When does old age really begin? Science has the answer.

At what age does old age really begin? This is one of the most debated questions in society, and now science offers an answer based on biological data. A group of researchers from Stanford University, in collaboration with other experts, has published a revealing study in the prestigious journal Nature Medicine. According to their findings, old age begins, from a biological perspective, at 78 years of age, breaking with many traditional conceptions of aging.

The scientific team reached this conclusion after analyzing the proteins present in the blood plasma of more than 4,200 people, aged between 18 and 95. In total, more than 3,000 proteins per individual were examined, of which 1,379 showed significant changes over time. These variations allowed the researchers to divide adulthood into three clearly differentiated stages: adulthood (between 34 and 60 years of age), late adulthood (60 to 78 years of age), and old age (from 78 years of age).

The study's most notable feature is that these stages were not defined by social or cultural criteria—such as work or family roles or stereotypes—but rather by molecular markers that reflect the functional state of the human body. This offers a much more objective perspective for understanding the aging process.

Blood plasma analysis revealed that the production of certain proteins changes over time, acting as a mirror of the body's biological state. For example, significant fluctuations in these proteins were identified around age 34, marking the beginning of a gradual process of physical deterioration. However, it isn't until age 78 that molecular changes reach a threshold that scientists consider the onset of old age.

These discoveries not only redefine how we understand the different stages of life, but also highlight that external factors, such as stress, can accelerate aging. Although these factors do not alter the general chronology of the established stages, they do underscore the importance of emotional and physical well-being in maintaining quality of life during aging.

This molecular approach to aging could have practical applications in the future, such as the development of personalized strategies to delay the effects of aging and improve care throughout the different stages of life. It also invites reflection on the importance of adopting healthy habits from an early age to optimize well-being during middle age and old age.

The Stanford study not only expands our understanding of aging, but also offers a hopeful perspective: old age, from a biological perspective, begins later than most people might imagine. This reminds us that each stage of life has its own timing , and that a proactive approach to health can make a big difference in how we experience each stage.

*This content was rewritten with the assistance of artificial intelligence, based on information from La Nación.*