Tea and coffee reduce MRSA

Methicillin-resistant Staphylococcus aureus (MRSA) can cause serious infections, but some people carry the organism in their noses. As tea and coffee have some antimicrobial effects, a study in the US has investigated whether the consumption of these drinks influence nasal carriage of the bacteria.

Data came from the National Health and Nutrition Survey. A random sample of participants had nasal swabs taken for culture.

In a sample of 5555 people, approximately half had drunk tea and 61% had drunk coffee in the preceding month. MRSA was found in 1.4% of the participants.

The odds of having MRSA were reduced by half in tea and coffee drinkers. There was a similar reduction in people who drank both tea and coffee.

In people who drank iced tea there was no reduction in nasal carriage of MRSA. Soft drinks also had no effect.

Children do not drink a lot of tea and coffee, so an analysis was performed on adults only. This also found a significant reduction in MRSA in tea and coffee drinkers.

Comment
At present, antibiotics are needed if eradication of nasal MRSA is required. This study suggests hot tea and coffee could help.

These beverages contain several substances which could have an effect. One theory is that they reduce absorption of the iron the bacteria need to proliferate.

As only hot tea and coffee had an effect, it is possible the substances reach the nose in the vapour rather than by absorption from the gut, alternatively the substances may be more active when warmed up.

Matheson EM, Mainous AG, Everett CJ, King DE. Tea and coffee consumption and MRSA nasal carriage. Annals of Family Medicine 2011; 9:299-304