Taking multivitamins does not reduce the risk for heart disease, a review of studies has found.

The analysis, in Circulation: Cardio­vascular Quality and Outcomes, pooled data from 18 studies with more than 2 million participants. All took supplements that included at least three vitamin and mineral ingredients and no herbs, hormones or drugs. Eleven of the studies were done in the United States, four in Europe and three in Japan. Follow-up varied from five to 19 years. Two were randomized controlled trials, and the rest prospective observational studies. The pooled data showed no association between multivitamins and the risk for cardiovascular disease, coronary heart disease or stroke incidence or mortality. In observational studies, there was a small association with coronary heart disease incidence, but none in randomized controlled trials.

Long workweek raises diabetes risk in women

Women who work long hours may be at increased risk for diabetes, a new study has found.

Canadian researchers studied 7,065 workers, following their working hours and health over an average of 12 years. They recorded diabetes diagnoses beginning two years after the subjects enrolled in the study.

They found that compared to women who worked 35-40 hours a week, those who worked 45 hours or more had a 51 percent increased risk of diabetes. But there was no effect of working hours on diabetes in men.

The study, in BMJ Open Diabetes Research & Care, controlled for many other health and behavioral factors that could affect the development of diabetes, including age, ethnicity, body mass index, high blood pressure and extended sitting.