How Old Are You, Really?

Updated December 9, 2022

“Age is just a number,” as the saying goes – but which number, exactly? Of course, you can count to this year from the one you were born in, but that’s far from the most relevant one.

You’ve likely had one or more double-takes upon learning a new friend was five years older than you thought…. or more awkwardly, the opposite. Was it their face that didn’t match the number? Was it their energy, demeanor, or something even more profound that you couldn’t quite nail down?

Perhaps it was actually their bio age, which measures the health of their cells and DNA instead. It’s no great leap to say your bio age matters more than your chronological one. In the sections ahead, I’ll walk you through what your bio age is and I’ll even tell you how to take your first steps towards lowering it. Or if you’re the impatient type, you can take either the free Biological Age Self-Assessment Quiz or access my recommended Biological Age Lab Test now.

Why Chronological Age Matters Less Than Biological Age

Your chronological (or calendar) age is the one you already know, but it’s also the one that tells you the least. For example, three 45-year-olds might share a chronological age, but it wouldn’t have much to say about their various life expectancies. Health, happiness, and vitality would likely differ amongst all three, possibly significantly.

As we get older, it’s a fact of life that our bodies begin to function less efficiently and slowly collect damage from both internal and external causes. Some of these causes are natural, but many are avoidable.

While one of the 45-year-olds mentioned above might have the average physiology of most people their age, another’s body might be damaged enough to resemble a 53-year-old’s. Likewise, the third might have a lifestyle that gives them the body of an average 39-year-old. Vanity aside, what’s the big reason this matters? According to the World Health Organization, people spend roughly the last 20% of their lives (on average) managing chronic illnesses. By the age of 65, a full 80% have at least one chronic condition, such as heart complications, cancer, or dementia. A substantial majority has at least two. While these might be grim statistics, the younger your bio age, the less likely you are to fall into them – regardless of chronological age.

You can think of it like this: while your chronological age tells how many years you’ve been alive, your bio age shows how your body has largely spent those years. Bio age differs from chronological age in another crucial way – while the latter can only go one direction, bio age can go forward or backward, depending on damage and repair. In other words, with the right tactics, your physiology can grow younger. Really!

What Goes Into A Biological Age?

When determining your bio age, several factors are at play that can either accelerate or reverse it. Here’s just a sample:

Factors That Decrease or Slow Biological Age

• Good Gut Bacteria
• Balanced Exercise
• 7-9 Hours of Sleep (for most)
• Meditation/Mindfulness Practice
• A Healthy, Diverse Diet, especially one rich in epinutrients
• Cuddling & Physical Touch (Yep, that’s right!)

Factors That Increase or Accelerate Biological Age

• High Blood Sugar
• Environmental Toxins
• Not Enough or Too Much Exercise
• Certain Medications
• Bad Gut Bacteria
• Excess Stress

What all these factors affect, either positively or negatively, is an epigenetic process called DNA methylation which essentially decides what genes get turned on and what genes get turned off. In my book, Younger You, I explore how this process works (and you can read about its direct link to bio aging right here). What matters most is that as much control as DNA methylation wields over your biological age, our everyday choices wield just as much control over DNA methylation.

How We Got Here

Dr. Elizabeth Blackburn first popularized the link between DNA and biological aging via genetic material known as telomeres. Telomeres gather at the end of our DNA strands to protect them from fraying, but as we age, they get shorter and shorter. That leaves our DNA strands exposed, and the more exposed they are, the greater our chances of contracting diseases. But while telomeres can say a lot about overall health and disease risk, scientists found that measuring them alone resulted in only a 40% correlation with real age. (As a side note, I do include telomere length measurement as an addition to my bio age lab testing since it is helpful to know if you do happen to have short telomeres).

Dr. Steve Horvath of UCLA went further, going past telomeres to analyze hundreds of sites on the genome. His studies correlated all that DNA data to .96 of chronological age. What was exciting about this? That missing .04 was not an error – it represented the average difference between chronological age and bio age.

Horvath’s DNAmAge epigenetic clock – also known simply as the Horvath clock – is a complete analysis of methylation across the genome. As a result, the Horvath clock can accurately assess your bio age, even as it changes, by analyzing the methylation patterns across hundreds of specific sites. This makes it an essential tool for studies like mine designed to measure the effects of bio age-altering interventions.

Since the Horvath clock gained widespread use – and became more accessible to non-researchers – advanced tools like the GrimAge and PhenoAge clocks also became available. These second-generation clocks offer specific correlations between DNA and health-related factors such as disease or mortality risk.

Now, though, we also have third-generation biological age assessments. Instead of training their correlations on chronological age, third-generation aging tests train their algorithms on age-related biomarkers and diseases (such as cardiovascular disease, Alzheimer’s disease, ability to balance, muscle mass, IQ and mental processing speed, and skin aging. Third generation bio age assessments have also been available at a more affordable price point for general consumers.

What began a decade ago with Dr. Blackburn’s telomere observation has quickly evolved into a cutting-edge bioanalysis system. The promise these tests show for not only mapping the factors that age us but learning how to reverse them is suddenly enormous – and enormously exciting.

Put Yourself To The Test

All that research has led us here. If you want to find out how well you’re aging, there are two options I recommend:

One is to take a simple quiz-based health habits assessment and roughly learning your own bio age. I say “roughly” because this quiz is NOT designed to compete with laboratory based tests for accuracy. It is simply a way to get a better-than-ballpark estimate of how old your physiology really is. We call this the Bio Age Self-Assessment quiz, and it’s a valuable way to highlight what you’re already doing well – along with any habits that could be making you older. No matter what number you get, remember that you can lower it as I teach people in Younger You.

What To Do With What You Know

Whatever your results, they are actionable. The strategies used during my initial study successfully lowered bio age by an average of 3.23 years in participants compared with controls, and since then, my team has already learned more, as revealed in Younger You. It really is possible to not only extend life but quality of life, warding off disease and decline through easy-to-implement diet and lifestyle changes. The resources are all here; now it’s up to you to put them to good use. Age may just be a number, but never forget it’s a number you can choose.

Thank you for taking the time to read this blog, and if you do give either of the assessments a go, please leave a comment below on what you think of your results – I’m always curious to hear from our amazing community!

Author: Kara Fitzgerald, ND

https://www.drkarafitzgerald.com/

Kara Fitzgerald, ND, received her doctor of naturopathic medicine degree from the National University of Natural Medicine in Portland, Oregon. She completed the first Counsel on Naturopathic Medicine-accredited post-doctorate position in nutritional biochemistry and laboratory science at Metametrix Clinical Laboratory under the direction of Richard Lord, PhD. Her residency was completed at Progressive Medical Center, a large, integrative medical practice in Atlanta, Georgia. Dr. Fitzgerald is the lead author and editor of Case Studies in Integrative and Functional Medicine and is a contributing author to Laboratory Evaluations for Integrative and Functional Medicine and the Institute for Functional Medicine (IFM)’s Textbook for Functional Medicine. With the Helfgott Research Institute, Dr. Fitzgerald is actively engaged in clinical research on the DNA methylome using a diet and lifestyle intervention developed in her practice. The first publication from the study focuses on reversal of biological aging and was published 04-12-2021 in the journal Aging. She has published a consumer book titled Younger You as well as a companion cookbook, Better Broths and Healing Tonics and has an application-based Younger You Program, based on the study. Dr. Fitzgerald is on the faculty at IFM, is an IFM Certified Practitioner and lectures globally on functional medicine. She runs a Functional Nutrition Residency program, and maintains a podcast series, New Frontiers in Functional Medicine and an active blog on her website, www.drkarafitzgerald.com. Her clinical practice is in Sandy Hook, Connecticut. Additional publications

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