You probably know that bananas contain nutrients like potassium, fiber, vitamins C and B6 — all of which support heart health.But bananas actually contain thousands of different compounds, as hinted by the graph below, depicting results of a Dole-sponsored analysis of banana flesh.

Such research adds to a growing body of knowledge about bananas and the nutrients they contain.For example, here are four little known facts about banana nutrients that are bound to surprise you.

1. Bananas boost iron absorption. Bananas are a top source of prebiotic fiber, which increased iron absorption by 28% in one Cornell University animal study.Bananas are also an excellent source of vitamin C, which helps “prep” iron in plant sourcesfor absorption.The absorption effect only works when the vitamin C and iron sources are consumed together.
2. Bananas & boy baby gender. Dietary research on potassium intakes during pregnancy may bolster the old wives’ tale linking bananas with having boys.Compared to those who gave birth to girls, mothers of boys consumed 300mg more potassium, on average per day.One banana contains 450mg potassium.
3. Bananas preserve muscle mass. Potassium, this time on the other side of the age spectrum: Seniors with higher potassium intakes had more lean muscle massthan their potassium-poor peers.Researchers believe the metabolic by-products of potassium help to maintain the body’s alkaline balance, counteracting excess acidity.
4. Bananas fiber may stimulate fat metabolism.Bananas contain resistant starch, which ferments in your large intestine, creating by-products (butyrates) that block conversion of some carbohydrates into fat.

Bonus: Bananas’ prebiotic fiber also helps curb hunger.