segunda-feira, 1 de março de 2010
01:26 | 
Publicada por
Luis Guerreiro
- Which better prevented tumors, red grapes or green tea?
- A May 2006 study found that the polyphenol, resveratrol, found in red grapes, is more effective than the polyphenol, epigallocatechin-3-gallate (EGCG), the major catechin found in green tea in preventing breast tumors in rats. Starting at birth, rats were given either dietary resveratrol, drank EGCG, or had regular food. At 50 days' old, the rats were given the carcinogen, DMBA. The rats on resveratrol had fewer tumors, and there was a delay in time to the developmentof the tumors. Analysis of the mammary tissue revealed that resveratrol treatment resulted in more differentiated lobular structures. Plus, there was a significant reduction in proliferative cells in mammary ductal structures, making the mammary tissue less susceptible to damage from carcinogens. (See Whitsett TG et al., Resveratrol, but Not EGCG, in the Diet Suppresses DMBA-Induced Mammary Cancer in Rats, J Carcinog 2006.)
- Anti-Inflammatory Turmeric Fights Breast Cancer
- Inflammation is associated with a wide variety of cancers, including breast cancer. Women with atypical hyperplasia in benign tumors in their breasts, who went on to develop breast cancer, were found to have significantly high levels of COX-2, which is produced in the body when there is inflammation. (See Mechanisms' Section.) In a key 2005 study, curcumin, which is derived from turmeric, was found to down-regulate COX-2. In India, where women consume curcumin, 79 in a million women develop breast cancer, while in the US, where women do not consume curcumin, 660 women per million develop breast cancer. (See Turmeric in Supplements' Section.)
- Anti-Inflammatory Fish Oil Fights Breast Cancer
- Omega-3 fats, found in fish oil, inhibit the growth of breast cancer cells in culture and in grafts in mice. Dietary fish oils lead to incorporation into membrane lipids. Increased cell death is attributed to inhibition of the COX-2, enzyme which promotes the cancer process. Plus, fish oil activates PPAR, a regulator of lipid metabolism capable of modulating proliferative activity in breast cells. (See Stoll BA, n-3 Fatty Acids and Lipid Peroxidation in Breast Cancer Inhibition, Br J Nutr 2002.) Women in Japan who consume iodine-rich seafood have a lower incidence of breast cancer (See Iodine and Breast Disease.)
- Cabbage Family's I3C's Anti- Breast Cancer Mechanisms
- The cabbage family, including cabbage, cauliflower, and broccoli, contain phytochemicals that act against cancer in many different ways. Cabbage, alone, has 200+ chemicals. There has been important new research on the phytochemical, indole-3-carbinol (I3C), which is derived from the cabbage family, finding that I3C influences cancer genes and a receptor site. Plus, phytochemicals in the cabbage family are able to induce phase 2 enzyme activity to protect against chemical carcinogens. In a 2006 Georgetown University study, indole-3-carbinol (I3C) phytochemicals in broccoli, cauliflower, and cabbage, were found to boost the production of DNA proteins BRCA 1 and BRCA 2 - that repair damaged DNA that are decreased in cancer cells. (See Rosen E et al., Veggies May Protect Against Cancer, British Journal of Cancer 2006.) Dr. Eliot Rosen, the lead researcher in the Georgetown study, commented, "It is now clear that the function of crucial cancer genes can be influenced by compounds in the things we eat. Our findings suggest a clear molecular process that will explain the connection between diet and cancer prevention." Another I3C study, a November 2005 study, exploring the anti-tumorigenic properties of the indole-3-carbinol food component in cruciferous vegetables, found that the anti-tumor effects of I3C in human cancer cells may be I3C's ability to reduce estrogen receptor-alpha expression.(See Wang TT et al., Estrogen Receptor Alpha As a Target for Indole -3- Carbinol, J Nutr Biochem 2005.) In a broccoli sprouts' study in rats, broccoli sprouts were found to be an exceptionally rich source of inducers of enzymes that protect against chemical carcinogens. Extracts of three day old broccoli sprouts were highly effective in reducing the incidence, multiplicity, and rate of development of mammary tumors in rats. (See Fahey JW., Broccoli Sprouts: An Exceptionally Rich Source of Inducers of Enzymes that Protect Against Chemical Carcinogens, Proc Natl Acad Sci USA 1997.)
- Berries Help Fight Breast Cancer
- A Harvard study tracking the diet and health of 1,271 people wholove strawberries found an overall 70% decrease in all cancers. A 2004 cell study investigated the specific effects of ten different extracts of fruits and berries, including rosehips, blueberries, black currant, black chokeberries, apple, sea buckthorn, ligonberries, cherries, and raspberries, on breast cancer cells and colon cancer cells. The extracts decreased the proliferation of both the breast cancer cells and the colon cancer cells. The inhibition effect for the highest concentration of the fruits and berries varied - an average of 52% for the breast bancer cells. Since this rate of anti-proliferation could not be found by ascorbate standard alone, there was a suggestion of a synergy between vitamin C and other substances. For breast cancer cells, the anthocyanins , which are the red to blue pigments founds in the fruits and belong to the class of compounds known as flavonoids, may contribute their powerful antioxidant power to the inhibition of the cancer cells. (See Olsson M. et al., Inhibition of Cancer Cell Proliferation in Vitro by Fruit and Berry Extracts and Correlations with Antioxidant Levels, J Agric Food Chem 2004.)
- Tomatoes' Anti-Breast Cancer Mechanisms
- Hot News: While carotenoids have been well known as being free-radical scavengers, a 2006 study sought to determine the mechanism of action of tomato carotenoid lycopene and retinoic acid on inhibiting IGFs - insulin-like growth factors - in the proliferation of cancer cells, including breast cancer cells. In the cell study, the cyclin D1 levels, that act as a growth factor sensor, appeared to be the target of lycopene's action. The weakening of the cyclin D levels by the lycopene and the retinoic acid is an important mechanism for reducing the IGFs' role in malignant cell proliferation. (See Nahum A et al., Lycopene Inhibition of IGF-Induced Cancer Cell Growth Depends on the Level of Cyclin D1, Eur J Nutr 2006.) Organic Strawberries Better Inhibited Breast Cancer Cell Proliferation Organically grown strawberries provided higher antioxidant levels and better inhibited cell proliferation than conventionally grown strawberries in breast cancer cells. In a 2006 study, the higher level of ascorbate (vitamin C) antioxidants found in organic strawberries correlated with a higher inhibition of breast cancer cell proliferation. The significance of the effect of ascorbate on cancer cell proliferation might be in a synergistic action with other compounds. (See Olsson ME et al.,Antioxidant Levels and Inhibition of cancer Cell Proliferation In Vitro By Extracts From Organically and Conventionally Cultivated Strawberries, J Agric Food Chem 2006.)
- Oranges. Investigators have now found that oranges contain more than 170
- photochemicals, including more than 20 from the potent carotenoid family alone. In addition, compounds called limonoids - which give citrus fruit their slightly bitter taste - appear to be highly active anti-cancer agents as well.
- Tomatoes. Besides loads of vitamin C, tomatoes are one of the richest sources of the flavonoid, lycopene.
- Berries, particularly blueberries. The rich, colored pigments of berries,
- belonging to the class of compounds known as flavonoids, have repeatedly been shown to protect against several cancers.
- All cabbages - including their kin broccoli, cauliflower, kale, brussel sprouts
- bok choy, red cabbage and red beets.
- Asparagus contains a number of health-promoting phytochemicals capable of antifungal, antimutagenic, cytotoxic and antiviral activities. In a lab study, crude saponins (like lycopenes, in the terpenoid class of phytochemicals), obtained from asparagus, were found to have anti-tumor activity. (See Shao Y et al., Anti-Tumor Activity of the Crude Saponins Obtained
- From Asparagus, Cancer Lett 1999.)
- Spinach. The University of Minnesota Environmental Health Services and others have found that people who include two or more servings of spinach per week in their nutrition have considerably lower lung and breast cancer rates.
- Garlic. Studies show the sulphur compounds that give it its strong flavour have now been shown to protect against cancer by neutralizing carcinogens and slowing tumor growth. In a recent Iowa Women's Health study, investigators found that women who consume garlic at least once a week also have a 32% lower incidence of breast cancer.
- Beans. Research in the food sciences has established that all kinds of beans are loaded with protease inhibitors, compounds that make it hard for cancer cells to invade adjacent tissue.
- Horseradish. This stimulating root is an excellent detox food. Stronger varieties have been studied for anti-cancer properties.
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