There may be some tiny amount of truth to this. Red meats contain more L-Glutamine which is required for muscle growth. It is the most abundant amino acid in our body. That said, taking more of it will also feed tumors by increasing the production of HGH. An extreme example of this is performance athletes that take human growth hormone. Those with tumors meet their demise rather quickly because their body did not have time to terminate the cells, or could not keep up with the growth rate. This is of course an extreme example. Red meats only contain enough L-Glutamine to increase your HGH on a much smaller scale.