Then there are nitrosamines, suspected source of all our troubles, were first identified in burned meat and can induce tumors in laboratory animals. It seems, however, that these substances are not responsible for tumors in humans. Hence, the mechanisms that underlie carcinogen-mediated tumor initiation after a rich meat diet remain a mystery. Meat contains little fiber and has no natural antioxidants. Eating meat on a daily basis frequently means that you eat fewer vegetables, which are rich in antioxidants.
Red meat is also the leading source of methionine in the diet.
This amino acid is the direct metabolic precursor of homocysteine, another amino acid, which does not become a building block of protein, but is harmful to arteries. It is also plausible, through not demonstrated, that a high intake of meat can raise levels of homocysteine in the bloodstream. Bearing this in mind, the dietary guidelines established by the American Department of Agriculture in recent years is unconvincing. These guidelines recommended, for example, eating 140-196 grams of meat per day in a healthy diet. Traditionally, Mediterranean populations eat little meat and have fewer health risks, but most important of all, have individual and public health profiles that are far better than those found in industrialized nations that eat more meat.