Women who breastfeed are at lower risk of developing type two diabetes, a new study has claimed.
Researchers from Harvard Medical School found women who breastfed for one year were 15 per cent less likely to get type two diabetes.
The study, published in the Journal of American Medical Association (JAMA), found the effect lasted for up to 15 years after a woman's last baby is born and each additional year of breastfeeding was associated with reduced risk from diabetes.
Conversely, women who took medication to stop lactation had an increased risk of contracting the condition, which causes the body to stop producing enough insulin to take essential sugars from the bloodstream to cells in the body.
The researchers also found that if women who already had gestational diabetes breastfed, they did not appear to be protected from type two diabetes.
The Harvard team studied more than 157,000 women and discovered that if a woman had two children and breastfed each child for a year, her risk of diabetes would be reduced by a third.
The authors said: "In conclusion, increased duration of breastfeeding was associated with reduced risk of type two diabetes in two large cohorts of women.
"Together with clinical evidence of improved glucose homeostasis [equilibrium] in lactating women, these data suggest that lactation may reduce the risk of type two diabetes in young and middle-aged women."
Previous studies have also shown a link between breastfeeding and improved glucose tolerance, which reduces the risk of diabetes.
Recent statistics from the charity Diabetes UK have revealed 1.8 million people in Britain have diabetes, most of whom have type two diabetes, the most common form of the condition.
The charity says cases of diabetes are rising at an "alarming" rate in the UK and the number of people with diabetes has risen by 400,000 in the last eight years.
Commenting on the Harvard research, Roopinder Brar, care advisor at Diabetes UK, said: "This is an interesting study."
"Breastfeeding has been shown to help the health of the baby and mother in a variety of ways. Women who give birth to large babies and those who develop gestational diabetes during pregnancy have an increased risk of developing type two diabetes later in life.
"A balanced diet and regular physical activity have already been proven to reduce this risk, but we will need to wait for the results of further research before we can see if breastfeeding also plays a part."