The China Study #1: Protein and Cancer
I'd heard about this book for a year before I read it. Since reading it, it has become one of my must read books for every person concerned with how diet effects health. This is the beginning of a series on key items discussed in the book.
T. Colin Campbell, the author, is a leading researcher in the field of nutrition.
Around 1970 he worked on a project in the Philippines with children that were malnourished. The belief at the time was that the primary nutrient that malnourished people needed was protein. So they looked for a good local source of protein. It turned out to be peanuts.
To use peanuts as a source of protein they had to solve another problem. Peanuts are frequently contaminated by a mold called aflatoxin, one of the most carcinogenic compounds known. It’s also common on corn.
In testing peanut butter they found that it contained 300 times the US acceptable level. Whole peanuts were within US safe levels. Peanut butter was much higher because the “best” peanuts go into whole peanut products and the “worst” peanuts go into the butter. (Makes me wonder about US peanut butter.)
There were two areas of the country with high liver cancer levels in children. One was an area of high peanut butter consumption and the other one high corn consumption.
This didn’t make sense. World statistics seemed to say that liver cancer was highest where protein levels were the lowest. But, here they were with two populations with high liver cancer who consumed high levels of protein. The high corn consumption group was also a wealthy group of children whose diets were similar to high meat western diets.
While trying to find the common link, Campbell heard of a study done in India where aflatoxin induced tumor growth was compared to the amount of protein fed to rats. The rats fed a diet with 5% protein didn’t die from the tumors and rats fed a diet with 20% protein died from the tumors. The most common reaction was that something was wrong with the study, since it didn’t conform with the prevailing research. It was suggested that they must have somehow switched the groups, or some other major error.
Campbell however thought this might be linked to the cancer results of two groups in the Philippines. So they gave rats tumors created with aflatoxin. When the protein was at 20% ALL of the rats DIED. When the protein in their diet was at 5% ALL of the rats LIVED. In fact, they could turn the tumor growth on and off by adjusting the level of protein in the diet. Just like turning a light switch on and off.
What he says totally blew his mind, was that the results were 100% to 0%.
All the rats died or all the rats lived. No grey area.
They also discovered that with the low protein diet, the rats could eliminate the aflatoxin with no apparent negative effects.
And in subsequent studies they found they couldn’t cause tumor growth with 20% plant based protein. ONLY with ANIMAL protein.
This experience was the beginning of his questioning the assumptions, research results and the conclusions of prevailing nutritional studies and conclusions. It was the beginning of his career studying the connections between protein, diet and cancer.