DOTING grandparents unwittingly increase the cancer risk among children by doling out treats and subjecting them to second-hand smoke, according to a Scottish study.

Grandchildren are being over-indulged with cakes, biscuits and sweets and allowed to play video games or watch TV instead of running about outside, warn scientists.

Grandparents also tend to expose them to second-hand smoke through cigarettes which also makes them more likely to pick up the habit when older.

The harm is unintentional but causes tension in families and public health campaigns must address the issue, said the researchers.

Herald View: Why too much kindness is bad for the grandchildren

Changes in social conditions – such as more women in the workforce, childcare costs and an increase in lone parenting – have led to an increased focus on the role of grandparents’ in children’s lives.

Lead author Dr Stephanie Chambers, of the University of Glasgow, said: “From the studies we looked at, it appears parents often find it difficult to discuss the issues of passive smoking and over-treating grandchildren.

“Given many parents now rely on grandparents for care, the mixed messages about health children might be getting is perhaps an important discussion that needs to be had.”

Her team analysed 56 studies with data from 18 countries concerning the care provided by grandparents and found overall they were having an adverse impact on youngsters’ health.

This was especially true in the areas of weight and diet through “treating”, overfeeding and lack of physical activity.

Herald View: Why too much kindness is bad for the grandchildren

Grandparents tend to be less energetic and so are more likely to stay in the home with the children than take them out.

The review also identified problems regarding tobacco smoke as grandparents are not complying with parents’ wishes regarding second-hand smoke and being role models who don’t indulge in unhealthy behaviours.

Dr Chambers said: “While the results of this review are clear – that behaviour such as exposure to smoking and regularly treating children increases cancer risks as children grow into adulthood – it is also clear from the evidence that these risks are unintentional.

“Currently, grandparents are not the focus of public health messaging targeted at parents and, in light of the evidence from this study, perhaps this is something that needs to change given the prominent role grandparents play in the lives of children.”

The study, published in PLOS One and financed by Cancer Research UK, aimed to identify potential influence grandparents’ habits may have on youngsters’ health.

Herald View: Why too much kindness is bad for the grandchildren

Professor Linda Bauld, Cancer Research UK’s prevention expert, said: “Children’s health can be affected by a range of factors, and this study reinforces the importance of the broader family picture.

“With both smoking and obesity being the two biggest preventable causes of cancer in the UK, it’s important for the whole family to work together.

“Children should never be exposed to second-hand smoke but it’s also important for children to maintain a healthy weight into adulthood and, in today’s busy world, it’s often the wider family who have a role to play in keeping youngsters healthy. If healthy habits begin early in life, it’s much easier to continue them as an adult.”