Toward equity in healthy aging
Public health and medicine have successfully expanded lifespan; the next critical challenge is to make these added years healthy ones.
In the U.S., public-health interventions have added 30 years to average life expectancy, and we can now expect to outlive the vast majority of humans that came before us. However these gains in life expectancy have come at the cost of a dramatic rise in age-related noncommunicable diseases, which creates enormous human suffering and imposes a huge burden on health care systems and the economy.
Life expectancy gains in the last century did not result from slowing how our bodies age, but by drastically reducing early life mortality. Therefore for the first time in our history, huge numbers of us are living beyond the point our bodies can maintain function. Without effective cellular and tissue maintenance, age becomes the greatest risk factor for the majority of chronic diseases, including neurodegenerative disorders, cardiovascular disease, stroke, cancer, metabolic disease and osteoporosis.
The vision
Public health and medicine have successfully expanded lifespan; the next critical challenge is to make these added years healthy ones by expanding healthspan — the time we spend living disease-free and functional. And we must do this for all communities, so progress does not exacerbate existing inequities.
How do we get there?
Increasing healthspan significantly will require a preventative public health approach that discovers and implements interventions that slow the rate at which our bodies age. Rather than current disease-centric therapeutic strategies that focus on end of life pathology, the new field of ‘Geroscience’ treats age as a risk factor that can be mitigated. This approach will yield a longevity dividend — the compression of multiple morbidities in older adults that dramatically increases their quality of life while reducing the economic and societal burden age-related pathologies currently impose.
Why now?
Biological aging is now measurable and modifiable. Recent breakthroughs in research allow scientists for the first time to distinguish a person’s chronological age (how long they have been alive) from their biological age (whether their body is aging faster or slower than expected). Through the integration of omics and artificial intelligence, sophisticated methods exist that can measure the rate of biological aging in human cohorts, and in cells, tissues and animal models in the laboratory.
Measuring biological aging greatly increases our capacity to discover preventative approaches that promote healthspan and compress morbidity in older adults, as they allow efficacy of interventions to be measured in real time using molecular predictors of disease risk. This is hugely advantageous when compared to using disease onset as the measurable outcome.
Critically, in lab settings and cohort studies, geroscience has shown that the rate of biological aging varies between individuals, and is modifiable. Conserved genetic, nutritional and pharmacological interventions have been proven to slow biological aging and increase healthspan in animals ranging from invertebrates, to mice and non-human primates. Many of these discoveries are now moving into clinical trials.
What can we do now?
While we await the outcome of moonshot clinical trials, the answer lies in the integration of public health and the biology of aging: any intervention that promotes healthy aging acts at the level of our biology and can therefore be measured at a cellular level.
Excitingly, early studies integrating lab-based measures of biological aging into traditional domains of public health have begun to define factors that accelerate or decelerate human biological aging, leading to inequities in health outcomes. These risk factors span domains from nutrition/metabolic health, environmental exposure, and immune challenge, to social and behavioral factors such as social integration and optimism.
This work reveals that the rate of biological aging greatly contributes to inequities in public health, with ZIP codes at birth and social inequity influencing the very rate at which our bodies age and succumb to age-related pathology.
Changing the conversation
I believe that no matter how much we invest in Aging Biology, Longevity, and Healthspan — nothing will get real traction unless we also work to change how the public and policy makers think about the problem. This does not mean pushing for biohacking, or making false claims. It means helping to frame the discussion, and educating all of us on what is feasible now, and what may be in the future. This will take leaders, deep-thinkers and orators.