Neurology

“These ‘silent strokes’ are more significant than the name implies, because they have been associated with an increased risk of falls and impaired mobility, memory problems and even dementia, as well as stroke,” study author Joshua Z. Willey from the Columbia University in New York, said.

Previously in 2009, researchers at the University of California in Los Angeles found being overweight or obese can result in brain shrinkage and an increased risk of Alzheimer's disease.

However, the present study conducted by a team of Swedish researchers is the first of its kind to claim being overweight can result in memory problems, and maintaining a healthy weight is the best way to avoid mental decline in old age.

Lead researcher Marty Mrazik, professor in the educational psychology department, and a colleague from Rider University in the U.S., said an excess level of testosterone exposure may be linked to giftedness--having an IQ score of 130 or higher.

Mrazik said,"There seems to be some evidence that excessive prenatal exposure to testosterone facilitates increased connections in the brain, especially in the right prefrontal cortex".

"That's why we see some intellectually gifted people with distinct personality characteristics that you don't see in the normal population," he added.