englberger, who presented her findings this week in Penang, Malaysia, at an international conference on bananas and plantains.