Biological age: the hidden metric that's redefining how we understand ageing

Nov 20, 2023

Key takeaways

  • Chronological age is the number of years you’ve been alive while biological age is a measurement of how well your body functions at any given time, giving insight into your overall well-being and risk for chronic disease.

  • Only about 20-30% of ageing factors are hereditary. The remaining factors you can be influenced by as environment and lifestyle elements.

  • You can determine your biological age with modern tests  including those that look at blood biomarkers, epigenetics, and the microbiome. 

  • Knowing your levels enables optimisation of lifestyle factors with small but powerful habit changes such as nutrition, activity, sleep and other factors in your control. 

Ageing is a natural part of life, influencing the way our bodies and minds interact with the world. Ageing is also associated with loss of vitality and increased risk of disease. Discover the hidden health metric called your biological age, how it's redefining how we understand ageing, and ways in which it can steer personalised habit changes. 

How is age more than just a number?

Age is more than just a number, or the length of time we’ve been alive. The ageing process is a gradual one that happens to our physical body as we accumulate life experience along the way. With modern beauty routines, products and procedures, we can look younger but thanks to biological age and longevity research we can also feel younger. 

Chronological vs. biological age

As your birthday cake candle count increases, it represents what’s called your chronological age, or how old you are in calendar years. 

Chronological age can be misleading because it doesn’t tell you anything about your health status. Perhaps you know someone in your life who appears to look much younger than they actually are? This could be because their biological age differs from their chronological age. Indeed, someone who is 60 years old can have the same biological age as someone who is 30 years old, or vice versa!

Biological age is a measurement of how well your body functions at a specific time. It can provide insight into your overall well-being and risk of chronic disease (1). Biological age can be altered through certain lifestyle habits, such as what we eat and how well we sleep.

Factors determining your biological age

Did you know that only about 20-30 percent of your ageing process is predetermined by your genes, i.e. what gets passed down from your biological parents? (3) Biological age is also impacted by your environment, such as the air quality in your neighbourhood, and lifestyle choices like diet and exercise. This means you have control over a good portion of the rest of your ageing process. Let’s look more closely at some of these factors and discover ways to ensure they positively impact you and your biological age.

Genetic factors

One way to determine the likely rate of your biological age is to look at your family. What gets passed down from your biological parents gives you an element of insight into your biological age. 

One long term study found that women who have mothers that lived past 90 years old have a 25 percent increased chance of doing the same (4). Although environmental factors are considerably impactful, considering your parents’ chronic disease history may be useful as a possible influence on the rate of your biological age.  

Only about 20-30% of ageing factors are hereditary. Genetic instability, for example, is when a part of our genome (which carries hereditary information) breaks or gains extra chromosomes. In some cases, this could lead to disease (5). If we’re able to test for and catch these weaknesses, we have the potential to work with our genes in order to influence the rate of ageing. The remaining factors related to rate of ageing can be influenced by environmental and lifestyle elements. 

Environmental exposure

Where and how you spend most of your time, including your location, pollution exposure, and access to nature all have an impact on biological age. Living near green areas like parks or forests, can even affect how healthily we age. One study suggested that people who had about 20 years of exposure to green space experienced changes in their DNA methylation epigenetic age. This is the mechanism that influences how our genes are expressed. In this study, participants were reported to be 2.5 years younger in terms of their biological age! (6). 

Oxidative stress is when the balance of free radicals and antioxidants in our bodies are thrown out of kilter (7). Free radicals are unstable molecules that can cause damage in our bodies, potentially increasing the biological ageing process, while antioxidants are protective molecules which we get from certain foods, such as fruits and vegetables. 

Many studies have shown that oxidative stress, which comes from a processed Western type diet and pollution, is linked to the shortening of telomeres (8). Telomeres are caps that protect our chromosomes. Over time, these telomeres shorten which can limit how effectively our cells divide. This has a negative impact on our health and the effectiveness of our organs (9). 

Limiting exposure to pollution and harmful environments can slow the rate of biological ageing. If you live somewhere that makes it difficult to reduce the hazards you’re exposed to, you still have a chance to slow ageing by means of other healthy lifestyle choices such as getting better sleep or improving what you eat. 

Lifestyle choices

Our biological age is also related to our lifestyle choices, including how and what we eat, whether or not we smoke, the amount of physical activity we take, and even our social interactions. Blue Zones are areas around the world known for having some of the longest living and healthiest people. Communities in Okinawa, Japan; Sardinia, Italy; Nicoya, Costa Rica; Ikaria, Greece; and Loma Linda, California choose healthy lifestyles, consuming more plant-based natural foods, staying active, and building strong social bonds (10). 

Being part of a community of people you enjoy and who support you can help positively impact your biological age. Social isolation and feeling lonely has long been associated with health problems such as dementia in older adults (11). Inclusion in a tight knit social enclave can also help us be more resilient as a result of being supported in times of stress. 

Stress is another aggressor when it comes to speeding up biological ageing. In one study, the effects of stress, resulting from health issues such as infection and surgery, showed a quick increase in biological age through DNA methylation. The good news is that it  decreased once the stressor was removed (12). Stress management also improves our sleep.

Beauty sleep is so-called for good reason. Poor sleep can negatively impact our biological age and therefore our looks, overall health, and vitality. Better sleep may actually decrease biological ageing caused by pollution (13). A factor that may benefit sleep is keeping active. Indeed, research has found an association between estimated biological age and fitness level, suggesting that older individuals who keep active can reduce the rate of biological ageing (14). Keeping active on a daily basis not only improves sleep, it also increases brain derived neurotrophic factor (BDNF) which can prevent age related disease and aids in stabilising telomere length (15). 

Another lifestyle choice worth mentioning here is smoking. Cigarette smoke damages our tissues, which may in turn increase epigenetic ageing (16). Stopping smoking has been known to positively impact biological age. Epigenetics are the way our DNA presents itself. 

Benefits of measuring your biological age

So how do you know what your biological age is? There are simple tests you can take that give you a comprehensive and personalised picture of what’s going on in your body.

Blood biomarkers

Biomarkers (measurements of our body’s processes) in the blood are indicators of your health. They give insight into what’s happening inside your body, how well certain organs are functioning, and how efficiently systems are working. Examples of biomarkers that affect longevity and biological age are white blood cells, triglycerides, and albumin.

Regularly testing biomarkers can create a roadmap, with signs indicating how your lifestyle changes are making a difference. It’s also important to test on a regular basis, because our environments and bodies change over time. It’s recommended to repeat blood biomarker testing every six months for an up to date and accurate picture of your overall health and biological age.

Epigenetic markers

Epigenetics are changes in our gene expression, influenced by our environment. They can be “switched on” or “switched off” as a result of what we’re exposed to. We may have two cells with the same DNA which function completely differently. 

They can change throughout your life and affect the efficiency of important processes in your body. They provide a main insight into your biological age. For instance, eating certain foods such as healthy fats, fruits, and vegetables, can result in an expression of less overall inflammation and decreased disease risk (22). 

An epigenetic clock is a test that can be used to measure our biological age. It shows how much epigenetic modifications have changed, rather than specific genes. Epigenetic clocks, such as the Horvath clock, calculate the age of our blood and tissues through DNA methylation (17). Ageing is strongly associated with changes in DNA methylation.  

Microbiome diversity

Beyond blood markers and epigenetics, your gut is a window into the ageing process. Your gut is home to tens of trillions of bacteria, fungi, viruses and other tiny living organisms. These microorganisms can be harmful or completely essential to our mental and physical state. The key to a healthy microbiome is balance. 

The microbiome can significantly affect your health, disease risk, and biological age due to the foods they help you digest and the compounds they produce. For example, these bacteria produce energy– improving B vitamins and the happy brain chemical called serotonin. You can boost healthy and helpful microbes through diet and lifestyle. For example, eating more fibre rich foods like fruits and vegetables, fuels these bacteria. 

Studies have also shown that our microbiomes change and become less diverse as we age (18). This accelerates biological ageing because of an increased risk of disease. The exact mechanisms of the microbiome impacts ageing aren’t clear, but it’s thought to be because an imbalance of gut bacteria may limit stem cells from regenerating (21). Stem cells can reduce signs of ageing by improving cell function and reducing inflammation. 

How to influence and optimise your biological age

Once you know your biological age, you can take action to promote a more youthful version of you. There are science-backed ways to optimise your biological age. However, keep in mind that your body and medical history is unique. Everyone responds differently to certain foods or lifestyle habits. 

Boost nutrients 

Providing your body with adequate nutrients allows it to function at its peak, supporting DNA methylation and epigenetics while helping to reduce the likelihood of developing chronic disease. Whole foods can also decrease inflammation in your body, an influence on ageing (19). 

Increase your nutrient intake by adding fresh fruits and vegetables – add a handful of greens to eggs or a sandwich, or have a piece of fruit with a snack.

Substitute processed foods for nutrient-rich whole foods – if you eat refined white bread, pasta, or rice then consider switching to whole grain versions. Next time you want a convenient snack, consider a handful of nuts or unsweetened yoghurt instead. 

Manage stress  

Sometimes life gets overwhelming. It’s the perceived stress that’s likely more destructive to health and ageing; in other words, the story we tell ourselves versus the actual stressful event. Consider keeping a stress journal where you can log  stressors in your life, try to identify the cause of it, how you responded, what you did, and what helped you feel better. 

Another way to tackle stress is using breath work. When you notice signals of stress arising in your body, such as an increased heart rate, take a moment for yourself and try inhaling five deep breaths in through your nose and out through your mouth. 

Make sure to contact your mental healthcare professional if you haven’t been able to manage stress or if it's impacting your day to day life. 

Stay active 

Staying active has incredible benefits for our mind and body. Getting that gym session in can really make a difference in staying mentally and physically healthy. The key is to find what you enjoy doing so you’re motivated to keep doing it.

If you aren’t a fan of the  gym or sports, consider other ways you can stay active. If you take the metro to work, get off at an earlier station and walk a bit. If you drive, park a bit further away from your destination to get those extra steps in. 

Improve sleep quality 

One of the best ways to improve sleep quality is to keep a regular sleep cycle. Set an alarm an hour before bed to remind yourself to start winding down. At this time, turn off devices with a blue light which can interrupt our natural sleep cycles. In the daytime, making sure you get enough natural light may positively impact your sleep quality at night (20). 

Strengthen relationships 

Strong social connections and relationships can benefit our mental health and turn back our biological age. Strengthen your relationships by regularly speaking to friends arranging to meet people. 

If you’re trying to build a network, search for groups in your area of like minded people. It takes effort, but a strong community you can rely on and relate to is priceless, especially when it comes to ageing and overall health. 

Preventative measures against diseases

On top of efforts to positively improve diet and lifestyle choices, it’s important to get regular checkups from a doctor or healthcare provider who knows you well. This includes annual physical exams and routine tests to make sure you’re functioning at tip top shape. 

Take a genome test to better understand what to expect from that 20-30 percent genetic accountability from your family and test your biological age to discover which factors have the strongest impact. You’ll have a better idea if you are at increased risk for chronic diseases and can focus on healthy habits to prevent it as much as possible.  

Looking beyond the calendar: your true age journey

Understanding your biological age and the effects of blood biomarkers, microbiome composition, and genetics can provide invaluable insights for making targeted and personalised decisions about your health. It enables you to focus on specific areas that need attention, allowing you to take proactive steps to optimise your well-being and potentially extend your healthy years.

Knowledge is power and you’re already taking the steps to help reduce your biological age by learning. It’s never too late to start making changes. It’s not about making huge, overwhelming shifts, rather focusing on little lifestyle tweaks that add up to big biological age dips. 

Ready to test your biological age and take control of your life? 


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