Biological age describes how a person is aging on molecular, cellular, and physiological levels. At the present time, biological age is not something that can be fully quantified and aging itself is far too complicated to be captured by a single layer of information. As such, it is relegated to being an abstract and somewhat vague idea. In this sense, biological age is remarkably similar to health. Health, like biological age, is not well defined and too multifarious to be summarized with a single biomarker. Given their similarities, it is intriguing to consider whether or not biological age and health are synonyms. Indeed, these two ideas can be cleanly swapped with each other in a variety of scenarios. If someone appears uniquely vigorous and capable for their chronological age, that person can be described as either quite healthy or being biologically youthful. However, there are situations where biological age and health diverge from each other. It is possible, for instance, to have a short healthspan but a long lifespan. While biological age is otherwise comparable to health as an abstract idea, it is possible that biological age and health will be confidently quantifiable in the future. Indeed, such quantification may be unlocked by the integration of multimodal data and artificial intelligence. In such a scenario, biological age offers a clear advantage over health in that it operates on a more intuitive, familiar scale as opposed to an artificially created index.
