Dr. John Beard, professor of productive aging at the Columbia University Mailman School of Public Health defines this new term as the following: “‘Intrinsic’ means all those attributes that you can attribute to the individual from the skin in,” he said. “And ‘capacity’ is looking at their functioning.”

Experts are hoping intrinsic capacity will be the ruler against which therapeutics and medication are measured.

The term was first formally definited in 2015 by the World Health Organization (WHO) as part of their healthy aging initiative in an effort to move health care professionals towards focusing on aging adults’ functional abilities rather than their diseases.

The score is a composite of five different areas: cognition, locomotion (strength and mobility), sensory capacity (vision and hearing), psychological well-being and vitality (overall energy levels and resilience to physical stressors). Some of these tests are already used to evaluate health in older adults, including grip strength and walking speed.

Changes in capacity are key to determining interventions for a better quality and long-term life, experts say. Currently this measure applies best to aging adults as younger, healthier people get perfect or almost-perfect scores, but experts are trying to determine metrics that could be useful at every age.

Intrinsic capacity is currently being studied in multiple clinical trials across the US and research is still preliminary. There are not any pharmaceuticals to improve this metric for a variety of reasons, including longevity of required tests to determine changes in lifespan outcomes. And the FDA doesn’t consider aging a disease, so they don’t regulate drugs that impact the aging process in this way. There is some progress, however. In 2022, the WHO added “aging associated decline in intrinsic capacity” to its 11th edition of the International Classificaiton of Diseases list, even though most countries (including the US) use a previous iteration of that list.

The Advanced Research Projects Agency for Health (ARPA-H) is trying to determine if someone’s intrinsic capacity corresponds to how they feel or function or their lifespan, and if it’s possible to improve a person’s intrinsic capacity with interventions like exercise, or drugs currently available that may contribute to a longevity benefit (such as GLP-1s). As Dr. Andrew Brack, who is leading the ARPA-H program says, “We have to be clear, we don’t know if this will work…we’re scientists; we have to do the experiment.”

Original article here.