Foodconsumer.org released an interesting article focused on the findings of Dr. T. Colin Campbell. Dr. Campbell is a co-author of the world reknowned book The China Study, an in depth 35 year research program on health and nutrition. His findings have provoked many new studies, and provided important insights into several areas of the typical American diet and lifestyle. One interesting dicovery from Dr. Campbell’s clinical research was a strong connection between protein intake and cancer, more specifically milk protein.
In one study, Dr. Campbell’s team exposed rats to aflatoxin and then fed them with either a diet with 5 percent protein or a diet with 20 percent casein for 100 weeks. This is often considered an entire life time for rats. All of those on the high casein diet died, or nearly died, from liver tumors at 100 weeks while all of those who were on the low protein diet were still “alive, active and thrifty, with sleek hair coats at 100 weeks.”
The study also found dramatic effects from protein shifts in the rats diets. The rats that started out on the high protein diet, but shifted halfway to the low protein diet were found to have 35 to 40 percent fewer cancers. On the contrary, the rats that were initially on the low protein diet, but switched at 50 weeks to the high protein diet started developing cancers. This indicates that a low protein diet can also have a protective effect in the progression stages of cancer development.
Dr. Campbell found that low protein diets can not only lower the activity of an enzyme that converts non-toxic chemicals, such as aflatoxin, into a toxic form, but also help prevent toxins from entering cells. And his studies directly indicated that a high intake of casein, which accounts for 87 percent of dairy protein, promotes cancer development. According to Dr. Campbell, low protein diets have a protective effect against the cancer in all three stages of cancer development: initiation, promotion, and progression.
Although his studies were done on animals, Dr. Campbell points to the statistics as evidence for humans. China has had a much lower incidence of cancer than the U.S. Chinese typically eat no more than 10 percent protein in their diets, and about 90 percent of this protein comes from plants. But Americans average more than 15 percent protein in their diets, and more than 80 percent of this protein comes from animals. He believes that the differences in protein consumption may cause at least a seven-fold difference in cancer risk.