Wednesday, January 17, 2007

Cancer patients warned off soy-rich foods

This will upset the Tofu brigade

Cancer patients are being warned to avoid foods rich in soy because they can accelerate the growth of tumours. The Cancer Council NSW will issue guidelines today, warning about the dangers of high-soy diets and soy supplements for cancer patients and those people in remission from cancer. At particular risk are people suffering from hormone-dependent cancers, including breast and prostate cancer - the two most common types of cancer in Australia. Cancer survivors are also being urged to avoid high doses of soy, as they may be more vulnerable to a relapse.

Research has found high consumption of soy products can also limit the effectiveness of conventional medicines used to treat the disease. "There is evidence to suggest that women with existing breast cancer or past breast cancer should be cautious in consuming large quantities of soy foods or phyto-oestrogen supplements," a position statement from the Cancer Council says. "Women with current or past breast cancer should be aware of the risks of potential tumour growth when taking soy products. "The Cancer Council does not support the use of health claims on food labels that suggest soy foods or phyto-oestrogens protect against the development of cancer."

Health experts are particularly concerned that breast-cancer sufferers who take soy or phyto-oestrogen supplements could feed the disease and reduce the effectiveness of their treatment. Soy, which is present in soy beans, soy milk, tofu, tempeh and some breads, contains phyto-oestrogens that mimic the actions of hormones in the body. This means it may interfere with cancer drugs such as Tamoxifen, which works by suppressing the female hormone oestrogen.

Men with prostate cancer are also being warned against high soy consumption, as phyto-oestrogens may imitate the male hormone androgen. Although the Cancer Council has warned against soy supplements, it believes an occasional intake of soy food is still safe for cancer patients. Cancer Council nutritionist Kathy Chapman said soy supplements could contain dangerously high doses of phyto-oestrogens. "If you were a woman with breast cancer and thought, 'I'm going to radically change my diet and have very large portions of soy at every meal', it could be a problem," Ms Chapman said. "For someone who has tofu once or twice a week and drinks a bit of soya milk, it's not so much of a problem."

Soy has earned a reputation as a natural "superfood" that cuts the risk of breast or prostate cancer, and is commonly included in women's health supplements. This claim was based on findings that cancer rates were lower in Asia, where soy consumption is high. But soy would lower the risk of contracting cancer "only a little", according to the Cancer Council. "While they may have a protective effect, there is also some evidence that phyto-oestrogens may stimulate the growth of existing hormone-dependent cancers," the council's statement said. The risk of contracting other non-hormone-dependent cancers, including bowel cancer, would be unaffected by soy intake.

The Cancer Council was prompted to investigate the issue after being inundated with questions about the role of soy in cancer patients' diets. "We felt we were getting a lot of calls on our hotline about this topic," Ms Chapman said.


The chewing gum that may aid slimming

An appetite-suppressing injection or even chewing gum could one day be used to tackle Britain's obesity problem. Scientists have been given funding to develop a treatment to help clinically obese patients to "feel full" and to eat less. The injection would contain a naturally occurring hormone that curbs appetite and is often lacking in overweight people. Within a decade the injection could provide the first effective treatment for obesity, which contributes to about 1,300 deaths a week in Britain, the scientists say.

The research, announced today, is among the first projects to benefit from a 91 million pound scheme by the Wellcome Trust to fund new medicines. It promises to be safer and more effective than present treatments, which culminate in drastic "stomach- stapling" operations. The hormone, pancreatic polypeptide (PP), is normally released from the small intestine as food is consumed, signalling to the brain that the body has had enough. In preliminary trials, an intravenous infusion that boosted levels of the hormone led to a big reduction in appetite among healthy volunteers.

Thirty-five healthy volunteers who were given the PP treatment consumed fewer calories, with the effect lasting for about 24 hours. Steve Bloom, who led the research at Imperial College and Hammersmith Hospital, London, said: "Even a 1 per cent reduction in appetite could lead to significant weight loss over a year." Professor Bloom has received a grant of 2.3 million pounds to develop the drug as a longer-lasting weekly injection. Other ways to administer the hormone could include a pump or even chewing gum, he said.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.

The use of extreme quintiles (fifths) to examine effects is in fact so common as to be almost universal but suggests to the experienced observer that the differences between the mean scores of the experimental and control groups were not statistically significant -- thus making the article concerned little more than an exercise in deception


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