NEW YORK (Reuters Health) – New study findings indicate that when women breast-feed their infants for a year, there are health benefits for both mother and infant. As reported in the May issue of Obstetrics and Gynecology, increased duration of lactation may lower the mother’s risk of hypertension, diabetes, hyperlipidemia, and cardiovascular disease after menopause.

For their study, Dr. Eleanor Bimla Schwarz at the University of Pittsburgh and associates evaluated data from the Women’s Health Initiative, which enrolled generally healthy postmenopausal women ages 50 to 79 years of age, starting in 1994. Close to 140,000 women with at least one live birth and known history of lactation were included.

The effect of lactation on cardiovascular risk factors appeared to be dose-dependent, even after adjusting for sociodemographic and lifestyle variables, family history, and BMI.

For example, women with a lifetime history of more than 12 months of lactation were significantly less likely than women who never breast-fed to have hypertension (odds ratio 0.88), diabetes (OR 0.80), hyperlipidemia (OR 0.81), and cardiovascular disease (OR 0.91).

However, the cardiovascular benefits tended to decline with age. For women ages 50-59, odds ratios for cardiovascular disease ranged from 0.84 to 0.75 as duration of lactation increased from 7 months to 2 years or more.

On the other hand, women in their 60s were protected only if duration of lactation was 13-23 months; women older than 70 years retained no cardiovascular protection, regardless of their lactation history.

Dr. Schwarz and colleagues speculate that "lactation does more than simply reduce a woman