November, 2007 through December, 2007
Research Update
Researchers from Around the World Provide Further Insights into the Myriad Health Benefits of Tea
From Supporting Brain Health and Reducing Body Fat to Prevention of Heart Disease,
Here’s News You Can Drink To
Leading nutrition scientists from around the world recently met in Washington, DC for the 4th International Scientific Symposium on Tea & Human Health to review the latest findings on the potential health benefits of tea, including studies on how it may help maintain a healthy body weight, control blood sugar, help us think more clearly, and reduce the risk for several chronic diseases. Here, we look at some of the major research highlights that came out of the conference:
Tea Improves Attention and Focus
Research presented on theanine (an amino acid found almost exclusively in tea leaves) shows that it actively alters the attention networks of the brain. Theanine, which is present in green, black and oolong and white varieties, is known to be absorbed by the small intestine and cross the blood-brain barrier where it affects the brain’s neurotransmitters, and increases alpha brain-wave activity. This alpha brain rhythm is known to induce a calmer, yet more alert, state of mind. Theanaine has been shown to help improve attention spans and concentration and there appears to be no negative side-effects from this all-natural amino acid as it is quickly cleared from the body.
Tea May Help Maintain Brain Health
Numerous studies have concluded that diets rich in fruits and vegetables support the body in fighting neurological decline through antioxidant mechanisms, associated with their high flavonoid content. However, the importance of polyphenolic flavonoids in supporting healthy brain cells appears to go beyond the simple oxygen species scavenging, and may act on numerous biological pathways to help keep human brain cells from dying and even help repair damaged DNA. One study found that when animals with induced neurological disease are fed tea polyphenols the flavonoid helps prevent brain cells from dying, and shows improvements in reducing compounds that lead to lesions in the brains of animals with Alzheimer’s disease.
Tea and Heart Health
New research presented at the conference from Italian researchers provided additional insights into how tea flavonoids provide support for cardiovascular health by promoting healthy endothelial function. In these new studies, tea flavonoids improved endothelium-dependent vasorelaxation and decreased arterial stiffness in study participants, thereby suggesting that tea consumption may have favorable effects on cardiovascular disease. Tea flavonoids are thought to support cardiovascular health through several mechanisms, including: providing antioxidants to help temper inflammatory markers such as C-reactive protein; reducing blood cholesterol levels; and providing dilation of blood vessels to help manage blood pressure.
Tea is Tops for Flavonoids
Flavonoids are a type of antioxidant that are known to be biologically active and are found primarily in plant-based foods and beverages, including fruits and vegetables, chocolate, wine and tea. Intake of flavonoids has been inversely associated with the incidence of many chronic diseases, including cardiovascular disease and certain cancers. Using the latest national food consumption databases and the USDA flavonoid database, Michigan State University researchers were able to differentiate tea drinkers from non-tea drinkers and analyze their diets, based on diet recalls, for flavonoid intake. The flavonoid intake of tea drinkers was more than 20 times higher than flavonoid consumption of non-tea drinkers. Tea drinkers averaged nearly 700 mg flavonoids while non-tea drinkers averaged about 33 mg per day. A cup of tea contains approximately 125 mg flavonoids, which is more than most non-tea drinkers consume in an entire day.
According to the meeting organizers, given the robust body of evidence of tea’s role in helping individuals maintain good health and vitality, and a lack of medical evidence of any risk associated with drinking typical amounts of tea, it only makes sense to enjoy tea as part of a healthy diet and lifestyle.
Researchers from Around the World Provide Further Insights
Tea and Weight Management
With over two-thirds of the US adult population overweight or obese, scientists are looking for medically sound ways to help consumers manage their weight. Several research studies conducted in recent years suggest that green teas rich in catechins may aid in weight management by reducing body fat and in particular visceral fat, the deep belly fat associated with increased risk for heart disease and type II diabetes. It is thought that tea polyphenols increase resting energy expenditure and fat oxidation. While not a weight loss magic bullet, since green and black tea can be enjoyed without added calories, tea drinkers may find that they can eliminate liquid calories in their diet by drinking tea in lieu of sugar-laden beverages that are nutrient-poor but calorie-rich.
Contact: Pollock Comm., 212-941-1414/Tea Council of the USA, 212-986-6998
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