Monday, August 27, 2007

Eating healthy fruit, vegetables won't stop cancer

This has been known for years (e.g here). It's just that people do not want to believe it. It gives people a sense of power to think that what they put in their mouth matters. The researchers below are not bold enough to tell the whole truth about "obesity", though -- that it is only the grossly obese who are at slightly higher risk

FRUIT and vegetables provide no protection against cancer, according to latest Australian research that has shocked nutritionists. In a discovery that turns conventional advice on its head, experts have admitted there is "zero evidence'' that eating fruit and vegetables can help people avoid a disease that kills nearly 40,000 Australians every year.

Research presented for the first time at last week's CSIRO Prospects for Cancer Prevention Symposium shows that what people eat is far less important in cancer prevention than previously believed. Instead, the three prime risk factors driving up Australian cancer rates have been identified as obesity, drinking too much alcohol and smoking. Staying within a healthy body weight range was found to be more important than following particular nutritional guidelines. This means a slim person who doesn't eat enough fruit and vegetables would probably have a lower risk of developing cancer than someone who is overweight but eats the recommended daily amount of fruit and vegetables.

The findings emerged from the Cancer Council's Melbourne Collaborative Cohort Study, an ongoing research project involving 42,000 Australians who have been monitored since 1990. Revealed exclusively to The Sunday Telegraph, they challenge widespread belief in the power of juices and vegetable-based ``anti-cancer'' diets to avoid or fight various types of the disease.

Dr Peter Clifton, director of the CSIRO's Nutrition Clinic, told The Sunday Telegraph there was ``zero evidence'' that eating fruit and vegetables could protect against cancer. Heart disease is Australia's biggest killer, so fruit and vegetables are still regarded as important in maintaining health. Professor Dallas English, of the Cancer Council of Victoria, told the symposium that despite decades of research, there was no convincing evidence on how Australians could modify their diet to reduce the risk of cancer. ``The most important thing about diet is limiting energy (kilojoule) intake so people don't become overweight or obese, because this has emerged as a risk factor for a number of cancers, including breast, prostate, bowel and endometrial (uterus),'' he said. The link between eating red meat and bowel cancer was ``weak'' and the Cancer Council supported guidelines advising people to eat red meat three or four times a week, Professor English said. His advice comes after Health Minister Tony Abbott last week backed a report, funded by Meat & Livestock Australia, on the dietary role of red meat.

Surprisingly, fibre was deemed to have no significant benefit in avoiding bowel cancer _ although calcium was associated with a 20 per cent reduced risk. Likewise, a high intake of fat, considered a prime culprit since the 1970s, was found to have only a ``modest'' link to breast cancer. Smoking caused one in five cancer deaths, while regularly drinking too much alcohol boosted the risk of several cancers including breast and bowel, Professor English said.

He and Dr Clifton acknowledged that eating fruit and vegetables might help people avoid obesity, as they were lower in kilojoules than other foods. ``The risk of every type of cancer is increased by obesity,'' Dr Clifton added. Both experts predict a surge in cancer as a result of Australia's obesity epidemic, but say exercise can play a vital role in cutting cancer rates, potentially halving the risk of some cancers.


The "Mindfit" claim

Don't line the pockets of the lady below until an independently replicated double-blind evaluation of it emerges in the journals. It's theoretically possible that it is helpful but my guess would be that the effects in adults are marginal and temporary

Baroness Susan Greenfield, the neuroscientist, is to launch an exercise programme for the brain that she claims is proven to reverse the mental decline associated with ageing. Greenfield, who is also director of the Royal Institution, maintains that Britain's baby-boomers are discovering that concentrating on physical fitness is no longer sufficient preparation for old age. "What concerns me is preserving the brain too," she said. "There is now good scientific evidence to show that exercising the brain can slow, delay and protect against age-related decline."

Greenfield will launch MindFit, a PC-based software program, at the House of Lords next month, for the "worried but well" - people in their middle years who are healthy and want to stay that way. Created by researchers in Israel and already on sale in America, it offers users inter-active puzzles and tasks that are claimed to stimulate the brain just as using a gym exercises the body's muscles. "There is evidence that such stimulation prompts brain cells to start branching out and form new connections with other cells," said Greenfield.

The baroness's decision to lend her name to MindFit and to take a significant stake in Mind-Weavers, the company promoting it, could raise eyebrows among fellow scientists. Her high profile in the media has rankled with some and she was twice snubbed by the Royal Society.

The idea that the performance of the brain can be improved by exercises or potions has a long and controversial history. There have also been scientific battles over the claims made for dietary supplements, especially fish oils, and so-called smart drugs. The latter have been shown to cause a short-term increase in IQ but the long-term secondary effects are unknown.

Greenfield's decision to promote MindFit, which will retail for around 70 pounds, follows the release of new scientific research apparently showing clear benefits. In the latest research, conducted at the Sourasky Medical Centre at Tel Aviv University in Israel, 121 volunteers aged over 50 were asked to spend 30 minutes, three times a week, on the computer, over a period of two years. Half were assigned to use MindFit and the other half played sophisticated computer games. The results, released at a recent academic conference and due for formal publication shortly, showed that while all the volunteers benefited from using computer games, the MindFit users "experienced significantly greater improvement in short-term memory, visuo-spatial learning and focused attention".

Greenfield, who also runs an Oxford University laboratory researching the causes of degenerative brain diseases such as Alzheimer's, found out about MindFit through her extensive links with Israel and decided to bring it to Britain. "It is clear that there is no drug on the horizon to treat Alzheimer's or age-related mental decline so I have long been interested in seeing whether stimulating the brain might offer a way of Greenfield is launching a program designed in Israel. Kidman, left, is the new face of Nintendo, which already sells Brain Training games slowing down these changes," she said.

Other researchers are also convinced that people can rejuvenate their brain with exercise. Ryuta Kawashima, professor of neuroscience at Tohoku University in Japan, spent 15 years investigating how mental exertion helps the brain grow. His work became the basis of the Brain Training and More Brain Training computer games, produced by Nintendo, the console manufacturer. Nicole Kidman, the actress, fronts its latest British advertising campaign. Nintendo itself makes no formal scientific claims for the programs but Kawashima said in a recent book: "My brain exercises increase the delivery of oxygen, blood and various amino acids to the prefrontal cortex. The result is more neurons and neural connections, which are characteristics of a healthy brain."

Other researchers accept such ideas in principle but warn that any system claiming to boost mental ability must prove itself in clinical trials.



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.


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