Brain activity

In a study of 300 people, those with higher activity in the amygdala were more likely to develop cardiovascular disease - and sooner than others.

Stress could be as important a risk factor as smoking and high blood pressure, the US researchers said.

Heart experts said at-risk patients should be helped to manage stress.

Emotional stress has long been linked with an increased risk of cardiovascular disease (CVD), which affects the heart and blood vessels - but the way this happens has not been properly understood.

Brains naturally lose white matter - the part of the brain that transmits information - as people age.

But a Cambridge University team found that loss was exacerbated with extra weight - so an overweight 50-year-old had a lean 60-year-old's brain.

Researchers said it shows we need to know relatively more about how extra weight affects the brain.

The team, from the Cambridge Centre for Ageing and Neuroscience, looked at the brains of 473 people aged between 20 and 87, dividing them into lean and overweight categories.

"When we misalign our behaviour with our circadian clock, for example by creating jet lag, or by working as a night owl, we do not only disrupt normal physiological processes such as cycles of appetite and body temperature," said one of the researchers Albrecht von Arnim from University of Tennessee, Knoxville, US.
 

"This work in plants suggests that we may also be interfering with a more fundamental cellular process, protein synthesis," Mr Arnim noted.