Green Tea May Do Wonders for the Brain

17, 2006 -- Elders who drink green tea regularly may have sharper minds than those who don't drink green tea.

The finding comes from a Japanese study published in The American Journal of Clinical Nutrition.

The study included about 1,000 Japanese people aged 70 and older. Participants took tests of mental status including memory, orientation, ability to follow commands, and attention. They also told the researchers how often they drank beverages including green tea.

Those who reported drinking the most green tea were least likely to show cognitive impairment, based on their test scores, write Shinichi Kuriyama, MD, PhD, and colleagues.

Kuriyama works in the department of public health and forensic medicine at Tohoku University's medical school in Sendai, Japan.

How Much Green Tea Does It Take?
Drinking at least two daily cups of green tea was tied to the lowest risk of cognitive impairment in Kuriyama's study.

Compared with people who drank a cup of green tea up to three times weekly, those who drank two or more daily cups of green tea were 54% less likely to have test scores in the range of cognitive impairment.

Drinking green tea a little less often wasn't bad. People who drank a cup of green tea four to six times per week were 38% less likely to show cognitive impairment than those drinking green tea less than three times weekly.

Coffee, black tea, and oolong tea didn't show the same results. Green tea is a popular drink in Japan. More than seven in 10 participants reported drinking at least two cups of green tea daily.

Reading the Tea Leaves
The study doesn't prove that green tea deserves the credit for the elders' sharp minds.

The researchers didn't ask anyone to change their tea consumption for the study's sake. Instead, they checked test scores and tea habits.

Data was only gathered once. So it's not clear if participants' tea habits had lasted a lifetime or if their test scores changed over time.

Kuriyama's team considered factors linked to cognitive impairment, including diabetes, smoking, and advanced age. They also adjusted for potentially helpful habits, such as physical activity, social ties, consumption of fish and vegetables, and self-reported overall health.

Even after considering all those factors, high consumption of green tea was still associated with a lower risk of cognitive impairment, the study shows.

Next Steps
"To our knowledge, this is the first study to examine the association between consumption of green tea and cognitive function in humans," Kuriyama's team writes.

They note that natural compounds in green tea -- especially a chemical called EGCG (epigallocatechin-3-gallate) -- have shown promise in experiments on brain diseases in animals.

However, something else about green tea might help the brain, the researchers write.

For instance, people in Japan often socialize over green tea. Socializing could be good for the brain, note Kuriyama and colleagues.

They add that healthy people might be more likely to drink green tea. If so, those people would have a built-in brain advantage because of their general good health.

By Miranda Hitti
WebMD Health News

Reviewed by Louise Chang, MDFeb.

SOURCE: Kuriyama, S. The American Journal of Clinical Nutrition, Feb. 1, 2006; vol 83: pp 355-361.
© 2006 WebMD, Inc. All rights reserved.

Green Tea Fights Fat: Green Tea Ingredient May Promote Healthy Weight Loss

Jan. 26, 2005 -- Need another healthy reason to drink green tea? Aside from fighting heart disease, cancer, and other diseases, a new study shows that drinking green tea may also fight fat.

The study showed that people who drank a bottle of tea fortified with green tea extract every day for three months lost more body fat than those who drank a bottle of regular oolong tea.

Researchers say the results indicate that substances found in green tea known as catechins may trigger weight loss by stimulating the body to burn calories and decreasing body fat.

The findings appear in the January issue of the American Journal of Clinical Nutrition.

Green Tea: Fat Fighter?
Black tea, oolong tea, and green tea come from the same Camellia sinensis plant. But unlike the other two varieties, green tea leaves are not fermented before steaming and drying.

Most teas contain large amounts of polyphenols, which are plant-based substances that have been shown to have antioxidant, anticancer, and antiviral properties.

However, green tea is particularly rich in a type of polyphenols called catechins. These substances have also been shown to have anti-inflammatory and anticancer properties, but recent research in animals show that catechins may also affect body fat accumulation and cholesterol levels.

In this study, researchers looked at the effects of catechins on body fat reduction and weight loss in a group of 35 Japanese men. The men had similar weights based on theirBMI (body mass index, an indicator of body fat) and waist sizes.

The men were divided into two groups. For three months, the first group drank a bottle of oolong tea fortified with green tea extract containing 690 milligrams of catechins, and the other group drank a bottle of oolong tea with 22 milligrams of catechins.

During this time, the men ate identical breakfasts and dinners and were instructed to control their calorie and fat intake at all times so that overall total diets were similar.

After three months, the study showed that the men who drank the green tea extract lost more weight (5.3 pounds vs. 2.9 pounds) and experienced a significantly greater decrease in BMI, waist size, and total body fat.

In addition, LDL "bad" cholesterol went down in the men who drank the green tea extract.

The catechin content varies by amount of green tea used and steeping time. But general recommendations, based on previous studies on the benefits of green tea, are at least 4 cups a day. Green tea extract supplements are also available.

Researchers say the results indicate that catechins in green tea not only help burn calories and lower LDL cholesterol but may also be able to mildly reduce body fat.

"These results suggest that catechins contribute to the prevention of and improvement in various lifestyle-related diseases, particularly obesity," write researcher Tomonori Nagao of Health Care Products Research Laboratories in Tokyo, and colleagues.
A little extra support goes a long way when it comes to diet goals. Get the free help you need from WebMD!

By Jennifer Warner
WebMD Health News

Reviewed by Michael W. Smith, MD

SOURCE: Nagao, T. American Journal of Clinical Nutrition, January 2005; vol 81: 122-129.

© 2005 WebMD, Inc. All rights reserved.

Chemicals in Green Tea May Help With Memory and Learning Problems Associated With the Common Sleep Disorder

May 16, 2008 -- A cup of green tea may be just what the doctor ordered if you have learning and memory problems related to obstructive sleep apnea, the most common type of sleep-related breathing disorder.

Obstructive sleep apnea (OSA) starves the body of oxygen during sleep. Persons with the condition experience pauses in breathing while sleeping. This condition can cause a drop in oxygen levels, which can affect organs of the body. OSA increases your risk for high blood pressure, heart attacks, and strokes, and affects cognitive function such as learning and memory.

The powerful antioxidants found in green tea may help thwart such cognitive problems, according to a study published in this month's second issue of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine. Green tea contains compounds called polyphenols, which animal studies suggest can protect against neurodegenerative changes related to Parkinson's and Alzheimer's disease. Green tea polyphenols (GTP) work by counteracting oxidative stress in the brain. Oxidative stress is cell damage brought on by harmful molecules called free radicals. Antioxidants protect against this damage. Oxidative stress is believed to play a role in many diseases.

Signs of oxidative stress and changes in the brain have been documented among some patients with OSA, the study cites.

"OSA has been increasingly recognized as a serious and frequent health condition," study author David Gozal, MD, professor and director of Kosair Children's Hospital Research Institute at the University of Louisville, says in a news release. "A growing body of evidence suggests that the adverse neurobehavioral consequences imposed by [intermittent hypoxia] stem, at least in part, from oxidative stress."

The current study involved male rats that were intermittently deprived of oxygen during a 12-hour "night" cycle for two weeks. The intermittent oxygen deprivation was similar to that experienced by adults with OSA. The researchers gave half the rats water containing GTP and the other half plain water, and then tested the rats for markers of inflammation and oxidative stress.

After receiving the GTP cocktail or plain water drink, the rats entered a maze designed to test their spatial learning and memory abilities. In this case, the rats had to remember the location of a hidden platform.

The experiments showed that the rats treated with GTP made their way through the maze better than the other rats. The researchers say their findings suggest that the chemicals in green tea can calm learning problems related to OSA-induced hypoxia. They also found that there was chemical evidence of less oxidative stress in the rats given GTP.

GTPs "may represent a potential interventional strategy for patients" with sleep-disordered breathing," Gozal says.

Polyphenols are found in many foods and beverages, including tea, wine, and certain fruits and vegetables.

By Kelli Miller Stacy
WebMD Health News

Reviewed by Louise Chang, MD

SOURCES:

News release, American Thoracic Society.

Burckhardt, I. American Journal of Respiratory and Critical Care Medicine. May 2008: vol 177; pp 1135-1141.

© 2008 WebMD, LLC. All rights reserved.

What Everyone Should Know About The Health Benefits of Tea by Jeffrey Lorien

For literally thousands of years, humans have extolled the nutritional and health benefits of tea. The tea plant Camellia Sinensis is the source of all teas in the world. These include green, oolong, white, and black tea as well as the Chinese Tea known as Pu-erh Tea, which is prepared by fermentation of tea leaves. Both formal scientific studies and anecdotal evidence suggest that tea really can work wonders for the body. Here’s how:

Tea May Boost the Metabolism

Whether you are looking to burn off a few extra calories or simply get a little more energy during your day, drinking tea may be a good solution. Of course, it’s important not to add sugar to your tea, or you will undo the positive metabolic effects. Instead, add a sugar free substitute, like Splenda, Equal, or Sweet N' Low for taste.

Tea May Be an Effective Cancer-Fighting Agent

Nutritionists hypothesize that the antioxidants contained in tea may have powerful cancer fighting effects. Some scientific studies suggest that drinking several cups of green, white, or oolong tea a day may indeed reduce the likelihood that you'll develop cancer.

Tea Improves Focus and Brainpower

Tea leaves contain an important protein building block called L-Theanine, which stimulates cerebral activity but doesn’t over-stimulate like the caffeine in coffee.

Tea Can Relax the Body and Help You De-Stress

A hot cup of decaffeinated tea can soothe the body and reduce levels of the stress hormone cortisol in the bloodstream.

Tea Can Hydrate the Body Effectively and Efficiently -- Without Adding Extra Calories

In a world packed with energy drinks, colas, fruit juices, and other sugary beverages, tea offers a low calorie, low-carb alternative -- and a tasty one at that. Mounting evidence supports the hypothesis that obesity may be caused by too many simple sugars and carbohydrates in the diet. By switching from soda or fruit juice to tea, you can substantially cut out your daily intake of simple carbohydrates and improve your prospects for long-term good health.

Tea Supports the Immune System

Whether you are battling an infection or simply trying to stimulate the immune system, tea can be an important arrow in your immune system’s quiver.

Tea Is an Effective Digestive

The Chinese have known about tea’s positive postprandial effects for over 2,000 years. Scientists suggest that the tannins found in tea may improve the digestive process.

Tea May Be Very Heart Healthy

Studies suggest that drinking oolong tea or green tea can lower blood pressure, protect against heart disease, and guard against stroke and blood clotting.

The Polyphenols in Tea Can Act as Anti-Inflammatories

These polyphenols can be particularly effective in combating diseases and irritations of the intestines, such as irritable bowel syndrome. An agent in Rooibos, found in red tea, may also act to reduce stomach cramping.

Tea Can Fight Tooth Decay and Plaque.

While tea can also stain your teeth if you are not careful, the beverage supplies the body with both tannins and fluoride, which can support good dental health. To get these benefits without the cost (staining), rinse your mouth with water after you drink black or oolong tea.

Tea Can Be Good For the Skin

One study showed that tea functioned as well as or better than benzoyl peroxide in treating patients with acne. Many moisturizers, hair products, and other dermal solutions contain green tea extract. One of the reasons why green tea is so popular in these skin products is that the natural antioxidants contained in green tea can salve skin damage and guard against future damage.

Tea Offers Protection against Numerous Diseases and Conditions, Such As Parkinson's Disease, Influenza, Arthritis, and Diabetes

While tea is by no means a panacea, the beverage contains a host of compounds (discussed above -- tannins, antioxidants, polyphenols, etc), which can simultaneously boost the immune system’s capacity, enhance metabolism, reduce stress, and simultaneously invigorate. Tea also boasts a compound called alkylamine antigen, which may partially explain why regular consumption of tea is so well correlated with better health. A recent paper in the Journal of Allergy and Clinical Immunology reported another surprising finding: that regular tea drinking may inhibit the proliferation of the HIV virus in infected patients.

Avoiding Over Treatment with Tea

While tea offers a veritable cornucopia of health benefits, anything when taken to excess can cause health problems. Drinking too much tea can lead to jitteriness and insomnia, and the oxalates contained in some teas can lead to the formation of calcium oxalate crystals in the kidneys.

If You Experience Insomnia or Kidney Stones, See Your Doctor and Consider Taking Time off from Your Daily Tea Regimen

Similarly, the milk, sugar, and other additives you put into tea can cause negative health effects. A typical chai tea latte drink, for instance, may contain 50 grams of carbohydrates or more -- enough to cause blood sugar spikes and subsequent insulin crashes. The journal New Scientist also reported that putting milk in tea can reduce the nutritional benefits outlined above.

About the Author

Zhi Tea is a leading retailer of top-grade green and Oolong teas online. They provide a full line of organic and Fair Trade teas teas and custom tea gift baskets from around the world for you to enjoy.

Found at www.goarticles.com