The future of healthy aging: translation of geroscience discoveries to public health practice

The global population is aging. The number of persons aged 60 years and over was 962 million in 2017 and will reach ∼2.1 billion by 2050.1 Health promotion/disease prevention interventions targeting the elderly have been an almost totally neglected area in health promotion programs before the turn of the millennium, just accepting simply the fact that the health benefits from such programs measured solely by increase in life expectancy are limited. The documents of the WHO on ‘Active ageing: a policy framework’ developed in 2002 and replaced in 2015 by ‘Healthy ageing’ introduced a new conceptual approach. 2 They emphasize that developing/maintaining the functional ability enables older people to remain a resource to their families, communities and economies. The three traditional action areas have been to ensure that communities foster the abilities of older people; to deliver person-centered integrated care and primary health services responsive to older people; and to provide access to long-term care for older people. A new action area is now defined ‘to change how we think, feel and act towards age and ageing’. It represents a paradigm shift: healthy aging of the population is now viewed as an opportunity rather than a challenge to society. From a public health point of view, maintaining the functional ability of the older generations is important not only to fulfill the pledge of the 2030 Agenda for Sustainable Development (‘leave no one behind’) but also to induce/improve the economic prosperity in countries with ageing populations. During the first two decades of the 21st century when in the domain of public health the importance of healthy population aging became recognized, basic science breakthroughs revolutionized the field of geroscience and changed how we think about aging in biological terms. Today one of the most challenging questions in our field is how the translation of geroscience discoveries to public health practice can enhance programs promoting ‘healthy aging’. Aging is the single most important risk factor for morbidity and mortality from a wide range of non-communicable diseases, far outweighing genetic and environmental sources of risk. There is a growing recognition that a causal relationship exists between biological mechanisms of aging and pathogenesis of diverse age-related diseases. Advances in the field of geroscience have elucidated evolutionarily conserved cellular/molecular processes that underlie biological aging and contribute to the pathogenesis of virtually all age-related diseases.3 Large scale experimental studies, including the multi-institutional Interventions Testing Program of the NIA, have started to identify interventions (drugs, dietary supplements and diets) that delay biological aging, extend lifespan and delay/prevent several age-related diseases in preclinical models. Effective experimental geroprotective interventions with translational potential include treatments that reduce mitochondrial oxidative stress, improve mitochondrial function, repurposed diabetes drugs (metformin, acarbose) and drugs that selectively eliminate senescence(definition) cells.4 In the past few years, human studies have begun to translate these experimental findings into clinical applications. In the up-coming decade, public health research targeting healthy aging also has to undergo a paradigm shift and consider advances in geroscience. Epidemiological studies should consider the mechanistic links between lifestyle risk factors and aging processes and include as outcome measures newly developed transcriptomic, epigenetic, proteomic and metabolomic biomarkers of aging to identify groups of people who are aging faster.5 Public health interventions that enhance healthy aging should be designed with cellular/molecular mechanisms of aging kept in mind. Established public health interventions addressing traditional behavioral and biological risk factors, such as smoking cessation, promotion of physical activity, control of hypertension, diabetes and hypercholesterolemia, pay dividends for preventing/delaying morbidity and mortality from age-associated diseases in the near-term. In the future, developing public health interventions that target fundamental aging processes should be the ultimate goal. To that end, the development of novel anti-aging dietary interventions is of particular interest. The anti-aging effects of caloric restriction(definition) are well established, however, it is not a viable translational approach at the population level. The search for alternative dietary modifications that are more tolerated yet may confer health similar benefits is highly promising. These include low protein/methionine restricted diets, intermittent fasting/time-restricted feeding paradigms and diets enriched in NAD+ precursors and compounds that exert mitochondrial protection and/or activate specific longevity assurance pathways (e.g. polyphenols)4. Incorporation of functional foods, which contain biologically active components with demonstrated anti-aging action, into dietary recommendations is of particular interest. These emerging concepts can be incorporated into a complex anti-aging paradigm, which also involve recommendations on physical activity and cognitive trainings to interrupt the bridge between aging and physical/intellectual decline. We advocate that interdisciplinary Healthy Aging programs that bring together expertise in public health, geroscience, nutritional sciences and preventive medication against non-communicable diseases are needed to successfully address the growing socio-demographic challenges associated with rapid population aging.