Medicine and Nutrition
The Risk of
Hormone Replacement Therapy
The New England Journal of Medicine
of June 15, 1995, reported that hormone replacement therapy
increases the risk of breast cancer.1 This was not news
to most doctors. But many have continued to prescribe hormones
because they feel that the benefits to the heart and bones
outweigh the cancer risk. In the doctor’s mind, it is a case of
“choosing your disease.” Will it be heart disease and osteoporosis
from too little estrogen, or breast cancer from too much?
But before we reach for the prescription
pad, it is worth considering other approaches to menopause and the
problems that sometimes follow it.
The most popular estrogen product is
Premarin, from Wyeth-Ayerst Laboratories. Although doctors
sometimes describe it as “natural” for women, it is actually a
horse estrogen. On farms in North Dakota and Canada, 75,000 mares
are impregnated and then confined from the fourth month through
the end of their eleven-month pregnancy so their urine can be
gathered in a collection harness. After they give birth, the mares
are reimpregnated. Their foals usually end up as horse meat, and
the urine estrogens are packed into pills. The trade name
“Premarin” is simply a condensation of the words “pregnant mares’
urine”—hardly a natural substance for human beings to swallow.
While Premarin contains estradiol and estrone, two types of
estrogen which are made in humans, it also contains an enormous
amount of equilin, a horse estrogen that never occurs at
all in humans.
Estrogen supplements can have serious side
effects. They are particularly risky for women with clotting
disorders, undiagnosed vaginal bleeding, liver disease, a past
history of breast cancer, or a strong family history of breast
They increase the risk of uterine cancer,
unless progesterone (or a synthetic progesterone-like drug) is
added to the regimen. They increase the risk of breast cancer,
whether progesterone is added or not. Women taking estrogen
supplements have 30 to 80 percent more breast cancer risk than
So why are so many doctors prescribing them?
Most of the push relates to osteoporosis and heart disease.
Osteoporosis is very common in Caucasian women, less so among
other races. About one-quarter of white women over 60 have
compression fractures of their vertebrae, and many develop hip
fractures due to the gradual loss of bone. But estrogens are not
nearly as good at protecting the bones as women may be led to
believe, and they rarely arrest bone loss. At their best,
estrogens simply slow the rate of bone deterioration.
Other approaches can be much more effective,
and they do not cause cancer. For example, a major article in the
American Journal of Clinical Nutrition reported last year
that eliminating animal protein from the diet can cut urinary
calcium losses in half,2 resonating with other studies
showing that populations that follow plant-based diets have
enviably low rates of hip fracture. Cutting salt intake can reduce
your calcium losses even further.3 Limit your caffeine
consumption to no more than two cups of coffee per day, and you
will hold onto still more calcium. If you don’t smoke, you’ll also
avoid the 10 percent loss of bone that plagues chronic smokers.4
If you put these factors together, they are a powerful and safe
approach for strong bones.
When osteoporosis has developed, a different
hormone, called natural progesterone, has demonstrated the ability
to actually encourage new bone growth. Unlike estrogens, which
simply slow bone loss, progesterone actually increases bone
density.5-7 It is derived from yams or soybeans, has no
significant side effects, and is sold without a prescription as a
transdermal cream. For more information, call Professional and
Technical Services (800-648-8211), Women’s International Pharmacy
(800-279-5708), or Klabin Marketing (800-933-9440).
For heart disease, hormones are no match for
lifestyle changes. As Dr. Dean Ornish’s pioneering work has shown,
a combination of a low-fat vegetarian diet, mild exercise, stress
reduction, and smoking cessation is powerful enough to actually
reverse heart disease in 82 percent of patients in one year.8
But Americans want pills, and they don’t
want to change their diets, say some doctors. The truth is, many
people will gladly change their diets and other aspects of their
lifestyle if they understand the benefits of doing so and are
assisted in the process.9 The real problem is, even
though a mountain of research has shown the value of dietary and
lifestyle approaches, many doctors still know little about them.
Of course, it is not just estrogen pills
that increase cancer risk. Estrogen production within a woman’s
body is increased by high-fat diets and overweight. The result is
a higher risk of cancer. The National Cancer Institute reports
that cutting fat to 20 percent of calories will reduce a woman’s
estrogen levels by 17 percent, which is a good first step in
There Is No
Japanese Word for Hot Flashes
It has long been known that menopause is
much easier for Asian women than it is for most Westerners. Hot
flashes are reported by only about 10 percent of Japanese women at
menopause. Not only are hot flashes much rarer, but bone strength
is not assaulted to the extent it often is among Western women.
Broken hips and spinal fractures are much less common.
The most likely explanation is this:
throughout their lives, Western women consume much more meat and
about four times as much fat as do women on traditional Asian
rice-based diets, and only one-quarter to one-half the fiber. The
result is a chronic elevation of estrogen levels. At menopause,
the ovaries’ production of estrogen comes to a halt, causing a
violent drop in estrogen levels. Asian women have lower levels of
estrogen both before and after menopause, and the drop appears to
be less dramatic. The resulting symptoms are much milder or even
non-existent. Those who enter menopause on a low-fat vegetarian
diet often breeze right through it. This does not mean that women
who have more symptoms have somehow failed, but it is a good
reason to learn about how foods can affect this aspect of health.
1. Colditz GA, Hankinson SE, Hunter DJ, et al. The use of
estrogens and progestins and the risk of breast cancer in
postmenopausal women. N Engl J Med 1995;332:1589-93.
2. Remer T, Manz F. Estimation of the renal net acid excretion by
adults consuming diets containing variable amounts of protein. Am
J Clin Nutr 1994;59:1356-61.
3. Nordin BEC, Need AG, Morris HA, Horowitz M. The nature and
significance of the relationship between urinary sodium and
urinary calcium in women. J Nutr 1993;123:1615-22.
4. Hopper JL, Seeman E. The bone density of female twins
discordant for tobacco use. N Engl J Med 1994;330:387-92.
5. Lee JR. Osteoporosis reversal: the role of progesterone.
International Clin Nutr Rev 1990;10:384-91.
6. Prior JC. Progesterone as a bone-trophic hormone. Endocrine Rev
7. Prior JC, Vigna Y, Alojado N. Progesterone and the prevention
of osteoporosis. Canad J Ob/Gyn 1991;3:178.
8. Ornish D, Brown SE, Scherwitz LW, et al. Can lifestyle changes
reverse coronary heart disease? Lancet 1990;336:129-33.
9. Barnard ND, Akhtar A, Nicholson A. Factors that facilitate
compliance to lower fat intake. Arch Fam Med 1995;4:153-8.
10. Prentice R, Thompson D, Clifford C, Gorbach S, Goldin B, Byar
D. Dietary fat reduction and plasma estradiol concentration in
healthy postmenopausal women. J Natl Cancer Inst 1990;82:129-34.
This article was originally printed under
the title Hormone Replacement Increases Cancer Risk in the
Autumn 1995 issue of