The Lancet Reports Extremely Positive Data on Green TeaJanuary 2005
By Stephen Laifer
Protecting Aging Brains
Researchers believe that green tea may slow the effects of normal aging and its associated brain regression. A 2004 study investigated the effect of long-term green tea catechin intake on aging and oxidative damage, using aged mice with cerebral atrophy and cognitive dysfunction. Catechin intake was shown to effectively suppress further atrophy and cognitive dysfunction,23 strongly suggesting that green tea can at least partially improve the negative functional alterations that occur naturally in aging brains.
Another recent clinical trial found that green tea also offers protection against brain-deteriorative functions typically associated with stroke. As noted earlier, green tea catechins have potent antioxidant properties, protecting the body from atherosclerosis, a trigger of stroke. In this recent trial, catechins were further shown to reduce both the area and volume of damage to the brain following a stroke.24 According to the research-ers, daily intake of green tea catechins adds a measurable level of protection to the brain, helping shield it from “irreversible damage due to cerebral ischemia [stroke] and consequent neurological deficits.”24
The neurodegeneration that occurs in Parkinson’s disease, Alzheimer’s disease, and other neurodegenerative disorders is believed to involve a complex set of toxic reactions, including inflammation, neurotoxicity, increases in iron and nitric oxide, and depletion of antioxidants. These factors, among others, all lead to the breakdown and eventual failure of neurons. This has led to the current notion that drugs directed against a single target may be ineffective, while a drug or drug combination that attacks the condition in a variety of ways may be efficacious in treating neurodegenerative disorders.25
Green tea catechin polyphenols, known to be effective scavengers of free radicals, are believed to play a role in various cellular mechanisms related to neuroprotective activity. Researchers increasingly suspect catechins may be deeply involved in the activation of survival genes and in cell signaling pathways, as well as in the regulation of healthy cellular metabolism. As a result, catechins are receiving significant attention as therapeutic agents for the treatment of neurodegenerative diseases involving brain regression.25
Healthy Blood Sugar Levels
Green tea may help to normalize and maintain healthy blood sugar levels. Epidemiological data suggest that green tea consumption prevents type II diabetes.26 In healthy human volunteers, green tea promoted healthy glucose metabolism, as determined by oral glucose tolerance tests.26 Green tea also lowered blood glucose levels in diabetic mice without affecting serum insulin levels.26 Green tea therefore appears to have anti-hyperglycemic effects. Green tea may be a helpful agent in preventing type II diabetes and in promoting healthy glucose metabolism.
Relief from Arthritis
Scientists believe that the antioxidants in green tea may also fight inflammation and help prevent arthritis.
Ongoing research at Case West-ern Reserve University suggests that green tea supplementation can postpone the beginning—and decrease the severity—of at least one type of arthritis.27 In this study, mice that were fed green tea polyphenols were significantly less susceptible to the development of collagen-induced arthritis, which is similar to rheumatoid arthritis in humans. Researchers noted that the arthritic mice that received the polyphenols had later onset of arthritis and developed less severe forms of the disease. The animals receiving green tea also showed a marked decrease in inflammatory mediators, including cylcooxygenase-2 and tumor necrosis factor-alpha.
Another study examined the effects of green tea catechins on human and bovine cartilage in vitro. Green tea catechins were found to inhibit the breakdown of proteoglycan and type II cartilage, which are components of healthy joint tissue. The study authors concluded, “green tea catechins are chondroprotective and consumption of green tea may be prophylactic for arthritis and may benefit the arthritis patient by reducing inflammation and slowing cartilage breakdown.”28
Green tea is an ancient beverage with a bright future of applications in preventing disease and promoting health. A powerful source of antioxidants, green tea may help to prevent cancer, protect the cardiovascular system, promote healthy blood sugar levels, and alleviate the neurological effects of aging. Green tea is thus a safe and effective natural remedy for promoting a long and healthy life.
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