The China Study by Thomas Campbell

206 THE CHINA STUDY

CHART 10.1: ASSOCIATION OF URINARY CALCIUM EXCRETION

WITH DIETARY PROTEIN INTAKE

100 (2).

E ::J

'u m

u

~ rc

c

§

.~^50

OJ Vl

rc ~

.f: u

";R. 0

0

100

% Increase in Protein Intake

.(5)

Y = 0.50X

r = 0.85

.(4)

• (1)
  .(33)


• (2)

200

cium. Chart 10.1 is taken from the 1981 publication. 10 Doubling protein
intake (mostly animal-based) from 35-78 glday causes an alarming 50%
increase in urinary calcium. This effect occurs well within the range
of protein intake that most of us consume; average American intake is
around 70-100 glday. Incidentally, as mentioned in chapter four, a six-
month study funded by the Atkins Center found that those people who
adopted the Atkins Diet excreted 50% more calcium in their urine after
six months on the diet. 12
The initial observations on the association between animal protein
consumption and bone fracture rates are very impressive, and now we
have a plausible explanation as to how the association might work, a
mechanism of action.
Disease processes are rarely as simple as "one mechanism does it all,"
but the work being done in this field makes a strong argument. A more
recent study, published in 2000, comes from the Department of Medi-
cine at the University of California at San Francisco. Using eighty-seven
surveys in thirty-three countries, it compared the ratio of vegetable to
animal protein consumption to the rate of bone fractures (Chart 10.2).1
A high ratio of vegetable to animal protein consumption was found to
be impressively associated with a virtual disappearance of bone frac-
tures.
These studies are compelling for several reasons. They were published
in leading research journals, the authors were careful in their analyses and