Many Local Bananas are Vitamin A-rich

by Dr. Lois Englberger

The Karat Banana is not the only local vitamin A-rich banana, there are 10 others identified so far. This is important because these bananas protect against vitamin A deficiency disorders and also diabetes, heart disease, and certain cancers.

Some of the bananas are rare like Karat, Utin Yap, and Ihpali (in Kosrae Usr Kulasr, Kolontol, and Usr Wac es Sie), but there is one vitamin A-rich banana that is very common, Taiwang. This banana has a low status because it is so available and is often used for feeding the pigs but in Kosrae it is also valued for making the traditional fafa dish because it is very sweet and tasty.

The substances in plant foods that convert to vitamin A in the body are called carotenoids. Epidemiological research shows that carotenoid-rich foods protect against a number of chronic diseases, including diabetes, heart disease, and certain cancers. So these local carotenoid-rich foods provide double benefits, against vitamin A deficiency and chronic diseases.

In 1998, the Karat banana was the first of the bananas in the Federated States of Micronesia to be analyzed. Then a series of analyses of 16 banana varieties were analysed from the year 2000 to 2002 for different nutrients. All bananas were from Pohnpei and Kosrae, except one banana from Chuuk. The analyses were carried out at five laboratories, the Cancer Research Center of Hawaii, Honolulu, Hawaii; University of the South Pacific, Suva, Fiji; Roche Vitamins Ltd, Basel, Switzerland; Covance Laboratory, Madison, Wisconsin; and Food and Drug Administration Atlanta Center of Nutrient Analysis, Atlanta, Georgia.

Yellow and orange coloration of the edible portion of the banana was very much related to the amount of carotenoid contained. Those banana varieties with a deeper yellow or orange coloration had a higher carotenoid content. For example, Utin Yap has the darkest coloration of all, and it had by far the highest carotenoid content. This means that people in the community can use coloration of the banana flesh as a rough indicator of the carotenoid content.

What about rice? How much of provitamin A carotenoid does it contain? Absolutely none, zero!!! Also wheat flour and rice contain no provitamin A carotenoid. All bananas (and other local foods like taro and breadfruit) contain at least some carotenoids, so all the local foods provide some protection against vitamin A deficiency, diabetes, heart disease, and cancer, whereas rice does not provide that benefit.

Diabetes particularly is an increasingly serious problem in the community. One report showed that over 90% of the surgical admissions in the Kosrae State Hospital were from diabetes-related complications. Vitamin A deficiency disorders include problems with vision and eye health, but also involve increased rates of many kinds of infections, particularly skin, respiratory, and diarrheal infections.

Thus, there is great potential in consuming many local vitamin A- and carotenoid-rich bananas for protecting against these health problems. See table below.

Results of analyses carried out by USP, Covance, and Roche laboratories. Most samples were cooked.

1. Most names are from Pohnpei or Kosrae. Yap and Chuuk names are provided for Karat.
2. Stover and Simmonds classification by genome and subgroup
3. Color of edible portion by visual comparison
4. Sum of beta-carotene (the carotenoid contributing most to vitamin A status) and half of alpha-carotene (its vitamin A activity is half that of beta-carotene). Beta-carotene equivalents then can be converted to Retinol Equivalents, for comparing to estimated daily requirements of vitamin A (retinol). About ½ cup of banana equals 100 gram (g). A small banana may weigh between 60-100 g and some Karat bananas weigh 200 g.