Introduction
Living longer does not necessarily mean spending more years in good health. But how much of the decline we associate with aging is inevitable, and how much reflects disease, inactivity, and other potentially modifiable factors?
Nutrition presents a particular challenge in later life: energy requirements often fall, while the need for many nutrients remains unchanged or increases. How should we interpret claims about protein, plant-based diets, supplements, and bone health?
To discuss this is Prof. Charlyn Black, a long-time health services and policy researcher at the University of British Columbia, whose work includes the prevention of chronic disease and the role of nutrition in healthy aging.
[02:42] Interview start
[05:38] Chronic disease burden
[07:16] Healthspan versus lifespan
[09:09] Modifiable ageing factors
[13:35] Start early but its never too late
[17:12] Diet patterns with most evidence
[20:54] Nutrients of concern for older adults
[27:31] Bone health
[30:55] Policy and food environments
[34:28] Key ideas
Episode Resources
- Join the Sigma newsletter for free
- Subscribe to Sigma Nutrition Premium
- Enroll in the next cohort of our Applied Nutrition Literacy course
- Book: Plant Powered Seniors
Guest Information
Prof. Charlyn Black, MD, ScD is recently retired after being an internationally recognized health services researcher for several decades. Much of her work focused on creating population-based information systems, using administrative data to monitor the quality and effectiveness of medical care, and developing data-driven tools to improve health care delivery.
Before retiring she was Associate Director of the School of Population and Public Health at the University of British Columbia. Prof. Black obtained her medical degree from the University of Manitoba and her doctorate in health services and policy research from Johns Hopkins.
In recent times she has taking an interest in the lifestyle and dietary interventions that can improve outcomes in older adults, which includes both chronic disease prevention, increasing healthspan, and maintaining functional capacity.
Study Notes
Healthy aging involves preserving physical function, independence, and quality of life while preventing or delaying chronic disease. In this episode, Prof. Charlyn Black explains why the foundations of a healthy diet remain relevant throughout adulthood, while the practical task of meeting nutrient needs can become more demanding in later life.
The central nutritional challenge is a mismatch: energy requirements often decline, but requirements for many nutrients remain similar, and some increase. A diet therefore needs to provide sufficient protein and micronutrients within a potentially smaller food intake. This sits alongside resistance training, bone-loading activity, management of cardiovascular risk, and environments that make healthy behaviours feasible.
Useful terminology
- Lifespan: The total duration of a person’s life. At population level, life expectancy estimates average expected survival under specified mortality conditions.
- Healthspan: Years lived in good health. Definitions vary according to whether health is assessed through disease, disability, physical function, or perceived wellbeing.
- Primary aging: A conceptual term for intrinsic biological changes associated with advancing age.
- Secondary aging: Decline associated with disease, inactivity, other behaviours, and environmental exposures. The distinction helps identify opportunities for intervention, although the two processes interact.
- Nutrient density: The amount of a nutrient provided relative to a food’s energy content. Foods can be dense in different nutrients; no single food supplies everything required.
- Anabolic resistance: A reduced muscle protein synthesis response to an anabolic stimulus, such as protein ingestion. This contributes to the rationale for adequate protein and resistance exercise in older adults.
- Atherosclerosis: Plaque accumulation in arterial walls. It can be present for years before symptoms or a cardiovascular event.
- Bone mineral density: A measure of bone mineral content relative to area or volume. It informs fracture-risk assessment but does not capture every determinant of bone strength or falls.
- Osteopenia and osteoporosis: Categories of low bone mass; osteoporosis also encompasses clinically important skeletal fragility and can be diagnosed in the context of fragility fractures.
- Substitution analysis: A statistical estimate of the association with replacing one dietary exposure with another while holding specified factors constant. An observational substitution estimate does not itself demonstrate the effect of making that replacement.
Healthy aging: preserving function alongside longevity
Why longer life does not necessarily mean more healthy years
- Black’s emphasis is on how added years are experienced: mobility, vitality, independence, and the ability to participate in everyday life.
- Chronic disease and disability overlap, but they are not interchangeable. A person can live with a well-managed condition while retaining good function.
- A 2024 analysis of 183 WHO member states found that gains in health-adjusted life expectancy had lagged gains in life expectancy. Its US estimate was a 12.4-year gap