Obesity can damage children’s ability to fight disease, Crumlin study finds

Irish scientists say weakened immune system struggles to combat cancer and diabetes

Childhood obesity: “It’s not sustainable if we want a healthcare system that can cope over the next 20 years,” said Prof Donal O’Shea. Photograph: iStock/Getty

Childhood obesity: “It’s not sustainable if we want a healthcare system that can cope over the next 20 years,” said Prof Donal O’Shea. Photograph: iStock/Getty

 

Childhood obesity can severely compromise the body’s ability to fight off multiple cancers, type-2 diabetes and other diseases, according to new research by Irish scientists.

The study, which was funded by the National Children’s Research Centre and Children’s Medical Research Foundation, involved 100 children between six and 17 years of age at Our Lady’s Children’s Hospital in Crumlin. Half of the children were a healthy weight, and the other half were obese.

“We found that in obese children there was a significantly reduced frequency of natural killer cells present in the body,” said Dr Andrew Hogan, one of the paper’s authors. Natural killer, or NK, cells are a crucial part of the body’s immune system that target infected and cancerous cells. A lack of fully functional natural killer cells has been linked in patients with recurring viral infections and incidence of certain cancers.

“We found that the levels of NK cells present in the bodies of obese children were about 50 per cent less than those present in those of normal weight,” Dr Hogan said. “While this is bad news for those suffering from childhood obesity, the situation is far from hopeless. Research suggests that the damage to immune systems can be reversed and the frequency and functionality of the NK cells restored once a child’s weight is brought back within healthy levels.” The researchers also found that obese children’s remaining cells were only about half as effective at eliminating tumour cells from the body.

“It’s not sustainable”

Prof Donal O’Shea, Dr Hogan’s coauthor and the HSE’s clinical lead on obesity, warned that “policymakers need to take note of what are stark results”. “We know obesity is responsible for our trolley crisis, through driving multiple common diseases. This work shows that we simply have to increase the efforts at preventing overweight and physical inactivity in children . . . The seeds of adult chronic-obesity-driven diseases are being nurtured in our children. It’s not sustainable if we want a healthcare system that can cope over the next 20 years.”

Almost a third of Irish children are overweight, and the country ranks 58th out of 200 countries for its proportion of overweight young people, according to data compiled by the NCD Risk Factor Collaboration. Just 1 per cent of children in the State were classed as obese in 1975; this has risen to 9 per cent among girls and 10 per cent among boys.