Keep studying and stay open to new experiences if you want to live longer, is one of the inferences of a major study that looked at the connection between genes, lifestyle choices, and longevity. The genome-wide association meta-analysis, carried out by scientists at the University of Edinburgh, included data from 600,000 people and their parents. The results indicated that every extra kilogram carried by an overweight individual cuts their life expectancy by about 2 months, whereas every extra year of studying past school adds almost a year to lifespan. Lifelong smoking of one pack of cigarettes per day was shown to cut the average lifespan by 6.8 years, although people who give up smoking might expect to live just as long as someone who has never smoked. Body fat and other diabetes-linked factors were also linked with shorter lifespan; body mass index reduced life expectancy by 7 months per unit.
Commenting on the studies, Jim Wilson, D.Phil., one of the team leaders at the University of Edinburgh's Usher Institute for Population Health Sciences and Informatics, said, “The power of big data and genetics allows us to compare the effect of different behaviors and diseases in terms of months and years of life lost or gained, and to distinguish between mere association and causal effect.” The team’s findings are published today in Nature Communications, in a paper entitled “Genome-Wide Meta-Analysis Associates HLA-DQA1/DRB1 and LPA and Lifestyle Factors with Human Longevity.”
The University of Edinburgh study included data from 25 separate population studies across Europe, Australia, and North America, and from the UK Biobank initiative. Data analysis was designed to rule out confounding factors and identify exactly which lifestyle factors were associated with longer, or shorter, lifespan. “Up to 25% of the variability in human lifespan has been estimated to be genetic,” the researchers note, “but genetic variation at only three loci (near APOE, FOXO3A and CHRNA3/5) have so far been demonstrated to be robustly associated with lifespan.” The team’s findings validated previously identified associations between longevity and the three loci, and also with CDKN2A/B and SH2B3. Their findings separately identified two new regions—HLA-DQA1/DRB1 and LPA—that were linked with longevity.
“Of more than 90 tested phenotypes, seven risk factors (cigarettes smoked per day, HDL [high-density lipoprotein] cholesterol, LDL [low-density lipoprotein] cholesterol, fasting insulin, systolic blood pressure and CRP [C-reactive protein]) and six disease susceptibilities (Alzheimer’s disease, breast cancer, CAD [coronary artery disease], ischaemic stroke, squamous cell lung cancer and type 2 diabetes) significantly associated with mortality,” the authors wrote. “… giving up smoking, educational attainment, openness to new experience and high-density lipoprotein (HDL) cholesterol levels are most positively genetically correlated with lifespan while susceptibility to coronary artery disease (CAD), cigarettes smoked per day, lung cancer, insulin resistance and body fat are most negatively correlated.”
“Our results show that longevity is partly determined by the predisposition to common diseases and, to an even greater extent, by modifiable risk factors,” the team concludes. “The genetic architecture of lifespan appears complex and diverse and there appears to be no single genetic elixir of long life.”