Medical Conditions Disclaimer
Statements on this website have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure or prevent any disease. The information on this website is designed for educational purposes only. It is not intended as, nor should it be construed as, a substitute for informed medical advice. Please consult a doctor with any questions or concerns you might have regarding your health.
THE FOLLOWING MEDICAL AND SCIENTIFIC MATERIAL IS FOR CONSUMER INFORMATIONAL AND EDUCATIONAL PURPOSES ONLY UNDER SECTION 5 OF DSHEA.
Cancer is characterized by the development of abnormal cells that divide uncontrollably. These abnormal cells can infiltrate and destroy normal body tissue and spread throughout the body. There is currently a wealth of evidence supporting the use of micronutrients for the prevention of cancer. The information listed below provides one of the most exhaustive lists of information and referenced studies on this topic currently available.
Cancer is the second leading cause of death in the United States (heart disease is first). It is estimated that more than 500,000 cancer deaths occur in the U.S. each year. Although cancer can develop in people with no known risk factors, there are many factors known to increase a person's risk of cancer. These include certain lifestyle choices, inherited conditions, certain chronic health conditions, and your environment. Although not all of these can be modified, there are many choices that each individual can make to reduce his/her cancer risk. When healthy choices are consistently made, even in those with an inherited risk, the occurrence of cancer may be less likely.
Because several lifestyle choices are known to substantially increase the risk of cancer, making healthy choices in these areas is very important for anyone who wants to prevent cancer or wants to help prevent a recurrence. Maintaining a healthy weight, staying physically active throughout life, consuming a healthy diet, avoiding exposure to tobacco products, and limiting alcohol consumption can substantially reduce a person's lifetime risk of developing cancer.1,2,3
• It is estimated that excess weight and obesity contribute to 14% to 20% of all cancer-related deaths in the United States.4 Research has shown a clear association between overweight and obesity and an increased risk for breast cancer in postmenopausal women, colon cancer, endometrial cancer, adenocarcinoma of the esophagus, kidney cancer, and a probable link between obesity and the risk of cancers of the pancreas, gallbladder, thyroid, ovary, and cervix; and for multiple myeloma, Hodgkin's lymphoma, and aggressive prostate cancer.5,6,7,8,9,10,11 It is obvious that maintaining a healthy weight is important for cancer prevention. Two of the most important steps for achieving optimal weight are a healthy diet and regular exercise, both of which have clearly been tied to a decreased risk of cancer.
• There is good evidence that regular physical activity may reduce the risk of several types of cancer, including cancers of the colon, prostate, breast, and endometrium.12,13,14 In addition to the fact that regular exercise helps with the maintenance of a healthy weight, it may also reduce cancer risk through its effects on regulating insulin, sex hormones, and prostaglandins while also boosting immune function.15,16,17 Incorporating a combination of resistance training (weight lifting) and regular aerobic exercise into your everyday life can be a powerful weapon to help prevent cancer.
• Quitting smoking reduces the risk of several of cancers. Lung cancer is the leading cause of cancer death in the United States, with smoking tobacco believed to cause more than 85% of it. Tobacco smoking is also tied to an increased risk of colorectal cancer, bladder cancer, kidney cancer, pancreatic cancer, cervical cancer, and others. Avoiding exposure to tobacco by quitting smoking and/or quitting chewing tobacco is crucial for cancer protection. Avoiding exposure to secondhand smoke is also important. No one would ever say that quitting smoking is easy, but there are many programs and techniques that have helped many people quit. Doing whatever is necessary to finally eliminate tobacco from your life is one of the most powerful things anyone can do to reduce their cancer risk.
• Excessive alcohol consumption is another risk factor for cancer. In particular, the risk of developing cancers of the mouth, pharynx, larynx, esophagus, and liver increases significantly with an intake of more than two drinks per day.18 Alcohol is also a significant risk factor for breast cancer19,20 and a likely contributor to the development of colorectal cancer.21 It is generally recommended that among people who drink alcohol, consumption should be limited to no more than two drinks per day for men and one drink per day for women.22
• Practicing safe sex is another lifestyle choice that can help reduce cancer risk. Transmission of human papilloma virus (HPV) can occur sexually and is tied to increased risk for several cancers, including cervical cancer, anal cancer in both men and women, some cancers of the vagina and vulva, and probably penile cancer as well. Transmission of hepatitis B and hepatitis C viruses can also occur sexually and may eventually lead to liver cancer. Choosing to consistently practice safe sex can decrease your risk of exposure to these viruses.
• Consuming a nutrient-rich diet is vitally important. Research has shown that consuming a diet that is high in processed foods and red meats, low in fruits, vegetables, and whole grains is a risk factor for several of the most common types of cancers, including colorectal cancer.23,24 Consuming instead a diet that is loaded with fiber- and nutrient-rich fruits and vegetables and whole grains, as well as minimizing animal protein, helps provide protection against cancer.
In a major review of approximately 200 studies that examined the relationship between fruit and vegetable intake and cancer, it was found that for most types of cancer, people with low fruit and vegetable intake have about twice the risk of developing cancer compared with those with high intake.25 These studies provide strong evidence of a protective effect for a higher intake of both fruit and vegetables against cancers of the pancreas, stomach, lung, colon/rectum, bladder, cervix, ovary, endometrium, and breast. Higher fruit intake was significantly protective against cancers of the esophagus, oral cavity, and larynx. Another review that looked at 137 studies came to much the same conclusion; that consumption of higher levels of vegetables and fruit is consistently associated with a reduced risk of cancer at most sites in the body.26
A third review, looking at the results from 206 human epidemiologic studies and 22 animal studies, found that the types of fruit and vegetables that appear to be the most protective against cancer are raw vegetables, followed by allium vegetables (such as onions, shallots, leeks, garlic, and chives), carrots, green vegetables, cruciferous vegetables (such as broccoli, cauliflower, kale, collard greens, cabbage, Brussels sprouts, bok choy, kohlrabi, turnips and turnip greens, mustard greens, rutabaga, radish, daikon, and watercress), and tomatoes.27 Clearly, increasing their intake of fruits and vegetables is one of the most important things a person seeking protection against cancer can do.
Fruits and vegetables contain potent amounts of vitamins, minerals, fiber, and a wide variety of phytonutrients that may help prevent cancer so it's not surprising that increased their intake is associated with a decreased risk. The color in fruits and vegetables indicates the types of micronutrients which they contain. To consume a broad spectrum of these protective micronutrients, aim for eating a colorful variety of fruits and vegetables (orange, red, yellow, green, blue, and purple).
Certain fruits and vegetables may be particularly protective. For example, one study found a higher intake of tomatoes, pumpkin, spinach, watermelon and citrus fruits--foods that are rich in carotenoids like lycopene, alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, and zeaxanthin--were associated with a significant reduction in prostate cancer risk.28 Many studies have shown that increased consumption of tomatoes and tomato-based products such as pasta sauce are associated with reduced risk of cancers of the prostate, lung, and stomach, with some studies also suggesting a benefit for cancers of the pancreas, colon and rectum, esophagus, oral cavity, breast, and cervix.29 Studies have also shown that eating larger amounts of cruciferous vegetables (Brassica oleracea), including broccoli, cabbage, cauliflower, Brussels sprouts, kale, collard, and kohlrabi, is clearly associated with reduced cancer risk.30 And there are many other studies showing that higher intake of fruits and vegetables provide protection against many cancers. The bottom line is simple--eating lots of fruits and vegetables every day provides important protection for the body.
The American Cancer Society recommends including fruits and vegetables with every meal plus choosing them as snacks in place of high-fat, sugar-loaded fast and junk foods like French fries, chips, and sweets.31 The ACS also recommends eating whole grain rice, bread, pasta, and cereals in place of white-flour products and high-sugar baked goods.
Because of the many studies that have found an association between cancer (especially colorectal32,33,34,35 and prostate36,37) and the consumption of red meats (beef, pork, or lamb) and processed meats (cold cuts, bacon, hot dogs, and other processed meats), the ACS recommends limiting those meats and instead choosing fish, poultry, or beans as good sources of protein. When meat is eaten, the ACS recommends choosing lean cuts, consuming smaller portions, and cooking meat by baking, broiling, or poaching rather than by frying or charbroiling, practices that can create carcinogenic chemicals in meat.
Standard Medical Therapies
With regard to standard cancer treatments, we at K-PAX strongly recommend that any advice or decision about how to treat this condition should be discussed with a medical expert. While we strongly recommend the use of natural products to help support a robust immune system in patients both on and off standard medical treatments, your doctor's recommendations should supercede anything you read on this website.
Ensuring optimal intake of all the key micronutrients that provide important building blocks for supporting immune function and providing protection against oxidative stress may help provide protection against the development of cancer. There have also been multiple studies showing the possible benefits of various nutrient supplements for protection against the development of cancer.
Most research studies have focused on a single nutrient rather than on supplementing a broad spectrum of nutrients which might better support immune function and provide protection against cancer. Not surprisingly, some of the best results have been seen in studies that used a combination of nutrients. However, even single-nutrient studies have shown benefits. There have also been studies that supposedly showed negative effects of supplements on cancer risk. Because these studies have been strongly criticized, we will discuss them separately.
In the end, it is clear that the best protection from micronutrients comes when they are consumed, and preferably with all the other bioactive compounds found in a nutrient-rich diet composed of whole foods. The combination of such a health-supporting diet plus supplementation is almost certainly the approach most likely to offer protection against cancer.
• Multiple vitamin/mineral supplements can help ensure that the body always has a potent supply of a broad spectrum of micronutrients. Micronutrients, including vitamins, minerals, and many associated nutrient factors, are important building blocks which the body uses when it creates and maintains its structure. They are also used in the countless chemical reactions that the body must create every day in order to function properly. Many micronutrients also serve to protect the body against assaults such as oxidative stress. In an ideal world, it would be nice to think that everyone could obtain all the micronutrients needed for health through diet alone. However, according to the United States Department of Agriculture (USDA) Agricultural Research Service, fewer than 50% of all Americans are getting adequate levels of multiple important nutrients from the food they eat.
According to the most recent data from "What We Eat in America" (WWEIA), the dietary intake interview component of the National Health and Nutrition Examination Survey (NHANES), provided by the USDA on its Community Nutrition Map, 38 only 18.6% of Americans get enough vitamin E. Only 45.7% get enough vitamin A. Only 44.1% get enough calcium. Only 23.4% get enough potassium. Many other nutrients are also in short supply. Vitamin C intake is adequate in only 53.9% of Americans, magnesium in only 54%, folate in 60.4%, and so on through a long list of nutrients being obtained in inadequate levels from the diet by a large number of people. These data are national averages based on Estimated Average Requirements (EARs) of micronutrients, levels which many experts believe are much too low for optimal health.39 And Americans are not even reaching those levels.
Daily supplementation with a potent multivitamin/mineral supplement can help to make up for such inadequate intake of micronutrients from the diet, and help to ensure a continuing supply of many important vitamins, minerals, and other micronutrient factors that the body needs. Studies have shown that multivitamins may provide some protection against cancer. As one example, in one large study by the Fred Hutchinson Cancer Research Center in Seattle it was shown that both men and women who took multivitamin supplements daily during the entire ten years of the study had one-half the risk of colon cancer compared with those who never used multivitamins during this time period. 40 Other studies, discussed in the Antioxidants section, have also shown benefits from supplementation with a combination of several micronutrients.
• Antioxidants are needed to protect against oxidative stress in the body. Oxidative stress occurs when the body's supply of antioxidants is insufficient to counter the unstable molecules called free radicals that are constantly created in the body when oxygen is used and during normal metabolism. Free radical production is increased even more when infections occur (when immune cells called phagocytes produce free radicals to destroy bacteria or viruses), when a person smokes, and any time there is any exposure to radiation. The mitochondria that produce much of the body's energy also produce large quantities of free radicals. Free radicals can damage DNA (the cells' genetic material), RNA (which contains the genetic code for production of proteins), protein, fat, membranes, and other cell components in a way which may influence the development of cancer. 41 It is the body's antioxidant defense systems that help to counter this. The body gets some antioxidants from diet or supplements, and makes others internally from a variety of nutrients. Ensuring an optimal supply of all the important micronutrients that either work directly as antioxidants or are used by the body to create them can help provide continuing protection against oxidative stress.
In addition to their role in countering oxidative stress, antioxidants fulfill several other important functions in the body. According to Kedar Prasad, Ph.D., the director of the Center for Vitamins and Cancer Research at the University of Colorado School of Medicine, antioxidants also prevent the formation of harmful chemicals when food is eaten, stimulate the immune system, help repair the damage caused by chemicals and radiation, reduce the level of gene mutations that can occur as the result of dietary and environmental toxins, and regulate gene activity in cancerous cells such that their growth is limited. 42
Important antioxidant nutrients include vitamin A, vitamin C, vitamin E, carotenoids (including beta-carotene, lutein, lycopene, zeaxanthin, xanthophyll and at least six hundred other carotenoids), coenzyme Q-10, NADH, plant-derived antioxidants (including flavonoids such as quercetin, resveratrol, rutin, catechins, anthocyanins, and many others), selenium, sulfhydryl compounds (such as glutathione which can be raised in the body with supplemental N-acetyl-cysteine), and alpha-lipoic acid (which also raises levels of glutathione). These antioxidants work in different parts of the body and constantly interact and recycle and regenerate each other. For example, vitamin C works in the watery parts of the body such as the blood, while beta-carotene and vitamins A and E work in the lipid (fatty) parts of the body, including the cell membranes. Alpha-lipoic acid works in both watery and lipid parts of the body, and helps to recycle and regenerate other antioxidants. The fact that antioxidants work together in so many ways to protect the body is a strong indicator that a broad spectrum of antioxidants is much more likely to be effective for cancer protection than taking a single one at a high dosage.
Studies have shown a reduced risk of various cancers in people taking certain antioxidant nutrient supplements. During the 12 years of the Health Professionals Follow-Up Study, it was found that the use of vitamin E supplements by men was associated with a reduced risk of bladder cancer.43 Taking vitamin E supplements for ten years or longer was shown to decrease the risk by more than 30 percent. The study also showed that higher doses of vitamin C supplements may be associated with reduced risk of bladder cancer.
In another study, men and women who supplemented with 200 IU or more of vitamin E per day for 10 years had a 57% reduction in colon cancer risk compared with non-users of vitamin E. 44 In that same study, higher average daily intake of two other antioxidants, vitamin A and vitamin C, during a ten-year period was also associated with reduced risk of colon cancer. In a third study, there was a 32% reduction in prostate cancer and a 41% reduction in deaths from this cancer among the men who received supplemental vitamin E.45
A number of studies have shown cancer protection benefits from supplementation with selenium, including protection against primary liver cancer, 46 as well as protection against lung, prostate, and colorectal cancers.47 Studies have shown that supplementation with vitamin C is associated with a reduced risk of bladder cancer in men, and colon cancer in women.48
A large study using data from the Nurses Health Study found that a substantially reduced risk of breast cancer was associated with higher blood levels of cysteine, the precursor of glutathione, which is best taken orally as N-acetyl-cysteine (NAC). 49 Glutathione is very important in the body for several reasons. It protects cells from the DNA damage that can result from oxidative stress, while also helping the body with detoxification and elimination of damaging chemicals and drug breakdown products. 50,51,52,53 Glutathione is also known to modulate immune function.54,55 The Nurses Health Study researchers concluded that N-acetyl-cysteine (NAC) might be a promising agent for the prevention of breast cancer, and noted that other researchers have pointed to NAC as one of the most promising agents for cancer prevention.56
Studies that combine supplementation with more than one antioxidant, sometimes with the addition of other micronutrients, have also shown substantial benefits for cancer protection. In one very large study, supplementation with a combination of beta-carotene, vitamin E, and selenium resulted in a 13% reduction in cancer deaths, including a 21% decrease in deaths from stomach cancer, a 41% decrease in gastric noncardia cancer deaths, and a 4% decrease in deaths from esophageal cancer, with the reduced risk beginning to arise about 1-2 years after supplementation with these micronutrients. 56(57) The beneficial effects of the micronutrient combination remained evident for ten years after the trial concluded.
In a related study with 3318 people with esophageal dysplasia, a precursor to esophageal cancer, those who received a daily supplement of 14 vitamins and 12 minerals dosed at several times the US RDA for 6 years had a reduced likelihood of the dysplasia continuing.57
In another study, smokers who were given a twice weekly supplement containing vitamin A, riboflavin, zinc, and selenium had a significantly greater rate of complete remission of precancerous oral lesions compared with those given a placebo. 58 Those without pre-existing lesions who were given the supplements also had significantly fewer new lesions than those in the placebo group.
In a study of patients who had previously been surgically treated for colon cancer, those who were given a combination of selenium, zinc, vitamin A, and riboflavin had a lower incidence of recurrent polyps than those who were randomized to a placebo.59
Although these studies show some promising results, the fact is that there have been no trials to date using a truly broad spectrum of antioxidants and the other micronutrients required for immune support in doses that might be considered optimal for cancer protection. Far too many studies continue to use low doses of synthetic forms of only a single (or at most a handful) of the micronutrients that are used by the body to protect itself.
• B vitamins may also provide protection against some cancers. Several large studies have shown reduced risk of breast cancer in women with a higher intake of folate, particularly in women who consume one alcoholic drink or more daily.60,61,62 In one large study, high blood levels of folate was clearly associated with a lower risk of breast cancer, as were higher levels of B-6 and B-12. 63 As in other studies, the association between higher folate levels and lower risk of breast cancer was particularly strong among women who consumed moderate amounts of alcohol. The researchers concluded that both folate and vitamin B-6 may be effective in breast cancer prevention, and that ensuring adequate levels of these B vitamins by consuming foods that are rich in them (such as oranges, orange juice, and fortified breakfast cereals), or by taking vitamin supplements that contain them may lead to reduced breast cancer risk.
A number of studies have also shown reduced risk of colon cancer in people with higher folate intakes. In the Nurses' Health Study, women with folate intakes of more than 400 mcg daily were found to have a 31 percent lower risk of colon cancer than women with intakes of less than 200 mcg daily.64The women who had been taking multivitamins that contained folic acid for 15 or more years were 75 percent less likely to develop colon cancer than were women who did not take multivitamins. Other studies have shown that increased folate intakes are also tied to a reduced risk of colon cancer in men.65,66
• Calcium and magnesium have both been shown to provide protection against colorectal cancer. In one large study of 45,354 women without a history of colorectal cancer, calcium supplementation in doses above 800 mg daily was shown to reduce the risk of colorectal cancer by approximately 25%. 67 Simultaneously high consumption of calcium from diet and calcium from supplements resulted in even greater risk reduction. In another study, higher daily intake of calcium during the ten-year period that ended two years prior to the study was associated with reduced risk of colon cancer.68
A large study that followed women for nine years found that total daily calcium intake, as assessed at the beginning of the nine years, was strongly associated with a reduced risk of developing rectal cancer, with the protection the strongest at the highest intake of calcium.69 Reduced risk was also seen in women consuming higher levels of vitamins A, C, and D. The best protection was seen in women who consumed higher levels of both calcium and vitamin D. Compared with women who consumed low levels of both total calcium (from both diet and supplements) and vitamin D, those in the highest intake group of both nutrients had a 45% reduced risk of rectal cancer.
A review of clinical trials involving 1,279 colorectal cancer patients, who had previously had cancerous growths removed, showed that long-term calcium supplementation can reduce the risk of cancer recurrence.70
Two studies have also shown that increased magnesium intake is associated with a lower incidence of colon cancer. In a study of Swedish women aged 40-75 years, those with the highest intake of magnesium had a substantially lower risk of colorectal cancer. 71 The researchers suggested that magnesium might prevent colon cancer by reducing oxidative stress, by improving insulin sensitivity, or through other effects that reduce proliferation of cells in the colon. In another large study of 35,196 Iowa women aged 55â€“69 years, it was found that higher magnesium intake was associated with a reduced risk of colon cancer.72
In another large study, it was found that higher intakes of calcium and vitamin D were also associated with a reduced risk of developing premenopausal breast cancer, and that the protective effects might be more pronounced for more aggressive breast tumors.73
• Vitamin D deficiency is thought to be associated with increased risk of multiple cancers, including the risk of colon,74 breast,75,76 ovarian, 77,78 kidney, 79 and prostate 80 cancer. In a major review of 63 studies of vitamin D status in relation to cancer risk, it was found that the vast majority of studies found a protective relationship between adequate vitamin D and reduced risk of cancer.81 The researchers concluded that the evidence suggests that improving vitamin D status through supplementation could reduce cancer incidence and mortality at a low cost.
In a study that assessed intake of micronutrients by women at the beginning of the study and then followed them for almost a decade, the risk of rectal cancer was reduced in women with higher levels of vitamin D intake.82 The best protection was seen in women who consumed higher levels of both calcium and vitamin D. Women with high levels of both total calcium and vitamin D were found to have a 45% reduced risk of rectal cancer compared to women with low levels of these nutrients.
In a large study that used data from the Women's Health Study, it was found that higher intakes of calcium and vitamin D were associated with a reduced risk of developing pre-menopausal breast cancer, and that the protective effects might be more pronounced for more aggressive breast tumors.83 In another study, women with the highest blood levels of vitamin D (127 nmol/l) were 50 percent less likely to have breast cancer compared with women with the lowest blood levels (25 nmol/l or less).84 The women with the lowest blood levels of vitamin D clearly had the highest rates of breast cancer, with the rates decreasing as the blood levels of vitamin D increased. The researchers noted that women could reach a protective vitamin D blood level (80 nmol/l) by either consuming 2,000 IU of vitamin D per day or by spending approximately 12 minutes per day in the noontime sun (and longer on cloudy days), with 50 percent of their skin exposed to the sun.
In a review of several studies that looked at vitamin D intake and 25-hydroxy vitamin D (the blood level of vitamin D), it was found that intake of 1000 IU/day of Vitamin D (or serum 25-hydroxyvitamin D levels of at least 33 ng/ml) were associated with a 50% lower risk of colorectal cancer.85
In another recent study, people with the highest blood levels of vitamin D had half the incidence of colon cancer compared to those with the lowest vitamin D levels.86 The researchers concluded that the evidence suggests that daily intake of 1000-2000 IU of vitamin D could reduce the incidence of colorectal cancer with minimal risk.
In a major review of the importance of vitamin D for human health, vitamin D expert Michael Holick, M.D., Ph.D. suggests that maintaining adequate vitamin D should be a high priority.87 He recommends that measurement of 25-hydroxy vitamin D concentrations (a blood test for vitamin D level) should be part of normal yearly physical examinations, with a 25(OH)D concentration of 75-125 nmol/L the optimal level for health.
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