A Key to Prevent Cancer is Shown to be False
The likelihood of developing cancer is largely attributed to an individual's genetic inheritance, but can also be affected by lifestyle choices and what we eat. In a 2009 article, the American Cancer Society recommended eating at least five servings of fruits and vegetables per day to prevent cancer. Now, a new study from the University of Oxford suggests that fruits and vegetables, while important for a healthy diet, are unlikely to protect against cancer.
The study, published in the British Journal of Cancer, examined evidence from the last decade for the connection between the consumption of fruits and vegetables and cancer development. The researchers concluded that the only diet-related factors to affect the risk of cancer were obesity and alcohol. Tobacco smoke, technically not diet-related, remains the single largest cause of cancer.
According to Tim Key of the Cancer Epidemiology Unit at Oxford University, "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."
Obesity can cause very difficult-to-treat forms of cancer in the bowel, pancreas, kidney, esophagus, and breast. Alcohol can cause cancer of the mouth, throat, breast, bowel, and of course, liver.
The researchers stress that the best ways to prevent cancer is keep a healthy weight, stop smoking, and limiting alcohol to one drink per day for women and two for men. Eating fruits and vegetables up to a certain level is essential for the body to obtain vital nutrients.
However, as the law of diminishing returns dictates, consumption exceeding that certain level provides fewer, if any, benefits. It does not make the tissues super-healthy or indestructible. So while the American Cancer Society is not giving bad advice, it may have to change its message in light of new evidence.
Link to published article: http://www.nature.com/bjc/journal/v101/n1/abs/6605098a.html