The China Study (41 page)

268                        THE CHINA STUDY
occur. It doesn't involve large payoffs being delivered to secret bank
accounts or to private investigators in smoky hotel lobbies. It's not a
Hollywood story; it's just day-to-day government, science and industry
in the United States.

_______________________________________________1_ ________________________ __ _ _ _ _ _ _ _ _
4
Scientific Reductionism
WHEN OUR NATIONAL ACADEMY OF SCIENCES (NAS) Diet, Nutrition and
Cancer Committee was deciding how to summarize the research on diet
and cancer, we included chapters on individual nutrients and nutrient
groups. This was the way research had been done, one nutrient at a
time. For example, the chapter on vitamins included information on
the relationships between cancer and vitamins A, C, E and some B vita-
mins . However, in the report summary, we recommended getting these
nutrients from fbods, not pills or supplements. We explicitly stated that
"These recommendations apply only to foods as sources of nutrients-
n o t to dietary supplements of individual nutrients.'"
The report quickly found its way to the corporate world, which saw
a major money-making opportunity. They ignored our cautionary mes-
sage distinguishing foods from pills and began advertising vitamin pills
as products that could prevent cancer, arrogantly citing our report as
justification. This was a great opening to a vast new market-commer-
cial vitamin supplements.
General Nutrition, Inc., the company with thousands of General
Nutrition Centers, started selling a product called "Healthy Greens,"
a multivitamin supplement of vitamins A, C and E, beta-carotene, se-
l e n i u m and a miniscule half-gram of dehydrated vegetables. Then they
advertised their product by making the following claims2 :
[The Diet, Nutrition and Cancer reportl recommended we increase
among other things our amounts of specific vegetables to help
safeguard our bodies against the risk of certain forms of cancer.
269

270                           THE CHINA STUDY
These vegetables recommended by the [National Academy of Sci-
ences reportl ... are the ones we should increase[:l cabbages, Brus-
sels sprouts, cauliflower, broccoli, carrots and spinach .... Mom
was right!
Research scientists and technicians at General Nutrition Labs,
realizing the importance of the research, instantly went to work
to harness all of the vegetables and combined all of them into a
natural, easy to take potent tablet.
[Tlhe result is Health Greens [sic], a new potent breakthrough
in nutrition that millions of people can now help safeguard their
well-being with ... the greens that the [National Academy of Sci-
ences Committeel recommends we eat more of!
GNC was advertiSing an untested product and improperly using a
government document to support its sensational claims. So the Federal
Trade Commission went to court to bar the company from making these
claims. It was a battle that lasted years, a battle that was rumored to
cost General Nutrition, Inc. about $7 million. The National Academy
of Sciences recommended me as their expert witness because of my co-
a u t h o r s h i p of the report in question and because of my harping on this
point during our committee deliberations.
A research associate in my group, Dr. Tom O'Connor, and I spent
three intellectually stimulating years working on this project, including
my three full days on the witness stand. In 1988, General Nutrition,
Inc., settled the false advertising charges relating to Healthy Greens and
other food supplements by agreeing to pay $600,000, divided equally,
to three different health organizations. 3 This was a small price for the
company to pay, considering the ultimate revenues that were generated
by the exploding nutrient supplement market.
FOCUS ON FAT
The focus on individual nutrients instead of whole foods has become
commonplace in the past two decades, and part of the blame can be put
on our 1982 report. As mentioned before, our committee organized the
scientific information on diet and cancer by nutrients, with a separate
chapter for each nutrient or class of nutrients. There were individual
chapters for fat, protein, carbohydrate, vitamins and minerals. I am
convinced it was a great mistake on our part. We did not stress enough
that our recommendations were concerned with whole foods because

SCIENTIFIC REDUCTIONISM                           271
many people still regarded the report as cataloging the specific effects of
individual nutrients.
The nutrient that our committee focused on the most was fat. The
first gUideline in the report explicitly stated that high fat consumption
is linked to cancer, and recommended reducing our fat intake from 40%
to 30% of calories, although this goal of 30% was an arbitrary cutoff
point. The accompanying text said, "[Tlhe data could be used to justify
an even greater reduction. However, in the judgment of the committee,
the suggested reduction is a moderate and practical target, and is likely
to be beneficial." One of the committee members, the director of the
United States Department of Agriculture (USDA) Nutrition Laboratory;
told us that if we went below 30%, consumers would be required to re-
duce animal food intake and that would be the death of the report.
At the time of this report, all of the human-based studies showing
fat to be related to cancer (mostly breast and large bowel) were actu-
ally showing that the populations with more cancer consumed not
just more fat, but also more animal-based foods and less plant-based
foods (see chapter four). This meant that these cancers could just as
easily be caused by animal protein, dietary cholesterol, something else
exclUSively found in animal-based foods, or a lack of plant-based foods
(discussed in chapters four and eight). But rather than wagging the fin-
ger at animal-based foods in these studies, dietary fat was given as the
main culprit. I argued against putting the emphaSiS on specific nutrients
in the committee meetings, but only with modest success. (It was this
point of view that landed me the expert witness opportunity at the FTC
hearings.)
This mistake of characterizing whole foods by the health effects of spe-
cific nutrients is what I call reductionism. For example, the health effect
of a hamburger cannot be simply attributed to the effect of a few grams
of saturated fat in the meat. Saturated fat is merely one ingredient. Ham-
burgers also include other types of fat, in addition to cholesterol, protein
and very small amounts of vitamins and minerals. Even if you change the
level of saturated fat in the meat, all of the other nutrients are still present
and may still have harmful effects on health. It is a case of the whole (the
hamburger) being greater than the sum of its parts (the saturated fat, the
cholesterol, etc.) .
One scientist especially took note 4 of our focused critique of dietary
fat, and decided to test the hypothesis that fat causes breast cancer in
a large group of American women. He was Dr. Walter Willett of the

272                          THE CHINA STUDY
Harvard School of Public Health, and the study he used is the famous
Nurses' Health Study.
Starting in 1976, researchers at the Harvard School of Public Health
had enrolled over 120,000 nurses from around the country for a study
that was intended to investigate the relationship between various dis-
eases and oral contraceptives, post-menopausal hormones, cigarettes
and other factors, such as hair dyes. 5 Beginning in 1980, Professor Wil-
l e t t added a dietary questionnaire to the study and four years later, in
1984, expanded the dietary questionnaire to include more food items.
This expanded dietary questionnaire was mailed to nurses again in 1986
and 1990.
Data now have been collected for over two decades. The Nurses'
Health Study is widely known as the longest-running, premier study
on women's health. 6 It has spawned three satellite studies, all together
costing $4-5 million per year. 6 When I give lectures to health conscious
audiences, upwards of 70% of the people have heard of the Nurses'
Health Study.
The scientific community has followed this study closely. The
researchers in charge of the study have produced hundreds of scien-
tific articles in the best peer-reviewed journals. The design of the study
makes it a prospective cohort study, which means it follows a group of
people, a cohort, and records information on diets before disease events
are diagnosed, making the study "prospective." Many regard a prospec-
tive cohort study as the best experimental design for human studies.
The question of whether diets high in fat are linked to breast cancer
was a natural outgrowth of the fierce discussion going on in the mid-
1970s and the early 1980s. High-fat diets not only were associated with
heart disease (the McGovern dietary goals), but also with cancer (the
Diet, Nutrition and Cancer report). What better study to answer this
question than the Nurses' Health Study? It has a good deSign, massive
numbers of women, top-flight researchers and a long follow-up period.
Sounds perfect, right? Wrong.
The Nurses' Health Study suffers from flaws that seriously doom its
results. It is the premier example of how reductionism in science can
create massive amounts of confusion and misinformation, even when
the scientists involved are honest, well intentioned and positioned at
the top institutions in the world. Hardly any study has done more dam-
age to the nutritional landscape than the Nurses' Health Study, and it
should serve as a warning for the rest of science for what not to do.

273
SCIENTIFIC REDUCTIONISM
CARNIVOROUS NURSES
In order to understand my rather harsh criticism, it is necessary to ob-
t a i n some perspective on the American diet itself, especially when com-
p a r e d with the international studies that gave impetus to the dietary fat
hypothesis. 7 Americans eat a lot of meat and fat compared to developing
countries. We eat more total protein, and even more Significantly, 70%
of our protein comes from animal sources. The fact that 70% of our total
protein comes from animal sources means only one thing: we are con-
s u m i n g very few fruits and vegetables. To make matters worse, when
we do eat plant-based foods , we eat a large amount of highly processed
products that often have more added fat, sugar and salt. For example,
the United States Department of Agriculture (USDA) national school
lunch program counts French fried potatoes as a vegetable!
In contrast, people in rural China eat very little animal foods; they
provide only about 10% of their total protein intake. The striking dif-
ference between the two dietary patterns is shown in two ways in Chart
14.1. 8
These distinctions are typical of the dietary differences between
Western cultures and traditional cultures. In general, people in Western
countries are mostly meat eaters, and people in traditional countries are
mostly plant eaters.
So what about the women in the Nurses' Health Study? As you might
guess, virtually all of these women consume a diet very rich in animal-
b a s e d foods, even richer than the average American. Their average
protein intake (as % of calories) is around 19%, compared with a U.S.
CHART 14.1: PROTEIN INTAKE IN THE U.S. AND RURAL CHINA8
c
·w 100
....
>,
...
a
100
ro
~ 80                                           80
Cl.
63                       ]
60
a     60
<1.'-
60
~
I-
ro                                     '+-
40
+'
a
40
.f:
c
·w                                             20
Ol
20
....                                    ....
ro
e                                       c
0
0                            Cl.                                     u
Qj               US
US                                                     China
China          Cl.
I_ Animal Prote in 0 Plant Protein I
I_ Animal Protein 0 Plant Protein
,                                       1
~

274                           THE CHINA STUDY
CHART 14.2: PERCENTAGE OF TOTAL PROTEIN
THAT COMES FROM ANIMAL FOOD
100
90
c
'2     80
0
0:     70
Iii
..,    60
~                                                    o Plant Protein
50
'0                                                   .Animal Protein
40
OJ
01
II)
30
C
OJ
u
20
Qj
a..
10
0
US
Nurses                    China
average of about 15-16%. To give these figures some perspective, the
recommended daily allowance (RDA) for protein is only about 9-10%.
But even more importantly, of the protein consumed by the nurses in this
study, between 78% and 86% comes from animal-based foods ,9 as shown in
Chart 14.2.8, 9 Even in the group of nurses that eat the lowest amount of
total protein, 79% of it comes from animal-based foods .9 In other words,
virtually all of these nurses are more carnivorous than an average American
woman. They consume very few whole, plant-based foods.
This is a crucially important point. To get further perspective, I must
return to the 1975 international comparison by Ken Carroll shown ear-
lier in Charts 4.7 to 4.9. Chart 4.7 is reproduced here in Chart 14.3.
This chart became one of the most influential observations on diet
and chronic disease of the last fifty years. Like other studies, it was a
Significant part of the reason why the 1982 Diet, Nutrition and Cancer
report recommended that Americans cut their fat intake to 30% of total
caloric intake in order to prevent cancer. This report and other consen-
s u s reports that followed thereafter eventually set the stage for an explo-
s i o n of low-fat products in the marketplace ("low-fat" dairy products,
lean cuts of meat, "low-fat" sweets and snack foods).
Unfortunately, the emphasis on fat alone was misguided. Carroll's
study, like all the other international comparisons, was comparing
populations that mostly ate meat and dairy to populations that mostly
ate plants. There were many more differences between the diets of these
countries than just the fat intake! What Carroll's graph really shows is