Biological Age vs Chronological Age, and Do Anti-Aging Hacks Actually Do Anything?

The idea that our biological age might differ from our chronological age isn't new. In the 1980s, for instance, new forms of cosmetics emerged that combined sunscreens, moisturizers, anti-wrinkle components and anti-free radicals, contributing to a broader rise in anti-aging trends within the cosmetic industry.

Fast-forward a few decades, when celebrity influencers like the Kardashians are showcasing anti-aging routines and procedures to their many followers. A perfect example: Blood tests for biological age began emerging after 2011 when a team of researchers at UCLA, including Sven Bocklandt, Steve Horvath and Eric Vilain, demonstrated the capacity for DNA methylation patterns to be used for measuring biological age.

Biological age vs chronological age: What is the difference?

In short, chronological age is the number of years since birth, and biological age is a more comprehensive assessment of how "old your body appears from a biological and functional standpoint," according to Diogo Barardo , director of R&D at NOVOS , a biotechnology company that sells longevity supplements and a biological aging test. Barardo emphasizes that this "distinction is crucial as being biologically older than your chronological age increases your risk for various age-related diseases, whereas being biologically younger reduces that risk."

We have no control over our chronological age, but it will change consistently throughout our lives. Every year, you have another birthday and add another number to your age. That is chronological age, and it's effectively set in stone. It will continue to grow at the same rate as long as we live. Biological age is a bit more mutable, however.

Our biological age, instead of the number of years we've lived, "refers to how old your body seems to be based on various biomarkers, like skin elasticity, bone density and even blood markers," according to Dr. Hannah Kopelman . She points out that when people take good care of their health, they may be more likely to have a biological age younger than their chronological age. This matters because keeping your biological age lower than your chronological one can help reduce the risk of numerous illnesses and injuries while generally increasing the odds of a higher quality of life.

How to calculate biological age

Several indicators and measurements can be used independently or together to estimate a person's biological age. DNA can be analyzed to determine how extensive methylation is, which is an indicator of age because methylation patterns change as we grow older . DNA methylation is one of several epigenetic mechanisms that control gene expression, so when methylation patterns change as we age, some genes may be expressed more than others, causing age-related diseases.

Biomarkers like blood pressure, cholesterol levels and inflammation can also provide insight into someone's biological age. Immune system function, metabolic rate and organ health - with a focus on the liver, kidneys and heart - may further help doctors understand a person's biological age.

Biological age blood tests

In the last decade, various biological age blood tests have become available on the market. NOVOS, the anti-aging company where Barardo works, offers a biological age testing kit that utilizes an epigenetic clock and includes a telomere length test. (A telomere refers to the DNA sequences at the end of a chromosome, which shorten with age and may indicate certain diseases .) The Horvath test, named after Steve Horvath, is another biological age test that uses a broad spectrum of biomarkers to calculate a person's age. Both tests are built on the epigenetic clock Horvath and fellow UCLA researchers pioneered in 2011.

Free biological age tests and calculators can be found online, but there is little to guarantee their accuracy in most cases. Still, some are offered by companies like NOVOS, which has a free AI-trained biological test available online. While free tests are abundant online, it may be challenging to get an accurate reading without utilizing a more clinical approach, like epigenetic clock tests.

Factors that influence your biological age

Barardo says, "Biological age is dynamic and influenced significantly by lifestyle choices, unlike genetic factors, which are fixed. Positive changes such as quitting smoking, engaging in regular exercise and dietary adjustments can reduce your biological age, while pregnancy and temporary sickness have a negative impact - increasing biological age. This implies that much of our health is within our control, given that, at most, 20% of longevity is dictated by genetics ."

These are just a few of the factors that can influence your biological age:

Smoking: Smoking can cause significant problems with our health and age us prematurely. A study in 2010 found that stopping smoking could reduce a person's biological age by up to 13 years.

Exercise: Regular exercise has long been known to have anti-aging effects and has even been correlated to longer telomeres in individuals who exercise versus those who are more sedentary. Longer telomeres are generally associated with a lower biological age. Among the anti-aging effects of exercise are reduced risks for several illnesses, including cardiovascular diseases.

Diet: Diet has long been correlated to health and wellness, and modern research has shown a strong connection between diet and biological age. Indeed, researchers at UC San Francisco uncovered a correlation between a younger biological age and a diet that minimizes sugars while focusing on vitamins and minerals.

Pregnancy: Research has shown an increase in biological age for pregnant people, yet research increasingly indicates that this accelerated aging may reverse after pregnancy. The studies found that pregnancy may increase a woman's biological age by two years during pregnancy but that some individuals had a reversal of as much as eight years in their biological age after pregnancy.

Illness: Illnesses, even temporary ones, have been shown to impact our biological age. An ambitious study in the UK , published in 2023, has been attempting to chart some of the correlations between biological age and health-related outcomes. The general finding is that illness and biological age have an inverse correlation, meaning higher rates of illness tend to coincide with older biological age.

How to reverse your biological age: Do anti-aging hacks work?

While we can impact our biological age in both directions, how well any given technique will work can vary significantly between approaches and individuals. Kopelman points out that "anti-aging hacks can certainly help slow down the visible signs of aging, but they don't truly reverse biological age in a significant way." Barardo reminds us that anti-aging hacks are currently widespread and minimally regulated; therefore, "their effectiveness varies, and many lack robust scientific support."

Many current trends in anti-aging either lack robust research and scientific support or are promoted almost solely by the manufacturers of the products in question.

In short, our experts agree that there are actions we can take to impact our biological age and slow it down, but we need to be careful of trends when considering our approach. On a positive note, however, Barardo says, "Some dietary and supplemental interventions have positive effects on biological age with stronger supporting evidence. Switching to a more plant-based diet and moderate exercise are two simple things that might improve one's biological age in a matter of weeks." Likewise, Kopelman tells us that "lifestyle changes like eating a healthy diet, staying physically active , managing stress and using skincare with proven ingredients like retinol or antioxidants can help you appear younger and improve overall health."

Is a biological age test worth it?

The emergence of biological age as a measurable metric that varies from chronological age is a relatively new phenomenon, especially regarding how biological age is measured. With these tests being a new and developing technology, there is still some debate about their efficacy. Kopelman says, "Biological age tests can provide some insights into how well your body is aging, but they're not perfect...the results aren't always 100% accurate or reflective of your overall health. They're worth it if you're curious about the impact of your lifestyle on aging, but I wouldn't rely on them as the ultimate measure of health."

Barardo points to similar difficulties with such tests but reminds us that some withstand the standard of scientific inquiry. Diogo says, "Biological age tests, if scientifically validated, are the most accurate tools we have to measure biological age. It's challenging to generalize whether all such tests are worth it because their validity varies. The great majority of such tests are indeed invalid from a scientific point of view."

Still, Barardo indicates what to look for in a biological age test to increase the odds of it being a valid and worthwhile endeavor. He recommends checking each test before purchasing it to see if it has been published for scientific evaluation and peer review and to assess its consistency and reliability. For instance, if one test gives you several very different biological ages in a short amount of time, it may not be particularly trustworthy.

The takeaway

Ultimately, we're left with the impression that biological age tests can be accurate and worthwhile and that some approaches to anti-aging do work. However, these are more often those techniques and strategies that fit into the category of lifestyle changes rather than anti-aging hacks.