Green Tea – Fighting Bacteria and Viruses

In 2007, researchers reported that green tea catechins fight bacteria by attacking DNA gyrase, an enzyme necessary for bacterial reproduction and the target of many antibiotics. Other studies demonstrate more specific antibacterial applications for green tea. At a 2005 symposium of the American Chemical Society, researchers provided evidence that green tea extract kills several common food-borne bacteria, including salmonella. The results of a 2001 study in the Journal of Medical Microbiology show that green tea fights streptococcus mutans and Streptococcus sobrinus bacteria, both of which contribute to tooth decay. And in 2003, researchers reported using green tea to inhibit the growth of bacteria responsible for strep throat and tooth decay.

Green tea also has antiviral properties. Researchers investigated the effects of green tea catechins on the influenza virus. According to the results of their study, published in 2005 in the journal Antiviral Research, two catechins, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), inhibited viral reproduction. In 2008, Chinese researchers published a study in the same journal showing that green tea extract inhibited the hepatitis B virus in laboratory settings.

Protecting Against Cognitive Impairment

In a study published in the American Journal of Clinical Nutrition in 2006, researchers surveyed a group of 1,003 subjects over the age of 70 about their green tea consumption. After comparing the survey data against the rate of cognitive decline experienced by the study’s participants, the authors wrote, “The prevalence of cognitive impairment decreased with increasing frequency of tea consumption”. They concluded that “higher consumption of green tea is associated with lower prevalence of cognitive impairment in humans”. While more research needs to be done in this area, initial results are promising.

The Bottom Line

Because of the wide-range health benefits of green tea on so many different systems in the body, it makes sense to drink green tea and take green tea supplements to promote and preserve good health.

Green Tea Fast Facts

Uses and Benefits: Green tea acts as an antioxidant, helps protect against cancer, fights bacterial infections and tooth decay, lowers cholesterol levels and may delay the onset of atherosclerosis.

Sources: The most common source of green tea is an infusion made from tea bag or loose tea leaves. Green tea extracts and capsules are also widely available.

Special Considerations: Drink green tea without milk, which may bind with some beneficial compounds in the tea and make them unavailable to the body. Some experts suggest drinking four to 10 cups of green tea a day; if this seems like too much, consider a green tea supplement. Be aware that green tea contains small quantities of caffeine.

Black tea does not offer the same health benefits as green tea. Unlike green tea leaves, which are gently steamed, black tea is fermented, a process that destroys polyphenols.

USANA’s powerful bioflavonoid supplement combines the highest quality grape-seed extract with vitamins C (as Poly C®) for additional antioxidant protection