Researchers, at the University of Haifa have found that babies who were breastfed for at least six months had a 19% lower risk of going on to develop leukaemia in childhood than those who were breastfed for a shorter period or not at all.
They suggested more should be done to educate women on the health benefits of breastfeeding, while there should also be efforts to make it easier for women to do it in public.
Scientists said they made the findings after reviewing 18 different studies, while a separate analysis of 15 studies found that ever being breastfed compared with never being breastfed was associated with an 11% lower risk of childhood leukaemia.
Leukaemia is the most common cancer diagnosed in childhood and accounts for about 30% of all childhood cancers but little is known about its cause.
Breastfeeding is recommended by the NHS as the healthiest option for feeding babies up to the age of six months, but many parents feed with formula instead.
The amount of women who breastfeed in the UK is increasing, according to the Royal College of Paediatrics and Child Health (RCPCH), with 55% now breastfeeding at six weeks and 34% at six months, but younger mothers and those living in areas of higher deprivation are the least likely to breastfeed.
The research is published online in JAMA Pediatrics, with the study authors suggesting several biological mechanisms of breast milk may explain their results, including that it contains many immunologically active components and anti-inflammatory defence mechanisms that influence the development of an infant’s immune system.
“Because the primary goal of public health is prevention of morbidity, health care professionals should be taught the potential health benefits of breastfeeding and given tools to assist mothers with breastfeeding, whether themselves or with referrals to others who can help,” they said.
“The many potential preventive health benefits of breastfeeding should also be communicated openly to the general public, not only to mothers, so breastfeeding can be more socially accepted and facilitated.”
Dr Colin Michie, chairman of the RCPCH’s Nutrition Committee, welcomed the findings.
He said: “The benefits of breastfeeding to populations of children are well established. Breastfed babies are less likely to contract chest and ear infections, suffer from sickness and diarrhoea or become obese.
“Earlier this year, a study highlighted that breastfeeding was associated with better school performance, a higher IQ and higher incomes in later life.
“So this latest development is not only a very important discovery, but further adds weight to the benefits of breastfeeding.”
Janet Fyle, professional policy advisor at the Royal College of Midwives, said: “This research underpins yet again why breastfeeding should be encouraged and supported. It is without doubt one of the most positive ways for a woman to give her newborn the best possible start in life.
“The important issue is to ensure that women have access to skilled advice and support to help them to initiate and sustain breastfeeding. With the continuing shortage of midwives in England, sometimes the NHS struggles to give women the advice and help around breastfeeding that they need and deserve.
“Breastfeeding is a fundamental contributor to better public health; it lays the foundations for better health and has a positive impact on the health and wellbeing of mothers and their babies.
“The beneficial effects of breastfeeding last a lifetime. Given the increasing focus on public health, we should be doing all we can to encourage it. This includes investment in staff.”