By comparing brain scans of groups of healthy young and old adults, Massachusetts Institute of Technology (MIT) neuroscientists discovered a relationship between loss of memory and cognitive performance in older people and the deterioration of the white matter in the parts of their brains related to those functions.

White matter is made up of the neuronal axons that connect neurons in the "gray matter" brain regions. White matter also helps the regions of the brain to communicate with one another.

"Historically, a lot of people have put their eggs in the gray matter basket. This study suggests that what might really be important are the connections and the integrity of the connections," lead author David Ziegler, a graduate student in the MIT department of brain and cognitive sciences, said in a news release issued by the university.

The finding means that medication, diet or exercise that enhances the white matter might provide a new way to fight the typical mental declines experienced with old age, he said.

The study was published in the December online edition of Neurobiology of Aging.

More information

The Alzheimer's Association has more about brain health .