As opposed to chronological age, which is a literal count of the years you’ve been alive, biological age measures how your body performs.
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Key Takeaways:
Unlike chronological age, biological age reflects how well your body functions, and you can influence it with lifestyle choices.
Tools to measure biological age are becoming more accurate and clinically relevant.
Diet, exercise, sleep, and stress management are among the lifestyle shifts that can help slow biological aging.
Measuring your biological age can help you identify risk areas and take action to extend your health span and lifespan.
Age is just a number, right? Well, not exactly. The number of candles on your birthday cake doesn’t always match the age at which your body is actually functioning. That’s where biological age comes in. As opposed to chronological age, which is a literal count of the years you’ve been alive, biological age measures how your body performs.
Physiological factors like muscle mass, body fat, and visceral fat are closely tied to biological age and serve as key predictors of overall healthspan, lifespan, and risk of age-related diseases. Lifestyle habits such as diet, exercise, and sleep quality can, in turn, influence these physiological factors, helping to shift biological age for better or worse.
Below, we’ll outline the methods for calculating biological age, how lifestyle habits can influence your biological age, and whether any treatments may slow or reverse the aging process.
Biological age is an estimate of how well your body functions compared to your chronological age. It’s calculated using complex models that combine biomarkers, rather than being a single, definitive measure. Chronological age is simpler: It measures your age based on when you were born. In many cases, biological age may provide a more accurate picture of your overall health and risk of disease.
Biomarkers can have different meanings in medicine. Generally, they are data points that show how healthy you are. They can also point to something being wrong. Think of them as little biological signals that give clues about your body’s condition. Examples of biomarkers include blood pressure, cholesterol, hormone levels, or even changes in your DNA. They can also be used to track how well your body responds to a treatment for a disease.
Essentially, chronological age is fixed and unchanging, whereas biological age is alterable to some extent. That malleability makes biological age a valuable measurement for understanding and improving your health.
Lifestyle and environmental factors can shift biomarkers of aging, sometimes making biological age appear younger or older than your actual years.
Several physiological factors can shape your biological age, including muscle mass, overall body fat, and especially visceral fat (the fat stored deep around the organs). A large imaging study of over 21,000 adults in the European Heart Journal found that visceral and liver fat were among the strongest predictors of cardiovascular aging.
Similarly, other research shows that muscle mass and grip strength are closely tied to frailty and disability, which itself is considered a hallmark of advanced biological age. In other words, maintaining muscle and strength may help protect against the physiological decline associated with aging.
“Chronological age works the same for everyone — a year goes by, and everyone's chronological age goes up by one,” says Mike Bohl, MD, a general practitioner and Senior Director of Medical Content & Authority at Hims & Hers. “But biological age is flexible and depends on things like your health, your lifestyle choices, and your environment. A year goes by, but your biological age could change more or less than somebody else who had a different experience than you during that year.”
While your chronological age specifies how long you’ve been alive, your biological age reflects how well your body functions.
Knowing your biological age can provide useful insights into your overall health. Biological age estimates may:
Reflect cumulative biological stress and functional decline
Highlight risk factors for conditions like cardiovascular disease, diabetes, heart disease, dementia, Alzheimer’s disease, disability, etc.
Offer a broader picture of long-term health and potential lifespan trends, though they cannot predict exact life expectancy
There’s more than one way to measure biological age. Some models look at overall health status, such as frailty scales that capture your health deficits (thus measuring how “frail” you are). Other approaches rely on biomarkers drawn from blood tests, genetic data, or physical performance.
Among the most widely studied molecular models for measuring a biological clock is epigenetic clocks, which track the shifts in DNA methylation (DNAm) patterns as we age. Another molecular measure is telomere length. Telomeres are DNA patterns that shorten when cells divide. Shorter telomere length is often linked to faster aging and higher disease risk. While telomere shortening was once considered a primary marker of biological aging, research suggests it’s less reliable than newer measures like epigenetic clocks. Still, research associates very short telomeres with increased disease risk and reduced longevity.
As science develops, new tools — including machine learning models that analyze large datasets or even medical images — are making biological age estimation more accurate and relevant for preventive healthcare.
Numerous lifestyle factors influence your biological age, from sleep quality to diet and exercise routines. Research suggests that lifestyle interventions can slow biological aging and, in some cases, even lower biomarker-based age estimates.
Have you ever heard the saying “you are what you eat”? Research supports that a high body mass index (BMI), obesity, and low-level physical activity may increase biological age.
A small study of 107 adults older than 65 with obesity linked dietary changes to modest improvements in biomarker-based measures of biological age. Combining diet with exercise showed the most pronounced benefits for overall health. The finding highlights the importance of both diet and exercise for improving overall function.
Here are a few tips for eating well and adding more movement to your day:
Avoid fad diets. Aim for simplicity by focusing on fruits, vegetables, whole grains, lean proteins, legumes, and healthy fats. The Mediterranean diet is a good place to start. You can explore additional effective weight-loss diet plans here.
Hydrate more. Water is a vital nutrient that supports our cells, regulates our temperature, flushes out waste, and so much more. Staying well-hydrated complements other healthy lifestyle habits. To ensure you’re drinking enough of it, set timers, invest in a water bottle you’ll actually want to carry around, or opt for flavored water if doing so will entice you to take more sips.
Expand your fitness routine. Ideally, you should aim for at least 150 to 300 minutes of moderate-intensity aerobic activity a week and at least two weekly strength training sessions that target all major muscle groups. Check out these weight loss workout plans for ideas.
Chronic stress is linked to markers of accelerated aging, including shorter telomere lengths, altered telomerase activity, as well as an increased risk of cardiometabolic diseases, mood disorders, and addiction. Stress can also alter neuro-hormonal signaling pathways, driving metabolic changes such as insulin resistance and shifts in gut hormones. Over time, these disruptions may contribute to obesity and visceral fat accumulation — both of which are closely tied to accelerated biological aging and higher risk of chronic disease.
However, people with strong emotional regulation skills and higher levels of self-control may have less age acceleration — even at similar stress levels. One study suggests that being mentally and physically resilient (meaning your mind and body can keep itself balanced under stress) can help reduce the impact of stress on biological aging. The good news is that it’s possible to hone these skills through a number of psychological interventions:
Meditate. Research shows that meditation can have anti-aging effects on the cellular level by helping to balance hormone levels. Meditation may raise DHEA, lower the stress hormone (cortisol), and reduce oxidative stress (which can help protect telomere length). Together, these shifts may help cells stay healthier for longer.
Try yoga. Studies support that, in addition to meditation, yoga may help slow biological aging by improving key cellular markers. Preliminary studies suggest meditation and yoga may influence stress hormones, inflammation, and telomere biology. While more research is needed, such changes support cellular longevity and give credence to the idea that yoga may delay age-related decline and promote longevity.
Establish supportive social connections. Strong, nurturing relationships can also buffer against stress and its harmful effects on the body. Research shows that people with more social support and close friendships tend to have slower biological aging, based on epigenetic clocks and telomere length. Healthy relationships may, then, help protect cells and promote longevity by lowering stress and inflammation.
Poor sleep can accelerate aging by triggering DNA damage and chronic inflammation, making sleep quality an important metric for determining biological age.
A study of U.S. adults found that meeting five low-risk sleep factors — getting seven to eight hours of sleep, falling asleep easily, staying asleep, not relying on sleep medication, and waking up rested most days — was linked to a lower risk of premature death and longer life expectancy.
To improve sleep quality and potentially lower your biological age, try to:
Practice good sleep hygiene. Going to bed and waking up at the same time each day; limiting screen time before bed; and keeping your room cool, quiet, and dark are just a few sleep hygiene tips you can follow to improve the quality of your sleep.
Limit caffeine. Avoiding caffeine before bed may not be enough to fully protect your sleep: You may also want to cut back during the day. Studies show that consuming caffeine even six hours before bedtime may reduce sleep by more than an hour.
Manage stress better. Another way stress might accelerate aging is by wrecking your sleep. Practicing those previously mentioned stress-busting techniques before may also help you get better sleep.
Observational studies connect long-term exposure to pollutants and toxins with accelerated biological aging, likely through mechanisms such as oxidative stress and DNA damage.
For example, one study found that exposure to fine particulate matter in air pollution is associated with faster cardiovascular aging and higher blood pressure. Workers exposed to industrial chemicals like benzene and trichloroethylene also showed accelerated epigenetic aging on several DNAm clocks. Other research has linked heavy metals — such as cadmium, arsenic, and lead — to a higher mortality risk.
Some steps you can take to reduce harmful environmental exposures include:
Limit your exposure to air pollution. Avoid outdoor exercise during high-smog days, and consider using indoor air filters if you live in a high-pollution area.
Reduce plastic use. Phthalates, which are found in many plastics and personal-care products, are endocrine disruptors. Switch to glass or stainless steel and check labels to make sure you’re using phthalate-free items.
Check your water and home. Test for contaminants like lead, especially in older homes, and use certified filters if needed.
Make healthy lifestyle choices. Eating a healthy diet rich in antioxidants, regularly exercising, and not smoking can all help counter some of the oxidative stress you encounter from unavoidable exposures.
Smoking is one of the most potent accelerators of biological aging. Cigarette smoke is packed with free radicals that fuel oxidative stress and inflammation, damaging DNA and tissues throughout the body. Studies show smokers have lower levels of natural antioxidant defenses and essential vitamins, leaving cells more vulnerable to age-related decline.
Smoking has also been linked to faster telomere shortening, which may contribute to immune system decline. In addition to being a well-known cause of heart disease, cancer, and respiratory illness, smoking is also associated with dementia, osteoporosis, and other age-related conditions, reducing not just life expectancy but also quality of life.
All of that being true, quitting smoking — even later in life — slows the biological damage. Evidence shows that non-smokers live longer, healthier lives, and stopping smoking remains one of the best ways to protect your cells and extend your health span.
Some actions you can take to quit smoking include:
Seek support. Talk to your healthcare provider about creating a personalized plan to quit. Combining counseling with medications like bupropion is often most effective.
Consider nicotine replacement therapy. Patches, gum, or lozenges can help manage cravings by allowing you to consume controlled doses of nicotine without the harmful chemicals found in cigarettes.
Build new routines. Replace smoking triggers (like after meals or with coffee) with healthier habits, such as walking, chewing sugar-free gum, or practicing deep breathing.
Biological age offers a clearer picture of how well your body is functioning than chronological age alone. It reflects the overall impact of lifestyle, environment, stress, and genetics on your cells and tissues. And unlike your date of birth, your choices can influence your biological age.
Research shows that positive lifestyle changes, such as following a healthy diet, getting better sleep, and managing stress better can help slow or improve biological age markers. By paying attention to these factors, you can protect your cells, extend your health span, and maybe prove that age really is just a number.
Chronological age measures how many years you’ve been alive. Biological age describes how you are aging and reflects how well your body functions, based on multiple factors and biomarkers. Your biological age can be older or younger than your chronological age, depending on your health and lifestyle.
Yes. While you can’t change your birthdate, research suggests that lifestyle changes like diet, exercise, and stress reduction can slow or improve biological age markers.
Tools like epigenetic clocks and DNA methylation (DNAm) analysis are among the most reliable models, though no test is perfect. Results are best used as a guide to inform healthy lifestyle choices, not as an exact measurement.
Smoking, poor diet, chronic stress, lack of sleep, physical inactivity, and environmental toxins are all linked to accelerated biological aging.
Biological age can more accurately reflect your functional health and disease risk than chronological age alone. Knowing your biological age can help you identify areas for improvement and take steps to maintain long-term health.
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