Biomarkers of Aging: A Comprehensive Guide
Published by Dr. Venn-Watson

Dr. Eric Venn-Watson’s Highlights
- Our bodies age in two ways: chronologically and biologically. While chronological age may be measured by the passage of time, biological aging is harder to define. Biological aging refers to the age of our cells, which may be older or younger than our chronological age. Certain markers can be used to determine our biological age, and learning our biological age can help us make necessary changes to preserve our longevity.
We are fascinated by aging. Slowing it, managing it, and making it a healthy experience are primary focuses of not just us as individuals, but researchers who study patterns of aging and how aging works.
The how and why of aging has remained mysterious. Sure, we know that we age chronologically because the calendar turns another year.
But if we all only aged chronologically, that would mean we’d all have the same amount of wrinkles or be able to do the same activities at each respective age. In other words, why do some people seem young for their age while others seem older?
The answer is because of biological aging. Biological aging refers to how our cells age. When our cells age, our bodies age, and that rate of aging happens differently in every person.
Biological markers of aging can help us estimate how old our bodies are, although determining which biological markers are most reliable is a topic of scientific debate. Together, we’ll explore the most commonly used biomarkers, how they are tested, and what we can do to reverse the aging process in our cells.
Understanding Biological Aging
Before we look at the biomarkers used to estimate our biological age, let’s talk about how biological age happens. Researchers have identified 12 processes in our cells that cause aging to happen.
These are referred to as the Hallmarks of Aging, and include:
- Genomic instability
- Telomere attrition
- Epigenetic alterations
- Loss of proteostasis
- Disabled macroautophagy
- Deregulated nutrient-sensing
- Mitochondrial dysfunction
- Cellular senescence
- Stem cell exhaustion
- Altered intercellular communication
- Chronic inflammation
- Dysbiosis
For an in-depth look at how each of these processes works and how they cause the body to age, click here.
To summarize, our cells begin to lose their function over time. Loss of cellular function can happen due to changes in our environment, changes we make to our bodies, illness, and our own genetic makeup.
Because cells make up every tissue, organ, and system in our bodies, the loss of function within them causes a trickle-up effect that leads to system-wide changes and accelerated aging.
Biomarkers That Measure Our Age
A biomarker is a measurable indication of something else, in this instance, our age. Biomarkers can include blood tests, physical tests, scans, or anything else that can provide data to help us understand more about our bodies.
There are numerous measures we can take to help us understand how our bodies age biologically. Not all of them are as effective in producing a good measure of our age as others.
Here are some of the most common biomarkers that researchers use to determine biological age.
Telomere Length
A quick biology lesson: DNA inside our cells replicates into new cells. At the end of each sequence of DNA is a protective cap, called a telomere. Telomeres prevent the DNA chain from becoming damaged, but with each replication, the telomere shortens. Eventually, the telomere is too short to protect the DNA, and programmed cell death is triggered.
Measuring a person’s telomere length can give us an idea of how biologically old the person is. There are online tests available, but your healthcare provider may also be able to administer the test for you. The test usually requires a simple blood draw, which is then returned to a lab.
Even though telomere length can help us estimate a person’s biological age and alert us to a possible increased risk of diseases like diabetes and heart disease, there is currently no medical standard for what constitutes a “healthy” telomere length. Additionally, test results vary, so it can be difficult to interpret test results accurately.
Mitochondrial Dysfunction
As we age, the organelles inside our cells that produce energy, the mitochondria, begin to lose function. As mitochondrial function declines, less cellular energy (ATP) is produced, and more reactive oxygen species (ROS) are released, which causes damage to our cells. Declining mitochondrial function is associated with age-related illness and accelerated aging.
Mitochondrial dysfunction can be tested through various methods, including cheek swabs and blood tests. The tests assess mitochondria for DNA mutations and signs of cellular stress.
Gut Microbiome
Living within the gut are communities of microflora that can give us information about our overall wellness. When the microbial communities in the gut are balanced, immunity is likewise balanced. Changes in the gut microbiome (called dysbiosis) have been associated with age-related illnesses, like obesity, heart disease, and Alzheimer’s disease.
Gut microbiome testing is usually done by obtaining a stool sample from the patient. From the sample, the lab is able to determine whether or not the gut microbiome is balanced or unbalanced.
Inflammation Markers
Chronic, low-level inflammation is a biomarker of accelerated aging and also indicative of age-related illness. High levels of C-reactive protein and cytokines in a person’s body can indicate higher levels of inflammation.
Chronic inflammation can also lead to cellular senescence, or the presence of non-functioning cells that are still present in the body. Testing for inflammatory markers is usually done with a blood test.
DNA Methylation
Another way to test a person’s cellular function is by measuring their DNA methylation patterns. Methylation turns certain genes on and off, influencing how cellular function is working. Variations in these patterns can indicate the potential for disease or accelerated aging. DNA methylation testing involves either a blood or a saliva sample.
These tests may give us a closer idea of the body’s actual biological age, but what is more important is what we do with that information once we have it. If we learn we are biologically older than our chronological age, we can actively take steps to reverse the cellular aging process.
Reversing Cellular Aging
It’s possible, and it’s research-backed. In addition to steps like maintaining a healthy weight, eating a balanced diet, and getting plenty of exercise, there are additional steps we can take to protect our cellular health and actually reverse our biological age.
Lifestyle
Our lifestyle choices can lead to changes in our cells that cause us to age faster or slower. Smoking, for instance, is known to increase the rate at which a person ages.
Drinking excessive amounts of alcohol, getting too much sun exposure, and leading a sedentary lifestyle can all cause you to age faster than you have to. Making lifestyle changes plays a major role in your longevity.
Stress Management
Chronic stress affects you at the cellular level. Chronic, low-level stress can lead to the loss of cellular function and cellular senescence. Managing stress can help lower your levels of proinflammatory cytokines, which are a key driver in the aging process and are common when both physical and mental stress levels are high.
Prioritize Sleep
Sleep is essential to reduce biological aging. During sleep, your body repairs damaged tissues, but it also helps promote homeostatic balance.
Research shows that accelerated aging directly coincides with the number of sleep disturbances a person has, and that levels of inflammation are higher when a person does not get adequate sleep. Most adults need between seven and nine hours of sleep each night.
Take a Cellular Supportive Supplement
We’re all looking for the best additions to our health stack, and taking a cellular supportive supplement is a smart way to reverse cellular aging and slow down the biological aging processes that can underlie age-related illness.
Fatty15 is a scientifically proven supplement that contains just one ingredient that slows and reverses aging at the cellular level.
What Is Fatty15?
Fatty15 is a C15:0 supplement. C15:0 is an odd-chain, saturated fatty acid that is essential, which means our bodies need it to thrive but can’t readily make it on their own.
C15:0 works at the cellular level to:
- Regulate the inflammatory response and calm levels of proinflammatory cytokines.
- Strengthen cellular membranes by up to 80%.
- Clear away damaged, senescent cells.
- Activate AMPK to regulate whole body homeostasis, glucose uptake, and immunity.
- Rescue failing mitochondria, increasing ATP by up to 350% and reducing ROS by 45%.
- Activating PPARɑ and PPARẟ receptors. By activating these receptors, C15:0 has been shown in peer-reviewed studies to support metabolic, immune, heart, and liver health in relevant models. These receptors also help to improve mood and deepen sleep.
C15:0 also helps:
- Improve gut microbiome levels
- Lower bad LDL cholesterol
- Improve liver enzymes
- Support metabolic, immune, cognitive, and red blood cell health
- Support long-term health and wellness
Fatty15 is a smart choice for supporting your cells and your overall health.
Getting C15:0 In Your Diet
C15:0 was discovered by a team of doctors and scientists from the US Navy studying healthy aging and longevity in bottlenose dolphins. They found that C15:0 was a predictor of the healthiest aging dolphins.
Since their initial discovery was published in Nature’s Scientific Reports in 2020, there are now over 100 peer-reviewed publications supporting the benefits of C15:0 to our health.
Unfortunately, C15:0 is not easy to get in our diets because it is only found in trace amounts in some fish (in their heads and skin) and in full-fat dairy products like whole milk and full-fat butter, which we do not generally consume.
Interestingly, populations of people living in Blue Zones, where residents live up to and over 100+ years of age, have much higher levels of C15:0 than the normal population. Their diets generally consist of full-fat dairy and cheese that comes from cows and goats that graze on grass at high altitudes.
C15:0 levels in milk from grazing animals are significantly higher than those fed a corn diet. However, increasing our levels of C15:0 through full-fat dairy products may not be the ideal solution for several reasons.
- First, it's not as efficient in absorption. In milk (and other foods), C15:0 is attached to branches of lipids called triacylglycerides, aka triglycerides. That means our gut has to use digestive enzymes to break down these triacylglycerides to release C15:0 as a free fatty acid. Once C15:0 is released, it is ready to be absorbed. These multiple steps can make our absorption of C15:0 from foods less efficient.
- Dairy products have good C15:0, as well as the bad, proinflammatory, even-chain saturated fat. While the good C15:0 fatty acid is present in whole-fat dairy products in trace levels, there are much higher levels of 'bad' even-chain saturated fatty acids that continue to be associated with poorer health. That is probably why studies evaluating the effects of milk on our health are mixed.
- It is highly caloric. Whole-fat dairy products provide a wallop of calories, including sugars (aka lactose). The calories in whole-fat milk likely explain why large-scale studies show that adults who drink more whole-fat milk are more likely to have a higher body weight.
- It involves cows. The movement to more plant-based milk and meat replacements are driven by a desire for more animal-free products, as well as a desire to veer from cows and cattle because of concerns around methane production. Interestingly, plant-based milk replacements lack C15:0 altogether.
A solution? Fatty15.
Fatty15 is the first and only supplement that contains the pure, vegan-friendly version of C15:0 and nothing else. At just one calorie per dose, and already in its most bioavailable free fatty-acid form, it’s a smart way to get C15:0 back into your diet, help slow cellular aging, slow your biological aging, and support your overall wellness.
Live Long and Live Well
Living well and reducing your biological age are possible, and fatty15 is a powerful tool in your healthy aging and longevity arsenal. Taking fatty15 each day and making necessary lifestyle changes can help improve your biomarkers of aging and, most importantly, enjoy a longer, healthier life.
Sources:
Ranking Biomarkers of Aging by Citation Profiling and Effort Scoring | PMC
The microbiome: An emerging key player in aging and longevity | ScienceDirect
When cells get stressed: an integrative view of cellular senescence | PMC

Eric Venn-Watson M.D.
CEO, Co-Founder
Senior Scientist, Co-Founder
Eric is a physician, U.S. Navy veteran, and Co-founder and COO of Seraphina Therapeutics. Eric served over 25 years as a Navy and Marine Corps physician, working with the special forces community to improve their health and fitness. Seraphina Therapeutics is a health and wellness company dedicated to advancing global health through the discovery of essential fatty acids and micronutrient therapeutics.
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