Reuters | Thursday, 17 April 2008

Caffeine acts as a sort of "sun screen" when given to mice before their skin is exposed to and damaged by ultraviolet B (UVB) radiation, and this ultimately prevents the development of skin cancer, according to researchers.

In the current issue of Cancer Research, the investigators also describe the mechanism that may be responsible for this protection. Specifically, caffeine triggers a process by which skin cells containing irradiation-damaged DNA are removed. Thus, these defective skin cells can not reproduce and become cancerous.

"The results of the present study," senior investigator, Dr Allan H Conney said Health, "provide a possible mechanism for earlier observations indicating that oral administration of caffeine inhibits ultraviolet light-induced skin cancer in mice."

Conney of Rutgers, The State University of New Jersey, in Piscataway and colleagues supplied animals with caffeine in their drinking water for 1 to 2 weeks before UVB exposure.

The caffeine concentration led to blood levels comparable to that achieved in humans after 3 to 5 cups of coffee per day.

The team also determined that caffeine applied in a cream or gel directly to the skin immediately after UVB radiation exposure caused the death of DNA-damaged skin cells as well.

"We believe that these results will extrapolate to humans," continued Conney, "but clinical studies need to be done." He pointed out that previous "studies indicate that coffee or tea drinkers have a lower risk of nonmelanoma skin cancer."

ScienceDaily (Apr. 25, 2008) — Depending on which variant of a certain gene a woman has, a coffee consumption rate of at least two-three cups a day can either reduce the total risk of developing breast cancer or delay the onset of cancer. This is shown in new research from Lund University and Malmö University in Sweden. The effect of coffee is related to estrogens, female sex hormones. Certain metabolic products of these hormones are known to be carcinogenic, and various components of coffee can alter the metabolism so that a woman acquires a better configuration of various estrogens. What’s more, coffee contains caffeine, which also hampers the growth of cancer cells.

LOUISVILLE , Ky., May 16 (UPI) -- Chemicals found in green tea may be able to stave off the cognitive deficits that occur with obstructive sleep apnea, U.S. researchers say.

Lead author Dr. David Gozal of the Kosair Children's Hospital Research Institute at the University of Louisville in Kentucky examined the effects green tea polyphenols, administered through drinking water, on rats that were intermittently deprived of oxygen during 12-hour "night" cycles, mimicking the intermittent hypoxia, known as IH, that humans with obstructive sleep apnea experience.

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Women who drink a lot of coffee may have less risk of developing cancer of the uterus, a Japanese study says.

The study led by Japan's health ministry monitored some 54,000 women aged 40 to 69 over about 15 years, during which time 117 women developed cancer in the womb, according to the medical team.

The researchers at Japan's National Cancer Center divided the women into four groups by the amount of coffee they drank.

They found the group of women who drank more than three cups of coffee every day were more than 60 per cent less likely to develop uterine cancer than those who had coffee fewer than two times a week, the study said.

"Coffee may have effects in lowering insulin levels, possibly curbing the risks of developing womb cancer," the study said.

The medical team also studied the effects of drinking green tea, but did not find any link to uterine cancer.

According to the US Centres for Disease Control, uterine cancer is the fourth most common cancer in women.