When you read health advice on the internet, it's difficult to arrive at the truth because, armed with Google, it is very easy to find studies that claim one thing and studies that claim the exact opposite. One way of discriminating between good health advice and bad health advice is to look at the quality of your source, and one way you can discriminate among research universities is to look at the latest university rankings (see Times Top 200 University Rankings 2010-11).
The American Cancer Council, in 2005, claimed that high consumption of red meat was linked to colon cancer. However, although they found a statistical link between consumption of red meat and incidence of colon cancer, they did not know what it was about red meat responsible for this result: "Researchers aren't certain what it is about red meat that might influence cancer risk. The iron and fat it contains may be culprits. For processed meat, the salt, smoke residue, and nitrates and nitrites used as preservatives may play a role." This may mean that although you can reduce statistically reduce your risk of getting colon cancer by avoiding red meat, it may not be the redness of the meat itself that is causing the increased risk of colon cancer but the likelihood that red meat is more likely to be processed and have more iron and fat.
The Harvard School of Public Health, in 2010, claimed that eating processed meats, but not unprocessed red meats, may raise risk of heart disease and diabetes. This is further evidence that processed meats, with added salt and preservatives, have serious adverse health effects.