To better understand the role of tea in preventing cancer, Iman Hakim and colleagues from the University of Arizona College of Medicine examined the tea-drinking habits of 234 people with squamous cell skin cancer. They compared them with the habits of another 216 people who did not have skin cancer but did have the same exposure to the Arizona sun.

Writing in the journal Cancer Epidemiology, Biomarkers and Prevention (Vol. 9, No. 7), the researchers report that both groups they studied drank about the same amount of tea. But people without skin cancer drank more strong, hot black tea than did the skin cancer patients. Iced tea consumption was the same for both groups as was consumption of weak black tea.

Researchers found the people without skin cancer drank their tea hotter and stronger. They brewed their tea for at least two to three minutes and as long as seven minutes and liked to drink it hot. Green tea was not studied because most people drank black tea. Herbal teas also were excluded from the study.

Although tea is an ancient beverage and the most widely consumed drink in the world other than water, little is known of its effects on health.

Tea comes in three varieties: black, green and oolong. Both black tea and green tea have been studied for their health effects. Some of these studies have looked at whether black or green tea prevents cancer or can even cause cancer. Most have come down on the side of tea having a protective effect. But it has been hard to prove and it is not clear whether it is green or black tea, or both, that is protective or which cancers might be prevented by drinking tea, according to the researchers.

The study authors point out that this is not the final word on tea and cancer and the study has limitations. However, it is known that tea contains certain chemicals called polyphenyls that have been able to block the development of cancer in cells in the laboratory. These chemicals may be lost in iced tea because they settle to the bottom of the container at low temperatures.

Before any recommendations on drinking tea for cancer prevention can be confidently made, confirmation of this study's results with further research is needed, according to the study authors. Also, this study was limited to only one type of cancer, and additional research on other cancers is also needed.

If confirmed by additional research, the results of this study might help reduce the number of cases of skin cancer. But it's important to remember that experts already know a lot about prevention of this disease, according to Herman Kattlove, M.D., an oncologist and medical editor for the American Cancer Society (ACS). "The main risk factor for skin cancer is excessive sunlight exposure," he says.

The best ways to lower risk of developing skin cancer are to:

• avoid being outdoors in the sun too long and seek shade, especially during the middle of the day when the ultraviolet rays are most intense;
• protect most of your skin with clothing, including a shirt and a hat with a broad brim; and
• use sunscreens with a sun protection factor (SPF) factor of 15 or more on areas of skin exposed to the sun, particularly when the sunlight is strong.

Squamous cell skin cancers develop in higher levels of the epidermis and account for about 20 percent of the 1.3 million skin cancers diagnosed each year in the United States, according to ACS estimates. They commonly appear on sun-exposed areas of the body such as the face, ear, neck, lip and the back of the hands.

These skin cancers tend to be more aggressive than basal cell cancers, which are more common. They are more likely to invade tissues beneath the skin, and slightly more likely to spread to lymph nodes and/or distant parts of the body.