What’s the secret to living longer? Scientists have been pondering this for some time now and while we understand that various lifestyle and environmental factors contribute to our longevity, it is also evident that genetics plays a role. In fact, family studies have indicated that genetic factors account for around 20-30% of the variation in adult lifespan. So what are these genetic secrets to longevity? A new study, published in Aging Cell, may have some answers.
Previous work identified a couple of candidate genes that researchers suspect may play a role in longevity. The genes identified were apolipoprotein E (APOE), which transports cholesterol around the body, and FOXO3A which may affect insulin sensitivity. Variations in these genes were found to be associated with longevity; however, neither had a large influence, which left scientists suspecting that there must be other factors at play.
To find out more, researchers from the Spanish National Cancer Research Center scoured the protein-coding genes, or exomes, of members of three separate families that all had exceptionally long-lived members. Three of the individuals sequenced lived to be 103 or older, and their siblings lived to be 97 or older. They then compared these with sequence data from 800 other people that acted as controls.
They found that rare variants in one particular gene cropped up in all three families—apolipoprotein B (APOB). Like the APOE protein, APOB is a cholesterol transporter. APOB helps to carry “bad cholesterol,” or low-density lipoprotein (LDL), in the blood. While our bodies need cholesterol, LDL has a bad rep because it can build up along the walls of blood vessels, blocking arteries and eventually leading to heart attacks in some.
It’s possible that these genetic variations reduce the levels of LDL in the blood, an idea that the researchers are now investigating. According to lead author Timothy Cash, if the long-lived individuals do have lower cholesterol levels, it would reinforce the idea that cardiovascular health is an important factor in the aging process. Interestingly, variations in APOE are also known risk factors for cardiovascular disease, which is likely due to elevated lipid levels.