A study published in the journal Cell Metabolism and fact in 6.318 men, suggests that middle-aged people should not consume high levels of protein, particularly animal, as it quadruples the risk of dying of cancer.
However, if the person in question are more than 65 years, so a diet rich in meat and animal products can help extend the life.
The reason, according to experts, may be that protein controls the growth hormone IGF-I, which helps to grow the body, but that also has been linked with susceptibility to cancer. The levels of this hormone fall precipitously after age 65, resulting in a possible weakness and loss of muscle mass.
An important aspect of the study was the vegetable protein. The researchers found that this type of protein (which can be found in grains) do not have the same effects of mortality than the animal.