How Old Are You? Your Body Might Disagree With That Answer

isbscience.org/news/2019/11/22/biological-vs-chronological-age/

Is age really just a number? Traditionally, our chronological age — the number of birthdays we’ve celebrated — has also broadly served as a marker of health, disease and mortality.

But what if our chronological age isn’t the best way to make those assessments?

ISB researchers harnessed deep molecular and physiological information to determine an individual’s biological age, which they found can serve as an effective and reliable predictor of overall health. Diseases were seen to be associated with a higher biological age estimate compared with chronological age, while participation in a wellness program was shown to have a positive effect on biological aging compared to chronological age. The findings were published in the Journals of Gerontology: Series A in a special issue on Healthy Aging, sponsored by AARP.

“A major interest of the Hood-Price Lab for Systems Biomedicine at ISB is understanding ‘wellness’,” said John C. Earls, lead author of the study. “Wellness is a term that is used a lot. While most people agree that they know it when they see it, holistic quantification of wellness has proven to be elusive. This study is one step towards making that quantification more rigorous and understandable by the general population.

Co-authors Dr. Nathan Price and John C. Earls.

“People don’t understand what it means that their biochemistry puts them in a certain region of high-dimensional space enriched for a negative phenotype,” Earls said. “That is not the sort of information a person can internalize and act on. On the other hand, telling a person that they have the biochemistry of a 50-year-old when they are only 40 is something that makes sense to people. Then being able to tell them that most of this deviation is coming from sugar levels or inflammation, gives them a path to improve their wellness.”

Earls, et al, applied an algorithm to longitudinal data collected from more than 3,500 people participating in a consumer wellness program. The personalized data consisted of genetic, clinical laboratory, metabolomic and proteomic assays.

Researchers found that biological age estimates from deep phenotyping changed in expected directions for both positive and negative health conditions — “healthy” behaviors (such as participation in a wellness program) were associated with delta age (biological age minus chronological age) becoming lower over the time periods tested, while “unhealthy” conditions (such as self-reported diseases) were associated with increased biological age compared with chronological age.

These findings suggest that biological age can be modified, and that lower biological age compared to chronological age could, in general, be a sign of healthy aging. “We believe biological age represents one general and interpretable metric for wellness that may aid in monitoring aging over time,” said Nathan Price, PhD, the corresponding author of the study and co-leader of the Hood-Price Lab.

“Importantly, not all measurements that change with age are bad,” Price said. “Some of them can be protective or important responses to damage over time. However, many of these are associated with decreased health and increased likelihood of developing disease, and so having a comprehensive view of biological aging across multiple systems can provide much actionable information about the current state of health and how it may be improved.”

The study sampled men and women who varied by age and health status and who participated in Arivale (now closed), which was a consumer data-intensive ‘scientific wellness’ program. The wellness program also included lifestyle coaching on exercise, nutrition, stress management, and sleep — all tailored to participants’ health goals, specific genetic markers, and clinical metrics.

The study used data collected over three years ending in July of 2018 from those who gave research consent. The Arivale data were de-identified following consent from program participants.

This study builds on other important ISB findings, notably that the alpha diversity of an individual’s gut microbiome can be accurately predicted by examining metabolites in the blood, and that combining personal, dense, dynamic data (PD3) clouds with tailored behavioral coaching can optimize wellness, and that the PD3 clouds can identify early transitions into disease states and facilitate the reversal of some disease states back to wellness.

“We are thankful to everyone in the Arivale program who wanted to provide their (de-identified) data for this research,” said Lee Hood, MD, PhD, who co-founded ISB in 2000. “These individuals are absolutely critical to understanding health and wellness, and transforming the health care system into the modern era. Arivale has made striking advances in the formulation of 21st Century Medicine.”