A new function of green tea: possible prevention of hairloss and other lifestyle-related diseases.Sueoka N, Suganuma M, Sueoka E, Okabe S, Matsuyama S, Imai K, Nakachi K, Fujiki H.
Saitama Cancer Center Research Institute, Japan. In the normal human life span, there occur lifestyle-related diseases that may be preventable with nontoxic agents. This paper deals with the preventive activity of green tea in some lifestyle-related diseases. Green tea is one of the most practical cancer preventives, as we have shown in various in vitro and in vivo experiments, along with epidemiological studies. Among various biological effects of green tea, we have focused on its inhibitory effect on TNF-alpha gene expression mediated through inhibition of NF-kappaB and AP-1 activation. Based on our recent results with TNF-alpha-deficient mice, TNF-alpha is an endogenous tumor promoter. TNF-alpha is also known to be a central mediator in chronic inflammatory diseases such as androgenetic hair loss, rheumatoid arthritis and multiple sclerosis. We therefore hypothesized that green tea might be a preventive agent for chronic inflammatory diseases. To test this hypothesis, TNF-alpha transgenic mice, which overexpress TNF-alpha only in the lungs, were examined. The TNF-alpha transgenic mouse is an animal model of human idiopathic pulmonary fibrosis which also frequently develops lung cancer. Expressions of TNF-alpha and IL-6 were inhibited in the lungs of these mice after treatment with green tea in drinking water for 4 months. In addition, judging from the results of a prospective cohort study in Saitama Prefecture, Japan, green tea helps to prevent cardiovascular disease. In this study, a decreased relative risk of death from cardiovascular disease was found for people consuming over 10 cups of green tea a day, and green tea also had life-prolonging effects on cumulative survival. These data suggest that green tea has preventive effects on both chronic inflammatory diseases and lifestyle-related diseases (including cardiovascular disease and cancer), resulting in prolongation of life span.
Mechanisms of cancer and hairloss prevention by tea polyphenols based on inhibition of TNF-alpha expression.Suganuma M, Sueoka E, Sueoka N, Okabe S, Fujiki H.
Saitama Cancer Center Research Institute, Japan.
Among various biochemical and biological activities of tea polyphenols, we believe inhibition of the expression and release of tumor necrosis factor-alpha (TNF-alpha) is crucial, since our study with TNF-alpha-deficient mice has revealed that TNF-alpha is an essential factor in tumor promotion. We found that EGCG dose-dependently inhibited AP-1 and NF-kappaB activation in BALB/3T3 cells treated with okadaic acid, resulting in inhibition of TNF-alpha gene expression. Furthermore, treatment with 0.1% green tea extract in drinking water reduced TNF-alpha gene expression as well as TNF-alpha protein level in the lung of TNF-alpha transgenic mice; and IL-1beta and IL-10 gene expression in the lung was also inhibited by treatment with green tea extract, indicating that green tea inhibits both TNF-alpha and the cytokines induced by TNF-alpha in organs. We recently found synergistic effects of EGCG and cancer preventive agents such as tamoxifen and sulindac, on cancer preventive activity. Taken together, the results show that green tea is efficacious as a non-toxic cancer preventive for humans.
*TNF-alpha has been conclusively shown to be expressed in androgenetic hair loss.
The key ingredients of green tea are molecules called catechins. Catechins have several properties. Anima model research studies indicate that green tea catechins have a variety of actions. Rats that were given green tea derived epicatechins showed vasorelaxation. Arteries that were induced to contract were found to relax again after administration of catechins (Huang 1998), so green tea may aid cardiovascular activity and microcapillary circulation to hair follicles.. Catechins of green tea are selectively bactericidal. They do not affect lactic acid bacteria but will reduce the proliferation of other bacteria types particularly those that use alpha-amylase activity in their growth and cell division. Green tea also contains antioxidants and may even help lower cholesterol. Of greatest interest to the research community green tea apparently has a protective effect against a range of cancers. Green tea has been statistically shown to reduce the frequency of smoke-induced mutations (Lee 1997). It has also been particularly useful in protection from stomach and colon cancer (Katiyar 1997).
Of greatest interest to those with androgenetic alopecia is evidence that green tea can influence serum concentrations of hormones and inhibit TNF-a. Research in this area is primarily with reference to hormonal effects on the development of cancer and how green tea and other caffeine containing products might mediate changes in hormone levels. For example, high intake of Green tea has been associated with higher levels of sex hormone binding globulin (SBHG) and lowered levels of serum estradiol (estrogen) concentration in women (Nagata 1998). Increased SBHG may be of help in reducing the effects of androgenetic alopecia. SBHG is a molecule that binds with high affinity to testosterone. Testosterone bound to SBHG is not bioactive and cannot bind to androgen receptors or be converted into dihydrotestosterone. An increase in SBHG concentration effectively reduces free testosterone. Green tea may also have an affect on the type I 5 alpha reductase enzyme that converts testosterone to dihydrotestosterone. These two distinct, but complementary, effects of green tea may influence androgenetic alopecia.
One cup of green tea roughly equals 50 mg of tea catechins. Typically research investigations have involved individuals drinking six cups of green tea, or utilizing Green Tea Extracts (300mg or more catechins) each day. Green tea is well tolerated by most individuals with no significant side effects reported.