According to Japanese Scientific Research, full ripe banana with dark patches on yellow skin produces a substance called TNF (Tumor Necrosis Factor) which has the ability to combat abnormal cells. The more darker patches it has the higher will be its immunity enhancement quality; Hence, the riper the banana the better the anti-cancer quality. Yellow skin banana with dark spots on it is 8x more effective in enhancing the property of white blood cells than green skin version.
As a banana ripens and turns yellow, its levels of antioxidants increases. These antioxidants in ripe bananas protect your body against cancer and heart diseases.
Eating 1-2 bananas a day increases immunity.