Don’t you just shake your head at all the studies being reported about the foods we eat? I certainly do. Many times I dismiss the reports but recently two interesting studies on tea and coffee were reported in separate well-respected medical journals. I thought I would bring them to your attention. Both studies were well-done and included large numbers of people.
Tea and coffee contain hundreds of chemicals. Many of these chemicals have an anti-bacterial effect. Both beverages are full of anti-oxidants which are beneficial in many ways. Coffee especially can affect the circulating levels of many hormones such as insulin, sex hormones, and others.
In the first study, hot tea and coffee were examined to determine whether their consumption reduced the risk of having Methicillin Resistant Staphylococcus Aureus, better known as MRSA.
MRSA is a major source of infection and death in the United States. It used to be found just in hospitalized patients. However, it is now widespread throughout the community. In 2005, 300,000 people were hospitalized for MRSA infections and there were more than 6,500 MRSA-related deaths. It is estimated that 1.4% of the population “carries” MRSA in their nasal passages. This means that the organism lives in the nose but does not cause an infection. However, the bug can be spread to open wounds both in the person who carries it and in others who come into contact with that bug.
Tea and coffee have been known to suppress bacterial growth in the lab and in patients. Both tea and coffee have strong antibacterial activity when applied to the skin. For instance, bed-ridden patients with MRSA-infected bed sores had their ulcers cleaned with either green tea or salt water. After one month, patients whose ulcers were treated with green tea had marked improvement and MRSA had disappeared in over half of the patients. Those with the salt water washes were basically unchanged.
The first study I reviewed found that there was a much lower likelihood of carrying MRSA in the nasal passages in individuals who drank hot tea, coffee, or both. Interestingly, the association was not found with iced tea or soda. Some might think that the caffeine is the active ingredient, but many sodas are caffeinated so it would appear that the effect is due to something other than the caffeine itself. It is possible that hot tea has a higher concentration of compounds or that the vapor from the hot liquids migrates up into the nasal passages to kill the MRSA. The investigators pointed out they did not know how the effect occurs, but proposed many complicated potential actions.
It is not known whether drinking hot tea or hot coffee to prevent carrying MRSA in the nose would prevent true MRSA infections. However, the effect of eliminating MRSA in the nose as seen in this study was described by the authors as “robust”.
The other study looked at the relationship of coffee consumption and prostate cancer. Past data has been very conflicting as to whether or not coffee has any affect whatsoever on prostate cancer. This study looked specifically at the effect on “lethal” (causing death) prostate cancer. It found that those who drank coffee showed a slightly lower risk of overall rates of prostate cancer, but there was a marked decrease in lethal and advanced prostate cancers. Those who drank the most cups of coffee (greater than 6 cups per day) had less than half the risk of lethal prostate cancer than non-coffee drinkers. The effect is seen with both regular and decaffeinated coffee. So, once again, it would appear that caffeine is not the active agent.
The conclusion from this second study was that men who consumed coffee regularly have a reduced risk of lethal or advanced prostate cancer but it is still premature to recommend that men increase coffee intake to improve their chances.
Interesting. Modern research, with its ability to manage tremendously large patient numbers using computers, is truly fascinating. Wouldn’t it be fun to be around in 25 to 50 years to see what the true effects end up being? Some of us will be and perhaps our coffee and tea habits will have helped us to be healthier seniors!
As always, consult your personal physician before making any health care decisions.
John L. Pfenninger, MD. President and Director, the Medical Procedures Center, PC, Midland Michigan. Clinical Professor of Family Medicine, Michigan State College of Human Medicine.