Prostate cancer risk increased in obese men

NEW YORK (Reuters Health) — Use of cholesterol-lowering statin drugs, especially long-term use, appears to raise the risk of prostate cancer among obese men, according to findings of a new study.

"Given the epidemic of obesity in the U.S. and the frequent use of statins, the positive association we observed raises substantial concern as to the safety of these widely prescribed agents," Dr. Janet L. Stanford of the Fred Hutchinson Cancer Research Center in Seattle and colleagues wrote in the American Journal of Epidemiology.

In a population-based, case-control study, the researchers matched 1,001 men with prostate cancer diagnosed between 2002 and 2005 with 942 age-matched cancer-free controls from King County, Washington.

No overall association was observed between the risk of prostate cancer and the current or past use of statin treatment. Duration of statin use was also not associated with prostate cancer risk.

"We also found no evidence that use of a statin was associated with risk of developing more aggressive subtypes of prostate caner," Stanford said in an interview with Reuters Health. "Overall we found no support for the current hypothesis that statin use may reduce risk of prostate cancer."

However, the results do suggest a significant increase in the risk of developing prostate cancer associated with current statin use and with longer durations of use among obese men (defined as a body mass index of 30 greater).

"Among obese men," Stanford told Reuters Health, "current use of a statin was associated with a 50 percent increase in risk of prostate cancer; and use for five or more years was associated with an 80 percent increase in risk of the disease; both of these risk estimates were statistically significant."

These findings warrant further investigation, she said.

DHEA may not boost brain power, well-being

NEW YORK (Reuters Health) — The hormone supplement DHEA is touted as an anti-aging panacea, but a new study suggests that it does nothing for healthy older adults' brain power or general well-being.

DHEA, or dehydroepiandrosterone, is a hormone produced by the adrenal glands that is converted into other steroid hormones, including testosterone and oestrogen. People's levels of DHEA naturally peak during their 20s, then taper off as they age. Because of this, over-the-counter synthetic DHEA supplements are marketed as a weapon against the effects of ageing.

Studies have come to mixed conclusions as to whether the supplements do in fact improve cognitive function, well-being, libido and depression symptoms in older adults.

Most of those trials were small or short-term, however. This latest study, reported in the Journal of the American Geriatrics Society, included 235 older adults who were randomly assigned to take DHEA or a placebo every day for one year.

By the year's end, the researchers found no clear differences between the two groups in tests of memory and other cognitive abilities.

Nor did DHEA seem to benefit participants' general well-being and quality of life — as measured by standard questionnaires on depression symptoms, life satisfaction, sexual function and general physical and mental health.

The bottom line is that healthy older adults should not turn to DHEA for the purpose of improving their cognitive function or overall well-being, lead researcher Dr. Donna Kritz-Silverstein told Reuters Health.

Whether the hormone supplement might be useful for other purposes, like treating depression or cognitive impairment, is not answered by this study, according to Kritz-Silverstein and colleagues at the University of California San Diego.

It's also unclear whether DHEA might be more effective in older adults who have particularly low natural levels.

Plant-based flavonoids may cut ovarian cancer

NEW YORK (Reuters Health) — High consumption of two types of flavonoids — antioxidant chemicals found in plant foods — may help protect women from ovarian cancer, research from Italy suggests.

Dr. Maria Rossi, of Istituto di Ricerche Farmacologiche "Mario Negri" in Milan, and her colleagues found that the women who took in the most isoflavones and flavonols were the least likely to have ovarian cancer.

"On the basis of our findings and the relevant literature, we infer that isoflavones, and perhaps flavonols, may have favourable effects with respect to ovarian cancer risk," they conclude.

Lab studies suggest flavonoids may also have cancer fighting properties in addition to their antioxidant effects, Rossi and her team note in the International Journal of Cancer.

The researchers compared flavonoid intake for 1,031 women diagnosed with epithelial ovarian cancer and 2,411 women who had been hospitalized for acute, non-cancer-related conditions, categorising them into five groups based on their intake of each of six different flavonoids.

After the researchers controlled for birth control pill use, number of children the women had, family cancer history and other relevant factors, they found that the women with the highest flavonol intake were 37 percent less likely to have ovarian cancer than women with the lowest flavonol intake.

High intake of isoflavones cut ovarian cancer risk by 49 percent.

The researchers found no relationship between intake of the other four flavonoid types, or total flavonoid intake, and ovarian cancer risk.