A banana that is completely ripe produces a substance called tumor necrosis factor.
TNF is able to destroy the abnormal cells in the body. As the banana becomes riper, dark dots start to appear.
A banana with more dots is more effective in improving the function of the immune system.
When bananas are ripe they can be easily digested as it is easy to absorb sugar. On the other side, harder bananas cannot be digested easily as the starch is still not converted into sugar.
Bananas also have more anti-cancer properties when they are riper.
According to studies, bananas also posses more anticancer agents than pears, grapes, watermelons and apples.