Japanese researchers have found that men who drink green tea have healthier gums. Based on self-reported green tea usage, the more green tea a man drank, the less likely he was to have periodontal problems.

The rule of thumb is that pockets three millimeters or deeper cannot be cleaned effectively at home.

Green tea is reputed to have so many health benefits. So far, scientific analysis has been mixed. There have been some promising studies, but few conclusive benefits have been shown. The National Institute of Health's Medline gives green tea a grade of C "scientifically unproven" in 17 areas ranging from cancer prevention to improved cardiovascular health. Time will eventually prove or disprove all these health claims. Meanwhile, many outside the realm of science continue to attribute various health benefits to green tea. A recent study of green tea's oral benefits has come up positive.

Gum disease, periodontal disease and periodontitis are different terms for the same condition. It occurs when the gums begin to separate from the teeth, leaving open spaces or pockets. Food particles become trapped in these pockets, forming an excellent environment for bacteria to grow. The rule of thumb is that pockets three millimeters or deeper cannot be cleaned effectively at home. Aside from being unsanitary, this can lead to eventual loss of teeth. The major destruction comes not from the bacteria themselves, but from an inflammatory immune response to them. Periodontal disease also has effects that go beyond the mouth. It has been linked to an increase in both cardiovascular disease and diabetes.

One alleged benefit of green tea consumption is an improvement in general oral health. Here, the researchers tested three standard markers of gum disease in the study subjects: pocket depth, loss of gum attachment and how much the gums tended to bleed. They found that all three markers were lower in men who drank green tea and continued to decrease as the men drank more green tea.

This was not a trial of green tea; it measured the health of the subjects' gums and compared this to how much green tea they said they drank (an epidemiological study). The high positive correlation the researchers found between gum health markers and tea consumption is not proof that the green tea caused the benefit, but it's certainly suggestive.

It is not certain how green tea might lower the incidence of gum disease. Previous research has shown that antioxidants present in green tea may reduce the body's overall inflammatory response; this may be what is occurring in the mouth. Other research has shown that green tea alters membrane fluidity, which may make it more difficult for the bacteria to attach to the gums. In either case, it's a healthy effect.

Anyone intrigued by the alleged health benefits of green tea should realize that a cup of green tea is not a medication, it is a beverage that has been popular in Eastern cultures for thousands of years. The most common side effects of drinking green tea stem from its caffeine content, which is similar to that of coffee.

The study was conducted on 940 males, aged 49-59. The study results were published in the March 2009 issue of Journal of Periodontology.