London - Mothers who breastfeed have a two-thirds lower risk of developing Alzheimer’s in later life, compared with women who never breastfeed their children, according to a study.
The longer the duration of breastfeeding, the more protection is gained by the mother, say researchers at Cambridge University.
They interviewed 81 British mothers aged between 70 and 100, who included women with and without Alzheimer’s. The team also spoke to relatives, spouses and carers.
Through these interviews, the researchers collected information about the women’s reproductive history, their breastfeeding history and their dementia status.
All of this information was then compared with the participants’ breastfeeding history. Despite the small number of participants, the study revealed a number of clear links between breastfeeding and Alzheimer’s.
These were not affected when the researchers took into account potential variables such as age, education history, the age when the woman first gave birth, her age at menopause, and smoking and drinking history, says a report in the Journal of Alzheimer’s Disease.
The researchers found women who breastfed had a 64 percent reduced Alzheimer’s risk compared with women who did not. Longer breastfeeding cut the risk further.
The study found women who breastfed for a year had 78 percent of the risk of Alzheimer’s of a woman who breastfed for four months.
And doing more breastfeeding offset the higher risk of Alzheimer’s linked to more months of pregnancy.
However, the protective benefits were far less for women who had a parent or sibling with dementia.
One theory is breastfeeding deprives the body of the hormone progesterone, which is known to desensitise the brain’s oestrogen receptors, making it more difficult for oestrogen to protect the brain against Alzheimer’s.
Another possibility is that breastfeeding increases a woman’s glucose tolerance by restoring her insulin sensitivity after pregnancy.
Dr Molly Fox, of the Department of Biological Anthropology at the University of Cambridge, who led the study, said: “Alzheimer’s is the world’s most common cognitive disorder and it already affects 35.6 million people.
“In the future, we expect it to spread most in low and middle-income countries. So it is vital that we develop low-cost, large-scale strategies to protect people against this devastating disease.”
She said the study was not able to compare the Alzheimer’s risk in mothers, whether they breastfed or not, and women who remained childless. But previous research suggested not having children might be linked with poorer cognitive function in old age, she added.
Dr Fox went on: “The worrying thing is that this older generation spent more time breastfeeding. Only one per cent of mothers in Britain today breastfeed exclusively for six months.”
Dr Simon Ridley, the head of research at Alzheimer’s Research UK, said “Preliminary studies like this one are important for highlighting associations worthy of further study, but we shouldn’t be quick to jump to conclusions quite yet.’”- Daily Mail