More than 800,000 child deaths worldwide could be prevented each year if more women breastfed their babies, a study has found.
Near-universal breastfeeding could also prevent an extra 20,000 annual deaths from breast cancer, experts claimed.
The claims comes as statistics show that women in the UK are among the least likely to suckle babies for a considerable length of time, with only one in a hundred children still breastfeeding on their first birthday.
Scientists analysed data from 28 systematic reviews of previous research to show that breastfeeding has a dramatic effect on life expectancy both for children and mothers.
In high-income countries, breastfeeding reduced the risk of sudden infant death by more than a third. It also had the potential to prevent about half of all infant cases of diarrhoea and a third of lung infections in low and middle-income countries.
In addition, breastfeeding increased intelligence, and there was some evidence that it protected against obesity and diabetes in later life.
For mothers, longer duration breastfeeding was said to reduce the risk of breast cancer and ovarian cancer.
The study, published in The Lancet medical journal, revealed that worldwide rates of breastfeeding were low, especially in high-income countries.
In the UK, fewer than 1% of babies were breastfed up to their first birthday. In Ireland, the figure was 2% and in Denmark 3%.
Lead researcher Professor Cesar Victora, from the Federal University of Pelotas in Brazil, said: “Breastfeeding is one of the few positive health behaviours that is more common in poor than richer countries, and within poor countries is more frequent among poor mothers.”
He added: “There is a widespread misconception that breast milk can be replaced with artificial products without detrimental consequences.
“The evidence contributed by some of the leading experts in the field, leaves no doubt that the decision not to breastfeed has major long-term negative effects on the health, nutrition and development of children and on women’s health.”
Professor Russell Viner, from the Royal College of Paediatrics and Child Health, said: “The benefits of breastfeeding have been widely publicised yet .. it’s clear that efforts are still falling far too short and the grave reality is that this is costing children’s lives.
“Britain has one of the lowest levels of breastfeeding compared to other rich countries - we worry that things will get much worse with the Government’s proposed budget cuts.”
Janet Fyle, from the Royal College of Midwives, said: “This report underpins and reinforces why breastfeeding is the most appropriate method of providing nutrition for a baby. It also highlights the pressing need to promote and increase the uptake of breastfeeding in the UK and globally.”