This study was confirmed by additional research showing that rats subjected to DMH and fed whey protein showed fewer tumors and a reduced pooled area of tumors. It is interesting to note that the concentration of glutathione in tumor cells is often much higher than in surrounding normal cells, meaning that cancer cells will respond differently to nutrients and drugs that alter glutathione status. This discrepancy in glutathione status between normal cells and cancer cells also makes it harder to kill cancer cells with chemotherapy. Because the surrounding cells have lower levels of glutathione to begin with, anything that further suppresses glutathione puts normal healthy cells in danger long before cancer cells are affected. Instead, cancer patients need a compound that can target cancer cells and deplete only their glutathione.
Whey protein appears to be just such a compound.
No other protein reported the same effect. Even the mechanism by which whey protein acts is not fully understood. It appears that whey protein interferes with the cancer cells' ability to regulate glutathione. Whey, with the highest biological value of any protein, is absorbed, utilized and retained in the body better than other proteins. This has caused athletes to make whey protein concentrate a best-seller.