© Vitamin Research Products Inc. 2001
Fish Oil and Fighting Cancer
Cancer: The word itself causes a strong reaction in most of us. It evokes images of a slow, painful death. Each year over 1.3 million Americans are diagnosed with cancer. Every minute one person dies from this disease. Traditional medicine offers us surgery, chemotherapy, and/or radiation as treatments. But these painful, toxic and sometimes even cancer-causing treatments only offer a less than 33% cure rate.Are there any ways we can prevent and fight cancer? Statistical data shows us that about 60% of women's cancers and 40% of men's cancers are related to nutritional factors. At least 40% of cancer patients die from malnutrition, not from the cancer itself. Based on numerous scientific studies, cancer researchers around the world have begun to believe that certain natural nutrients can prevent and sometimes cure cancer. This gives new hope for those suffering from cancer.
History of The Magic Fish Oil
Interest in the potential benefits of fish oils emerged from the observation that cardiovascular diseases and cancer incidence rates are generally low in the Eskimos of Alaska and Greenland. (1, 2) These populations eat a diet high in fish fat and low in carbohydrates this is contrast to the diets of North American and other western populations who also consume a high fat diet but mostly from animal and vegetable oils.Animal fats contain saturated fatty acids. Vegetable oils, like corn oil and safflower oil, contain high levels of polyunsaturated fatty acids of omega-6 type. Because a high intake of animal fat is related to an increased risk of heart disease, and intake of polyunsaturated fatty acids (such as corn oil) can lower cholesterol levels (believed to be beneficial to heart disease prevention), Americans tend to consume more vegetable oil than animal fats.
Researchers found that fish oil can significantly inhibit cholesterol production. The beneficial effects of fish oils come from their unique composition of high levels of the omega-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Additionally, these omega-3 polyunsaturated fatty acids can increase the HDL (so-called good cholesterol) levels. Fish oil also provides anti-inflammatory and anti-aggregatory effects which play a crucial role in the formation of atherosclerosis and thrombosis. Due to these findings, it is believed that both healthy people and heart disease patients can benefit from fish oil supplementation.
Fish Oil And Cancer
One exciting aspect of fish oil is its significant inhibitory effects against various human cancers in animal models, including breast cancer, colon cancer, skin cancer, pancreatic cancer, prostatic cancer, lung cancer, larynx cancer, etc. (3-8) Unlike fish oilwhich is high in omega-3 polyunsaturated fatty acidsfats that are high in omega-6 polyunsaturated fatty acids (like corn oil) can increase tumor growth. Using a chemical carcinogen-induced cancer model, researchers found that a high intake of fish oil significantly lowered the cancer incidence in animal studies as compared to animals fed either low fat diets or high corn oil diets. (9) By implanting human tumors into immune-deficient (nude) mice, researchers have found that a high fish oil diet can slow tumor growth. (9) These results suggest that fish oil can be used for both prevention and treatment of cancer.Proposed Mechanisms For Fish Oil's Tumor Growth-Slowing Effects
Although there is no clear mechanism to explain fish oil's significant anticancer effects, researchers have uncovered several potential models of action:
1. Alteration of cell membrane composition. After ingestion, fish oil is easily incorporated into cell membranes (especially tumor cells) which changes the cell membrane composition. This alteration will change the cell's response to growth factor, hormones, antibodies, etc.
2. Inhibition of prostaglandin production. Prostaglandin can stimulate tumor cell growth. Fish oil can inhibit the enzyme responsible for prostaglandin synthesis called prostaglandin synthase. After a high intake of fish oil, prostaglandin (especially in the tumor cells) is decreased significantly, which in turn, slows tumor growth.
3. Immune system stimulation.
4. Hormone profile changes, which may provide important benefits for hormone -related cancers like breast cancer.
5. Tumor cell toxicity, probably by causing lipid peroxidation in the tumor cells.Fish Oil And Metastasis
One of the big concerns in cancer treatment is metastasis the process by which tumor cells spread from the primary location to distant parts of the body. Metastasis is increased by a high intake of omega-6 fatty acids (i.e., corn oil), but is inhibited by fish oil. Using a nude (immune deficient) mouse implanted with human breast cancer, researchers found that feeding a high fish oil diet (23%) to the mice significantly reduced human breast cancer cell metastasis to the regional lymph nodes and lungs. (10) This indicates the significant beneficial effects of fish oil supplementation in cancer treatment.Fish Oil And Cachexia
Over 40% of cancer patients died from cachexia, not from cancer itself. Cachexia is the malnutrition and wasting away caused by cancer. Cachectic patients are characterized by extreme weakness and emaciation. If we can overcome this cancer -induced malnutrition, we can potentially save or prolong the life of over 40% of cancer patients.Researchers in England found that fish oil could significantly prevent cachexia in an experimental model. Feeding the animals a high fish oil diet (compared to either a low fat diet or a high corn oil diet), significantly decreased the loss of body weight caused by cachexia, and at the same time, muscle mass was significantly increased. Additionally, fish oil showed a dramatic anti-cancer effect which was as effective as some chemotherapy drugs. The researchers concluded that fish oil could significantly prevent the cachexia caused by cancer, and at the same time, provide potent anti -cancer action. (11)
Fish Oil And Chemotherapy
Researchers at Allie M. Lee Cancer Research Laboratory at the University of Nevada, Reno first declared that fish oil supplementation may be of benefit in cancer chemotherapy. By using a human breast cancer model, they found that feeding the animals a high fish oil diet both slowed the tumor growth and increased the tumor responsiveness to chemotherapy drugs by altering the drug activating systems. They also found that a high fish oil diet can significantly protect the host animals against the toxicity of chemotherapy drugs. The researchers concluded that fish oil supplementation will provide a three pronged attack on cancer:
1. A strong anticancer effect.
2. Protection from chemotherapeutic drug toxicity.
3. Cachexia prevention. (12,13)Summary
As a dietary supplement, fish oil shows significant benefits in cancer prevention and treatment. Due to the high incidence of cancers and the relatively low levels of fish oil intake in North American, it is likely that most people can benefit from fish oil supplementation.No information in this article is intended as a prescription. If you are concerned about preventing or treating cancer, please consult your physician.
© Vitamin Research Products Inc. 2001Highly recommended source of nutrients and supplements.
References
1. Bang, HO, Dyerberg, J, and Hjorne N. Acta Med Scand, 200: 69-73, 1976.
2. Neilsen, NH and Hansen JPH. J Cancer Res Clin Oncol. 98: 287-299, 1980.
3. Carroll KK. Lipids, 27:793-797, 1992.
4. Reddy BS. Lipids, 27: 807-813, 1992.
5. Rose, DP and Connolly, JM. Lipids, 27: 798-803, 1992.
6. Roebuck, BD. Lipids, 27: 804-806, 1992.
7. Begin, ME, et al. J Natl Cancer Inst, 77: 1053, 1986.
8. Booyens, J. IRCS Medical Science, 14: 396, 1986.
9. Welsch, CW. Cancer Res., 52: 2040s-2048s, 1992.
10. Rose, DP, Connolly, JM, and Liu, XH. Diet and Breast Cancer (ed. American Institute for Cancer Research), pp83-91, Plenum Press, New York, 1994.
11. Tisdale, M and Dhesi, JK. Cancer Res., 50: 5022-5026, 1990.
12. Shao, Y, Pardini, L and Pardini, RS. Cancer Res., 54:6452-6457, 1994.
13. Shao, Y, Pardini, L and Pardini, RS. Lipids, 30: 1035-1045, 1995.
