"Long life" gene might also make some smarter

A gene variant believed to "wire" people to live longer might also ensure that they keep their wits about them as they age, a new study reports.

People who carry this gene variant have larger volumes in a front part of the brain involved in planning and decision-making, researchers reported Jan. 27 in the Annals of Clinical and Translational Neurology.

These folks performed better on tests of working memory and the brain's processing speed, both considered good measures of the planning and decision-making functions controlled by the brain region in question.

"The thing that is most exciting about this is this is one of the first genetic variants we've identified that helps promote healthy brain aging," said study lead author Jennifer Yokoyama, an assistant professor of neurology at the University of California, San Francisco (UCSF). She noted that genetic research has mainly focused on abnormalities that cause diseases such as Alzheimer's and Parkinson's.

The gene involved, KLOTHO, provides the coding for a protein called klotho that is produced in the kidney and brain and regulates many processes in the body, the researchers said.

Previous research has found that a genetic variation of KLOTHO called KL-VS is associated with increased klotho levels, longer lifespan and better heart and kidney function, the study authors said in background information. About one in five people carries a single copy of KL-VS, and enjoys these benefits.

For this study, the researchers scanned the healthy brains of 422 men and women aged 53 and older to see if having a single copy of KL-VS affected the size of any brain area.

They found that people with this genetic variation had about 10 percent more volume in a brain region called the right dorsolateral prefrontal cortex, Yokoyama said.

This region is especially vulnerable to atrophy as people age, and its age-related decline may be one reason why older people can be easily distracted and have difficulty juggling tasks, she said.

Referring to the region as the "conductor of the brain's orchestra," Yokoyama said that it helps people "pay attention to certain types of things, to appropriately shift your attention and to engage working memory," which is the ability to keep a small amount of newly acquired information in mind.

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"Long life" gene might also make some smarter