BBC News Online
London, UK
8 April, 2007


Fat hormone 'boosts colon cancer'

A chemical produced by fat cells makes colon cancers grow faster, a US study has suggested.

The British Journal of Surgery study could help explain why severely overweight people appear to be at far greater risk of the disease.

A team at the University of California, San Diego found that the hormone leptin triggered increased growth in human colon cancer cells.

Obese people are up to three times more likely to develop colorectal cancer.

Other researchers have already found that some colon cancer cells appear to be set up to respond to leptin, with "receptors" for the chemical on their surfaces.

The more fat cells a person has, the more leptin will be in their bloodstream.

The San Diego team wanted to find further evidence of the link by watching what happened to human cancer cells exposed to the hormone.

In a laboratory, they added the hormone to different varieties of cancer cell.

Growth was stimulated in all the cell lines - and in two out of three tested, the hormone also hampered the usual process of programmed death that allows the body to replace normal cells, but which often malfunctions in cancers.

Dr Kim Barrett, who led the research, said: "These results may explain why obesity increases a person's risk of colonic cancer.

"The fact we have shown how leptin stimulates these cells means that drug companies may be in a better position to develop new treatments against the disease."

Obesity increasing

In the UK it is currently estimated that one in five men and a quarter of women are obese, with as many as 30,000 people a year dying prematurely from obesity-related conditions, including cancers.

Britain now has the most obese population in Europe.

A study published this week suggested that severely obese men doubled their risk of dying from prostate cancer, and obesity is also believed to increase the chance of developing breast cancer.

Professor Alan Clarke said: "This research builds on previous work suggesting that leptin, a hormone released from fat cells, may play a role in the link between obesity and cancer.

"The researchers have shown that leptin is involved in two molecular pathways known to play a role in bowel cancer development."

"Although at an early stage, the findings shed light both on the development of bowel cancer and the link between obesity and cancer."

http://news.bbc.co.uk/1/hi/health/6529677.stm

How about looking at the ammount of sugar people eat instead of "dancing around" looking at everything else that "may increase the risk" of having cancer

Cancer cells feed off sugar, too much sugar makes people fat, therefore.......

Just my opinion

I've recently heard this is a myth. Is that true??

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How about get a clue already and realize it isn't all about the amount of sugar people eat.



Cancer cells need growth factors, which can be increased and decrease because of many factors, and not just because of sugar. Excess energy intake is the cause of obesity. Higher protein and energy intake will make IGF-1 go up, you know many cancer treatments now target IGF-1r to stop cancer?

Cytokines secreted from adipose tissue cause chronic inflammation, leading to increase TGF-b level, which is a growth factor required for normal and abnormal cancer cells, and thus increases the metastasis and aggressiveness and growth of cancer cells.

So just having extra fat COULD be a risk factor. You can increase body fat by eating more calories than you burn, by being in a positive energy balance. Carbohydrates will NOT cause obesity if you do not go over your daily calorie needs. Even if your diet was 90% carbs.

Gee, Whoa. I wouldn't think this would set you off. Sugar is about the least nutritious thing on the planet. And eating a lot of sugar also packs a lot of calories. I'd think that'd be right up your alley.

Cough*BULLSH!T*Cough.

Cancer cells feed off sugar, but they also have an appetite for folate too, and many other nutrients and growth factors. It isn't all about sugar and thinking it is, is just pure ignorance. Cancer cells, tumors, will take the glucose from your blood anyhow, regardless. High insulin and glucose from ingestion of unrefined carbs is the problem... Carbs in general, like those from veggies and wholegrains are not the problem. Eating beef gives a bigger release of insulin than eating low GI whole grains or legumes.

I have no doubt that cancer cells love sugar, but its not the only factor in the development and growth stages.

Not 100% sure but most human cells can use glucose or ketones to survive, but cancer cells seem to only be able to use glucose. You're never without glucose in your blood, you would die if you didn't have it.

So it is conceivable that if cancer cells can't get enough glucose they won't be able to thrive. There's some researcher at the University of Alberta looking into a way to switch the body's cells to using ketones instead. The cancer cells will hopefully die because they can't get the energy they need.

I don't know if this is true of all cancers or just some.

There is some credibility to the theory that having high blood sugars gives any cancers you might have a lot of fuel to work with.

I once saw a mystery diagnosis about a guy who had a huge cancerous tumour (undiagnosed) that was sucking all the glucose out of him. Like a sugar-vampire. He'd get this horrible low blood sugar and nearly died from that. But his cancer was doing some very bizarre things.

Where did you get that idea Matt? Perhaps you should actually take a look at the insulin index

http://www.mendosa.com/insulin_index.htm

Peanuts, porridge white and brown pasta indeed have less insulemic effect than beef. Every other vegetable, grain, and legume tested, high or low GI, was higher. Besides theres the pesky little detail which you always seem to miraculously forget in regard to protein metabolism is that dietary protein, while eliciting some insulin response, also elicits an equal and balancing glucagon response, to eliminate the blood sugar lowering effect of insulin.

Here is a good paper on glucose and Insulin response for various foods. Full PDF file is free.

An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods

The aim of this study was to systematically compare postprandial insulin responses to isoenergetic 1000-kJ (240-kcal) portions of several common foods. Correlations with nutrient content were determined. Thirty-eight foods separated into six food categories (fruit, bakery products, snacks, carbohydrate-rich foods, protein-rich foods, and breakfast cereals) were fed to groups of 11-13 healthy subjects. Finger-prick blood samples were obtained every 15 min over 120 min. An insulin score was calculated from the area under the insulin response curve for each food with use of white bread as the reference food (score = 100%). Significant differences in insulin score were found both within and among the food categories and also among foods containing a similar amount of carbohydrate. Overall, glucose and insulin scores were highly correlated (r = 0.70, P < 0.001, n = 38). However, protein-rich foods and bakery products (rich in fat and refined carbohydrate) elicited insulin responses that were disproportionately higher than their glycemic responses. Total carbohydrate (r = 0.39, P < 0.05, n = 36) and sugar (r = 0.36, P < 0.05, n = 36) contents were positively related to the mean insulin scores, whereas fat (r = -0.27, NS, n = 36) and protein (r = -0.24, NS, n = 38) contents were negatively related. Consideration of insulin scores may be relevant to the dietary management and pathogenesis of non-insulin-dependent diabetes mellitus and hyperlipidemia and may help increase the accuracy of estimating preprandial insulin requirements.

good grief everyone seems grumpy today LOL!

My point really was that "they" keep trying to dig up new causes for cancer and some of their ideas are so tenuous. Why not look at the ammount of sugar the nation eats nowadays, afterall its one of the reasons why we are becoming so obese and we sure as hell dont need anywhere near the ammounts that the average person eats. I think its safe to say we overdose on it big time! That cant be good

There are quite a few studies proving that cancer thrives well on sugar, but this never really comes to light. How true is it??? Well who knows anything anymore, studies seem to prove whatever you want them to. But I certainly think there's a corralation.

But then of course, then there's all the chemicals and processed foods we eat, not to mention hereditary links.........

Here is some more light reading.
http://www.lowcarbluxury.com/newsle...3-no04-pg2.html

When ingesting carbs, the insulin response is important as the pancreas doesn't output any glucagon. When ingesting proteins, it is the insulin and glucagon response that are important.

Even if protein does cause an insulin release it doesn't cause a blip in the glucose, right? Insulin is needed, or so I've been told, to get the protein into cells.

just out of interest, both my parents died of colon cancer and most of their siblings. My mum was a veggie since she was a child, cos she just didnt like the taste or texture of meat, in fact she wasnt a big eater at all. My dad ate anything and everything, but in moderation

I've often tried to work out a link between them and their families as to why there is so much cancer in our family. I had one aunt that had no cancer and died from a stroke at 98 and she was the only smoker in the family. So i could say that smoking was the preventitive????

You see how silly it all gets??? Thats why I take very little notice of all the contradictary science and studies. I have my colonoscopy every two years and enjoy my life!

That's correct, Nancy. Because glucagon and insulin are released together in that instance and counteract each other, blood sugar remains stable.



Correct again! Insulin is an important part of protein anabolism in the body.