A recent book, The Chine Study, by Dr. Colin Campbell, outlines how their team's research indicates that an enzyme in animal protein acts as a catalyst on human cells to cause cancer. It operates in a manner allowing cells to receive carcinogens; whereas tumors reduced in size when subjects ate plant proteins like wheat gluten.

The following article shows that only two ounces of meat per day had a meassurable effect in breast cancer.

Eating even small amounts of red meat daily can increase the risk of breast cancer by 56 per cent in older women, according to British research published today.
As little as 2oz (57g) of beef, lamb or pork a day showed an effect. Post-menopausal woman who ate larger amounts, 3.6oz (103g), of processed meats such as sausage, bacon, ham or pies had an increased risk of 64 per cent.
Even younger, pre-menopausal women had a slightly raised risk if they ate red meat daily, the study from the University of Sheffield found.
The research, led by Prof Janet Cade, a professor of nutritional epidemiology and public health, involved 35,000 women aged between 35 and 69 who have been followed for nearly eight years.
The women all of whom completed 217-item food questionnaires, were divided into three groups depending on whether they were high, medium or low meat eaters. They were compared with women in the sample who were vegetarian.
The researchers took into account smoking, weight, fruit and vegetable intake, class, education and use of hormone replacement therapy.
"The findings are robust. Whatever we adjusted the data for we could still find an association," Prof Cade said yesterday. The study, in the British Journal of Cancer, says: "Women consuming the most total [all kinds] meat, red meat and processed meat were at the highest risk compared with non-meat eaters, although red and processed meat were only statistically significant post-menopausally".
 

A 2oz portion of meat equates to a half a lamb chop or two thin slices of roast beef and Sandy Crombie, the chairman of the Scottish region of The Guild of Q Butchers, said: "Two ounces is absolutely tiny. I have never heard such rubbish. It's a tiny amount. This is ridiculous, it's silly.
"Think of a quarter pounder burger, it's half of that. It's barely worth talking about."
Prof Cade said the researchers were quite surprised that only 2oz of red meat a day appeared to have an effect. "This is a complex piece of work and it was designed specifically to compare different patterns of diet," she said.
Earlier analysis from the study found that pre-menopausal women who had the greatest intake of fibre cut their breast cancer risk by half.
The Sheffield work supports other studies. In November, an American study found women who ate the largest amounts of red meat had a rising risk of breast cancer. But different studies have presented conflicting views.
Prof Cade said one reason why red meat may contribute to a raised risk of breast cancer is that it is a rich source of saturated fat. The women who ate the most meat were also more likely to be fatter.
"Really these results could apply to all women. At home I have cut down on the amount of red meat we eat as a family a week," she said.
"I am not suggesting that everyone should become a vegetarian, that would be unrealistic, but the findings were strong and I think we should pay attention to them."
Henry Scowcroft, of Cancer Research UK, said: "Our best dietary advice to women worried about their breast cancer risk is to maintain a healthy body weight by taking regular exercise and avoiding large regular portions of fatty foods like red and processed meat, and excess alcohol. It's also important to be breast aware, and to go for screening when invited by your GP."
Dr Alexis Willett, of the charity Breakthrough Breast Cancer, said: "We encourage all women to eat a balanced diet, limit alcohol consumption, exercise regularly and keep a healthy weight to maintain general good health."
Breast cancer is rising in Britain and 44,000 new cases a year are diagnosed. The disease kills 12,500 women a year.