BANANAS for CANCER / Banane z temnimi pegami – proti raku !

BANANAS PREVENT CANCER – JUST ANOTHER MYTH

This article about bananas prevent cancer is a rewrite of one I published almost four years ago, and that was subsequently written into a new article. Despite it’s age, it still ranks as the 8th out of 12 most read articles on this website in 2015. And people still believe bananas prevent cancer – it’s still a myth.

I wrote an article about how to critically analyze pseudoscience and misinformation so that you might skeptically analyze evidence supporting a claim, even if it appeared to be accurate. On Facebook, Twitter and many internet sites (including Wikipedia), there is an amazing tendency of individuals to accept what is written as “the truth” without spending the effort to determine if what is written is based on accurate science.

Twitter, of course, limits itself to 140 characters, which means you either have to click on a link to get more information, or just accept that what is stated within the 140 characters is factual. And if you can make a complex scientific argument in 140 characters, that would be impressive.

Bananas prevent cancer memes

Facebook is filled with false memes on just about everything from vaccines to Monsanto. The anti-vaccination crowd fills Facebook with their amusing and highly inaccurate memes, which only leads to people thinking they’ve done their research, and not vaccinating their kids. 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 “tumor 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 share them with a click of the button and move on to the next cute cat picture. It’s really the lazy person’s way of learning. Although who doesn’t enjoy the cute cat pictures?

But what are the facts? What can bananas do nor not do? Let’s start at the beginning.

The mysterious Japanese Study

 The actual study was published here (pdf) (or here, also pdf) in Food Science and Technology Research in 2009.  I have several issues with the article with respect to the banana meme, especially in trying to make any conclusion that bananas have anything to do with “curing cancer” in humans:

1. The authors do not make one single claim (as best as I can tell) that there is tumor necrosis factor (TNF) in a banana. No, this article does not say anything about bananas having TNF. Really, nothing else I write about this article really matters, because they just don’t make any claim whatsoever about TNF and bananas.
2. The study is in a mouse model, and many animal model experiments just don’t transfer to human clinical research. The percentage of animal studies being applicable to humans is small, that’s why there’s the old joke that “we’ve cured cancer in mice thousands of times.” So, even if the authors claimed that bananas had TNF (and that would be Nobel Prize winning research), we have no clue as to whether it has any clinical impact. But let’s not forget that the authors make not a single claim that TNF is in bananas.
3. The article is published in a low impact journal. This journal has an impact factor of less than 1.0, which indicates a very low quality journal and it’s not even indexed in PubMed, which further indicates its low value.
4. The bananas are not fed to the mice, and without getting into details about the study, they try to stimulate production of TNF by essentially placing slices of banana in the mouse–of course, there will be an inflammatory response. Shocking. I am not sure why the authors did that, and I am unclear what it is supposed to prove. That it induces TNF activity might be expected since the body would react to any foreign substance (an apple, viruses, bacteria, anything) injected into the peritoneum, and production of TNF might be expected. But the TNF does not flow out of the banana, it is just the immune system’s reaction to a banana injected into the body.
5. What is the clinical significance of what was induced? In other words, is there actually TNF isolated from the bananas in a form that actually can do something? Or is there some other effect just because there’s a blob of intraperitoneal banana extract which induces some other immune response.
6. 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. 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. But let’s clear about this. 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.
7. No one has repeated this experiment, and certainly no one has shown this effect in humans. There is not a single double-blind clinical trial to show that bananas induce a TNF-alpha response in humans. And one more point to remember: bananas do not produce TNF. It is simply an evolutionary impossibility, unless through some amazing instance of evolutionary convergence, the banana plant evolved the ability to produce the TNF molecule for a completely different purpose for the banana plant. This would violate several principles of evolution, since there are reasons why the TNF molecule evolved in mammals and not in plants.

Just for review–I dug up the original “Japanese scientific paper”, and what I found was essentially simple–the authors did not claim bananas produce TNF, but that wasn’t even the point of the article. The article actually didn’t show much, but it did not provide any convincing evidence that in humans, bananas had any effect on the immune system. Again, unless that human is chronically malnourished.

http://www.skepticalraptor.com/skepticalraptorblog.php/ripe-bananas-prevent-cancer/

Banane z temnimi pegami – proti raku!      www.derbybanane.si

Ko smo bili mladi, je bilo rečeno, da so banane z rjavimi pegami boljše. Znanstveniki šele sedaj odkrivajo, kar so naše babice vedele že 100 let nazaj. 

Popolnoma zrele banane proizvajajo snov TNF ki ima sposobnost, da se bori z nenormalnimi celicami. Ne bodite presenečeni, ko bodo police z bananami v trgovinah prazne. Medtem, ko banana zori, ustvarja temne lise na olupku. Več bo temnih peg, boljše bo to za odpornost oz, imunski sistem. 

Zato imajo Japonci radi banane iz upravičenih razlogov. V skladu z japonsko znanstveno raziskavo, banana vsebuje TNF, ki ima antikancerogene učinke. Raven antikancerogenih učinkov ustreza stopnji zrelosti sadeža – bolj ko je banana zrela, boljši je antikancerogeni učinek. 

V poskusu z živalmi, ki se izvajajo na univerzi v Tokiu, kjer preverjajo zdravilne lastnosti različnih sadežev: banane, grozdje, jabolka, lubenice, ananas, hruške, jabolka in japonska jabolka. 
Ugotovili so da, da banana daje najboljše rezultate. Povečuje število belih krvničk in izboljšuje odpornost proti raku, ker vsebuje antikancerogeno substanco TNF. 
Priporočajo, da se poje 1-2 banani na dan za dvig odpornosti proti boleznim, kot so prehladi, gripe in drugo.. 

Po mnenju japonskih profesorjev je banana z rjavimi pegami 8 krat bolj učinkovita v izboljšanju belih krvnih telesc kot zelena lupina.

vir :http://med.over.net/forum5/viewtopic.php?t=8318180