Breastfeeding a baby can significantly reduce a woman's chances of developing a condition linked to heart disease and diabetes, research has shown.
Breastfeeding could more than halve the risk of metabolic syndrome, a mix of symptoms including high blood pressure, obesity and cholesterol that if untreated can lead to major illness. For women with a form of disabetes associated with pregnancy, the effect was even stronger. Their risk was reduced by between 44 per cent and 86 per cent.
Previous research had shown that lactating women have improved blood levels of glucose and fats within several weeks after giving birth.
Scientists conducting the new 20-year study monitored the health of 704 women recruited at the age of 18 to 30. Over the follow-up period there were 120 new cases of post-pregnancy metabolic syndrome.
Study leader Dr Erica Gunderson, from US health care providers Kaiser Permanente in Oakland, California, said: "The findings indicate that breastfeeding a child may have lasting favourable effects on a woman's risk factors for later developing diabetes or heart disease."
The benefits did not appear to be due to differences in weight gain, physical activity, or other lifestyle factors affecting health. Women who did not develop metabolic syndrome typically had less belly fat and higher levels of "good" high density lipoprotein (HDL) cholesterol, which unlike "bad" cholesterol is protective.