The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) along with the Continuous Update Project (CUP), examined the relation between the risk for colorectal cancer and diet, physical activity, and weight. The result was a report that has confirmed that red and processed meat increases the risk for colorectal cancer.
What they found in these studies is that 45% of colorectal cancer cases could be prevented if people consumed more fiber-rich plant foods, consumed less meat and alcohol, became more physically active, and maintained a healthy weight. That would prevent more than 64,000 cases in the United States every year.
The World Cancer Research Fund/American Institute for Cancer Research recommend that the consumption of red meat be limited to 500 g/week, which is roughly the equivalent of 5 or 6 medium portions of beef, lamb, or pork. They also recommend that processed meat be avoided.
According to their data, if 3.5 ounces of red meat are consumed every day (24.5 ounces per week), the risk for colorectal cancer will be 17% higher than if no red meat is consumed. If the amount of red meat consumed is doubled (7.0 ounces every day; 49 ounces per week), the risk is 34% higher. However, the evidence found that there was very little increase in risk for individuals who ate less than 18 ounces of red meat per week.
The cancer risk associated with processed meat, which includes ham, bacon, pastrami, hot dogs, and sausages, was much higher. Consuming 3.5 ounces every day (24.5 ounces per week) was associated with a risk that is 36% higher than the risk of consuming no processed meat. As with red meat, the higher the rate of consumption, the higher the risk for colorectal cancer.
You can download the full report here: REPORT