Ripe Bananas - Another Cure For Cancer

Are Ripe Bananas The Cure For Cancer?

I’ve been seeing a lot on bananas lately on Facebook. If you have missed this post because you have friends who aren’t willing to believe everything they read, then well done. However, I have not been as fortunate. The post goes as follows:

“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.”

 

Is This True?

The story behind this took a little bit of tracing, but appears to arise from a study published here (or you can download the PDF for yourself here). First off, let’s hit the ‘science words’ used in this. Tumour Necrosis Factor is a cell signalling protein able to induce a wide range of immunological responses to combat diseases. If you happen to have access to this study, you will note that not once, ever, is it stated that bananas contain Tumour Necrosis Factor. 

Okay, so experimental design: The bananas were allowed to age for varying days to get a maturity level. The flesh of the banana was chopped up and centrifuged; the supernatant was then injected into mice. They then measured the amount of neutrophils, changes in macrophages and cytokine production (TNF’s) as well as dopamine and serotonin content in the banana. Essentially, they were trying to stimulate the production of TNF via the banana. Of course, there is a reaction and TNF activity is increased. There you have it. It is proven, the bananas cure cancer.

Hold on.

It isn’t exactly shocking TNF is produced. It is expected, even so much, they state it in their introduction:

“The immune system is an important biological defense mechanism and its balance is maintained by various factors. The immune system is affected by the nutritional state of the body and is impaired in states such as malnutrition. Therefore, to maintain an effective immune system, optimal nutrient intake is necessary.”

Anything that is in taken would, theoretically, induce a level of TNF to be produced. Let’s make this even clearer: I am talking about the human body here, a collection of cells working to produce a function: not the banana. This is the reaction of a normal immune system – maybe that is what the authors of the study were looking at, it isn't entirely clear why they did what they did. But no, someone has read that these bananas cure cancer, so it must be true. Furthermore, these scientists made no such claim of TNF being produced by a banana. That is simply an evolutionary impossibility. It is a protein that plays a huge role in the human immunological response system. A banana would have no need for TNF. I think the problem with these kinds of memes is the fact that they play on the words. Tumour Necrosis Factor implies that it will kill cancerous cells. Simply put; it does not. TNF doesn’t do what the name implies; it’s just pretty much its name. 

Bananas have been shown to produce serotonin and dopamine at different ripeness stages – these, in turn affect the production of the body’s natural defenses systems (neutrophils and macrophages). Thus, riper bananas MAY (cannot stress that word enough, seriously) induces a stimulation of white blood cells to help with your immune system. This effect is phenomenally small, it will (and I cannot stress this point enough) not fight off cancer. However, this small effect of a boost of immune system would only be prevalent in cases where the nutrition induced by a banana is lacking.

I’d also like to point out, as stated, this wasn’t easy to pinpoint – it’s the only study conducted, and it’s not without extraneous flaws. In the scientific community, we like science to be carried out properly. Extraordinary claims require extraordinary evidence, such as double blind clinical trials to show that bananas do indeed increase TNF – in humans, not in mice and certainly not in a banana. You would also have to consider the fact that IF they did contain this protein, your body would most likely destroy it. Just because your body requires it, doesn’t mean it will absorb. I have a disease in which my kidneys don’t absorb magnesium, thus I have a magnesium deficiency. I don’t eat things with more magnesium because I know it won’t be absorbed (lightly different, but you can abstract the picture).

Conclusion

Bananas can’t produce TNF, it’s a biological impossibility. Why would they need it? How many bananas do you see struggling through life, fighting off infection diseases? None. It doesn’t happen. The study was pointless, there was nothing to it, they just showed that banana took 10 days to turn black; even then, the conditions aren’t accounted for. I’m not saying bananas don’t have benefits, they have essential vitamins and dietary requirements required by the body; eat them, but if you expect it’s going to cure cancer, it simply will not. Propagating nonsense like this doesn’t help the situation, talking about how the science behind TNF works is fine, but they CLEARLY did not read the damn study. How hard is it to read?!

Now, I could have published 70% of this blog without even reading the paper, but that would have made me a bit hypocritical. Facebook is inundated with this kind of ‘science’ – which sometimes I enjoy reading, other times they are beyond absolute ridiculousness. If you are willing to believe something because someone has taken the time to create a meme for it, you need to re-evaluate your ability to question. We all like to think we have some form of natural defence mechanism for this kind of quackery and we aren’t gullible. This meme is something we see all the time, especially in investigative journalism, we see that journalists don’t read studies, but feel they can write an article entailing the science behind them and make absurd claims, even ones that aren’t concluded in the studies themselves. This is one of many of those, and I’m 100% sure this won’t be the last.