We should expect gene variants associated with human longevity to also be associated with lowered risk of age-related disease. Here is one example: "In a 2003 study, Dr. Lipton and his colleagues identified the cholesteryl ester transfer protein (CETP) gene variant as a 'longevity gene' in a population of Ashkenazi Jews. The favorable CETP gene variant increases blood levels of high-density lipoprotein (HDL) - the so-called good cholesterol - and also results in larger-than-average HDL and low-density lipoprotein (LDL) particles. The researchers of the current study hypothesized that the CETP longevity gene might also be associated with less cognitive decline as people grow older. To find out, they examined data from 523 participants from the Einstein Aging Study, an ongoing federally funded project that has followed a racially and ethnically diverse population of elderly Bronx residents for 25 years. At the beginning of the study, the 523 participants - all of them 70 or over - were cognitively healthy, and their blood samples were analyzed to determine which CETP gene variant they carried. They were then followed for an average of four years and tested annually to assess their rates of cognitive decline, the incidence of Alzheimer's disease and other changes. ... We found that people with two copies of the longevity variant of CETP had slower memory decline and [a] 70 percent reduction in their risk for developing Alzheimer's disease."