Longevity Briefs: Humans May Age In Waves At 44 And 60

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:

Scientists have known for a while now that ageing isn’t a linear process. Different facets of ageing progress at different rates at different stages of life, as does the deterioration of different tissues. Understanding in more detail how ageing progresses throughout life could allow us to focus on those periods that are particularly important, understand exactly what’s happening at a molecular level, and maybe fix it where and when it matters the most.

The discovery:

In this study, researchers profiled 108 participants aged 25 to 75 years and tracked them for a median of 1.7 years. To study ageing in these individuals, they used a multi-omics approach. What does this mean? Genomics is the study of an organism’s genome, proteomics is the study of all proteins within an organism, and metabolomics is the study of all metabolic molecules within an organism. These are examples of ‘omics’, so a multi-omics approach means the researchers collected multiple different types of molecular data to try to gain a complete picture of biological ageing.

The molecular changes that occurred throughout life were largely consistent with previous studies. However, the researchers found that these changes appeared to occur in two ‘waves’ during which a large number of molecules underwent significant changes, with peaks occurring at ages 44 and 60. Both peaks involved changes in molecules that are known to play a role in cardiovascular, muscle and skin function. Additionally, the peak around age 44 involved molecules important for lipid and alcohol metabolism, while the second peak around age 60 involved more molecules related to the immune system and to kidney function. These changes occurred in both men and women and could not be attributed to the menopause.

The implications:

This study suggests that ageing might be even less linear than we thought. It seems that there are ‘waves’ of ageing in our 40s and 60s in which levels of many molecules (and microbes) are disturbed. These disturbances are shared across molecules that are important to multiple different organ systems. The timing of these waves also matches results from a similar study that looked only at proteins. That study identified a third wave at around age 78, which this study didn’t detect since participants were no older than 75.

In this particular type of study, correlation is not causation. One’s 40s and 60s might be more likely to correspond to particularly stressful periods or adverse life events, which could contribute to these molecular changes through stress or the cessation of healthy activities. It’s not certain that our bodies are primed to suddenly deteriorate. Even if they are, mounting research is showing that healthy activities can delay age related disease and disability even when adopted in later life. Studying these molecular changes can, however, give us clues as to how we might further delay ageing with drugs in the future.