The China Study (13 page)

79
LESSONS FROM CHINA
adult leukemia,1 childhood brain, adult brain,1 stomach and esophagus
(throat) decreased. As you can see , this is a sizable list. Most Americans
know that if you have high cholesterol, you should worry about your
heart, but they don't know that you might want to worry about cancer
as well.
There are several types of blood cholesterol, including LDL and HDL
cholesterol. LDL is the "bad" kind and HDL is the "good" kind. In the
China Study higher levels of the bad LDL cholesterol also were associ-
a t e d with Western diseases.
Keep in mind that these diseases, by Western standards, were rela-
tively rare in China and that blood cholesterol levels were quite low
by Western standards. Our findings made a convincing case that many
Chinese had an advantage at the lower cholesterol levels, even below
170 mgldL. Now imagine a country where the inhabitants had blood
cholesterol levels far higher than the Chinese average. You might expect
that these relatively rare diseases, such as heart disease and some can-
cers, would be prevelant, perhaps even the leading killers!
Of course, this is exactly the case in the West. To give a couple of
examples at the time of our study, the death rate from coronary heart
disease was seventeen times higher among American men than rural Chi-
nese men. 13 The American death rate from breast cancer was five times
higher than the rural Chinese rate.
Even more remarkable were the extraordinarily low rates of coronary
heart disease (CHD) in the southwestern Chinese provinces of Sichuan
and Guizhou. During a three-year observation period (1973-1975),
there was not one single person who died of CHD before the age of six-
ty-four, among 246,000 men in a Guizhou county and 181 ,000 women
in a Sichuan county! 14
After these low cholesterol data were made public, I learned from
three very prominent heart disease researchers and physicians, Drs.
Bill Castelli, Bill Roberts and Caldwell Esselstyn, Jr., that in their long
careers they had never seen a heart disease fatality among their patients
who had blood cholesterol levels below 150 mgldL. Dr. Castelli was the
long-time director of the famous Framingham Heart Study of NIH; Dr.
Esselstyn was a renowned surgeon at the Cleveland Clinic who did a
remarkable study reversing heart disease (chapter five); Dr. Roberts has
long been editor of the prestigious medical journal Cardiology.

THE CHINA STUDY
80
BLOOD CHOLESTEROL AND DIET
Blood cholesterol is clearly an important indicator of disease risk. The
big question is: how will food affect blood cholesterol? In brief, animal-
based foods were correlated with increasing blood cholesterol (Chart
4.5). With almost no exceptions, nutrients from plant-based foods were
associated with decreasing levels of blood cholesterol.
Several studies have now shown, in both experimental animals and
in humans, that consuming animal-based protein increases blood cho-
l e s t e r o l l e v e l s . 1s- 18 Saturated fat and dietary cholesterol also raise blood
cholesterol, although these nutrients are not as effective at doing this as
is animal protein. In contrast, plant-based foods contain no cholesterol
and, in various other ways, help to decrease the amount of cholesterol
made by the body. All of this was consistent with the findings from the
China Study.
CHART 4.5. FOODS ASSOCIATED WITH BLOOD CHOLESTEROL
As intakes of meat,' milk, eggs, fish,'-" far and      Blood Cholesterol goes up.
animal protein go up ...
As intakes of plant-based foods and nutrients (in-     Blood Cholesterol goes down.
eluding plant protein,' dietary fiber," cellulose,"
hemicellulose,' soluble carbohydrate," B-vitamins
of plants (carotenes, B2 , B3 ) , ' legumes, light
colored vegetables, fruit, carrots, potatoes and
several cereal grains) go up ...
These disease associations with blood cholesterol were remarkable,
because blood cholesterol and animal-based food consumption both
were so low by American standards. In rural China, animal protein
intake (for the same individual) averages only 7.1 glday whereas Ameri-
cans average a whopping 70 glday. To put this into perspective, seven
grams of animal protein is found in about three chicken nuggets from
McDonald's. We expected that when animal protein consumption and
blood cholesterol levels were as low as they are in rural China, there
would be no further association with the Western diseases. But we were
wrong. Even these small amounts of animal-based food in rural China
raised the risk for Western diseases.
We studied dietary effects on the different types of blood cholesterol.
The same dramatic effects were seen. Animal protein consumption by

LESSONS FROM CHINA                            81
men was associated with increasing levels of "bad" blood cholesterolI I l
whereas plant protein consumption was associated with decreasing lev-
els of this same cholesterol. II
Walk into almost any doctor's office and ask which dietary factors af-
fect blood cholesterol levels and he or she will likely mention saturated
fat and dietary cholesterol. In more recent decades, some might also
mention the cholesterol-lowering effect of soy or high-fiber bran prod-
ucts, but few will say that animal protein has anything to do with blood
cholesterol levels.
It has always been this way. While on sabbatical at the University
of Oxford, I attended lectures given to medical students on the dietary
causes of heart disease by one of their prominent professors of medi-
cine. He went on and on about the adverse effects of saturated fat and
cholesterol intakes on coronary heart disease as if these were the only
dietary factors that were important. He was unwilling to concede that
animal protein consumption had anything to do with blood cholesterol
levels, even though the evidence at that time made it abundantly clear
that animal protein was more strongly correlated with blood cholesterol
levels than saturated fat and dietary cholesterol. 15 Like too many others,
his blind faith in the status quo left him unwilling to be open-minded.
As these findings poured in, 1 was beginning to discover that being
open-minded was not a luxury, but a necessity.
FAT AND BREAST CANCER
If there were some sort of nutrition parade, and each nutrient had a
float, by far the biggest would belong to fat. So many people, from
researchers to educators, from government policy makers to industry
representatives, have investigated or made pronouncements on fat for
so long. People from a huge number of different communities have been
constructing this behemoth for over half a century.
As this strange parade got started on Main Street, USA, the attention
of everyone sitting on the sidewalks would ineVitably be drawn to the
fat float. Most people might see the fat float and say, "I should stay away
from that," and then eat a hefty piece of it. Others would climb on the
unsaturated half of the float and say that these fats are healthy and only
saturated fats are bad. Many scientists would point fingers at the fat float
and claim that the heart disease and cancer clowns are hiding inside.
Meanwhile, some self-proclaimed diet gurus, like the late Dr. Robert
Atkins, might set up shop on the float and start selling books. At the

82                           THE CHINA STUDY
end of the day the average person who gorged on the float would be left
scratching his head and feeling queasy, wondering what he should have
done and why.
There's good reason for the average consumer to be confused. The
unanswered questions on fat remain unanswered, as they have for the
past forty years. How much fat can we have in our diets? What kind of
fat? Is polyunsaturated fat better than saturated fat? Is monounsatu-
r a t e d fat better than either? What about those special fats like omega-
3, omega-6, trans fats and DHA? Should we avoid coconut fat? What
about fish oil? Is there something special about flaxseed oil? What's a
high-fat diet anyway? A low-fat diet?
This can be confusing, even for trained scientists. The details that un-
derlie these questions, when considered in isolation, are very misleading.
As you shall see, considering how networks of chemicals behave instead
of isolated single chemicals is far more meaningful.
In some ways, however, it is this foolish mania regarding isolated as-
pects of fat consumption that teaches us the best lessons. Therefore, let's
look a little more closely at this story of fat as it has emerged during the
past forty years. It illustrates why the public is so confused both about
fat and about diet in general.
On average, we consume 35-40% of our total calories as fat. 19 We have
been consuming high-fat diets like this since the late nineteenth century,
at the onset of our industrial revolution. Because we had more money, we
began consuming more meat and dairy, which are relatively high in fat.
We were demonstrating our affluence by consuming such foods.
Then came the mid to late twentieth century when scientists began
to question the advisability of consuming diets so high in fat. National
and international dietary recommendations 2° -B emerged to suggest that
we should decrease our fat intake below 30% of calories. That lasted for
a couple decades, but now, the fears surrounding high-fat diets are abat-
i n g . Some authors of popular books even advocate increased fat intake!
Some experienced researchers have suggested that it is not necessary to
go below 30% fat, as long as we consume the right kind of fat.
The level of 30% fat has become a benchmark, even though there is
no evidence to suggest that this is a vital threshold. Let's get some per-
spective on this figure by considering the fat contents of a few foods, as
seen in Chart 4.6.

LESSONS FROM CHINA                        83
CHART 4.6: FAT CONTENT OF SAMPLE FOODS
Percent of calories
Food
derived from fat
Butter                                              100%
67%
McDonald's Double Cheeseburger
Whole Cow's Milk                                    64%
Hom                                                 61%
54%
Hotdog
42%
Soybeans
"Low-Fat" (or 2%) Milk                              35%
26%
Chicken
14%
Spinach
8%
Wheaties Breakfast Cereal
5%
Skim Milk
5%
Peas
4%
Carrots
3.5%
Green Beans
1%
Whole Baked Potatoes
With a few exceptions, animal-based foods contain considerably
more fat than plant-based foods .24 This is well illustrated by compar-
ing the amount of fat in the diets of different countries. The correlation
between fat intake and animal protein intake is more than 90%.2 This5
means that fat intake increases in parallel with animal protein intake. In
other words, dietary fat is an indicator of how much animal-based food
is in the diet. It is almost a perfect match.
FAT AND A FOCUS ON CANCER
The 1982 National Academy of Sciences (NAS) report on Diet, Nutri-
t i o n and Cancer, of which I was a co-author, was the first expert panel
report that deliberated on the association of dietary fat with cancer.
This report was the first to recommend a maximum fat intake of 30%
of calories for cancer prevention. Previously, the U.s. Senate Select
Committee on Nutrition chaired by Senator George McGovern 26 held
widely publicized hearings on diet and heart disease and recommended
a maximum intake of 30% dietary fat. Although the McGovern report

THE (HINA STUDY
84
generated a public discourse on diet and disease, it was the 1982 NAS
report that gave momentum to this debate. Its focus on cancer, as op-
p o s e d to heart disease, increased public interest and concern. It spurred
additional research activity and public awareness of the importance of
diet in disease prevention.
Many of the reports at the time 2 , 27, 28 were centered on the question of
0
how much dietary fat was appropriate for good health. The unique atten-
tion given to fat was motivated by international studies showing that the
amount of dietary fat consumed was closely associated with the incidence
of breast cancer, large bowel cancer and heart disease. These were the
diseases that kill the majority of people in Western countries before their
time. Clearly, this correlation was destined to attract great public atten-
tion . The China Study was begun in the midst of this environment.
The best known study,29 in my view, was that of the late Ken Carroll,
professor at the University of Western Ontario in Canada. His findings
showed a very impressive relationship between dietary fat and breast
cancer (Chart 4.7).
This finding, which corresponded to the earlier reports of others,3,3O
became especially intriguing when compared with migrant studies. 31 , 32
These studies showed that people who migrated from one area to an-
o t h e r and who started eating the typical diet of their new reSidency as-
s u m e d the disease risk of the area to which they moved. This strongly
CHART 4.7: TOTAL FAT INTAKE AND BREAST CANCER
.NETHERLANDS
25                                                                     .UK     • DENMARK
CANADA.       • NEW ZEALAND
FEMALE                                                     .SWITZERLAND
ci.
IRELAND • •
o                                                                                 .US
a.                                                                        BELGIUM
o 20
o                                                             AUSTRALIA •• SWEDEN
o
d                                                           AUSTRIA .   •• GERMANY
o
• ITALY            NORWAY. FRANCE
-; 15                                                  .CZECH
•      • FNLAND
I
'"
cr::                                        • PORTUGAL HUNGARY
.s
~                                        HONG KONG • POLAND
10                          CHilE    •
•     • BULGARIA  .SPAIN
'0
VEN~;~~A··         ~~~~~~VI:
~                                          ••          GREECE
V>
=>
~                   PHILIPPINES     COLOMBIA . PUERTO RICO
5
•    •      • MEXICO
cV                       JAPAN. TAIWAN
C\
THAllA~D .El SALVADOR
o
o               40                                            140
20                60                 100      120                  160
80                                             180
Total Dietary Fat Intake (g/day)