Why your biological age is a number to watch
We all want the same thing: the chance to live a full, rich, active life for as long as we can. Unfortunately, time only moves in one direction. Traditionally, most people have thought of the aging process as equally fixed. But while chronological age tells you how many birthdays you’ve had, biological age offers a different view of aging. It’s one that reflects your longevity habits, and how well your body is functioning over time.
What does chronological age mean? It’s the literal number of years we’ve been alive. There’s no changing this.
What does biological age mean? It refers to how old our physical cells are. It turns out we have some control here.
Longevity scientists are discovering why some people of similar chronological ages have much longer health spans. These people enjoy their chosen life adventures free of aging-related diseases. Understanding the difference between biological vs. chronological age can help you make more informed decisions about daily choices that may influence your health span vs. your lifespan.
How scientists measure biological age
Biological age is sometimes called epigenetic age because it refers to changes that occur in our genes that may keep them from promoting healthy cells. Longevity scientists use several biomarkers for aging to get a view of your cellular health. Some of the key biomarkers they focus on include:
Telomere length: Telomeres are segments of DNA found at the end of every chromosome that support cellular division. The more the cells divide, the shorter these caps get, until they can no longer support the division, leading to cell aging. Factors like stress and a poor diet can speed up this shortening process, which in turn accelerates aging.
Understanding epigenetic clocks: Epigenetic clocks measure DNA methylation, which are chemical tags in the cells that tell your genes to turn on and off. Your lifestyle significantly impacts methylation levels. An individual's epigenetic pattern is among the most accurate predictors of biological age.
The upshot: our cells age, stop doing their jobs, and leave us vulnerable to cardiovascular disease, lung disease, cancer, Alzheimer’s, and other consequences that ramp up our biological age.
Key biomarkers of aging in longevity science
As our understanding of aging grows, so does the list of hallmarks, with new discoveries continually being added. This is helping scientists develop strategies to slow down aging and improve overall health as we grow older. A review published in in Frontiers in Aging in 2024 lists these biomarkers of aging:
- Cellular senescence
- Mitochondrial dysfunction
- Deregulated nutrient-sensing
- Stem cell exhaustion
- Altered intercellular communication
- Chronic inflammation
- Gut dysbiosis
- Telomere attrition
- Genomic instability
- Epigenetic alterations
- Loss of proteostasis
- Disabled macroautophagy


