The China Study (24 page)

DIABETES                            153
CHART 7.2: INSULIN DOSAGE RESPONSE TO DIET
HCF DIET
CONTROL
(High-Carbohydrate,
High-Fiber Diet)
30
>-
«       20
Q
.....
II'
I-                                                             N=8
Z
:::l
Z'
::::;
10
:::l
II'
Type 2 Patients
~
IN=8
1-------
0
12   18                 42
-6                    6
0
DAYS
the benefits of a plant-based diet will last for years if the same diet is
continued. l 9
These are examples of some very dramatic research, but they only
scratch the surface of all the supporting research that has been done.
One scientific paper reviewed nine publications citing the use of high-
carbohydrate, high-fiber diets and two more standard-carbohydrate,
high-fiber diets to treat diabetic patients. 2o All eleven studies resulted
in improved blood sugar and cholesterol levels. (Dietary fiber supple-
ments, by the way, although beneficial, did not have same consistent
effects as a change to a plant-based, whole foods dietY l
THE PERSISTENCE OF HABIT
As you can see by these findings, we can beat diabetes. Two recent
studies considered a combination of diet and exercise effects on this
diseaseY' 23 One study placed 3,234 non-diabetic people at risk for dia-
betes (elevated blood sugar) into three different groupsY One group,
the control, received standard dietary information and a drug placebo
(no effect), one received the standard dietary information and the drug
metformin, and a third group received "intensive" lifestyle intervention,
which included a moderately low-fat diet and exercise plan to lose at
least 7% of their weight. After almost three years, the lifestyle group had

154                              TH E CH I NA STU DY
CHART 7.3: BLOOD CHOLESTEROL ON HIGH-CARBOHYDRATE,
HIGH-FIBER DIET
I
CONTROL            HCF DIET
(High-Carbohydrate,
N = 14
High-Fiber Diet)
V1
~     100                                              Type 1 Patients
e
1:                                              CHOLESTEROL
o
u
'0    80
>R.
o
60~------~------~------~------~-----
a
-6             6             18
12
Days
58% fewer cases of diabetes than the control group. The drug group re-
d u c e d the number of cases only by 31 %. Compared to the control, both
treatments worked, but clearly a lifestyle change is much more power-
ful and safer than simply taking a drug. Moreover, the lifestyle change
would be effective in solving other health problems, whereas the drug
would not.
The second study also found that the rate of diabetes could be re-
d u c e d by 58% just by modest lifestyle changes, including exercise,
weight loss and a moderately low-fat diet. 23 Imagine what would hap-
p e n if people fully adopted the healthiest diet: a whole foods, plant-
based diet. I strongly suspect that virtually all Type 2 diabetes cases
could be prevented.
Unfortunately, misinformation and ingrained habits are wreaking
havoc on our health. Our habit of eating hot dogs, hamburgers and
French fries is killing us. Even Dr. James Anderson, who achieved pro-
f o u n d results with many patients by prescribing a near-vegetarian diet,
is not immune to habitual health advice. He writes, "Ideally, diets pro-
viding 70% of calories as carbohydrate and up to 70 gm fiber daily offer
the greatest health benefits for individuals with diabetes. However, these
diets allow only one to two ounces of meat daily and are impractical for
home use for many individuals. "20 Why does Professor Anderson, a very

DIABETES                              155
fine researcher, say that such a diet is "impractical" and thereby preju-
dice his listeners before they even consider the evidence?
Yes, changing your lifestyle may seem impractical. It may seem im-
practical to give up meat and high-fat foods, but I wonder how practical
it is to be 350 pounds and have Type 2 diabetes at the age of fifteen, like
the girl mentioned at the start of this chapter. I wonder how practical it
is to have a lifelong condition that can't be cured by drugs or surgery; a
condition that often leads to heart disease, stroke, blindness or amputa-
tion; a condition that might require you to inject insulin into your body
every day for the rest of your life.
Radically changing our diets may be "impractical," but it might also
be worth it.

8
Common Cancers:
Breast, Prostate, large Bowel
(Colon and Rectal)
MUCH OF MY CAREER has been concentrated on the study of cancer. My
laboratory work was focused on several cancers, including those of the
liver, breast and pancreas, and some of the most impressive data from
China were related to cancer. For this lifetime work, the American In-
s t i t u t e for Cancer Research kindly presented me with their Research
Achievement award in 1998.
An exceptional number of books have summarized the evidence on
the effects of nutrition on a variety of cancers, each with their own
particularities. But what I've found is that the nutritional effects on the
cancers I've chosen to discuss here are Virtually the same for all cancers,
regardless of whether they are initiated by different factors or are lo-
cated in different parts of the body. Using this principle, I can limit my
discussion to three cancers, which will allow me space in the rest of the
book to address diseases other than cancer, demonstrating the breadth
of evidence linking food to many health concerns.
I have chosen to comment on three cancers that affect hundreds of
thousands of Americans and that generally represent other cancers as
well: two reproductive cancers that get plenty of attention, breast and
157

THE CHINA STUDY
158
prostate, and one digestive cancer, large bowel-the second leading
cause of cancer death, behind lung cancer.
BREAST CANCER
It was spring almost ten years ago. I was in my office at Cornell when I
was told that a woman with a question regarding breast cancer was on
the phone.
"I have a strong history of breast cancer in my family," the woman,
Betty, said. "My mother and grandmother both died from the disease,
and my forty-five-year-old sister was recently diagnosed with it. Given
this family problem, I can't help but be afraid for my nine-year-old
daughter. She's going to start menstruating soon and I worry about her
risks of getting breast cancer." Her fear was evident in her voice. "I've
seen a lot of research showing that family history is important, and I'm
afraid that it's inevitable that my daughter will get breast cancer. One of
the options I've been thinking about is a mastectomy for my daughter,
to remove both breasts. Do you have any advice?"
This woman was in an exceptionally difficult position. Does she let
her daughter grow up into a deathtrap, or grow up without breasts? Al-
t h o u g h extreme, this question represents a variety of similar questions
faced every day by thousands of women around the world.
These questions were especially encouraged by the early reports on
the discovery of the breast cancer gene, BRCA-l. Headline articles in the
New York Times and other newspapers and magazines trumpeted this
discovery as an enormous advance. The hoopla surrounding BRCA- I ,
which now also includes BRCA-2, reinforced the idea that breast cancer
was due to genetic misfortune. This caused great fear among people
with a family history of breast cancer. It also generated excitement
among scientists and pharmaceutical companies. The possibility was
high that new technologies would be able to assess overall breast cancer
risk in women by doing genetic testing; they hoped they might be able
to manipulate this new gene in a way that would prevent or treat breast
cancer. Journalists busily started translating selective bits of this infor-
m a t i o n for the public, relying heavily on the genetic fatalistic attitude.
No doubt this contributed to the concern of mothers like Betty.
"Well, let me first tell you that I am not a physician," I said. "I can't
help you with diagnosis or treatment advice. That's for your physician
to do. I can speak about the current research in a more general way,
however, if that is of any help to you."

COMMON CANCERS: BREAST, PROSTATE, LARGE BOWEL                 159
"Yes," she said, "that's what I wanted."
I told her a little bit about the China Study and about the important
role of nutrition. I told her that just because a person has the gene for a
disease does not mean that they are destined to get the cancer: promi-
n e n t studies reported that only a tiny minority of cancers can be solely
blamed on genes.
I was surprised at how little she knew about nutrition. She thought
genetics was the only factor that determined risk. She didn't realize that
food was an important factor in breast cancer as well.
We talked for twenty or thirty minutes, a brief time for such an impor-
t a n t matter. By the end of the conversation I had the feeling that she was
not satisfied with what I told her. Perhaps it was my conservative, scientif-
ic way of talking, or my reluctance to give her a recommendation. Maybe,
I thought, she had already made up her mind to do the procedure.
She thanked me for my time and I wished her well. I remember
thinking about how often I receive questions from people about specific
health situations, and that this was one of the most unusual.
But Betty wasn't alone. One other woman also talked to me regarding
the possibility of her young daughter undergoing surgery to remove both
breasts. Other women who already had one breast removed wondered
whether to have the second breast removed as a preventative measure.
It's clear that breast cancer is an important concern in our society.
One out of eight American women will be diagnosed with this disease
during their lifetimes--one of the highest rates in the world. Breast
cancer grassroots organizations are widespread, strong, relatively well
funded and exceptionally active compared to other health activist orga-
nizations. This disease, perhaps more than any other, incites panic and
fear in many women.
When I think back to that conversation I had with Betty, I now feel
that I could have made a stronger statement about the role nutrition
plays in breast cancer. I still would not have been able to give her clini-
cal advice, but the information I now know might have been of more
use to her. So what would I tell her now?
RISK FACTORS
There are at least four important breast cancer risk factors that are af-
fected by nutrition, as shown in Chart 8.1. Many of these relationships
were confirmed in the China Study after being well established in other
research.

THE CHINA STUDY
160
CHART 8.1: BREAST CANCER RISK FACTORS
AND NUTRITIONAL INFLUENCE
A diet high in animal foods
Risk of breast cancer increases
when a woman has •••                  and refined carbohydrates •••
· .. lowers the age of menarche
· .. early age of menarche (first men-
struation)
· .. raises the age of menopause
· .. late age of menopause
· .. increases female hormone levels
· .. high levels of female hormones in
the blood
... high blood cholesterol                · .. increases blood cholesterol levels
With the exception of blood cholesterol, these risk factors are
variations on the same theme: exposure to excess amounts of female
hormones, including estrogen and progesterone, leads to an increased
risk of breast cancer. Women who consume a diet rich in animal-based
foods, with a reduced amount of whole, plant-based foods, reach pu-
berty earlier and menopause later, thus extending their reproductive
lives. They also have higher levels of female hormones throughout their
lifespan, as shown in Chart 8.2.
According to our China Study data, lifetime exposure to estrogen l is
at least 2.5-3.0 times higher among Western women when compared
CHART 8.2: DIETARY INFLUENCE ON FEMALE HORMONE EXPOSURE
OVER A WOMAN'S LIFETIME (SCHEMATIC)
60.---------------------------~
~      50
:::J
Vl
o
~ 40
LU
,-----\
(J)
C
-     - Plant-Based Diet
o 30
E
....
I                                      -Animal-Based Diet
o
:r:
\
~      20
rtl
E
~ 10
O+--r--r-~~--~-r~--~~--~~
5 10 15 20 25 30 35 40 45 50 55 60
Woman's Age

COMMON CANCERS: BREAST, PROSTATE, LARGE BOWEL                161
with rural Chinese women. This is a huge difference for such a criti-
cally important hormone. 2 To use the words of one of the leading breast
cancer research groups in the world,3 "there is overwhelming evidence
that estrogen levels are a critical determinant of breast cancer risk. "4, 5
Estrogen directly participates in the cancer process. 6 , 7 It also tends to
indicate the presence of other female hormones8-1 that playa role in
2
breast cancer risk. 6 , 7 Increased levels of estrogen and related hormones
are a result of the consumption of typical Western diets, high in fat and
animal protein and low in dietary fiber.3, 13-18
The difference in estrogen levels between rural Chinese women and
Western women 19 is all the more remarkable because a previous report 20
found that a mere 17% decrease in estrogen levels could account for a
huge difference in breast cancer rates when comparing different coun-
tries, Imagine, then, what 26-63% lower blood estrogen levels and
eight to nine fewer reproductive years of blood estrogen exposure could
mean, as we found in the China Study,
This idea that breast cancer is centered on estrogen exposure3, 21 , 22 is
profound because diet plays a major role in establishing estrogen expo-
sure. This suggests that the risk of breast cancer is preventable if we eat
foods that will keep estrogen levels under control. The sad truth is that
most women simply are not aware of this evidence. If this information
were properly reported by responsible and credible public health agen-
cies, I suspect that many more young women might be taking very real,
very effective steps to avoid this awful disease.
THE COMMON ISSUES
Genes
Understandably, women who are most afraid of this disease have a fam-
ily history of breast cancer, Family history implies that genes do playa
role in the development of breast cancer, But I hear too many people say,
in effect, that "it's all in the family" and deny that they can do anything
to help themselves, This fatalistic attitude removes a sense of personal
responsibility for one's own health and profoundly limits available op-
tions,
It is true that if you have a family history of breast cancer, you are at
an increased risk of getting the disease. 23 ,2 However, one research group
4
found that less than 3% of all breast cancer cases can be attributed to
family history.24 Even though other groups have estimated that a higher
percentage of cases are due to family history,25 the vast majority of breast