Human aging is a complex process that does not follow a linear pattern, a study revealed. Instead, scientists have identified two distinct stages in midlife where the body undergoes dramatic changes related to aging.

Aging is the time-related deterioration of physiological functions required for survival and health. Many signs of aging, like gray hair and wrinkles, are visible on the surface, but numerous others occur at the cellular level and are not as easily seen.

Studies have shown that physiological changes are linked to factors such as chronic diseases, including diabetes, neurodegeneration, cancers, and cardiovascular diseases. A study published in Nature Aging evaluated the changes that occur at the cellular level and discovered that unlike previously thought, aging is not a linear process. The study also noted that the human body ages dramatically at ages 44 and 60.

The researchers tracked 108 participants aged 25 to 75 for an average of 1.7 years. The participants did not have any chronic diseases, including anemia, cardiovascular diseases, cancer, psychiatric illness, or underwent bariatric surgery. They were sampled for multi-omics data every 3-6 months for several years, to a maximum of seven years. During each visit, the researchers collected blood, stool, skin swab, oral swab, and nasal swab samples from the participants.

When the researchers evaluated the molecular markers, they noted that only 6.6% of these markers exhibited linear age-associated changes, while a substantial 81% displayed nonlinear patterns.

"The analysis revealed consistent nonlinear patterns in molecular markers of aging, with substantial dysregulation occurring at two major periods occurring at approximately 44 years and 60 years of chronological age," the researchers wrote.

The researchers believe that their discovery of a nonlinear aging pattern, with significant changes occurring around ages 44 and 60, along with insights into the molecular mechanisms underlying age-related diseases, could pave the way for developing early diagnosis and prevention strategies for these conditions in these age groups.

"These comprehensive multi-omics data and the approach allow for a more nuanced understanding of the complexities involved in the aging process, which we think adds value to the existing body of research. However, further research is needed to validate and expand upon these findings, potentially incorporating larger cohorts to capture the full complexity of aging," the researchers noted.

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