A gene variant called KL-VS linked to longer life was also found to make humans smarter and may help fight the effects of cognitive decline due to aging.

According to a team of researchers in San Francisco, California, said that the news is encouraging for the nearly 1 in 5 people who have a genetic trait variant of the klotho gene. When they studied 220 participants aged 52 years old to 85, they found that KL-VS did not prevent cognitive decline, it actually boosted brain faculties by around six IQ points without regard to the person's age.

If the findings are conclusive, KL-VS can be the most significant genetic agent of non-pathological intelligence variation. The team hopes this study will be key to developing tools for boosting and retaining intelligence in patients who suffer from cognitive losses both from normal aging and disease including Alzheimer's and schizophrenia.

The researchers discovered the effects of KL-VS on aging when they observed the participants' cognitive faculties of attention, memory, language and visio-spatial awareness. From the tests, the team formed multiple measures of cognition. The findings suggest that people with a VS version of the KL gene in their chromosomes showed better cognitive performance than those that do not have one.

Klotho appears to improve cognition by strengthening the communication lines connecting brain cells. Through experiments in mice the researchers showed that high klotho levels in the brain tissue were linked to high levels of GluN2B, a protein that builds synapses, which is the basis of memory. Previous studies showed links between cognitive performance and GluN2B levels. The researchers discovered that when GluN2B was blocked by a drug called ifenprodil, it abolished the mice's advantage. This means that high klotho levels increase GluN2B subunits in the brain's receptors of learning and memory circuits.

Neuroscientist Tony Wyss-Coray from Stanford University said that his team also discovered that brain damage from aging is not necessarily permanent. "What our article shows is that the old brain is not frozen in time," Wyss-Coray said. "You can potentially reactivate this old brain, and make it function again - at least in mice, at this point."

It could mean that people who have KL-VS in their genes might just be able to take a drug that increases klotho levels or mimics the protein's function and improve their cognitive performance altogether.