The China Study by Thomas Campbell

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THE CHINA STUDY

CHART 3.8: PROTEIN TYPE AND FOCI RESPONSE

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.20% Casein

.20% Gluten

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05% Casein

Protein Type

We also examined whether soy protein had the same effect as casein
on foci development. Rats fed 20% soy protein diets did not form. early foci,
just like the 20% wheat protein diets. Suddenly protein, milk protein in this
case, wasn't looking so good. We had discovered that low protein intake
reduces cancer initiation and works in multiple synchronous ways. As if
that weren't enough, we were finding that high protein intake, in excess
of the amount needed for growth, promotes cancer after initiation. Like
flipping a light switch on and off, we could control cancer promotion
merely by changing levels of protein, regardless of initial carcinogen
exposure. But the cancer-promoting factor in this case was cow's milk
protein. It was difficult enough for my colleagues to accept the idea that
protein might help cancer grow, but cow's milk protein? Was I crazy?

ADDITIONAL QUESTIONS

For those readers who want to know somewhat more, I've includ-

ed a few questions in AppendiX A.

THE GRAND FINALE

Thus far we had relied on experiments where we measured only the ear-
ly indicators of tumor development, the early cancer-like foci. Now, it
was time to do the big study, the one where we would measure complete
tumor formation. We organized a very large study of several hundred
rats and examined tumor formation over their lifetimes using several
different approaches.^36 , 43