Brain damage detected among obese teenagers

OBESE teenagers also show signs of brain damage, research has found.

Scans comparing their brains with those of adolescents of healthy weight found inflammation in the white matter, which may have made it harder for them to control their eating habits.

MRI scans of the brains showed changes in the areas related to control of emotions, and feelings of reward.

The findings presented at the Radiological Society of North America meeting in Chicago were based on MRI scans of 120 children aged between 12 and 16 – 59 obese and 61 of healthy weight.

Dr Pamela Bertolazzi, a biomedical scientist at Sao Paulo University in Brazil and report co-author, said: “Brain changes found in obese adolescents related to important regions responsible for control of appetite, emotions and cognitive functions.”

Researchers assessed a measure called fractional anisotropy, which correlates with the condition of the brain’s white matter – with a lower value indicating damage to the white matter.

The results showed changes in obese individuals to regions in the corpus callosum – a bundle of nerve fibres connecting the brain’s left and right hemispheres.

Degraded white matter was also found in the middle orbitofrontal gyrus, an area related to emotional control and the reward circuit. And there was a relationship between the pattern of damage and inflammatory markers such as insulin and leptin, a hormone made by fat cells that helps regulate energy levels and fat stores.

Dr Bertolazzi called for more studies to establish whether this inflammation in young obese people was a consequence of the structural changes in the brain and whether the brain changes were reversible through weight loss.

Last month, a study of 2,700 nine- to 11-year-olds in the United States, led by Cambridge University, found those with weight problems were likely to do worse in problem-solving and memory tests. They had a thinner cortex – a brain region which is key for reasoning.

The Cambridge team said fatty diet may cause damaging inflammation at a time when a child’s brain is still developing. However, it is also possible they had different brains before becoming obese, which made fatty and sugary foods more rewarding, cut willpower, and affected thinking abilities.

In the UK, one in five children is obese or overweight by the time they leave primary school.