Scientists Believe Humans Have A Hard Limit For Lifespan

A new study has been published that suggests humans have a hard limit for living, and once that limit is reached, the body is no longer able to repair itself. While scientists believe humans may live for between 120 and 150 years, we won't be able to live beyond a certain "absolute limit." The study suggests that after 120 to 150 years of age, the body would completely lose its ability to recover from stresses.The stresses include things like illness and injury. However, if therapies can be developed to extend the body's resilience, researchers believe humans could live longer and healthier lives. Professor Judith Campisi says that studies such as this rely on historic and present data from populations of people. She says, "it's guessing, but based on good numbers." Campisi wasn't part of the study.

Researchers analyzed large data sets from the US, the UK, and Russia that included anonymized medical data for over 500,000 people during the study. Data was utilized that came from simple blood tests available to almost anyone in the data set. Individuals took blood tests several times over a few months.

The researchers were looking for two numbers in the blood test results for three different age groups. The data included a ratio of two different types of disease-fighting white blood cells, and a measure of variability in the size of red blood cells. Those numbers increase as a person ages, which is something scientists call a biomarker of aging.

The scientist used a computer model to determine something known as a dynamic organism state indicator for each person, which is essentially a biological age measurement. That number was used to quantify how a person would recover from stress like injury or illness. Data suggests that sometime between 120 and 150 years old, this resiliency would entirely disappear, leaving the person unable to survive.