Tea Boosts Human Immune System

The onset of winter introduces new varieties of influenza viruses and throat infections.

Vaccines help but when mismatched to the season’s latest flu bug they offer little or no effect on shortening hospital stays, time off work or complications.

Tea is a potent immune system enhancer that can help ward off bacteria according to results of a joint study by Harvard Medical School in Boston and the University of New Hampshire, Durham.

Green tea contains antigens known to fight infection. In this study, gamma-delta T-cells (our first line of defense against infection) were exposed to these antigens before being exposed to bacteria that would cause an infection. Control gamma-delta T-cells were not exposed to the antigens before being exposed to the bacteria. The result was that the antigen-exposed gamma-delta T-cells fought back against the bacteria, by multiplying up to 10 times and secreting disease-fighting chemicals. Cells not exposed to the antigen showed no significant response.

In a separate study, published in the July/August Annals of Family Medicine, researchers found that tea and coffee drinkers are almost twice as likely to ward off Methicillin-resistant Staphylococcus Aureus (MRSA) in their nostrils.

Drinking either beverage is associated with the reduction of MRSA according to results of the government-funded study of 5,555 Americans ages 2 and older, representing a sample population of 182 million.

Drinking both tea and coffee in the past month was associated with a 67 percent reduction, according to Eric M. Matheson, MD, from the Department of Family Medicine, Medical University of South Carolina, Charleston and colleagues.

An estimated 88.6 million people (48.6% of the population) reported consuming hot tea in the past month. An estimated 110.7 million people (60.8%) reported consuming coffee.

Overall, 1.4 percent of the sample (an estimated 2.5 million individuals) had MRSA nasal carriage but only a few get sick. Lead researcher Matheson concluded that "consumption of hot tea or coffee is associated with a lower likelihood of MRSA nasal carriage."

The study did not find any significant relationship between iced tea drinking and risk for nasal MRSA carriage. "One possible explanation is that iced tea has lower levels than hot tea of polyphenolic compounds per unit volume, because many of the compounds in tea are more soluble at higher temperatures," the authors write.

Hot tea has proven antimicrobial properties, according to the researchers. Less research has been done on coffee compounds, but there is also some evidence of antibacterial properties in coffee.

Aaron E. Glatt, MD, president, chief executive officer, and professor of medicine (infectious diseases), St. Joseph Hospital, Bethpage, New York, and a spokesperson for the Infectious Diseases Society of America, told Medscape News the research was interesting but should be viewed cautiously.

It is too early to recommend changes in hot tea and coffee drinking habits, Dr. Glatt. "Information like this needs to be taken with a tremendous amount of thought. You don't want to suddenly recommend anything based on this, although it certainly merits further study."

Source: Medscape News, Annals of Family Medicine


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