Food for Life: How the New Four Food Groups Can Save Your Life (14 page)

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Overweight
. Your weight affects your risk of developing breast cancer after menopause.
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Before menopause, weight does not increase risk. For those who have cancer, overweight reduces survival, as we will see in more detail later in this chapter.

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Radiation
. All the cells of the body are very sensitive to the damage of radiation, which can turn normal cells into cancer cells. This is why doctors try to avoid unnecessary X-rays and why your dentist gives you a lead apron during an X-ray. Of all the different parts of the body, the breast is probably the most sensitive to X-ray damage, and there is no doubt that X-rays to the breast can cause cancer.
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This poses an obvious dilemma. Since mammograms are X-rays, can they cause the very kind of cancer they are designed to find? Mammography does contribute to the radiation to which women are exposed. However, most concern arises from older X-ray equipment that emits more radiation. Mammography equipment manufactured in the past several years uses much smaller X-ray doses and is unlikely to contribute measurably to cancer risk. In fact, very compelling evidence shows that mammograms can be lifesaving for women over the age of fifty. Even though mammograms do not detect cancers until the tumor is eight to ten years old, they still can improve survival for women over fifty. Below that age, however, scientists are not so sure that there is any benefit to routine mammograms, although it is valuable to have one mammogram done before age forty for later comparison. The problem is that many cancers are missed on mammograms, and women have sometimes been falsely reassured by a negative mammogram, leading to delays in diagnosis and treatment. Women should discuss their own risks and benefits with their physicians, and should schedule mammograms only at modem facilities that do them regularly and maintain new equipment.

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Genetics
. A genetic contribution to breast cancer exists, but is often overestimated. When cancer runs in families, it may well be due to dietary and other life-style factors that we learn from our parents, rather than from genetic inheritance. Even so, about 5 percent of cases are purely attributable to genetics.
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In such cases, cancer is passed from parent to child as a dominant trait, and the family tree is riddled with the disease. And for a larger group of individuals, genetics probably makes a contribution in subtle ways. For example, it may well be that different genes influence one’s susceptibility to carcinogens, the strength of the immune system to seek out and destroy cancer cells, the age of sexual maturation, body weight, and other factors that are relevant to cancer risk. Each of these is also influenced by diet.

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Toxic chemicals
. “Better living through chemistry” was a corporate slogan, and Americans have certainly lived by those words. There are more than 25,000
chemicals in common use, and the long-term toxic effects of most of them are unknown. Some of the chemicals that we inhale or ingest tend to concentrate in our fatty tissues, and breast tissue is high on the list. Could these chemicals play a role in breast cancer? They may well.

Breast cancer is not evenly distributed geographically. Counties that house toxic waste sites tend to have higher than average rates of breast cancer.
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That is true for other forms of cancer, too.

And you don’t have to live near a Superfund chemical waste site to be concerned about toxic exposures. Toxic chemicals are available at any grocery store in the form of pesticides. Happily, organic produce is now more widely available. Chemical contaminants also end up in meats. Pesticides are sprayed on grains that are fed to cattle, chickens, and other livestock. In storage bins, feed grains are sprayed again. Animals concentrate these chemicals in their tissues and, if you eat the muscle tissue or mammary secretions of an animal, you are on the receiving end of their chemical concentration process.

Some evidence suggests that high-fat diets may encourage the absorption of carcinogens into the body. Researchers have observed, for example, that when the carcinogens in cigarette smoke are absorbed through the lung tissue, they tend to travel along with fats in the blood.
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It may be that on a low-fat diet, the body is less likely to absorb and transport carcinogens.

Women who avoid eating animal products have much smaller concentrations of pesticides in their breast milk. In a 1981 study, vegetarians had only 1 to 2 percent of the national average levels of certain pesticides. And for all other chemicals tested except one, the breast milk of vegetarians was much freer of pesticides and industrial chemicals, compared to average Americans.
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The exception was poly-chlorinated biphenyls (PCBs), for which vegetarians had levels comparable to meat-eaters. PCBs often come from fish consumption, and the chemical remains in the body for many, many years after exposure. Once PCBs are in the body tissues, avoiding contaminated fish will reduce PCB levels only very slowly.

Meat-eaters have far higher chemical concentrations in their breast milk, and their breast tissues bathe in these chemicals for years. There are obvious implications for a nursing baby, but what about the mother? Carcinogenic pesticides and industrial chemicals concentrate in the breast tissue, and the degree of their contribution to cancer remains unknown.

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Time between puberty and first pregnancy
. The younger a girl is when puberty occurs, the higher her risk of breast cancer. Also, the later the age of her first pregnancy, the higher her risk. It may be that the early age of puberty has nothing to do with increased risk other than that it indicates an elevation of hormonal stimulation, as was described in
Chapter 1
. As high-fat, low-fiber diets have spread from the wealthy part of the population to, now, the entire population, the age of
puberty has dropped dramatically, from age 17 in 1840 to 12.5 today. It may be that early puberty and cancer are both the result of a hormonal aberration.

On the other hand, it may be that the time period between puberty and the first pregnancy is one in which the body is particularly sensitive to carcinogens, and the longer this time period is, the greater the risk.

Occasionally people who have cancer report feeling that, if food plays a role in cancer, then they are somehow to blame for their disease. Guilt and blame often become concerns for people dealing with cancer. However, my belief is that these burdens are not useful. Besides, it makes no sense to blame anyone for things they had no way of knowing. Until major public education programs spread the word about the role of dietary factors and help people to change, cancer will remain an epidemic.

What we can do is not only boost our own strength against cancer but also break the cycle for the next generation. Of all the women born in America, one in eight will get breast cancer at some time in her life. If they do not have information on the disease, they are unable to decide for themselves what to do.

Although the National Cancer Institute takes the link between diet and breast cancer seriously and has issued guidelines (albeit weak ones) for cancer prevention, most American women have not gotten the message. In 1991, the Physicians Committee for Responsible Medicine commissioned a survey by Opinion Research Corporation of Princeton, New Jersey, asking how many women had not yet learned of the connection between diet and breast cancer. The results were dismal: 80 percent of women had no idea there was any link.

Why would the leading killer of young women not be the subject of prevention campaigns? Unfortunately, public attention is focused on
finding
breast cancer by mammography and self-examination, not on
preventing
it. Each October for the past several years has been designated National Breast Cancer Awareness Month. The president signs an annual proclamation, and television programs and magazines pick up the story. But every year since its inception, the materials disseminated to the press focus on mammography and self-examination. While that educational effort has merit, information on prevention is completely left out. What the press does not know is that National Breast Cancer Awareness
Month is sponsored by Imperial Chemical Industries (ICI), the makers of tamoxifen, an anti-estrogen drug used in the treatment of breast cancer. ICI provides the funds for promotional efforts for the October program, and retains approval rights over the materials that are used. And ICI has consistently decided not to include information that might prevent breast cancer. While tamoxifen is a very helpful drug for women with cancer, Id’s decision to focus only on
finding
cancer through mammograms and examinations has meant that lifesaving prevention information is effectively squeezed out of air play and out of press space.

The incidence of breast cancer cannot be reduced by early detection because mammograms and self-examination only find existing cancers and are intended to make treatment more successful. Finding cancer on a mammogram or examination will never be as helpful as avoiding cancer entirely.

Meanwhile, back in Japan a tragedy is unfolding. The U.S. government has been pushing Japan to accept American agricultural products, particularly tobacco and beef. As demand for these deadly products declines domestically, sagging sales are propped up overseas. And there is no shortage of patrons for McDonald’s and Kentucky Fried Chicken in Tokyo and Osaka. Meat, poultry, and egg consumption has increased eightfold, and dairy consumption is fifteen times what it was in 1950. Fat intake in Japan climbed from less than 10 percent of calories in 1955 to 25 percent in 1987.
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Meanwhile, consumption of rice and green and yellow vegetables has dropped dramatically.
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Breast cancer death rates are increasing steadily, along with cancer of the colon, ovary, uterus, prostate, and pancreas.
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This is not to suggest that, without Western influence, Japan’s diet would be perfect. The Japanese diet is too high in salt and too high in pickled foods. They pay a price in stomach cancer,
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hypertension, stroke, and other health problems. But the Westernization of the Japanese diet is accompanied by Western diseases as well.

As the consumption of more meat, dairy products, and fried foods assaults women’s bodies, and the protection of vitamin-rich vegetables and fruits is neglected, the effects are all too apparent: altered hormonal function, an unnatural age of puberty, and an impairment of the immune system that might otherwise knock out cancer cells. But a healthful diet can diminish the risk while building the body’s defenses. To the extent that such a diet is put to work, we can hope to turn the tide on this epidemic.

The uterus and ovary, of course, are reproductive organs, and factors that affect hormone function can be expected to affect these organs as well. The risks of cancer of the uterus or ovary are higher in populations that have more breast cancer, suggesting that they may be caused by similar factors. Uterine cancer is linked to fatty diets and obesity,
^3
,
30
,
31
although other factors, including hormone supplements, also play an important role. Ovarian cancer is also more common where people eat higher-fat diets.
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,
32

We now have some new clues to preventing cancer of the ovary from a study by Dr. Daniel Cramer of Harvard University.
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Cramer studied hundreds of women with ovarian cancer, and had them record in detail what they normally ate. He compared them to a group of women who were similar in age and other demographic variables, but who had not developed cancer. There was one thing that the women with cancer had eaten much more frequently than women without cancer: dairy products, especially the supposedly “healthy” products such as yogurt.

The culprit may be a breakdown product of the milk sugar, lactose. As we saw in
Chapter 1
, lactose is broken down in the body to another sugar called galactose. In turn, galactose is broken down further by enzymes in the body. According to Dr. Cramer, when dairy product consumption exceeds the enzymes’ capacity to break down galactose, there is a buildup of galactose in the blood, which may damage a woman’s ovaries. Some women have particularly low levels of these enzymes, and when they consume dairy products on a regular basis, their risk of ovarian cancer can be triple that of other women. The problem is the milk sugar, not the milk fat, so it is not solved by using nonfat products. In fact, yogurt and cottage cheese seem to be of most concern because the bacteria used in their production increase the production of galactose from lactose. This is one of many reasons I recommend that dairy products be avoided, as we will see in more detail in
Chapters 5
and
6
.

Just as women on high-fat Western diets have more estrogens circulating in their blood and a higher risk of cancer of the reproductive organs, a similar process occurs in men. High-fat diets alter the amounts of testosterone, estrogen, and other hormones in both men and women, as we saw in
Chapter 1
. One in ten men will develop prostate cancer at some point in his life.

The prostate gland is just below the bladder in men, where it produces semen, to be mixed with sperm cells. Cancer of the prostate is the most common form of cancer in American men,
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occurring mainly in older men.

Cancer cells are found in the prostates of about 20 percent of men over the age of forty-five.
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In most cases, these cancer cells do not develop into cancerous tumors that affect the overall health or lifespan of the individual. However, in many cases the cancer does grow, invades surrounding tissues, and spreads to other parts of the body. Although the disease varies greatly from one person to the next, the average patient loses nine years from a normal lifespan.
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