About a quarter of the variation in life expectancy in developed countries can be attributed to genetic factors. The influence of both genetics and. This review focuses on the determinants of longevity in the industrialized world, with an emphasis on the results of recently established databases. Strong evidence is now available to show that in developed countries, maximum life expectancy and average life expectancy have increased considerably over the past century.
There is no evidence of a genetically determined life expectancy of around 85 years. On the contrary, the greatest absolute improvement in survival in recent decades has occurred among people over 80 years of age. The influence of genetic and environmental factors on longevity can be potentially modified through medical treatment, behavioral changes and environmental improvements. Siblings and children (collectively referred to as first-degree relatives) of long-lived people are more likely to stay healthy longer and to live to an older age than their classmates.
People with centenarian parents are less likely, by age 70, to have the age-related illnesses that are common among older adults. Brothers and sisters of centenarians tend to live longer lives, and if they develop age-related diseases (such as high blood pressure, heart disease, cancer, or type 2 diabetes), these diseases appear later than in the general population. Longer life expectancy tends to run in families, suggesting that shared genetics, lifestyle, or both of these factors play an important role in determining longevity. Hygienic living conditions are critical to preventing the spread of potentially deadly diseases.
Simple daily practices, such as proper waste disposal, adequate sanitation, and the use of clean water, help improve health outcomes. However, not everyone has access to these basic living conditions, a circumstance that often depends on one's economic situation. This disparity may contribute to a greater likelihood that some people will have a shorter life expectancy.
