Thursday, December 02, 2010

Five a day 'will not stop cancer'

Another blow at an official myth. The report below is still a bit credulous but it's a move in the right direction

Eating fresh fruit and vegetables will not protect you from cancer as they have little effect compared with alcohol and obesity, a study finds. Official guidelines recommend at least five portions of fruit and vegetables a day in order to be healthy but new research has found that this may not have a substantial effect on cancer.

The science suggests that people should be told that cancer risk is much more related to how much you eat and drink rather than what you eat.

The review, published in the British Journal of Cancer, looks at a decade of evidence on the links between fruit and vegetables and the development of cancer, but it concludes that the evidence is still not convincing. The only diet-related factors that definitely affect cancer risk are obesity and alcohol, they discovered.

Tobacco is still the single biggest cause of cancer. While smoking increases the risk of cancer by as much as 50 fold, even large consumptions of fruit and veg will only reduce the risk by a maximum of 10 per cent.

Professor Tim Key, an epidemiologist from Oxford University, said that while there are undoubted benefits in eating fruit and vegetables there is little hard evidence that they protect against cancer. But the evidence is indisputable that cancer is strongly linked to being overweight or obese, and drinking more alcohol than the recommended daily limits.

He said: “Fruit and vegetables are an important part of a healthy diet and a good source of nutrients. "But so far the data does not prove that eating increased amounts of fruit and vegetables offers much protection against cancer. “But there’s strong scientific evidence to show that, after smoking, being overweight and alcohol are two of the biggest cancer risks.”

Overweight people produce higher levels of certain hormones than people of a healthy weight and this can contribute to an increased risk of breast cancer. Being overweight can increase your risk of other common cancers like bowel and also hard-to-treat forms of the disease like pancreatic, oesophageal and kidney cancer.

When alcohol is broken down by the body it produces a chemical which can damage cells increasing the risk of mouth, throat, breast, bowel and liver cancers. In the UK 15,000 cases of cancer are caused by alcohol, it is believed, and 19,000 cases of cancer are caused by being overweight or obese.

Sara Hiom, director of health information at Cancer Research UK, said: “Too few people know about the significant cancer risks associated with obesity and drinking too much alcohol. "While stopping smoking remains the best way to cut your chances of developing cancer, the importance of keeping a healthy weight and cutting down on alcohol shouldn’t be overlooked. “Keeping alcohol intake to a maximum of one small drink a day for women and two small drinks per day for men and keeping weight within the healthy limits can have an enormous impact.”

The British research mirrors the findings of an American study published in April. For every extra two portions consumed the risk of cancer reduced by just three per cent, the research conducted by a team at Mount Sinai School of Medicine, in New York suggested.


Finger length is a marker for risk of prostate cancer

This does seem a bit bizarre but finger length has long been known to relate to various indices of masculinity

Men whose index fingers are longer than their ring fingers are much less likely to develop prostate cancer, a new study suggests. The association is so strong that researchers believe the simple test could be part of a screening process for the disease.

The study led by The University of Warwick and The Institute of Cancer Research (ICR) found men whose index finger is longer than their ring finger were one third less likely to develop the disease in their lifetime than men with the opposite finger lengths.

When it comes to the risk of developing the disease before they are 60 the link was even greater with longer index fingered men having 87 per cent less chance. “Our results show that relative finger length could be used as a simple test for prostate cancer risk, particularly in men aged under 60,” said the joint author Professor Ros Eeles from the ICR and The Royal Marsden NHS Foundation Trust. “This exciting finding means that finger pattern could potentially be used to select at-risk men for ongoing screening, perhaps in combination with other factors such as family history or genetic testing.”

For a 15 year period from 1994 to 2009, the researchers quizzed more than 1,500 prostate cancer patients along with more than 3,000 healthy cases. The men were shown a series of pictures of different finger length patterns and asked to identify the one most similar to their own right hand. The most common finger length pattern, seen in more than half the men in the study, was a shorter index than ring finger.

Men whose index and ring fingers were the same length (about 19 per cent) had a similar prostate cancer risk, but men whose index fingers were longer than their ring finger were 33 per cent less likely to have prostate cancer, a disease which kills 10,000 people a year in Britain. Risk reduction was even greater in men aged under 60 years– these men were 87 per cent less likely to be in the prostate cancer group.

The relative length of index and ring fingers is set before birth, and is thought to relate to the levels of the sex hormone testosterone the baby is exposed to in the womb. Less testosterone equates to a longer index finger, the researchers now believe that being exposed to less testosterone before birth helps protect against prostate cancer later in life.

Previous studies have found a link between exposure to hormones while in the womb and the development of other diseases, including breast cancer (linked to higher prenatal oestrogen exposure) and osteoarthritis (linked to having an index finger shorter than ring finger). Testosterone is known to be a driver of prostate disease once it has taken hold but this suggests it is also a major cause.

Professor Ken Muir, co-author from the University of Warwick, said: "Our study indicates it is the hormone levels that babies are exposed to in the womb that can have an effect decades later. "As our research continues, we will be able to look at a further range of factors that may be involved in the make-up of the disease."

Emma Halls, Chief Executive of Prostate Action, which helped fund the work published in the British Journal of Cancer, said: "This research brings us another step closer to helping determine risk factors for prostate cancer, which is possibly the biggest issue in current thinking about preventing and treating the disease. "However, we are still a long way from reducing the number of men who die of prostate cancer every year and need more research and education in all areas to achieve this."


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