Coffee and tea drinkers could be at lower risk of a developing a deadly drug-resistant staph infection, new research suggests.
As part of the 2003-04 National Health and Nutrition Examination Survey (NHANES), more than 5,000 Americans from across the country were tested for methicillin-resistant Staphylococcus aureus — better known by its abbreviation, MRSA — in the nasal cavity. Although carrying MRSA in the nose is not at all dangerous by itself, some studies show that nasal colonization may put people at higher risk of systemic MRSA infection throughout the body, and that can be fatal.
The MRSA “superbug” has become a major public-health concern in the last 15 years because it can spread quickly and is resistant to common antibiotic treatments. It is especially widespread in hospitals. In 2005, MRSA killed more Americans than AIDS.
The results of the NHANES testing, published in the July/August issue of the journal Annals of Family Medicine, showed that 1.4% of the nationally representative survey participants had nasal MRSA carriage. However, people who drank coffee or hot tea at least once a month were only about half as likely to be infected as those who did not — even after adjusting for age, race, sex, recent antibiotic use and hospitalization history, and a few other variables.
Coffee and tea drinkers saw advantages of about the same magnitude, no matter which drink they favored. The study authors say they cannot be sure why people drinking tea or coffee might be less likely to have nasal MRSA carriage, but that it could be the result of antimicrobial compounds known to exist in the beverages.
In the case of coffee, particular attention has focused on the potential antibacterial properties of trigonelline, glyoxal, methylglyoxal, and diacetyl. For tea, attention has focused on the antimicrobial properties of tannic acid and catechins. In addition, consumption of both coffee and tea decrease iron absorption, which may prove important because iron is critical for the growth of S. aureus.
The researchers did not find any difference in MRSA colonization rates between people who drank iced tea or soft drinks and those who did not. The sample size was not large enough to test whether drinking more coffee or tea was associated with even lower MRSA colonization rates, or to test whether coffee and tea drinkers have any difference in risk of systemic MRSA infection.
