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June 2008 HealthWatch

Stay up-to-date on the latest health and nutrition information with Virtual Health Info's monthly HealthWatch bulletin, America's premier source for health information. The June issue of HealthWatch features the following articles: Mens Health, National Men's Health Week, Action Plan For Lowering Blood Pressure, Antioxidant Rich Green Tea May Reduce Prostate Cancer Risk. Click here for more information.

Antioxidant Rich Green Tea May Reduce Prostate Cancer Risk

According to a recent study conducted by researchers at Japan's National Cancer Center in Tokyo, drinking green tea may reduce the risk of advanced prostate cancer. Prostate cancer is the most common form of cancer, other than skin cancer, among men in the United States. According to the details of the report, men who drank five or more cups of the antioxidant rich beverage might halve the risk of developing advanced prostate cancer compared with those who drank less than one cup a day. The study compiled data from 50,000 men aged 40-69, over a period of up to 14 years from 1990. Although the data is promising, more research is needed to confirm these findings. For more information go to the American Journal of Epidemiology, January 2008.

Green Tea and Breast Cancer

In a recent scientific research study, presented at the Experimental Biology 2008 conference, the green tea antioxidant EGCG (epigallocatechin-3-gallate) significantly slowed breast cancer growth in female mice. Earlier studies have suggested that this antioxidant may protect against breast cancer and other cancers, but the amount of research has been small, and the mechanics behind the physiological effects has not been understood. Researchers now have mounting evidence to help confirm that green tea's anticancer effects may be, in large part, because of its high content of EGCG. In this study, EGCG appears to protect the body's cells from becoming dam-aged and aging prematurely. Additional research would help to further understand the value of EGCG and its role in breast cancer. Click here for more information.

Antioxidant Rich Green Tea May Reduce Prostate Cancer Risk

According to a recent study conducted by researchers at Japan's National Cancer Center in Tokyo, drinking green tea may reduce the risk of advanced prostate cancer. Prostate cancer is the most common form of cancer, other than skin cancer, among men in the United States. According to the details of the report, men who drank five or more cups of the antioxidant rich beverage might have the risk of developing advanced prostate cancer compared with those who drank less than one cup a day. The study compiled data from 50,000 men aged 40-69 over a period of up to 14 years from 1990. Although the data is promising more research is needed to confirm these findings. For more information go to the American Journal of Epidemiology, January 2008.

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Research Shows Green Tea Has Positive Anti-Obesity Effects and Even More

Over the last ten years, the notion that green tea consumption is healthy has received significant scientific attention, especially as it relates to the areas of cardiovascular disease and cancer. Because of the ever-growing obesity pandemic, the anti-obesity effects of green tea are being increasingly looked at in cell, animal, and human studies. Green tea, green tea catechins, and epigallocatechin gallate (EGCG) have been demonstrated in cell and animal research to reduce adipocyte differentiation and proliferation, lipogenesis, fat mass, body weight, etc., as well as to increase beta-oxidation and thermogenesis. Human research has confirmed these findings. For additional confirmation, more research would help solidify what we know about green tea and since EGCG is regarded as the most active component of green tea, its specific effects on obesity should also be investigated in human trials. For more information go to Molecular Nutrition & Food Research, Volume 50, February 2006.

Green Tea Shows Evidence of Helping Stimulate Cancer Protection

Green tea consumption has been associated with a reduced risk of certain types of cancers in humans. For this reason, researchers from the University of Arizona set out to explain its anti-cancer effect by seeing if a concentrate of catechins (polyphenols in green tea) had any effect on levels of glutathione S-transferase (GST) enzymes. GST’s are known to modify cancer-causing molecules in such a way that they do not damage cellular DNA.

Their findings suggest that green tea polyphenol intervention could enable some people to strengthen their defense against carcinogens, thereby providing additional evidence to support the green tea group of supplements and food ingredients. For additional information about this study go to the journal Cancer Epidemiology Biomarkers & Prevention, August 2007. Read More.

Green Tea With EGCG and Caffeine May Play A Role In Body Composition

According to a study published in the American Journal of Clinical Nutrition, green tea extract (50 mg caffeine and 90 mg EGCG) has thermogenic properties, meaning that it increases energy production and promotes fat oxidation in the body. These properties, which are associated with fat burning, appear to be functioning beyond that which can be explained by the caffeine content alone. This would mean that green tea has a variety of rich components able to play a role in helping to control body composition. Source: The American Journal of Clinical Nutrition, Vol. 70, No. 6, 1040-1045. Click here for more Information.

Tea Rich Catechins Leads to Reduction in Body Fat

A 12 week double-blind study was performed in which the subjects ingested varying levels of catechin-rich teas.

It concluded that daily consumption of tea containing 690 mg catechins for 12 weeks reduced body fat, which suggests that the intake of catechins might be useful in the prevention and improvement of lifestyle-related diseases, mainly obesity. More research in this area would be helpful in confirming these findings. For more information go to the American Journal of Clinical Nutrition, Volume 81, 2005.
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Weight Loss and Weight Maintenance - Caffeine and Green Tea Intake

A recent study found that, compared to each other, caffeine intake was associated with greater weight loss, thermogenesis and fat oxidation than green tea with caffeine, while green tea and its antioxidant component EGCG with caffeine was associated with greater weight maintenance. For more information go to the journal Obesity Research, Volume 13, 2005.

Research Shows Green Tea Has Positive Anti-Obesity Effects and Even More Research Would be Helpful

Over the last ten years, the notion that green tea consumption is healthy has received significant scientific attention, especially as it relates to the areas of cardiovascular disease and cancer. Because of the ever-growing obesity pandemic, the anti-obesity effects of green tea are being increasingly looked at in cell, animal, and human studies. Green tea, green tea catechins, and epigallocatechin gallate (EGCG) have been demonstrated in cell and animal research to reduce adipocyte differentiation and proliferation, lipogenesis, fat mass, body weight, etc., as well as to increase beta-oxidation and thermogenesis. Human research has confirmed these findings. For additional confirmation, more research would help solidify what we know about green tea and since EGCG is regarded as the most active component of green tea, its specific effects on obesity should also be investigated in human trials. For more information go to Molecular Nutrition & Food Research, Volume 50, February 2006. Click here for more information.

Supplementing the Diet With Fruit, Vegetables, and Green Tea Can Prevent Oxidative Stress

A recent study where participants were asked to consume additional daily portions of fruit, vegetables, and 2-3 glasses of green tea concluded that an adequate supplement of antioxidants can prevent oxidative stress and correlated pathologies. For more information go to the journal Clinica Terapeutica, Volume 157, November 2006. Click here for more information.

Green Tea May Help Arthritis Sufferers

In a recent study, from the University of Michigan Health System, evidence shows that components in green tea may help prevent the formation of inflammatory molecules associated with joint damage in individuals with rheumatoid arthritis. The study, presented on April 29 at the Experimental Biology 2007 in Washington, D.C., looks at a potent anti-inflammatory compound in green tea called epigallocatechin-3-gallate (EGCG). Researchers found that EGCG inhibited the production of several molecules in the immune system responsible for inflammation and joint destruction. The results of this study add to an ever-growing body of science linking the consumption of green tea to a wide range of health benefits. For more information, click here.

Component in Green Tea Found Helpful in Alzheimer's Disease Prevention

Alzheimer's disease is a brain disorder that gradually affects a person's memory as well as their ability to learn, communicate, and carry out daily activities. Alzheimer's also leads to dementia, which is the destruction of brain cells and is characterized by brain-clogging tangles of proteins called plaques. According to a University of South Florida study, a component of green tea called ECGC (epigallocatechin-3-gallate) may reduce or prevent the formation of the detrimental plaques. ECGC is a known antioxidant. It helps the body fight harmful free radicals and promotes cellular longevity. The study also shows that the process of aging tea leaves tends to decrease the amount of antioxidants and that is the reason why green tea is considered to be more powerful in fighting diseases than other teas; black tea is aged the most and green tea the least. Additional studies on ECGC and Alzheimer's would help to confirm the findings of this study. For more information go to the Journal of Neuroscience, September 2005.

Supplementing the Diet With Fruit, Vegetables, and Green Tea Can Prevent Oxidative Stress

A recent study where participants were asked to consume additional daily portions of fruit, vegetables, and 2-3 glasses of green tea concluded that an adequate supplement of antioxidants can prevent oxidative stress and correlated pathologies. For more information go to the journal Clinica Terapeutica, Volume 157, November 2006.

Green Tea May Reduce Risk of Early Death

Green tea, long studied for its antioxidant properties, appears to reduce mortality. Researchers in Japan concluded in a recent study that drinking green tea is associated with reduced mortality from all causes, including cardiovascular disease, though not from cancer. Doctors theorized that the antioxidants in green tea reduce free radicals, which in turn allows for a reduction of LDL cholesterol and increase in HDL cholesterol. Furthermore, antioxidants can reduce arterial plaque buildup and help improve blood vessel function. In contrast, the hazard ratios of cancer mortality were not significantly different from 1.00 in all green tea categories compared with the lowest-consumption category. For more information, see the Journal of the American Medical Association, September 13, 2006, Volume 296, Number 10. Read More.

Epigallocatechin Gallate Inhibits Aryl Hydrocarbon Receptor Gene Transcription through an Indirect Mechanism Involving Binding to a 90 kDa Heat Shock Protein

The aryl hydrocarbon receptor (AAhR) is a ligand-activated transcription factor known to mediate the toxic effects of numerous environmental contaminants, including the polycyclic aromatic hydrocarbons (PAHs). Historically, binding of PAHs to the AhR and the events leading to the generation of DNA adducts have been associated with chemical carcinogens. Previous investigations have implicated green tea (GT) as affording protection against PAH-induced cancers in animal models. Investigations in our laboratory have demonstrated that the GT polyphenol epigallocatechin gallate (EGCG) is capable of antagonizing the AhR-mediated gene transcription, implicating the inhibition of AhR signaling as a potential chemopreventative mechanism. Read More.

The Protective Effect of Habitual Tea Consumption on Hypertension

Tea has long been believed to possess hypotensive effects in popular Chinese medicine. However, conflicting results have been shown among human trials and animal studies on the relation between tea consumption and blood pressure. Epidemiological evidence about the long-term effect of tea on hypertensive risk is also inconsistent. Read More.

In Vitro Anti-ß-Secretase and Dual Anti-cholinesterase Activities of Camellia Sinensis L. (Tea) Relevant to Treatment of Dementia

The primary target of licensed drugs for the treatment of Alzheimer's disease is the inhibition of the enzyme acetylcholinesterase, although preventing ß-amyloidosis is a prime target for drugs in development. The in vitro dual anti-cholinesterase and ß-secretase activities of Camellia sinesis L. extract (tea) is reported. Green and black tea inhibited human acetylcholinesterase (AChE) with IC50 values of 0.03 mg/mL and 0.06 mg/mL respectively, and human butyrylcholinesterase (BuChE) with IC50 values 0.05 mg/mL. Green tea at a final assay concentration of 0.03 mg/mL inhibited ß-secretase by 38%. These novel findings suggest that tea infusions contain biologically active principles, perhaps acting synergistically, that may be used to retard the progression of the disease assuming that these principles, yet to be identified, reach the brain. Read More.

The Protective Effect of Habitual Tea Consumption on Hypertension

Tea has long been believed to possess hyptensive effects in popular Chinese medicine. However, conflicting results have been shown amoung human trials and animal studies on the relation between tea consumption and blood pressure. Epidemiological evidence about the long-term effect of tea on hypertensive risk is also inconsistent.

VEGF Receptor Phosphorylation Status and Apoptosis is Modulated by a Green Tea Component, Epigallocatechin-3-gallate (EGCG), in B-cell Chronic Lymphocytic Leukemia

We recently reported that chronic lymphocytic leukemia (CLL) cells synthesize and release vascular endothelial growth factor (VEGF) under normoxic and hypoxic conditions. CLL B cells also express VEGF membrane receptors (VEGF-R1 and VEGF-R2), suggesting that they use VEGF as a survival factor. To assess the mechanism of apoptosis resistance related to VEGF, we determined the impact of VEGF on CLL B cells, and we studied the impact of epigallocatechin-3-gallate (EGCG), a known receptor tyrosine kinase (RTK) inhibitor, on VEGF receptor status and viability of CLL B cells. Read More.

Green Tea Consumption and Cognitive Function: A Cross-Sectional Study from the Tsurugaya Project

Although considerable experimental and animal evidence shows that green tea may possess potent activities of neuroprotection, neurorescue, and amyloid precursor protein processing that may lead to cognitive enhancement, no human data are available. The objective was to examine the association between green tea consumption and cognitive function in humans. Read More.

Green Tea's Anti-Cancer Mechanism Of Action Uncovered

According to research conducted at the University of Rochester Medical Center in New York, a potential new mechanism of action for green tea, particularly with respect to its active compounds' action against cancer, was recently uncovered. Green tea appears to protect against cancer by having an affect on a 'promiscuous' protein that drug industry experts are already targeting in their work on anti-cancer drugs. Source: Biochemistry, Volume 44, April 2005. Read More.

Tea Inhibits Enzymes Associated With Alzheimer's Disease

In a laboratory test conducted by a research team at the University of Newcastle in the United Kingdom, it was determined that tea, particularly green tea, inhibits the activity of the same enzymes in the brain currently targeted by drugs used to treat Alzheimer's disease. These novel findings suggest that tea infusions contain biologically active principles, possibly acting synergistically, that may be useful in retarding the progression of the disease assuming that these principles, yet to be identified, reach the brain. More research needs to be done to confirm and/or expand on these findings. Source: Phytotherapy Research, August 2004. Read More.

Component In Green Tea May Help Kill Leukemia Cells

Mayo Clinic researchers using laboratory cell cultures have found that a component in green tea called epigallocatechin-3 (EGCG) helps destroy leukemia cells by interrupting the communication signals needed for them to survive. The specific cells studied were from patients with B-cell chronic lymphocytic leukemia (CLL); the type most often diagnosed in patients in the mid-to-late sixties. There is currently no cure for CLL, though chemotherapy is given in extreme cases. Mayo Clinic scientist Dr. Neil E. Kay stated that one of the purposes of the study was to look for therapeutic agents that are nontoxic to the patient but kill the cancer cells.
Additional research in this area would help to support the findings of the study. Source: Blood, Volume 104, pps. 788-94. Read More.

Tea Helps Keep Blood Pressure Down

In a new study, conducted at the National Cheng Kung University in Taiwan, scientists examined the effect of drinking tea on the risk of newly diagnosed hypertension in subjects aged 20 or older who did not have a history of hypertension when the study began. Approximately 40% of the study participants were defined as "habitual tea drinkers", meaning they consumed at least 120 milliliters of green tea or oolong tea every day for at least one year. After all the data of the study was analyzed it was concluded that habitual moderate strength green or oolong tea consumption, 120 milliliters per day or more for one year, significantly reduces the risk of developing hypertension in the Chinese population. More research in this area would help to support a definitive conclusion. Source: The Archives of Internal Medicine, Volume 164, 2004. Read More.

Green And Black Tea Promising For Prostate Cancer

A study was recently conducted to see whether or not the polyphenols found in tea might slow the growth of prostate cancer cells. Polyphenols are compounds found in plants and possess antioxidant properties. Antioxidants are substances that protect cells from oxidative damage caused by molecules called free radicals. Based on several types of findings, researchers did see evidence linking green and black tea to the slowing of prostate cancer cell growth. Source: www.healthy.net.

Tea May Have Heart Health Benefits

According to researchers at the University of Western Australia School of Medicine, tea, which is rich in polyphenols, may have a protective effect on women's heart health. After looking at the relationship between tea consumption and blood pressure in a cross-sectional study of 218 women, all of whom were older than 70, the researchers saw that there may be a relationship between the long-term ingestion of tea and a favorable effect on blood pressure in older women. Source: www.nutrition.org. Read More.

Green Tea May Play A Role In Body Composition

According to a study published in the American Journal of Clinical Nutrition, green tea extract has thermogenic properties, meaning that it increases energy production and promotes fat oxidation in the body. These properties, which are associated with fat burning, appear to be functioning beyond that which can be explained by the caffeine content alone. This would mean that green tea has a variety of rich components able to play a role in helping to control body composition. Source: The American Journal of Clinical Nutrition, Vol. 70, No. 6, 1040-1045.

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