Longevity Briefs: What’s So Special About People Who Live Past 100?

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:

If we want to significantly improve human health and lifespan, we might learn a lot by studying those among us who live to an exceptional age. So-called ‘supercentenarians’ – people who live to the age of 110 – may not exactly be ‘healthy’ in an absolute sense. They are typically very frail and have a high mortality rate! However, they do seem to be exceptionally healthy for their age, and by some metrics seem to be just as healthy as people decades younger than them. 

What makes supercentenarians so special? In this study, researchers ask if the immune system could be playing an important role. Supercentenarians have survived the Spanish flu and COVID-19 pandemics, both diseases in which inflammation plays a significant role. We also know that inflammation plays an important role in the ageing process, so it is possible that exceptional longevity requires exceptionally low levels of inflammation.

The discovery:

Researchers looked at data from 249 participants within a wide age range: as young as 19 and as old as 110. They analysed two inflammatory scores called INFLA-score and SIRI, which are both calculated based on the counts of certain white blood cells and the presence of inflammatory molecules. They also calculated a score called ARIP (Aging-Related Immune Phenotype), which is a measure of immune ageing based on the presence and ratios of certain types of T cell.

They found that, while there was a trend for higher inflammatory scores with increasing age, supercentenarians and semi-supercentenarians (people aged 105-109) actually had slightly lower inflammatory scores on average than the age group below them (‘long-lived individuals’ aged 90 or more). The difference in inflammatory scores between semi-supercentenarians, supercentenarians and other age groups was not statistically significant. When it came to ARIP score, there was a trend for less favourable scores with age, but no statistically significant difference between the scores of the semi-supercentenarians and supercentenarians when compared to even the youngest age group. However, it’s important to note that there were only 13 people in the study with an age greater than 105, and the difference in the scores may well have become statistically significant had this age group been more numerous.

The implications:

This study suggests that supercentenarians and semi-supercentenarians don’t have significantly more chronic inflammation or disrupted immune systems when compared to people much younger than them. This is in line with the findings of previous studies, and overall the evidence does seem to suggest that in order to make it past age 100, you need to have less chronic inflammation than expected for your age. There are a few caveats, the first of which we already mentioned – supercentenarians are very rare, which makes statistically significant differences between them and other age groups hard to detect. Another limitation is that they are overwhelmingly female – only one of the 105+ year-old participants of this study was male. Women have lower baseline levels of chronic inflammation. Finally, since the study did not follow up participants throughout life, but instead provides a snapshot of their immune systems, it is not certain that lower levels of chronic inflammation contributed to exceptional longevity. The supercentenarians in this study could have had higher levels of chronic inflammation when they were in their 90s, for example.

Those limitations aside, how can we apply this knowledge to live longer and healthier lives? There is good reason to believe that minimising chronic inflammation may improve health and lifespan. This can be achieved through simple lifestyle interventions like exercise, sleep optimisation and a diet rich in anti-inflammatory and antioxidant compounds, while avoiding exposure to pro-inflammatory foods and pollutants. Some dietary supplements may also support reduced chronic inflammation. That said, it is thought that exceptional longevity is primarily genetic – lifestyle interventions will significantly improve your health in old age, but are unlikely to allow you to live past 100.