Spanish and Japanese men and women who live beyond the age of 100 have revealed that the key to longevity, at least in southern Europe, lies in their genes; specifically in a variant on chromosome 9p21.3, according to a recent study.

In addition to living more than 100 years, centenarians are people who live at least 15 years longer than the average individual in the West. The findings, published in the journal Age, establish that it's not entirely due to their lifestyle or diet that they are blessed with a long life, but that it is an inherited privilege.

This polymorphism - which is a particular sequence variation in the DNA among individuals from a particular population - located on chromosome 9p21.3 is responsible. It also has been previously proven to be associated with the risk of cardiovascular disease.

"This variant may be associated with extreme longevity, particularly among the Spanish population," lead author Alejandro Lucía, researcher at the European University, told SINC. "The study also revealed that the risk allele reduces the possibilities of reaching one hundred years of age."

Researchers analyzed the frequencies of this polymorphism among centenarians and healthy adults, separating them into groups based on geographical regions and ethnic groups.

Participants included 152 Spaniards aged between 110 and 111 years and 742 Japanese people aged between 100 and 115 years.

The frequency of the risk C variant - carrying the greatest risk for cardiovascular disease - in Spanish centenarians was 47 percent. That's lower than in the healthy control sample group (53 percent) and in individuals with cardiovascular diseases (51 percent).

But among the Japanese participants, the results were more uniform. The risk gene variant had a similar frequency in centenarians (46 percent) and in healthy controls (47 percent), but it was less frequent than in controls performed with cardiovascular disease (57 percent).

Although the biological mechanisms are not yet known, chromosome 9p21.3 plays a role based on these results, and coincides with past research on the Mediterranean population north of Italy, "therefore the effect of this gene seems to exist in southern Europe at least," Lucía concluded.