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.
Can cancer really be prevented? Thankfully, in many cases, the answer is an emphatic “Yes!” This is true even if cancer runs in your family. As we'll explain in the first part of this book, by reducing or eliminating as many risk factors as possible and by practicing healthy habits that strengthen your body's defenses, you'll greatly reduce your chances of developing the disease.
Your campaign to prevent cancer requires a lifetime commitment, beginning here, now, today. Fortunately, many prevention strategies-a good diet, the right kind of exercise, a positive attitude—are not just good for you, they actually add to your quality of life. You live longer, you'll live better
Good form you,They actually add to your quality of life you'll not only live longer,you will betterSelf-Assessment of Cancer Risk s to identify thing that might will develop.
One key strategy in the prevention of cancer is to identify the presence of risk factors. The term risk factor refers to anything that might increase your chance of developing the disease. The higher the number of risk factors, the greater the likelihood that cancer will develop. On the other, reducing the number of risk factors increases the chances prevention will succeed.
Cancer risk factors fall into two main categories: inherited and envi-ronmental. 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. But inherited genetic defects are responsible for only about 15 percent of all cancers. This statistic means that approximately 85 per cent 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 have that trait. For example, someone whose RR is 1.5 is 50 percent more likely to develop a condition than someone whose RR is 1. A relative risk of 2 means you are twice (100 percent) as 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--a thousand percent-m likely to get lung cancer than someone who never smoked.
We have constructed for this book a self-assessment of cancer risk based on many variables. By completing this survey, you will genrate score that indicates your relative risk of cancer. By reading the information in the Rationale column, you'll get a quick summary of the scientific data explaining why these variables are important.
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 others, who are smokers, never develop the disease. If you are a nonsmoker, we have no idea if you will be the one person in ten who doesn't smoke but who still gets lung cancer. If you are a smoker, we cannot accurately predict if you will be the smoker who evades the disease.
Our solution to this 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 cabbage family vegetables--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 cabbage family vegetables would still 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. We developed it based on our years of collective experience in the fields of nutrition and cancer management. 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.Instructions
For each of the following, please enter a 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.)Section 1:
Smoking Active (currenty smoking).
Ever active (for merly smoked,but have not smoked in at least 1 year)
High exposure to of passive smoke;(especially as a child)
|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 odds ratios for breast ) cancer is 4.5.|
|Immediate family members with cancer,grandparent(s) parent(s), or sibling(s)||2.5||Family member have a 2- to 3- fold increased risk of developing the same of cancer:|
|Electromagnetic radiation exposure (telephone installers, line workers, etc.)||2.0||Relative risk of 1.98 for pre-menopausal women in occupations with high electromagnetic field exposure in one study; 2.17 in all women who worked as telephone installers, repairers, and line workers in another study: 1.65 for system analysts/programmers; and 1.40 for telegraph and radio operators.|
|Not eating fish||2.0||During 30 years of follow-up, men who ate no fish had a 2- to 3- fold higher frequency of prostate cancer than did those who ate moderate or high amounts.|
|Red meat consumption 1 time per week or less >4 times per week If you usually eat meat welldone or smoked||1.5
|Researchers at the National Cancer Institute have found that those who ate their beef medium-well or welldone had more than 3 times the risk of stomach cancer than those who ate their beef rare or medium-rare. They also found that people who ate beef 4 or more times a week had more than twice the risk of stomach cancer than those consuming beef less frequently. Total meat intake of 1 time/week versus no meat intake Carrer with it a relative risk for colon cancer of 1.90.Wel-done meets (burgers,beefsteak,bacon) in-crease riskof developing breast cancer by a factor of 4.6.|
|Low consumption of fruits and vegetables (<1.5 servings /day)||1.65.||Individuals who consumed less than 1.5 servings of fruits and vegetables per day had a relative risk for developing colorectal cancer of 1.65.|
|Obesity /total calories||1.5||Obesity was associated with a statistically significant 50 to 60% increased risk of pancreatic cancer People who rank in the highest third of body mass index have a 1.9-fold higher risk of dying after breast cancer than those in the lowest third.|
|Above-average consumption of sugar (American average is about 5 ounces /day)||1.6||High levels of sucrose intake were associated with 1.59 relative risk of colon cancer among younger men for highest fifth compared with those in lowest fifth.' High refined sugar consumption had a relative risk for colorectal cancer of 1.4. Foods that produce sharper elevations in blood sugar levels were associated with a relative colorectal cancer risk of 1.8.|
|Depression||1.4||Depression is associated with an increased cancer risk.|
|Diesel emissions (heavy-equipment operators, tractor drivers||1.4||Thirty years of working on a job with diesel motor emission exposure combined showed an odds ratio of 1.43.|
|Dairy (> 1 serving/ day)||1.4||Women who consumed the highest amount of lactose (1 or more seryings of dairy per day) had a 44% greater risk for all types of invasive ovarian cancer compared with those who ate the lowest amount (s3 servings monthly)." Men who consumed 2.5 servings a day of dairy products had a 50% increased risk of prostate cancer.'|
|Refined-flour Intake||1.3||Colon cancer: 1.32 for an increase of 1 serving per day of refined - flour product (e.g., white bread, pasta).|
|Using omega-6 poly unsaturated oils (corn, saf flower, sunflower and soy oil), espe- cially for cooking.||1.4||Women who consumed the most poly unsaturated fats were 20% more likely to develop breast cancer. " Heating cooking oil to high tempera-tures was associated with a 1.64-fold increased risk of lung cancer."|
Men > 21 drinks/
Women >10 drinks/week
|Men who consumed 21 to 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." Excessive alcohol poses a relative risk of 1.28 for colon cancer. Consump-tion of more than 20 gram/day of alcohol (approximately 10 drinks per week) led to a relative risk of breast cancer of 1.23 One to 3 drinks per week, on average, did not increase the risk of breast cancer in this study.|
Taking a multi-vitamin with folate > 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 multivitamin that contained folic acid between 5 and 14 years were about 20% less likely to develop cancer|
|Fluid consumption (>2.5 |/day)||0.5||Consuming more than 2.5 liters of fluide per day resulted in a 49% lower incidence of bladder cancer than consuming less than 1.3 1/day|
|Selenium supplement (200 mcg/day)||.50||Selenium supplementation is associ-ated with reductions in incidence of all cancers, especially lung, colorectal, and prostate cancer, and is ass- ciated with a 50% decreased risk of mortality from cancer 24.|
|Fish consumption 3 times/week||0.50||During 30 years of follow-up, men who ate no fish had a 2- to 3- fold higher frequency of prostate cancer than did those who ate moderate or high amounts. Similar results have been seen in other cancers.|
|Cabbage family vegetables, including cabbages, kale, broccoli, Brussels sprouts, bok choy, and cauliflower (>5 servings/week)||0.5||Protective effect against lung, stomach, colon, and rectal cancers have been noted with cabbage family vegetables.26.27|
|Legume or soy milk consumption of >5 servings/ week||0.50||Soy milk (more than once a day) was associated with a 70% reduction in risk of prostate cancer,while a relative risk of 0.53 was seen for all cancers with a legume intake of >2 times/week versus < 1 time /week.|
|Zinc supplement||0.55||Zinc supplementation reduced relative risk of prostate cancer to 0.55.|
|Regular exercise of <= hours/week||0.45||Risk for many cancers (e.g., colon and breast cancer) is reduced by 40 to 50% among the most active individuals. compared with the least active.|
|Vegetable consumption of > 4 servings/day or > 28 servings/week||0.70||Colon cancer risk with frequent raw and cooked vegetable consumption was 0.85 and 0.69, respectively. In a study comparing >= 28 servings of vegetables /week with < 14 servings per week, the relative risk for prostate cancer was 0.65.|
|vitamin E Suppliment (400 IU/day)||0.70||Consumption of vitamin E showed a reduction in the rate of prostate cancer by 32%. After 12 years of follow-up, bladder cancer risk was reduced by 30%.|
|Green tea consumption <= 3 Cups per day of the use of green tea extract(300 MG/day)||0.70||A decreased recurrence of breast cancer was observed with consumption greater than or equal 3 cups of green tea. Green tea drinking decreased risk to 0.52 for stomach cancer. Consumption of 10 cups per day de creased incidence of all cancers to 0.55." However, this level produces caffeine side effects.|
|Garlic consumption of > 20 g (5 cloves/week)||0.60||Garlic consumption reduces colorectal cancer risk to 0.69 and stomach cancer risk to 0.53.|
|Olive oil consump - tion of > 1 table spoon/day||0.75||Women who consumed olive oil had a 25% lower risk of breast cancer.|
|Wine consuption (1-13 glasses/week)||0.80||Drinkers of 1-13 glasses of wine per week had a relative risk of 0.78 compared with nondrinkers of wine|
|Whole grains||0.85||Colon cancer risk was reduced to 0.85 with consumption of whole grains versus refined flour products.|
|fruit greated then equal servings/day||0.85||Citrus consumption reduced colon cancer relative risk to 0.86, other Fruit to 0.85|
To determine your relative risk, add your score in Section 1 and place it on the line indicated. Remember that if a factor does not apply to you, then enter a “l” in the “Score" column. After adding all of the scores, divide that number by 14. Indicate the result here:
Total score (Section 1) ------------ divided by 14 ----------
Now repeat that process for Section 2, only this time divide the result by
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 percent less likely to develop cancer.
Identifying Risk Factors Following is a description of the main cancer risk factors. When you finish the chapter, take the self-assessment survey (starting on page 4) to help you evaluate your risk of developing certain cancers. The higher the rating, the more aggressive your primary prevention strategies will need to be.
AGE 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 percent of new cancer cases and more than 70 percent of all cancer-related deaths occurred in people over age 65.
GENES Studies on identical twins (who share the exact same DNA) confirm that most cancers do not arise from genetic defects. Instead, diet and lifestyle usually play a significant role. Surprisingly, that's true even for cancers that tend to run in families. Still, researchers have identified about thirty genetic defects that increase risk for certain cancers. Some of these cancers are rare; they also tend to be types that develop more often in childhood.
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 a woman without such a family history. The same sort of relationship exists concerning prostate cancer in men. Even with a family history, in most cases lifestyle and dietary factors have been found to have a greater impact than genetics on cancer risk.
RACE | Overall, black Americans are more likely to develop cancer than persons of other racial and ethnic groups (Table 1-1). Each year, Should You Have Genetic Testing?
Perhaps the best-known example of cancer with a genetic basis is an in herited mutation in two genes whose function is to suppress the devel opment of breast cancer. Overall, these genes (known as BRCA1 and BRCA2; the letters stand for “breast cancer") are responsible for abe 10 percent 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 is not cov ered by some health plans. 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 l 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 age 70.
have only about a 50/50 chance of developing breast cancer before 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 sched ule more frequent exams to monitor for early signs of cancer. (For sp cific recommendations for some of the more common forms of came see Chapter 4.)
about 445 out of 100,000 blacks develops the disease. 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 percent higher rate of prostate cancer than any other group. In contrast, female breast cancer rates are highest among white women (114 per 100,000) and lowest among Native American women (33.4 per 100,000).
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 when evaluating data on race and cancer.
MEDICAL HISTORY | Sometimes, having one disease can increase your risk for developing another. Diseases known to increase 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 ulcers. The presence of any of these conditions requires a more concerted effort to reduce cancer risk. The use of certain medications such as long-term corticosteroids, immunosuppressive drugs, or chemotherapy agents can also increase the risk of cancer.
HORMONES 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 Chapter 4, Special Steps for Preventing Lung, Breast, Prostate, and Colon Cancer.
ENVIRONMENT 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 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. In Chapter we will 2 discuss natural ways to support the body's detoxification system to help be it remove harmful, cancer-causing chemicals.
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 the diseases that arise inadvertently as a result of medical or surgical treatment.
LIFESTYLE The importance of a healthy lifestyle in cancer prevenrion 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.
Smoking history: The evidence is overwhelming that smoking is the most preventable cause of cancer and premature death in the United State. Smoking is responsible for nearly 90 percent 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 percent of all cancer deaths. Smoking is also a major cause 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 cancers), and is an greater risk for causing heart disease. People who don't smoke bu inhale smoke from the environment may be even more suscepetible to free radical damage to their heart and arteries than smokers are Smokers are, 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 percent greater risk of getting lung cancer if she lives with a smoker. The U.S. Environmental Protection Agency estimates that passive smoking causes 3,000 lung cancer deaths each year.
Axwris level: 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.42.43
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, less than one or two glasses of wine; one beer; or 1 ounce of alcohol 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 like acetaldehyde that act as free radicals and damage DNA repair mechanisms, further raising the risk.
PSYCHOLOGICAL HEALTH Stress, personality, attitude, and emotional state are thought to predict the development of many diseases, including cancer. Although somewhat controversial, personality stereo types have emerged that reflect an increased risk for certain diseases. For example, the so-called Type A personality of being easily angered, competitive, and hard driving is associated with an increased risk for heart disease. The prototypical 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 con flicts, exaggerated social desirability, harmonizing behavior, overcompli ance, and overpatience, as well as high rationality and a tendency toward feelings of helplessness. The Type C personality displays on the outside a façade of pleasantness, but this outward expression quickly dissolves during times of stress. Typically the Type C personality deals with stress through excessive denial, avoidance, suppression and repression of emotions. This internalization is thought to the develepment of cancer by amplifying the negative effects that stres, produces on the immune system.
What research continues to tell us is that how a person handle stress is more crucial than the stressor itself and that the response to stress highly individualized. Two people might have the same stressfull experince, but they may react to it in entirely different ways, and as a result some may develop cancer and others may not." It is our belief that helping a person develop an effective method to deal deal with stress is more important than identifying a particular cancer personality.
But 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 the personality type. In contrast, in appropriate ways of dealing with stress such as suppression of emotion, denial, drinking alcohol, using drugs, or overeating—will likewise have a negative effect.
In Chapter 5 we discuss in much more detail the importance of attitude and emotions in cancer prevention, while in Chapter 9 we discuss the healing power of faith, hope, and prayer in cancer therapy and provide specific relaxation exercises that fight cancer and boost immune function.
Diet Poor diet is a 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 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.
The other reason poor diet is a concern is that it promotes obesity (extreme overweight). A recent report by RAND Corporation researchers found that obesity contributes as much or more to the development chronic degenerative disease—including cancer-as smoking does. Obesity severely disturbs the body's ability to regulate the complex interaction among diet, metabolism, physical activity, hormones, and growth factory Women who are obese after menopause have a 50 percent higher reliative risk of breast cancer . Obese men have a 40 percent relative higher colon cancer. Gallbladder and endometrial cancer risks are 5 times among obese individuals, and obesity appears to raise the risk of cancers of the kidney, pancreas, rectum, esophagus, and liver.Table 1-2. Diet and Cancer
|DIETARY FACTORS THAT INCREASE CANCER RISK||DIETARY FACTORS THAT DECREASE CANCER RISK|
In Chapter 2, we identify seven key dietary recommendations for cancer prevention. The goal of these recommendations is to reduce the intake of dietary factors that increase cancer risk while increasing the intake of substances that protect against cancer. Table 1-2 presents a quick overview of these factors. How Cancer Develops
To understand why natural prevention strategies are so effective, 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: the 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 simply die. 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 malignant tumor. There are two types of tumors: benign and malignant.
Cancer - Causing injury to cells and their DNA molecules usually comes from toxic atoms known as free radicals. Free radicals assault us from all directions. Some of these come from our environment, in pollutans such as chemicals or cigarette smoke, or from our diet in the form of fats damaged by frying or the presence of nitrates in smoked or cured meats. Even sunlight produces free radical damage. But free radicals also result from the cell's own metabolic activity.
Simply defined, a free radical is a highly reactive atom that can de-stroy body tissues. All atoms contain small particles called electrons. Normally, electrons come in pairs. But sometimes one of the electrons can get stripped away. By carrying an unpaired electron, the atom-now a free radical—becomes unstable. It sets off on a frantic search to find another electron to complete its set, grabbing on to any electron it can find. But by stealing electrons, free radicals destroy those other mol-ecules. Because the oxygen atom is most often involved as the donor of the electron, this damaging process is known as oxidation, and it is-similar to the process that causes apples to turn brown or cars to get rusty.
Like tiny ornery BBs, free radicals shoot through the cell's mem-branes, tearing gaping holes and putting the cell at risk. A free radical can also knock apart segments of DNA, leading to mutations and the development of cancer.
Because free radicals damage the cell's delicate structures, include DNA, the cumulative damage they cause leads to cellular aging: This ,in turn, contributes to a number of diseases, including the two biggest killers of Americans: heart disease and cancer. Most carcinogens (Cancer - causing compounds) are dangerous because they cause servire free - sex radical or oxidative damage to cell structures.
Fortunately, Nature counteracts free radicals and the oxidation they cause by neutralizing them with other molecules known as antioxi.
dants. These work by quenching the unpaired electron by donating one of its own electrons, effectively "calming down" the free radical. By mopping up free radicals, antioxidants are powerful weapons in the fight against cancer and other degenerative diseases. Because they protect cell integrity, antioxidants slow down the aging process, enhance immune function, reduce inflammation, and fight allergies.The Immune System
The immune system is one of your body's most important defenses against cancer. Cells of the immune system circulate through out the body, alert for the presence of invading organisms and abnormal cells. When the immune system detects an attack by bacteria or viruses, or notices the presence of proteins that did not originate within the body, it sounds an alert. In response, blood cells, proteins, and other compounds signal one another to attack the intruder, destroy it, and eliminate its remains from the body. The presence of cancer can be a sign that the immune system is not functioning well or that it has been outfoxed by the disease. One of the key principles in the natural prevention and treatment of cancer is to enhance immune function.So if you want to reduce your risk of cancer, it's important to:
Of course, preventing cancer from ever starting in the first place is the best way to avoid the disease. But there are no guarantees; cancer is so insidious that it can develop in people despite their best efforts to eat right, stay in shape, and lead a healthy lifestyle. If cancer does arise, the focus shifts. Now the goal is to keep it from getting worse.
Let's take a look now at how cancer runs its course. Understanding this
aspect of the disease will help you see why diet and addition nutritional support are so important once a diagnosis of cancer has been made.
Segments of your cell's DNA, known as proto-oncogenes,are re-sponsible for cell growth and activity. They control how often a cell di-vides. They also regulate the way a cell develops and carries out its specialized functions, a process called differentiation. Mutations in these genes can turn them into oncogenes (onco - means "tumor"). These abnormal genes "switched on all the time, ordering the cell to keep dividing at an accelerated rate. The cell continues to produce abnormal copies of itself; these cells, too, continue to proliferate, causi-ing a tumor to grow.
Like all living things, cells eventually die. Their life span—the num-ber of times they can reproduce—is programmed into their generated code. The medical word for programmed cell death is apoptosis. Al-though it's necessary that old cells die, their daughter" cells live on, Re-producing as often as needed before they, too, die. But damage to a genel known as p53 can disrupt the apoptosis program. When that happens, the cells become "immortal,” reproducing faulty copies in an endless cycle. Mutations in the p53 gene are thought to be involved in more than 50 percent of human cancers, including cancers of the lung, colon,and breast.
Your cells don't take this abuse lying down. Cells contain other genes, called tumor-suppressor genes, whose job is to be alert for such damage. When a dangerous mutation arises, these tumor-suppressor genes go into action, repairing the damage to DNA. But like other genes, tumor-suppressor genes are also susceptible to damage and may lose their abil-ity to function.
Like normal cells, cancerous cells need nutrients to survive. They get those nutrients from the same source as your other cells: the blood sup-ply. Tumor cells secrete proteins that cause the growth of new blood ves-sels. This process is known as angiogenesis. The growth of the tumor is critically dependent on developing these new blood vessels to diliver the nutrients it needs to grow.
Our Time the tumar grows, eventually taking over the part of the body where it originated. Sometimes the tumor damages the organ's cells so much that the organ can no longer perform its norm fun-tions. In other cases the tumor simply grows so big that it presses on tha organ and on neighboring tissues. Cancer pain often results from such pressure on nearby nerves.
Normal tissue cells are well connected to their neighbors. But that's not true of cancer cells. They're loosely connected and are likely to break off. These detached cells can enter the bloodstream or the lymphatic system and travel to other parts of the body. The lymphatic system is another circulatory system in your body, responsible for carrying fluid and filtering out many of the waste products. Eventually these migrating cells can lodge in other organs, where they create new tumors. The spread of cancer to a new site is called metastasis.
Typically, cancer spreads first to the liver, lungs, bones, or brain. But even when it has spread to another location, the cancer retains the characteristics of the original tumor. For example, breast cancer that spreads to the liver is known as metastatic breast cancer, not as liver cancer. That's an important distinction to make when it comes time to decide on the appropriate treatment strategy.
Cancer is classified by its appearance under a microscope, as well as by the part of the body in which it began. Different types of cancer vary in their rates of growth, patterns of spread, and responses to treatment.
As expressed clearly above, one key strategy in the prevention of cancer is to identify the presence of risk factors and take the appropriate actions to eliminate or reduce them. Another important step 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 of regular screening examinations by a health care professional is that it can lead to early detection of cancer (Table 1-3). 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. The earlier a cancer is discovered, the more likely it is that treatment will be successful. Self-examinations 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!