Dietary and Other Considerations
Cancer has an appetite for sugar and requires sugar for survival. Sugar plays an active role in reducing the immune response and energizes cancer, as tumors are primarily obligate glucose metabolizers.
There is a relationship between lactic acid, insulin, and angiogenesis. In tumors, hypoxic conditions occur through both inflammation, which reduces blood flow, and the chaotic development of blood vessels within tumors. These hypoxic conditions alter the pathways by which immune cells and tumor cells burn fuel (glucose) for energy, creating excessive lactic acid. In an oxygen-rich (aerobic) environment, glucose is burned in an efficient process that produces a maximum amount of energy and a minimal amount of lactic acid. However, tumor cells in chronic hypoxic conditions produce excessive lactic acid and inefficient utilization of glucose. Thus, there is a vicious cycle in which the reduced energy output stimulates the tumor cells to burn more glucose, which in turn produces more lactic acid. Tumor cells consume glucose at a rate three to five times higher than normal cells, creating a highly stimulated glycolysis (glucose-burning) pathway.
This glucose consumption can waste the cancer patient's energy reserves, and the increased production of lactic acid can stimulate increased production of angiogenic factors. The macrophage-mediated angiogenesis creates a complex interplay between opposing regulators. Insulin plays an active roll in promoting angiogenesis. Insulin is a growth factor that stimulates glycolysis and the proliferation of many cancer-cell lines through tyrosine kinase growth factors (Boyd 2003). In cancer patients, elevated levels of insulin are common in cancerous tissue and blood plasma. Obesity, and early stages of Type-II noninsulin-dependent diabetes mellitus (NIDDM), has been implicated as risk factors in a variety of cancers.
Based upon cancer's sugar dependency, a sugar-deprivation diet is strongly recommended. An effective tool in eliminating sugar from the diet is through following the Glycemic Index. The index is a list that rates the speed at which foods are digested and raise blood sugar levels. The ratings are based upon the rate at which a measured amount of pure glucose affects the body's blood sugar curve. Glucose itself has a rating of 100, and the closer a food item is to a rating of 100, the more rapidly it raises blood glucose levels. Foods with a low Glycemic Index, such as vegetables, protein, and grains, are suggested (please refer to the Obesity protocol for specific information about low glycemic foods).
With regard to depleting sugar from the diet, the following should be considered:
- Limit or avoid all white foods, including (but not limited to) sugar, flour, rice, pasta, breads, crackers, cookies, etc.
- Read labels. Sugar has many names (brown sugar, corn syrup, honey, molasses, maple syrup, high-fructose corn syrup, dextrin, raw sugar, fructose, polyols, dextrose, hydrogenated starch, galactose, glucose, sorbitol, fruit juice concentrate, lactose, brown rice syrup, xylitol, sucrose, mannitol, sorghum, maltose, and turbinado, to mention only a few).
- Limit all fruit juices; per glass they contain the juice of many pieces of fruit and a large amount of fructose (fruit sugar) but no fiber. Instead, infrequently eat low glycemic-rated fruit in small portions.
Natural compounds have also been reported to inhibit the cancer-promoting effects of insulin. For example, vitamin C has been reported to increase oxygen consumption and reduce lactic acid production in tumor cells. In addition, some natural compounds may help reduce insulin production by reducing insulin resistance. Insulin resistance occurs when cells are no longer sensitive to insulin and thus more insulin is produced in an effort to reduce glucose levels. Insulin resistance has been implicated as a risk factor for breast cancer, and diets high in saturated fats and omega-6 fatty acids promote insulin resistance. Although the exact pathway is unknown, it is thought that the mechanism of action is via chronic activation of PKC. Some of the known natural compounds that can reduce insulin resistance include omega-3 fatty acids, curcumin, flavonoids, selenium, and vitamin E.
As discussed earlier in the protocol, estrogen is a growth factor for most breast cancers. High-fat diets and associated increases in fat tissue can increase estrogen availability in a number of ways:
- Fat tissue is a major source of estrogen production in postmenopausal women. Therefore, there is an association between high body weight and decreased survival in breast cancer patients.
- Obesity and possibly insulin resistance can decrease the levels of sex hormone binding globulin (SHBG) in both men and women and increase breast cancer risk or cancer progression. This is an important factor in estrogen-dependent breast cancer cells because it is adequate levels of SHBG that act as an anti-proliferative and provides an anti-estrogenic effect.
- Obesity can alter liver metabolism of estrogen, allowing the retention of high estrogen byproducts with high estrogenic activity within the body.
- High-fat diets may reduce the amount of estrogen excreted in the feces. In contrast, low-fat/high-fiber diets can reduce circulating estrogen.
Another consideration when discussing diet and breast cancer is the reduction of dietary estrogen. Several foods contain naturally occurring hormones (found in animal sources); synthetic hormones that can mimic estrogen in the human body (found in commercially packaged meat, poultry, and dairy products); or naturally estrogenic properties that can encourage the body's production of estrogens (natural foods such as soy). Regardless of the source, try to avoid all commercial animal products (including, but not limited to, meats, poultry, and dairy). Also avoid the use of soft plastic food-storage products that can give off large amounts of polymers (e.g., by leaching into food contents), thought by environmentalists and some researchers to be a possible cause of breast cancer.
In order to reduce estrogen, a breast cancer patient should consider increasing dietary intake of fish high in omega-3 fatty acids, whey, eggs, and nuts, occasionally including hormone-free poultry and hormone-free, low-fat dairy products.
Monthly blood tests should include complete blood chemistry, with tests for liver function and serum calcium levels, prolactin, parathyroid hormone, and the tumor marker CA 27.29 (or CA 15.3). Additional blood tests to consider are the CEA and GGTP tests. These tests monitor the progress of therapies used and also detect toxicity from high doses of vitamin A and vitamin D3. The patient should insist on obtaining a copy of their blood workups every month.
When considering breast cancer treatment options, physicians and patients alike must sort through an overwhelming amount of information. This protocol attempts to simplify complicated scientific research and bring to the forefront the most up-to-date, multimodality approach to cancer treatment. It integrates surgery, anticancer drugs, irradiation, hormone therapy, nutritional supplementation, and diet modification in a comprehensive approach to counteract breast cancer.
As discussed in this protocol, cancer growth is based on many complicated interactions via numerous physiological pathways within the body. Despite the huge strides in scientific research, there are still many unanswered questions regarding cancer's growth and development. What we do know is that there is overwhelming research supporting an integrated approach to the treatment of cancer. Additionally, research supports using nutritional supplementation to improve the efficacy of chemotherapy drugs and radiotherapy (see the Cancer Chemotherapy and Cancer Radiation protocols for more information). In fact, combining certain supplements can create a synergism that can effectively block or impede certain cancer pathways.
Therefore, the supplementation regimen following is suggested. Please read the entire protocol before considering this regimen because there are certain cautions to consider. As always, consult your physician before beginning any nutritional supplementation regimen.
Contact the American Cancer Society, 1 (800) ACS-2345.
Sources for National Cancer Institute Information.