Jan 31, 2026
3 min read
Doctoral students at the Weizmann Institute say scientists want to know how much genetics and 'everything' contribute to our lives, considering that 50% of the group is the latter.
It must be the genes: Israeli research has found that genetics play a key role in human longevity
"Researchers want to know how much genes and 'everything' contributes to our lives," said the Weizmann Institute doctoral student, "determining that it is about 50% combined."
WASHINGTON (Reuters) - Many factors influence how long you live, including diet, exercise, smoking, alcohol consumption, the environment and more.It also helps prevent litter.But what about your genes?
A new study points to a larger role for genetics than previous studies, estimating that genes contribute about 50 percent to determining human lifespan.This is almost double what previous research has concluded and reflects the findings of aging studies in laboratory animals.
"Undoubtedly, a life span is shaped by many factors, including lifestyle, genes and, very importantly - take for example organisms that are identically raised in similar environments that die at different times," said Ben Shenhar, a doctoral student in Physics at the Weizmann Science Institute of Israel and the lead author of the study reviewed study on ThursdayScience.
"Our work, we have tried to help the difference between the genetic people that can be involved in the genetics and otherwise.
The researchers sought to explain a confounding factor in previous studies with Swedish and Danish twins, mostly dating from the 19th century.Those twin studies did not take into account deaths caused by violence, accidents, infectious diseases and other factors that arise outside the body, called extrinsic mortality, which the authors of the new study said distorted previous findings about the genetic component of longevity.
Cause of death was missing from historical records, which only gave age at death.So if one twin died at age 90 of natural causes and the other twin died at age 30, not of natural causes but of an infectious disease such as typhoid or cholera, data missing the cause of death could give a misleading impression of the role of heredity in life.
A new study has used a mathematical formula to explain extrauterine deaths among twins.Shenhar said out-of-home deaths at the time of the twins' studies, before the age of antibiotics, were 10 times higher than today, primarily due to infectious diseases that are easily treated today.
The researchers then validated the prediction that extrinsic mortality hides heritability by using previously unanalyzed and more recent data from Sweden.This analysis actually found that as extrinsic mortality decreases, heritability increases.
"Identical twins raised apart share their genes but not their environment. This helps remove genetics from environment, nature from nurture," said Weizmann systems biologist and senior study author Uri Alon.
Fraternal twins are also valuable in such studies because they share half their genetic makeup.
"Previous studies of twins have used statistical methods that work well for other characteristics — height, blood pressure, personality traits, etc. These traits are not affected by extrinsic mortality," Elon said.
"But life expectancy is a particular trait that is strongly influenced by extrinsic mortality. Cause of death is not recorded for classic twin studies, not adjusted for," Alon said.
The collections can be important for aging research.
"Mean heritability estimates can disrupt funding and research into the genetics of aging, suggesting that it was largely random or environmental. Our work supports research determining the genetics of longevity, showing that the genetic signal is strong but previously hidden by 'noise' in the data," said Shenhar.
Genes influence life in two directions.On the one hand, there are debilitating genetic defects that cause disease and can reduce longevity.On the other hand, genes that confer benefits for longevity have been identified.
"Centenarians live to be 100 years old without any serious illnesses," Shenhar said."These people clearly have protective genes that naturally protect against the development of age-related diseases. Few of these genes have been identified, although, like many complex traits, longevity is influenced by hundreds, if not thousands, of genes."
Times of Israel.
