78 THE CHINA STUDYmeasure dietary cholesterol any more than he or she can measure how
many hot dogs and chicken breasts you've been eating. Instead, the
doctor measures the amount of cholesterol present in your blood.
This second type of cholesterol, blood cholesterol, is made in the liver.
Blood cholesterol and dietary cholesterol, although chemically identi-
cal, do not represent the same thing. A similar situation occurs with
fat. Dietary fat is the stuff you eat: the grease on your French fries, for
example. Body fat, on the other hand, is the stuff made by your body
and is very different from the fat that you spread on your toast in the
morning (butter or margarine). Dietary fats and cholesterol don't nec-
essarily turn into body fat and blood cholesterol. The way the body
makes body fat and blood cholesterol is extremely complex, involv-
ing hundreds of different chemical reactions and dozens of nutrients.
Because of this complexity, the health effects of eating dietary fat and
dietary cholesterol may be very different from the health effects of
having high blood cholesterol (what your doctor measures) or having
too much body fat.
As blood cholesterol levels in rural China rose in certain counties,
the incidence of "Western" diseases also increased. What made this so
surprising was that Chinese levels were far lower than we had expected.
The average level of blood cholesterol was only 127 mg/dL, which is
almost 100 points less than the American average (215 mg/dL)! 12 Some
counties had average levels as low as 94 mg/dL. For two groups of about
twenty-five women in the inner part of China, average blood cholesterol
was at the amazingly low level of 80 mg/dL.
If you know your own cholesterol levels, you'll appreciate how low
these values really are. In the U.s., our range is around 170-290 mg/dL.
Our low values are near the high values for rural China. Indeed, in the
U.s., there was a myth that there might be health problems if cholesterol
levels were below 150 mg/dL. If we followed that line of thinking, about
85% of the rural Chinese would appear to be in trouble. But the truth is
quite different. Lower blood cholesterol levels are linked to lower rates of
heart disease, cancer and other Western diseases, even at levels far below
those considered "safe" in the West.
At the outset of the China Study, no one could or would have pre-
dicted that there would be a relationship between cholesterol and
any of the disease rates. What a surprise we got! As blood cholesterol
levels decreased from 170 mg/dL to 90 mg/dL, cancers of the liver,1I
rectum/ colon, II male lung; female lung, breast, childhood leukemia,