Health notes from around the globe

A study of twins reported in the New England Journal of Medicine found that cancer is largely determined by life, not genes. The study's head author, Dr. Robert Hoover, pointed out that the fatalistic approach to genes is often unfounded. In fact, genetic factors seemed to account for between 21 percent and 42 percent of risk, depending on the type of cancer, with an average of about 30 percent. In most cases, environmenal factors and lifestyle habits (e.g., drinking, smoking) accounted for most cancer risks.

Conducted by scientists from Sweden, Denmark and Finland, the study examined 44,788 pairs of twins born between 1870 and 1958. Cancer registries revealed that 10,803 of these people developed cancer.

By comparing cancers in identical twins to fraternal twins, the scientists were able to make firm conclusions about the role genetics plays in cancer. For example, prostate cancer had the highest rate of heritability: 42 percent. Most other cancers, however, were the result of environmental influences. Therefore, make sure prospects and member understand that a healthy lifestyle which includes sensible eating and exercise can reduce their risks of cancer, despite family history.

A study in the Annals of Internal Medicine found that exercise on its own can promote weight loss, even when the exerciser doesn't count calories. This conclusion came from Canadian researchers who studied 52 men with abdominal obesity. They found that the men in this group who either exercised or dieted over a 12-week period lost 16 pounds.