Research show worsening health trends for post-1946 generations

Younger generations appear to be experiencing poorer health earlier in life than previous generations, according to a review of studies comparing national birth cohort datasets involving tens of thousands of people across the UK born since 1946.

The trend – described by researchers as a 'generational health drift' – is most consistently seen for obesity and mental health, while evidence for diabetes was found in comparisons between Generation X and Baby Boomers. The authors of the review, which draws on more than 50 studies, say the findings suggest that more recently born generations may spend more years living in poor health than those born earlier.

The observed generational differences are unlikely to be explained fully by improvements in healthcare, screening, or diagnostic practices. Differences were observed for outcomes like obesity, which do not depend on diagnosis, and when using objectively measured biomarkers to identify conditions like diabetes.

Comparisons of mental ill-health were based on self-reported levels of depression and anxiety symptoms rather reports of diagnoses, and the measurement tools used have been extensively tested to ensure that they provide comparable measures across cohorts.

The expert team from University College London, King's College London and University of Oxford, examined changes in physical and mental health across the generations born after World War II. Health measures from people born in different years were compared at the point they reached similar ages.

The findings, published in the peer-reviewed journal Population Studies, have implications for the investment needed to care for increasing numbers living with long-term health conditions, add the authors. Health has worsened despite declines in smoking, increasing educational attainment, and improvements in material circumstances early in life.

"Evidence suggests that more recent cohorts are experiencing an earlier onset of poor health for several outcomes, particularly obesity and mental ill health," says lead author Laura Gimeno, a PhD student at the Centre for Longitudinal Studies, UCL.

"If more recent generations are 'drifting' backwards in health, it implies that society is not reaching the biological limits of health improvement. Instead, we're seeing the consequences of preventable social and environmental exposures that have shaped population health over time and across generations.

"The generational health drift has serious implications for policy, planning, and the funding allocations needed to be able to support a greater number of people living with long-term health conditions."

By 2050, a quarter of the British population will be aged 65 or over which will increase demands on health and social care systems, and on the economy. As such, it is important that people born more recently live not only longer but also in good health to meet the challenges of population aging.

Life expectancy in the UK improved dramatically during the twentieth century. More recent generations have experienced lower infant and child mortality and fewer deaths from heart disease.

However, increases in health expectancies have slowed or stalled since the early 2010s, driven by worsening health in midlife. Recently published data from the Office for National Statistics suggests that healthy life expectancy has fallen in recent years.

These findings suggest that recent declines in healthy life expectancy are likely driven by a combination of worsening mental and physical health in more recent generations."

George Ploubidis, Professor, Population Health and Statistics, Centre for Longitudinal Studies, University College London

This review drew on evidence from 51 studies on health outcomes published up to June 2024. Diabetes, high blood pressure, and cancer were among the health issues covered, with diagnoses either self-reported by patients or observed by researchers.

All 51 papers focused on data from British birth cohort studies, which followed babies born between 1946 and 2002. They are the National Survey of Health and Development (1946), National Child Development Study (1958), British Cohort Study (1970), Next Steps (1989–90), Avon Longitudinal Study of Parents and Children (1991–92), and the Millennium Cohort Study (2000–02).

The researchers found little suggestion of improvements in health for people born since 1946. They say more research is needed to understand the drivers of this trend which they add has probably been shaped by changing exposure to social and environmental risk factors (e.g., to "obesogenic environments") throughout people's lives, which are likely preventable.

The findings raise important questions about the apparent worsening of health, which the authors suggest is most plausibly driven by a genuine increase in poor health. Increasing survival rates are unlikely to explain the trend, given that generational differences are evident from early life through midlife. Similarly, the consistency of findings across both self-reported and objectively measured health outcomes makes it unlikely that changes in measurement alone underlie the observed pattern.

They add: "The relative importance of these explanations is likely to vary by health condition, and more research is needed to understand this fully."

A limitation of this review was that it focused on evidence from Britain's series of birth cohort studies, which are designed to be representative of the births that occurred in Britain in specific years. Because of this, the older birth cohorts are less ethnically diverse than the current British population of the same age. However, the authors explain that similar findings have been observed in other studies using different data that better reflect the ethnic diversity of the current British population.