Banana for Cancer: Myths and Facts

Do bananas really cure cancer or its just a myth? Read the actual study by the scientists and the facts. As per social posts some believe the bananas can boost immune system to fight the cancer. Let's learn the actual facts and the myths.

The Myth

• Social media like Facebook is filled with false memes on just about everything from vaccines to Monsanto. For more than a year, there have been dozens of photos of bananas with a few words that some Japanese scientists claim that ripe bananas have high levels of "Tumour Necrosis Factor", so eat ripe bananas to boost your immune system, thereby preventing or curing cancer. Facebook is famous for these things, little pictures with a few words, no sources of the information, and broad conclusions.
• Eat bananas. Cure cancer. And people blindly share them with a click of the button without trying to know the real facts.
• The actual study was published here (pdf) (or here, also pdf) in Food Science and Technology Research in 2009.
• The authors do not make one single claim (as best as I can tell) that there is tumour necrosis factor (TNF) in a banana. This article does not say anything about bananas having TNF. 
• Tumor Necrosis Factor (TNF) is a fairly complex protein, with a highly specific role in the human immune system (something notably lacking in a plant), so the chances that a banana would have some substance that exactly copies TNF is so tiny as to be close to impossible. 
• Even if we could assume that a banana makes TNF, the digestive tract would break down the complex proteins and substances, such as TNF, into its constituent components, such as amino acids, simple sugars, and fats, before being absorbed into the bloodstream. The TNF probably wouldn’t survive intact within the digestive tract. 

The Facts

• Bananas produce small amounts of serotonin (5-hydroxy tryptamine) and dopamine, depending on their stage of ripeness. 
• These can have a stimulatory effect on neutrophils and macrophages in a living organism, and these can in turn produce the touted TNF-a, Interleukin-12 (IL-12) and other cytokines (signal molecules for part of the immune system reaction to antigens). 
• In this role, serotonin and dopamine are said to serve as a “biological response modifier” (BRM). 
• In plain English, the stuff in ripe bananas can (but not necessarily will) stimulate a subset of white blood cells to produce chemical signals to deal with a variety of threats. 
• However, this is a small effect, and it will not help you fight off cancer. Bananas cannot stimulate or boost the immune system unless there’s some chronic malnutrition or disorder where you need to get more nutrition that bananas are adequate in providing. But, in healthy individuals, only vaccines can boost your immune system.