Tea Good for Heart Disease, Cancer
Cuts High Cholesterol, Aids Cancer Prevention
Tea and Cancer
This is the first randomized study to look at effects of regular tea drinking -- both black and green tea -- on smoking-associated cancer prevention.
Researchers in this study monitored urine levels of 8-OhdG, a measure of overall damage to DNA. Smoking is associated with high levels of this by-product .
DNA damage, If not repaired, can result in genetic mutations that -- over a lifetime -- are expected to affect a person's risk of cancer, writes lead researcher Iman A. Hakim, PhD, director of Health Promotion Sciences at the Arizona Cancer Center at the University of Arizona.
Because 8-OhdG is easy to identify in the urine, it provides a way for researchers to monitor whether cells have been damaged, he explains.
His study involved 143 men and women -- all heavy smokers -- divided into three groups. For four months, each group drank four cups a day -- one group drank decaffeinated green tea, the second group drank decaffeinated black tea, and the third drank water.
Every month, they returned to the clinic for blood tests and urinalysis. None of them cut back on smoking or changed their diet, Hakim says.
In the end: The green tea group had the lowest 8-OhdG levels; the black tea and water drinkers had no change in 8-OhdG levels. Black tea and water, therefore, seemed to have no effect in protecting smokers from DNA damage.
Green tea, however, significantly cut the cell damage in these heavy smokers, a sign that drinking tea daily could be effective in cancer prevention, writes Hakim.
Coffee drinkers, it's a message: Switching to tea can lower high cholesterol and help with cancer prevention.