Question: why are over ripe bananas bad for you?
Answer: When a banana becomes too ripe, its peel turns a few shades darker. The dark spots on the peel create Tumor Necrosis Factor (TNF), a substance that can kill cancerous and abnormal cells, mentions healthy-holistic-living.com, in one of its articles. According to sun-gazing.com, an overripe banana works as an antacid.