Duke Han, an assistant professor of neuropsychology at Chicago's Rush University, was surprised to see that Alzheimer’s disease made young minds perform better. He has been conducting research on Alzheimer's disease for years now.

Han earlier thought that he had committed some mistake and he did the analyses again confirm the findings.

Han studied a variant of a particular gene known as apolipoprotein E or APOE, epsilon 4.

For Alzheimer's disease this variant is the best established genetic risk factor.

He said, "We looked at young people in the military who sustained a mild to moderate head injury and we predicted that people who had this APOE, epsilon 4 allele, would do worse after a head injury just because it seems to be associated with Alzheimer's disease and at least in older people it seems to be associated with worse outcomes after head injury. Our analysis found the opposite actually that people who had this genetic trait fared better.”

He added that there are other reports also that state that young minds who had this genetic trait had better school grades.

Alzheimer's Australia’s Lynette Moore said the findings were not expected.