Aromatase is an enzyme produced in the body that is needed for the final step in the production of estrogen as part of the hormonal cascade during which hormones are made from other hormones in a series of conversions. This enzyme converts androgen to estrogen. Aromatase is expressed at a higher level in breast cancer tissue than in benign tissue. Estrogen biosynthesis can be suppressed by the prevention of aromatase expression in breast tumors or by the inhibition of aromatase activity. Without the aromatase enzyme, excessive production of estrogen stalls. This process is what makes aromatase inhibitors effective against hormone-sensitive tumor growth.
High estrogen levels are a well-known risk for breast cancer. Many breast cancers depend on estrogen to grow. In fact, seventy per cent of diagnosed breast cancers express Estrogen Receptor alpha (ER{alpha}) and are, therefore, likely to be hormone-responsive. Apart from commercial and synthetic aromatase inhibitors, where can you find natural sources of such inhibitors?
Natural aromatase inhibitors include flavonoids, flavones, flavanones, isoflavones, resveratrol, oleuropein and linoleic acid. These are healing foods for breast cancer and other hormone-sensitive diseases. If you have estrogen-dominant cancer, increase your consumption of whole foods containing aromatase inhibitors like:
Quercetin
Cabbage, kale, brussel sprouts, onions and garlic, citrus fruits, apples, parsley, tea, and red wine are the primary dietary sources of quercetin. Olives and olive oil, grapes, black currants, cranberriesm dark cherries, and dark berries such as blueberries, blackberries, bilberries, lingonberries and red raspberries are also high in flavonoids, including quercetin. Quercetin seems to work better when used in conjunction with bromelain, a digestive enzyme found in pineapples.
Chrysin
This is a flavonoid from the passion flower plant, bee propolis, bee pollen and raw honey. Chrysin has poor bioavailability so it is normally taken as a supplement along with piperine (from black pepper) which greatly enhances its bioavailability.
Naringenin
This is found in all citrus fruits, like orange, tangerine, lemon and lime. Avoid obtaining it from grapefruit or grapefruit juice, which has an inhibitory effect on the human cytochrome P450 isofrom, another enzyme in the same complex as the aromatase enzyme. This enzyme is involved in breaking down and metabolizing sex hormones and preventing their excess accumulation in the body, so inhibiting it will allow estrogen levels to rise.
Apigenin
Dietary sources include celery, parsley, artichokes, basil, chamomile, thyme, peppermint, gingo biloba, and other herbs like horsetail herb, lemon balm herb, perilla herb, vervain herb, and yarrow. The highest concentrations of apigenin seem to be in chamomile and thyme.
Genistein
This is an isoflavone found in herbs like red clover (the herb of Hippocrates), parsley, sage, green vegetables, fruits and particularly pulses and legumes like chick peas and beans, and soy. Soy and soy foods contain high amounts of plant estrogens or phytoestrogens. These estrogens are very weak and have almost no harmful effects. They compete with the estrogen receptor sites in the body, and prohibit the more potent and harmful estrogen. Phytoestrogens are only 1/500th as potent as estradiol, the most dangerous form of estrogen. The body senses the estrogen level to be high and stimulates the P450 system in the liver to metabolize the estrogen. This helps keep estrogen levels where they should be. There is some controversy about whether soy is protective against breast cancer or promotes it. Much depends on variables like genes. Asians have a long history of soy consumption and their bodies process it far more efficiently than Westerners.
Diadzein
Another isoflavone found in soy products. Genistein accounts for approximately 50% of total soy isoflavones, whereas daidzein accounts for about 40%.
Oleuropein
Oleuropein gives olive oil its distinctive flavor, It is found in abundance in the leaves of the olive tree.
Resveratrol
Good sources are the skin and seeds of red grapes, grape seed extract, and black and red berries. Muscadine grapes, often used to make red wine, have the highest content. Although supplements of resveratrol are popular and widely available, getting resveratrol from red wine allows you to get the entire grape polyphenol group of nutrients, a group that has been shown to work much better synergistically. Breast tumor growth and metastasis to bone and liver have been shown to be better inhibited by the complete grape polyphenol complex.
Linoleic Acid
An essential fatty acid from the Omega-6 family, linoleic acid can be found in common mushrooms like button mushrooms, shitake, portabello and crimin, as well as vegetables, fruits, nuts, grains and seeds. Good sources are oils made from safflower, sunflower, corn, soya, evening primrose, pumpkin, olives and wheat germ. In a study conducted by Dr. Shiuan Chen of the Beckman Research Institute of the City of Hope in Duarte, California, it was found that in laboratory and animal experiments, mushroom extracts reduced the proliferation of breast cancer cells. This study also surmised that it is the linoleic acid that may be responsible for the anti-cancer effects.
Interestingly, the study also found that white button mushrooms suppressed production of the enzyme 5-alpha reductase. This enzyme plays a big role in development of prostate cancer.
Progesterone
A popular source is wild yam extract cream for topical application, such as Neways’ “Endau” progesterone cream. A study (Formby and Wiley, Journal Nat. Cancer Inst. June 7997) shows that natural progesterone actually inhibits growth and induces cell death in breast cancer cells by affecting p53 and Bcl-2 gene expression.
This followed work by Chang, Lee et al (Fertility and Sterility vol 63 7995) that showed that whilst oestradiol (the most potent oestrogen hormone) increases the number of cycling epitbelial cells, natural progesterone actually decreases them. The study further states that natural progesterone secretion suppresses oestradiol receptors in both the endometrium and breast tissue, and has an anti-oestrogen effect (just as, for example, the latest aromatase inhibitors aim to do), but that very high concentrations of synthetic progestins can stimulate human breast cancer cells.
Zinc
The best sources are wheat germ, oysters and liver, Less zinc-rich sources include meat, sesame, sunflower and pumpkin seeds, nuts like pecans and brazils, spinach, mushrooms etc.
Those searching for an aromatase-inhibiting diet may wish to take a closer look at the Mediterranean diet, Fresh fruits, vegetables, olive oil and red wine are components of this diet, the one diet that has consistently correlated with lower death rates from all causes. Flavonoids from each of these foods inhibit aromatase activity to reduce incidence of breast cancer.
A final thought: the aromatase enzyme resides in fat cells. It is no surprise that being overweight and obese is linked with breast and other hormone-sensitive cancers. Fewer fat cells in the body means that less unbalanced estrogen is produced. High levels of insulin, a big factor in weight gain and fat mass accumulation, promote production of the aromatase enzyme. Avoiding processed foods and foods with chemicals helps keep insulin levels under control, in turn resulting in lower levels of aromatase and as a consequence, lower levels of unbalanced estrogen in the body.
Posted: October 18th, 2009 under Alternative Remedies, Cancer, Diet, Healing Foods, Hormone Health.
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