Longevity Briefs: Health Often Improves In Old Age, If You Believe It Can

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

Ageing involves an unavoidable decline in both physical and cognitive health. Scientific studies usually focus on trends over time and across large populations, and when health outcomes are averaged out in this way, a progressive decline in physical and cognitive health with age is the only possible finding. This often leads to the assumption that once a person reaches ‘old age’, long-term health improvements are impossible and one must simply accept a continuous health decline. However, research can sometimes overlook the potential for individuals to buck the trend, or the surprising frequency with which they do so. This study investigates whether a meaningful number of older people manage to improve their physical or cognitive function over time, and whether their attitude towards ageing influences the chance that they will.

The discovery:

Researchers looked at data from the Health and Retirement Study (HRS), which conducts surveys of around 20,000 Americans aged 50 and above every two years. The study included 11,314 participants for cognitive analyses and 4,638 for physical analyses. Cognitive health was measured by telephone interview, while walking speed was used as the metric for physical health. Some participants had been followed for as long as 12 years. Participants were also categorised as having either positive or negative beliefs about ageing according to their overall score in a questionnaire.

Researchers found that over this 12 year period, a remarkable 31.88% of participants showed improved cognition between their first and last measurement, while 28% had faster walking speed. If we measured cognition or walking speed for the same person on two different days, we would not expect the second score to be exactly the same as the first: it would fluctuate up or down due to random chance. To limit the impact of this, researchers repeated the analysis, but ignoring cognitive improvements of fewer than 2 points in the telephone interview and physical improvements of less than 5cm per second of walking speed (for comparison, the average change across all participants was a 1.39 point decline in cognitive score and a 11.69cm/s decline in walking speed). After making these exclusions, 22.5% of participants still showed cognitive improvements and 26.71% showed improved walking speed over the course of the study.

Researchers also found that positive beliefs about ageing showed a statistically significant association with health improvements. Among those classified as having positive ageing beliefs, the percentage of people whose performance was either better or unchanged over the course of the study was 51.06% for cognition and 37.56% for walking speed.

The implications:

This study suggests that the number of people who succeed in improving their health in old age, or at least halting health decline over an extended period of time, might be a lot larger than most people think. It also shows that there is a correlation between positive attitudes to ageing and resistance against age-related health decline, something that has previously been shown for cognitive decline and dementia. The issue here is that there is a significant confounding factor: people who have experienced little age-related decline in the past are obviously going to have more positive attitudes towards ageing at the beginning of a study, and are then going to maintain that ‘trajectory’ as the study progresses. In other words, resistance against age-related decline (due to genetic predisposition, for example) may cause positive attitudes, rather than the other way around.

There have been a few studies suggesting that interventions to promote ageing-positivity do lead to health improvements. It’s not hard to see how this could happen. People with positive attitudes to ageing are more likely to be positive people with good overall mental health. They may make more of an effort to preserve their health while others give up, believing that decline is inevitable regardless of what they do. The most important takeaway from this research is that while ageing may be a fatal disease with no cure, we probably have a lot more influence over our health and wellbeing in later-life than we realise.