The Intersection Between Chronological and Biological Aging
You're 45, but your body feels 60. Or maybe it's the other way around. Your chronological age (how old you are) is simply a number, but how you feel and function is a different story.
This is important because according to the WHO, there is a silver tsunami upon us—with a world population that is not only increasing but rapidly aging.
The global population of over 60s will surpass two billion by 2050: a 12-fold increase from 1950 (World Health Organization, 2021).
Aging is not a negative thing, but it must be done correctly. Suffering from illness and being on constant medication to get from year to year is not what real living is about. But there is a way to age gracefully and defy a sudden onset of ravages. It's time to uncover the truth about chronological versus biological aging.
What Is Chronological Age?
Chronological age is simply a numerical marker of time passed since birth. It's a static measure, like a milepost on a journey, indicating how long we've been a passenger on life's road. But it doesn’t tell us about how our body changes! As living matter, we constantly and dynamically transform, with numerous age-related alterations occurring the longer we live.
For example, two people may be the same chronological age—say, 50 years old—but one may have the body of a healthy, active individual, while the other may exhibit signs of aging or health problems, making them appear older.
So while chronological age is commonly used in research to determine a person’s risk for certain age-related conditions and diseases, it is not the best indicator of health because it fails to capture the nuances of individual vitality.
Simply put, the process of aging occurs at different rates in different individuals. To calculate these differences, we look at biological age, which offers a more comprehensive view of an individual's aging process.
What Is Biological Age?
Biological aging is the key to understanding the rate at which our body changes. It is the study of physiological alterations our bodies undergo over time. As aging occurs, the cells in the body gradually accumulate damage and become less able to divide and multiply. The rate at which this damage occurs depends somewhat on genetics, but more so on lifestyle factors, or our healthy conduct.
Just because someone is older doesn't mean they have to conform to age-related expectations. I've seen instances where some seventy-year-olds display greater functional ability than certain fifty-year-olds. They may even be more physically fit, mentally sharp, and possess a greater youthful enthusiasm for life. As long as these people maintain a healthy lifestyle, their biological age will be less than their chronological age. It really is the secret to exuding energy and vitality more akin to someone a decade or two younger.
What Shapes Your Biological Age?
Your biological age is a reflection of your body's true health and function at a given point in time. It more realistically reflects a dynamic measure of how well your organs and tissues are functioning, with several key factors influencing this internal clock:
Genetics: While DNA plays a role, it's not solely responsible for aging. Genetic predispositions can influence certain aging traits.
Diet: Nutrition is paramount. Foods rich in antioxidants combat inflammation, a primary driver of aging.
Exercise: Physical activity stimulates longevity genes, boosts immunity, and helps maintain a healthy weight.
Biomarkers: Blood tests can reveal insights into biological age by measuring factors like fasting glucose, cholesterol, vitamin D, cortisol and hsCRP (an inflammatory marker). Biomarkers are directly affected by nutrition, fitness, and lifestyle choices.
Sleep: Quality sleep is essential for cellular repair and combating inflammation, both crucial for healthy aging. Consistent sleep deprivation may potentially increase the production of pro-inflammatory cytokines and hsCRP (markers of inflammation).
Epigenetics: The Science Behind Aging
“At the heart of biological aging lies the field of epigenetics, a study of how our behaviors and environment can cause changes that affect the way our genes work. Unlike genetic changes, epigenetic changes are reversible and do not change our DNA sequence, but rather, how our body reads a DNA sequence.”
As discussed, factors including a healthy diet, more exercise, less stress, and increased sleep can significantly impact your biological age by modifying how your genes are expressed.
DNA methylation, telomere length, and oxidative stress are some of the biological markers scientists use to assess biological age. These markers reflect the cumulative impact of lifestyle factors on your body.
DNA methylation: Lifestyle factors like diet, exercise, and stress can influence DNA methylation patterns both positively and negatively. For example, chronic stress has been linked to increased methylation, potentially accelerating aging.
Telomere length: Lifestyle choices significantly impact telomere (protective DNA caps) length. Chronic stress, poor diet, lack of exercise, and smoking have been associated with shorter telomeres.
Oxidative stress: Lifestyle factors play a major role in oxidative stress. Smoking, excessive alcohol consumption, pollution exposure, and poor diet can increase oxidative damage.
OK, so that last part is a bit nerdy but in a nutshell, the complexities of the aging process can shift from a mere inevitability to the possibility of managing it. We can actually “slow down” the process at a cellular level by doing what’s right for our bodies. What a concept!
Aging isn’t just about the years in your life, but the life—or quality— in your years. How will you use this knowledge to influence your aging journey?
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