Biological Age: What is Biological Age, Why Does it Matter, and How Can You Decrease Your Biological Age?

Biological Age: What is Biological Age, Why Does it Matter, and How Can You Decrease Your Biological Age?

If you’ve ever been comforted on a birthday you’d prefer not to acknowledge with the phrase “age is just a number”, you may have rolled your eyes. But as it turns out, that classic saying is pointing to a concrete scientific movement: That you have two ages - and the one on your birthday cake isn’t the one that actually matters for your health, longevity, and wellbeing!

Reference Lab

OCT 12, 2021

01 Chronological Age versus Biological Age

Have you ever observed two people who have spent the same number of years on this earth, but who look (and likely feel) years apart? If so, then you’ve probably recognized that the aging process can occur at different rates for different people, and that rate can be greatly influenced by lifestyle choices.

This points to the idea of chronological age (how old we are) versus biological age (how old our bodies function).

02 What is Chronological Age?

Chronological age is the number of years you have been alive - When you blow out the candles on your birthday cake, you’re celebrating your chronological age. Your chronological age determines when you can vote, purchase your first martini at a bar, or drive a car. Milestones like your 18th birthday and your big 5-0 describe your chronological age and hard as we may try, chronological age cannot be changed.

03 What is Biological Age?

Biological age describes the age that your body behaves and feels. Unlike chronological age, biological age is malleable and varies from person to person, depending on how healthy they are.

Your cells, which make up your tissues and organs, experience aging as a reduction in their ability to function over time. The rate of this reduction can be influenced by factors such as genetics and lifestyle habits and ultimately determine your biological age.

Each of your organs or tissues have their own biological age, the sum of which determines your overall biological age. For instance, someone who spends a lot of time in the sun, but also eats a plant-based diet could have skin with a high biological age (meaning their skin looks, feels, and acts older than it is) and a heart with a low biological age (meaning their heart has been well-maintained and acts younger than it actually is).

As the field of longevity and aging research advances, biological age has become by and far the more important age to pay attention to, because as it turns out, our cells don’t regard our birthdays the same way we do. The good news? Your biological age is totally up to you! In fact, you can, for the most part, control your biological age through your daily habits.

04 Lifespan vs. Healthspan

Historically, scientists used chronological age and lifespan as primary measures of a population’s health - the longer people lived chronologically, the higher the average lifespan, and the healthier that population was considered to be. However, chronological age and lifespan bear no indication on the health of your body during the years that you live and are therefore not informative for a person’s wellbeing. As advancements in healthcare have led to increased lifespans, the importance of the quality of those extra years gained has become more apparent.

This is why the term “healthspan” has become increasingly important in healthcare, as it describes the number of years that you are healthy and free from age-related diseases rather than just the number of years that you’re alive. For example, someone could live until they are 80 years old, making their lifespan 80, but they could have lived the last 20 years of their life experiencing chronic illness, making their healthspan only 60 years.

As you may have guessed, healthspan - the number of years that you’re healthy - is intimately related to biological age. Keeping your biological age as young as possible will lend not just to a longer lifespan, but a longer healthspan too.

How can this be achieved? The lifestyle choices you make, such as diet, exercise, and the products you use, all have a cumulative effect on your healthspan and biological age.[1]

05 How is Biological Age Measured?

By now, we hope you’re thoroughly convinced that your biological age and your healthspan are important metrics that indicate your physical wellbeing. However, this may lead you to wonder how biological age can be measured.

The most reliable way to measure biological age is through something called a “biomarker”. A biomarker, short for “biological marker,” is an objective measure that indicates the health of a cell or organism. Cholesterol levels, blood sugar levels, and heart rate are examples of common biomarkers used to assess the healthiness of someone’s body.

Biomarkers are critical to determining biological age and there are two particular biomarkers that have been found to predict biological age most accurately.[2]


As you may remember from grade school biology, your genes are the parts of your DNA that determine how your body operates, including how you look, certain health conditions that you are likely to develop or experience, and even how you feel. While it’s true that your DNA is predetermined by which genes you inherit from your parents, scientists have found that how they’re regulated or expressed is generally open to modification.

Enter epigenetics. Epigenetics are factors that affect which of your genes are ultimately expressed, effectively turning genes “on” or “off”.[3],[4] Because of epigenetics, even though you may inherit a gene from one of your parents, whether you actually express that gene could depend on lifestyle choices. For example, you could inherit the propensity to develop diabetes from a parent (your genetics), but depending on your lifestyle choices, you could develop the epigenetics to keep that gene “off” and ultimately not ever develop diabetes.


One of the primary types of epigenetic modifications that occur as humans age is DNA methylation - a process by which functional groups (methyl groups) are added onto DNA over time. The amount of DNA methylation that is present on your DNA is directly correlated with how old your cells behave. The more methyl groups present on your DNA, the older your cells will behave, making the measure of DNA methylation the most reliable way to measure biological age.


Another biomarker that scientists utilize to measure biological age are glycans. Glycans are complex sugars that bind to lipids, proteins, and even RNA. Glycans sit on top of cells, thus modifying their function and enabling cell-to-cell communication.

Glycans attach to immunoglobulin G (IgG) proteins, the most abundant antibody in the blood, allowing them to help mediate immune system responses, and making them useful in measuring inflammation levels. The types of glycans that are attached to IgG proteins changes with age, amongst other factors, lending them useful in measuring biological age as well. When compared with other biological age clocks, GlycanAge, which analyzes the glycans attached to IgG molecules in the blood, has a significant association with multiple disease states and is the best clock in predicting the future risk of hospitalization.[5]

Aging Clocks

Both aforementioned biomarkers have been used to develop “aging clocks” - Tools that reliably predict the biological age of an organism or tissue by analyzing biomarkers. These aging clocks offer accessible ways to assess the rate of one’s aging and the health of one’s cells in order to determine biological age. Examples of aging clocks include GlycanAge and myDNAge, which utilize glycans and epigenetics, respectively, to predict one’s biological age.[6] These tools can be useful in determining the effectiveness of your lifestyle habits at prologoning your longevity.

Can You Decrease Your Biological Age?

An overwhelming amount of data and studies are revealing that while we still require a time machine to literally turn back the hands of time, you can wind your biological clock back. In fact, a 2019 article published in Nature demonstrated that an individual’s biological clock is not only malleable, but can actually be reversed. In a study of nine male volunteers, all showed biological rejuvenation of 2.5 biological years by adhering to a drug regimen of common therapeutic drugs.[7]

How can you reverse your biological age?

It turns out that reversing biological age doesn’t necessarily require a strict drug regimen like the aforementioned study, and can in fact be reached through relatively simple lifestyle changes. In fact, since lifestyle factors impact how your genes are ultimately expressed, your habits actually impact your biological age more than even your genes do. The following are a few steps you can take to decrease your biological age:

  • Restrict your calories. Restricting calories and adhering to a healthy diet is one of the most widely proven ways to reduce biological age. For example, a prominent study published in The Lancet evaluated the results from two years of calorie restriction in a group of non-obese men and women. The study found that calorie restriction improved all age-related risk factors for cardiovascular diseases. In fact, similar studies have been performed on multiple species, from rodents to primates, which all found that calorie restriction is a reliable way to extend longevity, partly because overconsumption, especially of processed foods, can lead to obesity, high-blood pressure, and inflammation which are linked to chronic and age-related diseases.[8],[9]
  • Consume a plant-based diet. A plant-based diet improves heart health and boosts the immune system. Research from the University of California in San Francisco discovered that adhering to a plant-based diet for three months positively affected the degradation of telomeres - another aspect of DNA that is closely correlated with biological age. Located at the ends of our DNA strands, telomeres’ length shortens as we age, which makes them a significant marker for biological age.[10]
  • Get adequate sleep (7-9 hours). According to studies compiled by the American Academy of Sleep Medicine (AASM), sleep deprivation may age us quicker than we’d like to admit by speeding up biological aging, as proven by increased DNA damage in blood samples of sleep deprived individuals. Obtaining an adequate amount of sleep every night, on the other hand, slows the onset of physical aging, improves mental health, and reduces the risk for chronic disease.[11] In fact, according to world-renowned neuroscientist, Matthew Walker, the correlation between sleep and longevity is simple - “The shorter your sleep, the shorter your lifespan.”
  • Exercise regularly. Physical exercise, specifically High-Intensity Interval Training (HIIT) can prevent telomere degradation and increase the ability for cell mitochondria to produce energy. A Mayo Clinic study of individuals ages 18 to 30 and 65 to 80 found that after three months of HIIT, mitochondrial energy output was boosted by 49 percent in the younger group and a remarkable 69 percent in the older group. In general, exercise also boosts blood flow, improving the cardiovascular system and nutrient delivery throughout the body.[12],[13]
  • Consume antioxidants. Studies evaluating the role of antioxidants show that they are able to help counter the external factors that encourage the aging process, like free radicals and oxidative stress. Consuming foods high in antioxidants reduces oxidative stress on cells and prevents cellular destruction. Green leafy vegetables and colorful fruit are all rich in antioxidants and can slow biological aging.[14],[15]
  • Maintain a healthy microbiome. A healthy microbiome boosts the immune system and prevents inflammation, leading to a younger biological age. For a healthy microbiome, the National Institute on Aging recommends avoiding sugars and processed foods. Consume a well-balanced diet that includes fermented foods like yogurt and kombucha. What’s more, recent studies suggest that establishing a healthy skin microbiome can reduce the external signs of aging, like wrinkles and loss of elasticity.[16],[17],[18]
  • Manage your stress levels. In a Brigham and Women’s Hospital (BWH) study published in PLoS, 5,423 middle-aged and older women who experience chronic anxiety had shorter telomeres, proving that stress can damage your body at the cellular level and accelerate your biological age. You can develop the ability to manage stress by meditating, avoiding triggers, and engaging in healthy leisure activities.[19],[20]
  • Engage in your community. A 2018 study of 113 men and women found that loneliness can decrease telomere length, increasing the signs of aging. Therefore, your social circle is an important factor in reducing your biological age. To help slow the biological signs of aging, foster a supportive social environment for yourself and participate in community engagement.[21],[22]
  • Have a positive mindset. A negative mindset adds unnecessary stress and can have an adverse effect on your mental health. In a 2019 study of both men and women, those who practiced an optimistic outlook were 11-15% more likely to have a longer lifespan. Keep your biological age in check by maintaining a positive mindset.[23]

06 Biological Age of Skin

As mentioned previously, each of your organs has its own biological age and we would be remiss if we didn’t arm you with some extra knowledge regarding your largest organ - skin!

As your immune system’s first defense, your skin is an immediate window into the state of your health, making its biological age a good predictor of your healthspan. That’s why we have gone one level deeper and coined the term ‘skinspan’ - the length of time that your skin is healthy and functional. Much like your healthspan is correlated with your body’s biological age, your skinspan is directly correlated with your skin’s biological age - the lower your skin’s biological age, the longer your skinspan. And the longer your skinspan, the more likely you are to extend your healthspan due to the skin’s impact on your overall health!

OneSkin’s MolClock

Although aging clocks like GlycanAge and myDNAge can be useful in assessing a person’s overall biological age, they don’t inform which organs are contributing positively and negatively to the reported biological age. Therefore, if the goal is to analyze the effects that certain molecules and products have on the biological age of a certain organ, such as skin, an organ-specific aging clock is necessary.

Enter OneSkin’s MolClock - the first ever aging clock specific to skin, designed to accurately measure skin’s biological age. By measuring epigenetics in skin, OneSkin is the first company to hold a validated tool to screen the effectiveness of products and molecules for their rejuvenation properties.

What does this mean for the products being developed by OneSkin? Since OneSkin holds a validated system to quantify the rejuvenation effects of molecules, we are able to screen and validate thousands of new and existing molecules to get the inside scoop on what works and what doesn’t.

Can you reverse skin aging?

OneSkin’s scientists screened over 1,000 peptides for their effects on skin’s biological age and discovered a proprietary peptide: OS-01, the first peptide proven to reduce skin’s biological age! OS-01 powers all of OneSkin’s products and takes the guesswork out of choosing effective anti-aging products.

Wondering how effective OS-01 really is? By using skin cells from a 79-year old donor, OneSkin grew 3D skin models in the lab and treated them with OS-01 for 5 days, assessing the biological age of the skin before and after treatment. Before the skin was treated with OS-01, it presented a biological age of 70.82 years. After treatment with OS-01, the same skin model presented a biological age of 68.22 years, indicating that OS-01 reduced skin’s biological age by 2.59 years with just 5 days of treatment.

So in short, yes, you can reverse the age of skin and OS-01 is your way to do it!

07 Looking Forward

Recent studies, including those performed by OneSkin, demonstrates that we’re not bound by our genetics or our chronological age, and we can in fact grow younger if we take the proper steps! Take the advice of renowned biologists and geneticist, Dr. David Sinclair, who claims that he is getting younger (biologically, that is) as time goes on - “Age reversal isn’t a miracle. It’s a lifestyle.”[24]

08 Conclusion

  • Chronological age cannot be changed, but Biological age plays a major role in how you feel and function. While chronological age cannot be changed, biological age is malleable and can even be reversed, allowing you to look and feel younger than your chronological age.
  • Aging clocks are tools that use biomarkers to assess the biological age of an organism.
  • OneSkin’s MolClock is the first aging clock that works exclusively to determine the biological age of skin, allowing OneSkin to assess products and molecules for their effectiveness at rejuvenating skin on a molecular level.
  • OneSkin’s proprietary peptide, OS-01, is scientifically proven to reduce skin’s biological age.
  • By exercising, managing stress, and paying special attention to what we place into and onto our bodies, we can slow down—and even reverse— our biological age.
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