Spending time with grandkids just once a week can reduce the risk of grandparents developing dementia, research shows - but there's a fine line all parents should know

Grandmothers who look after their grandkids once a week are less likely to develop dementia, research shows, but too much childcare time can have the opposite effect.

There are a number of developmental benefits to children spending time with grandparents. In fact, research has found that children who have a good relationship with their grandparents have less behavioural and emotional problems and that grandparents set grandkids up with 'habits to last a lifetime' such as cooking, knitting and gardening. But it's not just kids who benefit from this close bond. In fact, visiting a grandparent just once a month can help them live longer.

And now, research has shown additional benefits to spending time with grandkids that can improve quality of life for the older generations. A study conducted by the Women's Healthy Aging Project examined the effects of grandparenting on 186 grandmothers and found that spending one day a week minding grandchildren improved cognition, resulting in a lower risk of developing dementia and Alzheimer’s.

Cognition was tested using a Symbol-Digit Modalities Test (SDMT), which measures processing speed as well as motor speed, and a California Verbal Learning Test (CVLT), in which participants have to recall specific words. In addition, a problem-solving task known as the Tower of London test was also used.

The highest cognitive scores were mostly seen in participants who minded grandchildren for one day per week, while lower performance was demonstrated by participants who looked after their grandchildren for five days or more - suggesting that five days or more per week minding grandchildren could harm cognition.

Essentially, the research found that weekly visits from grandchildren have clear benefits, but daily care could be burdensome.

The study's findings have been backed up by scientific evidence elsewhere, too. Research published in the journal Social Science & Medicine used data from 10 Western European countries to show that grandparenthood improves health among those with close family contact. The exception was for grandmothers providing daily child care, for whom grandparenthood appears to reduce wellbeing.

The researchers suggested that involving grandparents non-intensively in child care may lead to beneficial side effects. It's good news for parents who rely on older family members for childcare, as it turns out that quality time together can benefit grandparents as well as the kids.

But we know that lots of families rely on more regular help from grandparents - particularly during the school holidays, when they might be looking after the kids all week. If this sounds like you, don't be hard on yourself. Raising tiny humans is hugely demanding, and juggling work, the school run and everything you have to do to keep kids fed and watered is no mean feat - they say 'it takes a village' for a reason.

In related news, research has found that mothers are less likely to struggle with their mental health if their kids’ grandparents live close by, while another study has found the age children lose touch with their grandparents. Elsewhere, grandparents have shared their thoughts on today's most popular parenting trends.