Twins, especially men, live longer
Gemini is an object of study for a huge number of studies, the purpose of which is to distinguish between the effects of genetics and environmental influences – the so-called phenomenon of "nature or upbringing". However, it was only recently that researchers at the University of Washington for the first time analyzed the impact of having a twin on life expectancy.
As part of their work, they analyzed data collected in the Danish Register of Twins, one of the oldest archives containing data on twins. The study included 2,932 pairs of same-sex twins born in Denmark between 1870 and 1900 and who lived to be at least 10 years old. At the time of the study, all participants had already completed their lives. Their age at the time of death was compared with mortality data for the general population of Denmark.
The results of the analysis showed that throughout life, identical twins of both sexes have a higher survival rate than for fraternal twins, while the survival rate of the latter is slightly higher compared to the general population.
The model developed by the authors distinguished sudden causes of death, such as accidents and situations related to behavioral characteristics, from natural causes of death in old age.
For female twins, the reduction in mortality extended only to cases of premature death from sudden causes. Whereas the life expectancy of male twins as a whole was longer due to a decrease in mortality from both sudden causes and from so-called natural causes over the age of 65. The researchers believe that this reflects the immediate and cumulative effects of safer behaviors chosen by gemini men.
At the same time, for men, the maximum positive effect of having a twin was at the age of about 45 years. The difference in mortality rates with the general population at this age was about 6%, that is, 84 out of 100 boys in the general population lived to this age, and 90 out of 100 twins survived. For female twins, the maximum positive effect occurred at the age of a little over 60 years, the difference in mortality rates with the general population was about 10%.
The results obtained indicate a pronounced positive effect of close social ties on the state of health. And a stronger positive effect on the life expectancy of identical twins compared to fraternal twins may reflect precisely the strength of the social bond.
The authors believe that the results reflect the benefits of social support, similar to the protective effect of marriage. Many studies have demonstrated that family life provides a kind of social protective network that provides positive effects in relation to psychological status and health status.
However, one question concerning the so-called hypothesis of the protective effect of marriage remained open. It is not yet clear whether family life has a positive effect on health or healthier people are more likely to get married (join a social group or have a wide circle of friends, which is also associated with better health).
The authors explain that the network of social connections can influence the state of health through various mechanisms. Friends and loved ones can form a company for sports and other active activities, as well as encourage you to get rid of bad habits. They can also provide material or emotional support, which has a positive effect on life expectancy.
The authors note the need to reproduce the results obtained for other databases. This will make sure that the revealed patterns for some reason apply not only to twins born in Denmark and the 19th century and who lived at least up to 10 years.
Article by David J. Sharrow, James J. Anderson A Twin Protection Effect? Explaining Twin Survival Advantages with a Two-Process Mortality Model is published in the journal PLOS ONE.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the University of Washington: Twins, especially male identical twins, live longer.
25.08.2016