Photo: Lesley Lawson

At a certain age, meetings with my old friends began to take the form of an “organ recital” of health challenges and woes. I resolved to use my research skills to produce a quick reference to current science and thinking on the topic, an A to Z of ageing.

The first big question was: what exactly is ageing?
There are scientific, cultural and psychological answers to this question.

The most important thing I learnt is that age is not a number. The foothills of old age are visible earlier than 70 years for some people, and much later for others. In other words, a person’s chronological age may differ widely from the age of their body (biological age) and self-perception (subjective age).
Compelling recent research backs up the old adage “You are only as old as you think you are.” A whole swathe of studies shows a link between peoples’ experience of age (subjective age) and their future health and longevity. For example, a study of over 2,500 US adults, around 75 years of age, found that people who felt older than their actual chronological age were more likely to be frail than those who felt younger. The researchers also concluded that subjective age could be used as a quick and economical way of screening for frailty risk. Encouragingly, 77 % of participants felt younger than their chronological age, 18 % felt the same, and only 5 % felt older.
A Korean study delved into the neurobiological basis of this phenomenon, concluding that perceptions of ageing may influence the structure of the brain itself. MRI scans showed that the brains of individuals who perceived themselves as younger than their real age had larger volumes of grey matter in certain regions of the brain, as well as a younger brain age.
Like much research on ageing, the studies above point to an association between subjective age and health. Causality could go in either direction—i.e. poor health could affect subjective age, or subjective age could predict poor health. However, an Irish study conducted over many years has clearly shown that negative attitudes about aging predict changes in older adults’ physical and cognitive abilities. Older adults with positive attitudes towards ageing showed a later physical decline (as measured in walking speed) as well as cognitive abilities. Interestingly, frail participants in this study who had positive attitudes about ageing had the same cognitive abilities as their non-frail peers.

While it is encouraging to believe we can think ourselves young, the reality is that people do grow older and frailer. We need to acknowledge that there is a sweet spot in attitudes to ageing that lies somewhere between delusion and despair. 

Photo: Centre for Ageing Better

On a sociological level, the definition of old age has varied widely throughout history and across cultures. Currently the United Nations sees 60 years as the age at which a person is ‘older’, whereas most high-income countries set retirement age (for men) between 62 and 67 years.
Instead of defining age in terms of years of life, it is more useful to talk of life phases. In the past, the life course was divided into three phases: youth (the age of dependence), middle age (the age of independence, work and procreation) and old age (the age of retirement and dependence).

As lifespans and healthspans have increased, “old age” is no longer considered one homogenous group and is divided into a Third Age of active retirement, and a Fourth Age of frailty and dependence.

The Third Age can be a period of fulfilment, a time when family and work responsibilities have decreased, and greater leisure time has allowed older people to develop new lives. The University of the Third Age is an international movement that epitomises this phenomenon. Originating in France in 1973 as an extramural university for older people, it has taken on a less formal character in other countries where it provides an arena for social engagement and lifelong learning.
The Third Age concept has been criticised as class and culture bound. In low-income countries, prosperous retirement is a privilege of the very few. Indeed, an age of fulfilment is unrealistic even in high-income countries like the UK, which have weak or failing social support systems. Age UK estimates that 2.1 million, or 18% of pensioners live in relative poverty, meaning that they have insufficient resources to cover their basic expenses and take part in society. Groups that are most at risk are private tenants, Asian and black British pensioners, and single women.

The Fourth Age is marked by progressive frailty, illness, dependence, physical and cognitive decline. However, it is important to note that the boundaries between the Third and Fourth Ages are not impermeable. For example, people can recover from hip fractures, cancer etc. and experience many future healthy years. The Fourth Age concept has been criticised as creating a catch-all category of no real conceptual value. Just because people have greater needs for support and care they are no more homogenous than any other population group.

A nuanced view of the Third and Fourth Ages in the UK comes from the Centre for Ageing Better. Using the English Longitudinal Survey of Ageing they propose that the over 50s can be segmented into six categories:

• Thriving boomers: The 21% who have assets, good health and good social connections;
• Downbeat boomers: The 21% who have assets and are in good health but are unhappy with their lives;
• Can do and connected: The 19% who may have health conditions and financial issues, but are happy - their well-being is rooted in strong social connections;
• Worried and disconnected: The 13% who have lower levels of well-being, fewer social connections and feel uncomfortable asking for support;
• Squeezed middle aged: The 14% who are still working and caring for children and/or parents, and who have low levels of well-being; and
• Struggling and alone: The 12% who have experienced life-long health problems, have poor social connections and are very unhappy.

Japan, which has the oldest population in the world, has a simpler way of looking at things. Here a distinction is made between “young-old”—people who are still active and independent—and the “old-old” who are frail.

Photo: Center for Better Ageing

However ageing is defined, it is an inescapable truth that there are more older people in the world than ever before. While there are huge regional variations, life expectancy at birth has increased globally by eleven years in the last three decades—from 62 years in 1980 to 73 years in 2019. In the wealthy countries of the world, average lifespans are over 80 years of age (Japan 84.3, Australia 83, UK 81.4).

At the same time, women are having fewer children. Globally, the number of births per woman has decreased from 3.7 in 1980 to 2.3 in 2020. This is particularly marked in high-income countries where populations are shrinking, for example Italy and Japan, with fertility rates of 1.3.

In short, the world’s population is ageing. In 2017 the number of older people (over 64 years) surpassed the number of children (under 5 years) for the first time in history. In England and Wales today nearly one in five people are over the age of 65 years.

The World Health Organization predicts that by 2050, the world will have 2.1 billion people over 60 years old. Of these, 426 million will be over the age of 80 years.

In most countries healthy life years (healthspans) have largely kept pace with lengthening lifespans. However, there is still a significant gap between the two. In the UK for example, the average lifespan is 81.4 years, and the average health span is 70.1 years. This means over ten years of poor health for growing numbers of people. These are years in which they need additional health and social care: a challenge for individuals as well as society.

Graphic: Centre for Ageing Better

As the world grows older it is strikingly obvious that we need to change our approach to ageing.
Mounting evidence points to the possibility of increasing the number of healthy years we have before we die. This is critical for our personal well-being, our health systems and national and global economies. Even modest improvements in the health of older people translate into billions of savings in health and social care costs each year.

There is a longevity dividend in these extra healthy years. In economic terms, the longevity dividend includes a larger skilled workforce as people voluntarily retire older or reskill; and increased consumer spending, particularly on recreation and culture.  The International Longevity Centre UK says that strategies to support older people as workers and consumers could add 2% a year to the UK GDP by 2040.

The Centre for Ageing Better estimates that older people already contribute £61 billion to the economy each year through work, caring and volunteering. With policies to improve their health, and overcome barriers to their participation, how much more could we gain?

Graphic: Centre for Ageing Better.

References:

• Yuxiao Li et al. Bidirectional relationship between subjective age and frailty: a prospective cohort study. BMC Geriatrics (2021) 21:395. 
• Seul Kwak et al. Feeiing how old I am: subjective age is associated with estimated brain age.  Front Aging Neurosci. 2018; 10: 168.
  
• Deidre Roberston. How negative attitudes towards ageing affect health in later life. TILDA Research Brief, January 2016.
• World Bank data: https://data.worldbank.org/indicator/SP.DYN.LE00.IN?view=chart
• International Longevity Centre. Healthy Ageing Index. 2023. 
• Hannah Ritchie (2019) - "The world population is changing: For the first time there are more people over 64 than children younger than 5".
• UK Office for National Statistics. National Population Projections: 2020-based interim.
• Age UK Briefing. Poverty in later life. June 2023.
• Katz J et al. Hearing the voices of people with high support needs. Journal of Aging Studies, vol. 27, no. 1. January 2013.
• Sally McNally et al. A focus on physical activity can help avoid unnecessary social care’, BMJ, 2017, 359, j4609.
• Centre for Ageing Better. Six later life categories. 2015