12-08-2004, 05:31 PM
Good Carbs, Bad Carbs, And Cancer
Date: Thu, 12 Aug 2004 08:05:15 -0000
Subject: NOTMILK - Guest Editorial by Dr. John McDougall
High Carb Diet Linked to Breast Cancer – More Deceit
Friday's (August 6, 2004) newspapers worldwide scared some people into
believing there is further reason to follow the low-carb diet craze, with
"High carb diet linked to breast cancer – Study finds Mexican women who ate
lots of carbohydrates twice as likely to get disease" (San Francisco
According to this newspaper article, these women from Mexico City were
getting their main carbohydrates from tortillas, soft drinks, and bread.
You might think it is time to change your diet – as far away from what
McDougall recommends as possible. Now is not the time for people to make
the switch to Atkins or South Beach to save their breasts, but rather now
is the time to sort out the undeniable truth.
Confusion has been created – and I believe willfully so by reporters and
researchers – by lumping highly processed foods, like sugars and refined
flours, and natural carbohydrates, like starches (corn tortillas),
vegetables and fruits, together. The only excuse for such obviously
irresponsible reporting is that sensational headlines justifying people's
bad habits sell newspapers and flatter the egos of researchers by providing
them a moment in the spotlight.
The truth, as mentioned much later in the article, is that the
cancer-producing diet is one high in sodas and desserts, and lacking in
insoluble fiber from whole grains, fruits and vegetables.
What the Study Actually Says
The study published in the August 2004 issue of the journal Cancer
Epidemiology, Biomarkers & Prevention clearly reported more breast cancer
in women who ate more calories, protein, total carbohydrates, sucrose, and
Sucrose is table sugar and fructose is the primary sugar found in soft
drinks (sodas); usually reported as high fructose corn syrup. Eating more
fiber and starch (often referred to as complex carbohydrates), both only
found in plant foods, meant less breast cancer according to the study.
The explanation for carbohydrates increasing breast cancer rates was that
an increase in dietary carbohydrate raises blood sugar and insulin levels.
This results in an elevation of Insulin-like Growth Factor-1 (IGF-1), which
raises the risk of cancer. IGF-1 does play an important role in cancer,
however, research shows this growth-stimulating hormone is increased in our
diets primarily by animal proteins, (2) and especially those derived from
dairy products. (3) My guess is these important facts were overlooked
because this information did not fit into the authors' pet theory.
Regardless, what is clear is that the diet of Hispanics in Mexico and the
USA has progressively deteriorated over the past 50 years, and as a result,
their rates of obesity, type-2 diabetes, heart disease, and cancer of the
breast, colon, and prostate have increased as expected. (4,5)
If you have been to a major city anywhere in Mexico, or Central or South
America, like Mexico City, then you know what I am talking about. There is
a fast-food restaurant on every corner; the supermarket shelves are lined
with greasy corn and potato chips, and other "junk" carbohydrates; and meat
and dairy products are coveted by people wanting to share in the American
Women Following the Traditional Mexican Diet Have Much Less Breast Cancer
The truth about the diet of women of Mexican ancestry and breast cancer is
summed up in an article from the New York Academy of Science (6):
"...the age-adjusted rate of breast cancer in countries such as Mexico is
among the lowest in the world. In addition, although one of the
fastest-growing minority groups in the United States, Hispanic women living
in this country have been shown to have the lowest incidence of the
mortality rates from this disease across most geographic regions of the
United States. Therefore, one might speculate that dietary factors, which
have been shown to play a role in breast cancer prevention, may account for
this difference. It is well recognized that the traditional Hispanic diet
is rich in protective nutrients such as dietary fiber. It is known that
through complex mechanisms, dietary fiber works to reduce the amount of
estrogens in the body."
The traditional Mexican diet has been one of corn (tortillas), beans,
fruits and vegetables. This kind of eating is associated with very low
rates of breast cancer and all other diseases common to people living in
Western societies. (7)
There are many qualities of traditional plant-based foods that prevent
diseases, qualities that include their dietary starch, fiber, vitamins,
minerals, and other phyto-nutrients. On the other hand, animal-based, and
highly-processed, foods encourage cancer growth because they lack these
plant-food ingredients and are high in cholesterol, fat, protein, and
environmental chemicals. (8)
Breast cancer in Mexico is on the rise, affecting younger women with more
frequency for one obvious reason. The younger generations are targeted by,
and most easily fall prey to, the marketing efforts of the food industries.
Articles like this one that appear in our press serve to confuse people and
further compound our worldwide health problems. Newspaper reporters who
write this nonsense, and researchers that allow this dishonesty to go on
uncorrected, should be ashamed of themselves, and may someday be held
accountable for the human suffering caused by twisting the truth.
1) Isabelle Romieu, Eduardo Lazcano-Ponce, Luisa Maria Sanchez-Zamorano,
Walter Willett, and Mauricio Hernandez-Avila Carbohydrates and the Risk of
Breast Cancer among Mexican Women Cancer Epidemiol Biomarkers Prev 2004 13:
2) Yu H. Role of the insulin-like growth factor family in cancer
development and progression. J Natl Cancer Inst. 2000 Sep
3) Holmes MD. Dietary correlates of plasma insulin-like growth factor I and
insulin-like growth factor binding protein 3 concentrations. Cancer
Epidemiol Biomarkers Prev. 2002 Sep;11(9):852-61.
4) Jimenez-Cruz A, Bacardi-Gascon M, Turnbull WH, Rosales-Garay P,
Severino-Lugo I. A flexible, low-glycemic index mexican-style diet in
overweight and obese subjects with type 2 diabetes improves metabolic
parameters during a 6-week treatment period. Diabetes Care. 2003
5) Rivera JA, Barquera S, Campirano F, Campos I, Safdie M, Tovar V.
Epidemiological and nutritional transition in Mexico: rapid increase of
non-communicable chronic diseases and obesity. Public Health Nutr. 2002
6) Jones LA, Gonzalez R, Pillow PC, Gomez-Garza SA, Foreman CJ, Chilton JA,
Linares A, Yick J, Badrei M, Hajek RA.. Dietary fiber, Hispanics, and
breast cancer risk? Ann N Y Acad Sci. 1997 Dec 26;837:524-36.
7) Malin AS, Qi D, Shu XO, Gao YT, Friedmann JM, Jin F, Zheng W. Intake of
fruits, vegetables and selected micronutrients in relation to the risk of
breast cancer. Int J Cancer. 2003 Jun 20; 105(3):413-8.
8) Kushi L, Giovannucci E. Dietary fat and cancer. Am J Med. 2002 Dec
30;113 Suppl 9B:63S-70S. Review.
9) Romieu I, Hernandez-Avila M, Lazcano-Ponce E, Weber JP, Dewailly E.
Breast cancer, lactation history, and serum organochlorines. Am J
Epidemiol. 2000 Aug 15;152(4):363-70.
Thanks to Dr. McDougall for the passion it took to
research and write this article!
Please visit Dr. John McDougall's website for
multiple doses of magnificent medical advice: