Women with multiple children have a lower risk of dementia.
Women with lots of kids are less likely to suffer from dementia
Experts have found that higher exposure to oestrogen throughout a female's life can lead to a healthier brain and those with more kids accumulate more exposure to the hormone.
It appears to lead to a reduced risk of cerebral small vessel disease - a condition resulting from damage to small blood vessels in the brain that is linked to dementia.
The researchers analysed 9,000 postmenopausal women with an average age of 64 living in the UK.
Study author Kevin Whittingstall, of the University of Sherbrooke in Canada, said: "Our study highlights the critical role of reproductive history in shaping the female brain across the lifetime."
He added that the results "emphasise the need to integrate reproductive history into managing brain health in postmenopausal women".