The Encyclopedia of Natural Medicine, 3rd Ed.

Cancer Prevention



No other disease strikes as much fear deep within our souls as cancer. The reason? Almost all of us have witnessed firsthand the ravaging effects of cancer, as well as chemotherapy and radiation, on a loved one. Cancer statistics in the United States present us with some sobering facts:

• More than 1.25 million new cases of invasive cancer will be diagnosed each year.

• An additional 1.5 million new cases of noninvasive cancers will be diagnosed each year.

• More than 500,000 people will die from cancer each year.

• Cancer causes one in five of all deaths.

• Cancer will affect one out of every three people alive today.

• Of those diagnosed with cancer, 50% will die of their disease.

• The annual economic toll of cancer is more than $110 billion.1

Despite dedicating significant resources to the battle against cancer, conventional medicine alone has had very limited success against this disease. Granted, there have been some tremendous advances for a few of the less common cancers, but for the most part we are losing the war on cancer—more people are dying of cancer today in America than ever before.

We’ve all heard it said: “An ounce of prevention is worth a pound of cure.” When it comes to cancer, that old saying carries a ton of truth. There is no guarantee, but the basic strategy for cancer prevention is reducing or eliminating as many risk factors associated with cancer as possible while at the same time focusing on those health habits, dietary factors, lifestyle components, and attitudes that are linked to a reduced risk of getting cancer.

Understanding and Preventing Cancer

To understand how natural prevention strategies are effective in preventing cancer, it helps to know some basic facts about the cells in your body and cancer. Your body contains trillions of cells. Within each cell is a central core known as the nucleus. Inside the nucleus lies the key to life itself: a long, twisted molecule of deoxyribonucleic acid, better known as DNA. Put simply, DNA contains the instructions (the genes) that the cell needs to make its vital proteins as well as replicate itself. Abnormal changes in a cell’s DNA are called mutations. Usually cells with mutations recognize they are damaged and simply die—a process called apoptosis. But sometimes they continue to divide at a rapid, uncontrolled rate to form clumps of cells that grow into the mass of tissue we call a tumor. There are two types of tumors: benign and malignant.

• Benign tumors are not cancerous because the cells are normal (they have not mutated) and do not usually pose a threat to life. They can usually be surgically removed or treated with drugs. Cells from benign tumors do not spread to other parts of the body.

• Malignant tumors are cancerous. Their mutated cells divide without control or order, and they can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system, forming new tumors in other organs.

Mutations are usually the result of DNA molecules coming into contact with free radicals—highly reactive atoms that can destroy or alter body structures, including DNA. Free radicals assault us from all directions. Some of these come from our environment, in pollutants such as chemicals or cigarette smoke; others come from our diet, in the form of fats damaged by frying or nitrates in smoked or cured meats. Even sunlight produces free radical damage. But free radicals also result from the cell’s own metabolic activity. Most carcinogens (cancer-causing compounds) are dangerous because they cause severe free radical or oxidative damage to DNA.

Fortunately, nature counteracts free radicals and the oxidation they cause by neutralizing them with other molecules known as antioxidants. By mopping up free radicals, antioxidants are powerful weapons in the fight against cancer and other degenerative diseases. So if you want to reduce your risk of cancer, it’s important to:

• Reduce free radical formation in the body.

• Limit exposure to dietary and environmental sources of free radicals.

• Increase your intake of antioxidant nutrients and other substances that support immune function.

Identifying Risk Factors

Cancer risk factors fall into two main categories: inherited and environmental. There’s not a lot we can do to eliminate genetic risk factors, because they’re passed on from generation to generation and are present at birth. However, inherited genetic defects are responsible for only about 15% of all cancers. This statistic means that approximately 85% of all cancers result from environmental risk factors, such as diet, lifestyle, and exposure to harmful substances.

In assessing the likelihood that an individual will develop a certain disease, specialists in epidemiology (observational and statistical studies of people and diseases) use a concept known as relative risk.Relative risk (abbreviated RR) is a number that shows how much more likely it is that individuals who possess a certain trait will develop a condition, compared with individuals who do not share that trait. For example, someone whose RR is 1.5 is 50% more likely to develop a condition than someone whose RR is 1. A relative risk of 2 means you are twice as likely (100% more likely), and so on.

Here’s one dramatic statistic that should make the point. Compared with nonsmokers, cigarette smokers are said to have a relative cancer risk of 10—in other words, they are 10 times, or 1,000%, more likely to get lung cancer than someone who never smoked.

A few words of caution: relative risk is a statistic that’s used to compare large numbers of people. So we cannot with any certainty predict your specific (absolute) risk as an individual. Some nonsmokers get lung cancer, while some smokers never develop the disease. If you are a nonsmoker, we have no idea if you will be, among every 10 people who develop lung cancer, the 1 who doesn’t smoke. If you are a smoker, we cannot accurately predict if you will be the rare smoker who evades the disease.

This chapter discusses the main cancer risk factors and then offers a self-assessment survey. By completing that survey, you’ll be able to evaluate your risk of developing certain cancers. The higher the rating, the more aggressive your primary prevention strategies will need to be.

Genetic Factors

Studies on identical twins (who share the exact same DNA) confirm the point we made above, that most cancers do not arise from genetic defects. Instead, diet and lifestyle play a more significant role. Surprisingly, that’s true even for cancers that tend to run in families. Still, researchers have identified about 30 genetic defects that increase the risk for certain cancers. Some of these cancers are rare; they also tend to be types that develop more often in childhood.


It’s a fact of life: the older you are, the more likely you are to develop cancer. As we age, our cells become less proficient at repairing damage to our DNA. As a result, there are more cells present in the body that possess mutations and that are prone to develop cancer. In the year 2000, more than 60% of new cancer cases and more than 70% of all cancer-related deaths occurred in people over the age of 65.



Perhaps the best-known example of cancer with a genetic basis is an inherited mutation in two genes whose function is to suppress the development of breast cancer. Overall, these mutated genes (known as BRCA1 and BRCA2) are responsible for about 10% of all cases of the disease. A little more than half of women who inherit mutations in these genes will develop breast cancer by age 70. These women also have a greater risk of ovarian cancer.

If you have a strong family history of cancer, it’s worthwhile to talk to your doctor about blood tests that can identify genetic mutations. It’s important to understand and weigh the benefits and risks of genetic testing before these tests are done. Testing is expensive, and some health plans do not cover the costs. There is concern that people with abnormal genetic test results will not be able to get life insurance, or coverage may be available only at a much higher cost.

We do not recommend genetic testing as a cancer screening method. This advice is especially true with respect to identifying the mutated BRCA genes, since only about one woman out of 850 carries these mutations. From the public health perspective, not enough women at risk would be identified to justify the enormous cost of widespread testing. In addition, even if you have the BRCA1 or BRCA2 mutation, you still have only about a 50/50 chance of developing breast cancer before the age of 70.

If you elect to undergo genetic testing and a mutated gene is found, you will need to be more aggressive in your prevention plan and schedule more frequent exams to monitor for early signs of cancer.


Family History

Some (but not most) cancers seem to run in families. For example, if a woman has two first-degree relatives (mother, aunt, or sister) who developed breast cancer, her risk for breast cancer is two to five times greater than that of a woman without such a family history. The same sort of relationship exists concerning prostate cancer in men.


Overall, black Americans are more likely to develop cancer than persons of other racial and ethnic groups (see the table below). The incidence of certain types of cancers also varies by race. Compared with other groups, black men are more likely to have cancers of the prostate, colon and rectum, and lung. In fact, black men have at least a 50% higher rate of prostate cancer than any other group. In contrast, breast cancer rates are highest among white women (114 per 100,000) and lowest among Native American women (33.4 per 100,000).

Overall Incidence of Cancer Among Ethnic/Racial Groups2


RATE (PER 100,000)





Asians/Pacific Islanders




Native Americans


Some of the differences in cancer rates among racial and ethnic groups may be due to factors associated with social class rather than race or ethnicity. Such factors include education, access to health care, occupation, income, and exposure to harmful substances in the environment. Diet is also critical to look at in evaluating data on race and cancer.

Medical History

Sometimes, having one disease can increase your risk for developing another. Diseases known to increase the risk of certain cancers include alcoholism, chronic hepatitis, diabetes, history of genital warts, HIV infection, inflammatory bowel disease (Crohn’s disease and ulcerative colitis), and peptic ulcer. The presence of any of these conditions requires a more concerted effort to reduce cancer risk.

Hormonal Factors

Certain cancers, most notably prostate and breast cancer, are affected by hormonal factors. In prostate cancer, the primary hormonal factor is testosterone, while in breast cancer the hormone of concern is estrogen. For more information, see the chapter “Breast Cancer (Prevention),” or the chapter “Prostate Cancer (Prevention).”

Environmental Factors

As described above, exposure to tobacco smoke is a leading cause of cancer, especially lung cancer. A long and growing list of other environmental factors linked to certain cancers includes pesticides, herbicides, heavy metals, asbestos, solvents, and possibly exposure to electrical power lines. The risk depends on the concentration, intensity, and duration of exposure. Substantial increases in risk have been demonstrated in occupational settings where workers have been exposed to high concentrations of certain chemicals, metals, and other substances.

Certain Medical Treatments

Sometimes medical treatment increases the risk of certain cancers. For example, radiation therapy and many chemotherapy drugs carry with them an increased risk for producing new cancers later on. Estrogen and oral contraceptives have been linked to an increased risk of breast cancer. The term iatrogenic refers to diseases that arise inadvertently as a result of medical or surgical treatment.

Lifestyle Factors

The importance of a healthful lifestyle in cancer prevention cannot be overstated. The key components are avoiding tobacco use and exposure to cigarette smoke; exercising regularly; and avoiding alcohol or drinking only moderate amounts.


The evidence is overwhelming that smoking is the most preventable cause of cancer and premature death in the United States. Smoking is responsible for nearly 90% of all lung cancers. Lung cancer mortality rates are more than 20 times higher for current male smokers and 12 times higher for current female smokers compared with people who have never smoked. Smoking is also associated with an increased risk for virtually every other cancer and accounts for at least 30% of all cancer deaths. Smoking is also a major cause of heart disease (the leading cause of death in the United States), strokes, chronic bronchitis, and emphysema.

Passive smoking—exposure to secondhand smoke—is an important risk for cancer (particularly lung and breast cancer) and is an even greater risk for causing heart disease. People who don’t smoke but who inhale smoke from the environment may be even more susceptible to the free radical damage the chemicals in smoke cause to their heart and arteries, because their bodies just aren’t used to dealing with such a heavy toxic load. One study found that a woman who has never smoked has an estimated 24% greater risk of getting lung cancer if she lives with a smoker.3 The U.S. Environmental Protection Agency estimates that passive smoking causes 3,000 lung cancer deaths each year.


A number of studies have found a link between low physical activity levels and an increased cancer risk. On the other hand, increased physical activity, whether from structured exercise or physical labor, has been found to cut the overall cancer risk nearly in half. The greater the activity level, the lower the risk. The association is strongest for colon and breast cancers. The preventive effects of exercise are seen even in people who have other risk factors, such as poor diet, excess body weight, and smoking.4,5

Alcohol Consumption

There is a clear association between alcohol consumption and many forms of cancer. The higher the dose (amount of alcohol), the greater the risk. While moderate consumption (that is, one glass of wine, one beer, or 1 fl oz hard liquor per day) poses little risk, drinking alcohol beyond this amount greatly increases the chance of getting cancer of the throat, liver, colon, or breast. Alcohol is metabolized into highly reactive compounds such as acetaldehyde that act as free radicals and damage DNA repair mechanisms, further raising the risk.

Psychological Factors

Stress, personality, attitude, and emotional state are thought to predict the development of many diseases, including cancer. Although this idea is somewhat controversial, personality stereotypes have emerged that reflect an increased risk for certain diseases. For example, the so-called type A personality—easily angered, competitive, and hard-driving—is associated with an increased risk for heart disease. The typical cancer personality is type C, associated with the denial and suppression of emotions, in particular anger. Other features of this pattern are “pathological niceness,” avoidance of conflicts, exaggerated social desirability, harmonizing behavior, overcompliance, excessive patience, high rationality, and a tendency toward feelings of helplessness. What the type C personality displays on the outside is a facade of pleasantness. However, this outward expression quickly dissolves during times of stress. Typically the type C personality deals with stress through excessive denial, avoidance, and suppression and repression of emotions.6 This internalization is thought to contribute to the development of cancer by amplifying the negative effects that stress produces on the immune system.

What research continues to tell us is that how a person handles stress is more crucial than the stressor itself and that the response to stress is highly individualized. Two people might have the same stressful experience, but they may react to it in entirely different ways; as a result, some may develop cancer, while others may not.7

It is our belief that helping a person develop an effective method to deal with stress is more important than identifying a particular “cancer personality.” Put simply, dealing with stress in a positive manner through exercise, relaxation techniques, and counseling appears to offer protection against cancer and boost immune function regardless of personality type. In contrast, inappropriate ways of dealing with stress such as suppression of emotion, denial, drinking alcohol, using drugs, or overeating will have a negative effect.

Two chapters—“A Positive Mental Attitude,” and “Stress Management”—provide general recommendations that have also been shown to fight cancer and boost immune function.


Dietary factors are the major cause of cancer in the United States. There are two main reasons. One is that a poor diet fails to supply the body with the nutrients and other dietary factors it needs to maintain healthy cells and tissues. A poor diet means the immune system is less able to defend against foreign invaders that can trigger the onset of cancer.

Another reason poor diet is a concern is that it promotes obesity. A report by RAND Corporation researchers found that obesity contributes at least as much to the development of chronic degenerative disease—including cancer—as smoking does.8 Obesity severely disturbs the body’s ability to regulate the complex interactions among diet, metabolism, physical activity, hormones, and growth factors. Women who are obese after menopause have a 50% higher relative risk of breast cancer. Obese men have a 40% higher relative risk of colon cancer. Gallbladder and endometrial cancer risks are five times higher among obese individuals, and obesity appears to raise the risk of cancers of the kidney, pancreas, rectum, esophagus, and liver.

In the chapter “A Health-Promoting Diet,” we focus on general dietary recommendations for good health that overlap with specific dietary recommendations for cancer prevention. The recommendations in the chapter “Supplementary Measures” provide a strong level of additional cancer-fighting support. The goal of these recommendations is to reduce dietary factors that increase cancer risk while increasing the intake of substances that protect against cancer.

Dietary Factors That Increase Cancer Risk


Dairy products

Total fat

Saturated fats

Refined sugar

Total calories


Dietary Factors That Decrease Cancer Risk


Whole grains



Other vegetables





By completing this self-assessment, you’ll generate a score that indicates your relative risk of cancer. Reading the information in the “Rationale” column will provide you with a quick summary of the scientific data explaining why these variables are important.

Our solution to the difficult task of determining cancer risk was to insert as many variables as we possibly could into a single self-assessment questionnaire. For example, we know from our research that smokers who eat a diet rich in the brassica vegetables—those in the cabbage family, such as broccoli, cauliflower, cabbage, watercress, bok choy, kale, and so on—have a lower relative risk of developing lung cancer. So the smoker who does not eat brassica vegetables would have a relative risk for developing lung cancer of 10, while the smoker who eats these foods would have a lower RR. By adding up two scores, one for factors that increase risk and another for factors that decrease risk, and then multiplying them together, you’ll get a general sense of where you stand on the cancer risk continuum compared with other people in this country.

Another caveat: This survey is for guidance only. It has not been scientifically validated in large clinical trials. Still, the information it provides may be useful as a guide to understanding your relative risk of developing cancer, and may help inspire you to take certain steps to reduce that risk through natural strategies, diet, and nutritional support, as described in the following chapters.


For each of the following, please enter 1 if the cancer risk factor does not apply to you. Otherwise, enter the appropriate risk number as shown. (Note: insert only one number for each factor 1 through 14.)








More than 30% of all cancer deaths are attributable to smoking. Quitting smoking dramatically reduces risk. For breast cancer, people who smoked at some time in their lives have a RR of 2.0 compared with people who never smoked or who were never exposed to high levels of passive smoke; for individuals exposed to passive smoke before age 12, the RR for breast cancer is 4.5.9

Active (currently smoking)



Ever active (ever smoked, but have not smoked in at least one year)



High exposure to passive smoke (especially as a child)



Immediate family member with cancer: grandparent(s), parent(s), or sibling(s)



Family members have a two- to threefold increased risk of developing the same type of cancer.

Electromagnetic radiation exposure (telephone installers, line workers, etc.)



Significant electromagnetic radiation from any source increases the risk of cancer. Certain occupations associated with electromagnetic radiation increase risk. In one study, RR was 2.17 in those who worked as telephone installers, repairers, and line workers; and in another 1.65 for system analysts/programmers.10

Not eating fish or not taking a fish oil supplement



During 30 years of follow-up, men who ate no fish had a two- to threefold higher frequency of prostate cancer than did those who ate moderate or high amounts.11

Red meat consumption

1 time per week or less

>4 times per week

If you usually eat meat well-done or smoked





Researchers at the National Cancer Institute have found that those who ate their beef medium-well or well-done had more than three times the risk of stomach cancer compared with those who ate their beef rare or medium-rare. They also found that people who ate beef four or more times a week had more than twice the risk of stomach cancer than compared with consuming beef less frequently. Eating meat one or more times a week carries with it a relative risk for colon cancer of 1.90 compared with eating no meat.12 Well-done meats increased the risk of developing breast cancer by a factor of 4.6.13

Low consumption of fruits and vegetables (<1.5 servings/day)



Fruits and vegetables contain an array of cancer-fighting compounds. Individuals who consumed less than 1.5 servings of fruit and vegetables per day had a relative risk for developing colorectal cancer of 1.65.14

Obesity/total calories



Obesity was associated with a statistically significant 50–60% increased risk of pancreatic cancer.15 People who rank in the highest third of body mass index have a 1.9-fold higher risk of dying from breast cancer than those in the lowest third.16

Above-average consumption of sugar (American average is about 5 oz/day)



High levels of sucrose intake were associated with a 1.59 relative risk of colon cancer.17 High refined sugar consumption had a relative risk for colorectal cancer of 1.4.18 Foods that produce sharper elevations in blood sugar levels were associated with a relative colorectal cancer risk of 1.8.19




Depression is associated with an increased cancer risk, probably through its effects on suppressing immune function.20

Diesel emissions (heavy equipment operators, tractor drivers)



30 years of working on a job with exposure to diesel motor emissions increased RR to 1.43.21

Dairy (>1 serving per day)



Women who consumed the highest amount of lactose (1 or more servings of dairy per day) had a 44% greater risk for all types of invasive ovarian cancer compared with those who ate less than 3 servings monthly.22 Men who consume 2.5 servings a day of dairy products had a 50% increased risk of prostate cancer.23

Refined flour intake



The RR of colon cancer increased 1.32 for an increase of 1 serving per day of refined flour products (e.g., white bread, pasta).24

Using omega-6 polyunsaturated oils (corn, safflower, sunflower, and soy oil), especially for cooking



Women who consumed the most polyunsaturated fats were 20% more likely to develop breast cancer.25 Heating cooking oil to high temperatures was associated with a 1.64-fold increased risk of lung cancer.26


Men > 21 drinks/week

Women > 10/week




Men who consumed 21–41 drinks per week or more than 41 drinks per week had relative risks of 1.23 and 1.57, respectively. Those who drank beer had a relative risk of 1.09 and 1.36, respectively. For spirits, the risk was 1.21 and 1.46, respectively.27 Excessive alcohol poses a relative risk of 1.28 for colon cancer.28 Consumption of more than 20 g per day of alcohol (approximately 10 drinks per week) led to a relative risk breast cancer of 1.23.29 One to three drinks per week, on average, did not increase the risk of breast cancer in this study.

Avoid the sun and don’t take vitamin D



Those with low levels of vitamin D have a two- to threefold increased risk of most cancers—2.63 relative risk for colon cancer and 2.33 relative risk for breast cancer.3032










Taking a multivitamin with folate

For 14 years or more

For 5 to 14 years




Women who took multivitamin supplements containing folic acid for more than 15 years were 75% less likely to develop colon cancer than women who did not use supplements. Women who took a folic-acid-containing multivitamin for 5 to 14 years were about 20% less likely to develop cancer.33

Fluid consumption(>2.5 1/day)



Consuming >2.5 liters of fluid per day resulted in a 49% lower incidence of bladder cancer than consuming less than 1.3 liters per day.34

Selenium supplement (200 mcg per day)



Selenium supplementation is associated with reductions in incidence of all cancers, especially lung, colorectal, and prostate cancer, and is associated with a 50% decreased risk of mortality from cancer.35

Fish consumption 3 times/week



During 30 years of follow-up, men who ate no fish had a two- to threefold higher frequency of prostate cancer than did those who ate moderate or high amounts.10 Similar results have been seen in other cancers.

Vegetables in the brassica family, including cabbages, kale, broccoli, brussels sprouts, and cauliflower (>5 servings/week)



Protective effect against lung, stomach, colon and rectal cancers have been noted with vegetables in the brassica family.36,37

Legume or soy milk consumption >5 servings/week



Soy milk (more than once a day) was associated with a 70% reduction in risk of prostate cancer,38 while a relative risk of 0.53 was seen for all cancers with a legume intake of >2 times/week vs. <1 time/week.39

Zinc supplement



Zinc supplementation reduced relative risk of prostate cancer to 0.55.40

Regular exercise, equal to or greater than 5 hours per week



Risk for many cancers (e.g., colon and breast cancer) is reduced by 40–50% among the most active individuals, compared with the least active.41

Vegetable consumption >4 servings/day or >28 servings/week



Colon cancer risk with frequent raw and cooked vegetable consumption was 0.85 and 0.69, respectively.14 In a study comparing those who ate more than 28 servings of vegetables/week with those who ate <14 servings per week, the relative risk for prostate cancer was 0.65 among the higher-consumption group.42

Vitamin E supplement (400 IU/day)



Consumption of vitamin E showed a reduction in the rate of prostate cancer by 32%.43 After 12 years of follow-up, bladder cancer risk was reduced by 30%.44

Green tea consumption of ≥3 cups per day or the use of green tea extract (300 mg per day)



A decreased recurrence of breast cancer was observed with consumption of more than 3 cups of green tea.45 Green tea drinking decreased RR to 0.52 for stomach cancer.46,47 Consumption of 10 cups per day decreased incidence of all cancers to 0.55. However, this level produces caffeine side effects.

Garlic consumption of >20 g (5 cloves)/week



Garlic consumption reduces colorectal cancer risk to 0.69 and stomach cancer to 0.53.48

Olive oil consumption >1 tbsp/day



Women who consumed olive oil had a 25% lower risk of breast cancer.25

Wine consumption (1–13 glasses/week)



Drinkers of 1–13 glasses of wine per week had a relative risk of 0.78 compared with nondrinkers of wine.49

Whole grains



Colon cancer risk was reduced to 0.85 with consumption of whole grains vs. refined flour products.24

Fruit, 2 servings/day



Citrus consumption reduced colon cancer relative risk to 0.86, other fruits to 0.85.12

Vitamin D3 supplementation 2,000 to 4,000 IU per day



Vitamin D has been shown to reduce the relative risk of all cancer by 0.30.3032






To determine your relative risk, add up your scores in Section 1 and place the sum on the line indicated. Remember that if a factor does not apply to you, then enter a 1 in the “Score” column. After adding all of the scores, divide the sum by 14. Indicate the result here:

Total score (section 1) = ____ divided by 14 = ____

Repeat that process for Section 2, only this time divide the result by 16.

Total score (section 2) = ____ divided by 16 = ____

Now take those two results and multiply them together.

Section 1 result ____ × Section 2 result ____ = RR ____

The result is an approximate guideline that indicates your risk of developing cancer. Remember, a relative risk of 2 means you are twice as likely to develop cancer as someone with a RR of 1. If your RR is 0.75, you are 25% less likely to develop cancer.


Putting It All Together

Constructing your own personal daily plan for preventing cancer involves strategies for strengthening the four cornerstones of good health detailed in Section II of this book:

• A positive mental attitude

• A healthful lifestyle

• A health-promoting diet

• Supplementary measures

Focusing on these foundations provides the strongest general protection against cancer.

For additional and more specific recommendations for preventing breast or prostate cancer, please go to the chapter “Breast Cancer (Prevention),” or the chapter “Prostate Cancer (Prevention).” For an even more extensive resource on cancer and natural medicine, see our book How to Prevent and Treat Cancer with Natural Medicine (Atria, 2002).



The connection between vitamin D deficiency and cancer was first made by Drs. Frank and Cedric Garland of the University of California, San Diego. After finding that the incidence of colon cancer was nearly three times higher in New York than in New Mexico, the Garland brothers hypothesized that lack of sun exposure (resulting in a lack of vitamin D) played a role. They published their hypothesis in 1980.30

Research now indicates that being deficient in vitamin D increases the risk of death and cancer almost as much as cigarette smoking.31,32 According to Michael Holick, M.D., Ph.D., a noted vitamin D researcher, avoiding sun exposure to prevent skin cancer resulted in such a drop in vitamin D levels that for every life saved from skin cancer, 55 women died from breast cancer and 55 to 60 men died from prostate cancer. While his assertion is controversial, the research is very clear that vitamin D deficiency dramatically increases risk of many cancers, especially breast and colon.

A four-year placebo-controlled study that investigated the effects of 1,100 IU vitamin D3 and/or 1,400 mg calcium on cancer risk in 1,179 postmenopausal women over age 55 showed that vitamin D supplementation produced a dramatic 60% drop in the risk of developing any form of cancer.50


Final Comments

One key strategy in the prevention of cancer is periodic screening. Screening means getting a regular checkup to look for cancer. Screening is especially important for people who have certain risk factors, such as a family history of certain cancers or exposure to environmental toxins.

The major benefit with regular screening examinations by a health care professional is that it can lead to early detection of cancer. Screening-accessible cancers—especially cancers of the breast, colon, rectum, cervix, prostate, testicles, oral cavity, and skin—account for about half of all new cancer cases. In general, the earlier a cancer is discovered, the more likely it is that treatment will be successful. Self-examination for cancers of the breast and skin may also result in detection of tumors at earlier stages. We can’t stress enough the importance of having a complete regular physical exam. Your life may depend on it!

American Cancer Society Recommendations for the Early Detection of Cancer



Cancer-related checkup

A cancer-related checkup is recommended every three years for people ages 20 to 40 and every year for people 40 or older. This exam should include health counseling and, depending on a person’s age and gender, might include examinations for cancers of the thyroid, oral cavity, skin, lymph nodes, and testes or ovaries, as well as for some nonmalignant diseases.


Women 40 and older should have a mammogram every two years and an annual clinical breast examination (CBE) by a health care professional. They also should perform monthly breast self-examination. Women ages 20–39 should have a CBE by a health care professional every three years and should perform monthly breast self-examination.

Colon and rectum

Beginning at age 50, men and women should follow one of the examination schedules below:

• A fecal occult blood test every year and a flexible sigmoidoscopy every 5 years

• A colonoscopy every 10 years

• A double-contrast barium enema every 5 to 10 years

A digital rectal exam should be done at the same time as sigmoidoscopy, colonoscopy, or double-contrast barium enema. People who have a family history of colon cancer should talk with a doctor about a different testing schedule.


The American Cancer Society recommends that both the prostate-specific antigen (PSA) blood test and the digital rectal examination be offered annually, beginning at age 50, to men who have a life expectancy of at least 10 years and to younger men who are at high risk. Men in high-risk groups, such as blacks and those with a strong familial predisposition (i.e., two or more affected first-degree relatives), may begin at a younger age (i.e., 45 years).


Cervix: All women who are or have been sexually active or who are 18 and older should have an annual Pap test and pelvic examination. After three or more consecutive satisfactory examinations with normal findings, the Pap test may be performed less frequently. Discuss the matter with your physician.

Endometrium: Women with a family history of cancer of the uterus should have a sample of endometrial tissue examined when menopause begins.

Source: Modified from information from the American Cancer Society, Inc.



• Cancer is the result of mutations in a cell’s DNA.

• To reduce your risk of cancer, it’s important to:

 • Reduce free radical formation in the body.

 • Limit exposure to dietary and environmental sources of free radicals.

 • Increase your intake of antioxidant nutrients and other substances that support immune function.

• In assessing the likelihood that an individual will develop a certain disease, specialists in epidemiology (observational and statistical studies of people and diseases) use a concept known as relative risk.

• Compared with nonsmokers, cigarette smokers are said to have a relative cancer risk of 10—in other words, they are 10 times, or 1,000%, more likely to get lung cancer than someone who never smoked.

• The key components of a cancer-preventing lifestyle are avoiding tobacco use and exposure to cigarette smoke; exercising regularly; and avoiding alcohol or drinking only moderate amounts.

• The typical cancer personality is type C, associated with the denial and suppression of emotions, in particular anger.

• Dietary factors are the major cause of cancer in the United States.

• A report by RAND Corporation researchers found that obesity contributes at least as much to the development of chronic degenerative disease—including cancer—as smoking does.

• Constructing your own personal daily plan for preventing cancer involves strategies for strengthening the four cornerstones of good health detailed in Section II of this book.

• In general, the earlier a cancer is discovered, the more likely it is that treatment will be successful.