Why Most At-Home Biological Age Tests Don't Track Inflammation — and Why That Matters

Biological age tests are not all measuring the same thing. Most measure genetic potential, historical methylation patterns, or acute blood chemistry, none of which capture the chronic, low-grade inflammation that drives age-related disease. GlycanAge is the only at-home biological age test that measures chronic inflammation directly, through glycans (complex sugars) attached to IgG antibodies in your blood.

For the full picture of how biological age is calculated and what it means for your long-term health, read Biological Age Testing: The Complete Guide to Measuring How Fast You're Actually Aging.

What are most at-home biological age tests actually measuring?

Most at-home biological age tests measure either DNA methylation patterns (epigenetic clocks), telomere length, or standard blood biomarkers such as glucose, CRP, and cholesterol. Each of these captures a different biological signal, and none of them directly measures chronic inflammation. Biomarkers like glucose and CRP change within minutes or hours, which makes them useful for acute health monitoring but not for understanding how your immune system is aging over time. To understand why standard bloodwork misses chronic inflammation, it is important to distinguish between acute spikes and the sustained inflammatory burden that drives aging.

Epigenetic tests that examine CpG sites on DNA are associated with aging, but it is not always clear what biological process is actually driving the changes, which makes it difficult to derive clear actions from the results. GlycanAge sits in a different category: it measures the active inflammatory biology that is happening in your body right now, not a historical snapshot or a fluctuating daily reading.

What is chronic inflammation, and why does it matter for biological aging?

Chronic inflammation is the persistent, low-grade activation of the immune system that accumulates silently over time and increases the risk of chronic disease and death. Unlike acute inflammation (the body's short-term defense against injury or infection), chronic inflammation involves the constant production of inflammatory molecules that gradually create conditions suited to disease development. As we age, levels of chronic inflammation increase, which over time leads to disease development; this is why older people are more susceptible to diseases and frailty.

Chronic inflammation is one of the 12 official hallmarks of aging, and inflammaging (the term for this age-related inflammatory drift) is estimated to be a leading contributor to a majority of deaths worldwide. Measuring it accurately is therefore not a peripheral concern in longevity medicine; it is central to understanding how fast someone is biologically aging.

Why is chronic inflammation so hard to measure?

Chronic and acute inflammation are fundamentally different processes, and most existing biomarkers are designed to capture acute inflammation, making chronic inflammation notoriously difficult to measure. Standard blood markers like CRP, glucose, and cholesterol fluctuate within minutes or hours depending on recent meals, stress, or illness. They reflect your body's state at a single moment, not the sustained inflammatory burden that accumulates over months and years. This is precisely why addressing elevated chronic inflammation is important before it reaches the point of no return, but the tools most people have access to are not built for that purpose.

How does GlycanAge measure chronic inflammation differently?

GlycanAge measures chronic inflammation by analysing glycans — complex sugars attached to Immunoglobulin G (IgG), the most abundant antibody in human blood. Certain glycan structures stimulate inflammatory pathways, making them pro-inflammatory, while others suppress those pathways, making them anti-inflammatory.

"Studying proteins without glycans is like studying birds without their feathers. You can understand their anatomy, but you cannot fully understand their function."

— Prof. Gordan Lauc, Chief Scientific Officer, GlycanAge; Professor of Biochemistry and Molecular Biology, University of Zagreb

As a person ages, the frequency of pro-inflammatory glycans increases, producing a predictable pattern that enabled the development of the first biological age biomarker based solely on glycans — the glycan clock. The overall profile of IgG glycans in a person, called the IgG glycome, reflects the levels of chronic inflammation inside their body. GlycanAge calculates biological age by combining the glycans most correlated with aging into a score and comparing it to a large baseline population of healthy individuals.

Why don't epigenetic clocks capture inflammation?

Epigenetic clocks measure changes at CpG sites on DNA (areas associated with aging), but the biological process driving those changes is not always identifiable, which makes it difficult to derive clear actions from the results. Methylation and telomere-based tests, on the other hand, change within years or even decades, which means they may reflect how quickly or slowly you are aging in a broad sense, but they will not be responsive or actionable when you introduce lifestyle changes. Chronic inflammation is not what epigenetic clocks are designed to measure, and the distinction matters: knowing your methylation age does not tell you whether your immune system is inflamed or whether an intervention is reducing that inflammation.

How quickly does GlycanAge respond to lifestyle or medical interventions?

GlycanAge responds on different timelines depending on the type of intervention. Pharmaceutical and hormonal interventions, such as HRT, typically produce measurable change within three to four months. Lifestyle interventions,such as diet, exercise, sleep, and stress management, generally take six to twelve months of sustained change to show up in your results. If you introduce a change and don't maintain it, it will not meaningfully shift your GlycanAge result. But sustained over the relevant window, a positive change becomes visible. This is what makes GlycanAge actionable in a way that epigenetic tests, which change over years or decades, are not.

Chronic inflammation is a dynamic marker of immune health, responsive to both lifestyle and medical interventions, and tracking it over time shows whether implemented changes are having the desired effect.

Professor Tim Spector, epidemiologist at King's College London and scientific co-founder of ZOE, has tracked his own GlycanAge for nearly a decade:

"I came out about 16 years younger than my real age, so I loved GlycanAge — I think it's marvelous. I've been tracking it for nearly ten years now, and it's been pretty constant over that time. For long-term tracking of health, it's really great."

— Prof. Tim Spector, Department of Twin Research and Genetic Epidemiology, King's College London

What can tracking biological age through GlycanAge tell you over time?

Tracking biological age through GlycanAge over time provides valuable insights into long-term health by helping to assess the effectiveness of interventions, identify early warning signs of future health decline, and personalise care plans. Because chronic inflammation sits at the intersection of genetics, natural aging, and lifestyle, GlycanAge reflects the cumulative impact of daily choices, such as diet, exercise, sleep, stress, and medical interventions, on immune function. This is what distinguishes it from a static DNA test or a single blood panel: it is a longitudinal signal that changes when your biology changes, and stays stable when it does not.

"We have other tests for immune system function — lymphocyte subset panels, senescent T-cell accumulation — and those are helpful, but they're not as linear across the age range as GlycanAge. Having this as another tool to look at whether I'm improving immune system function and reducing inflammation is really great. In terms of other biomarkers, this one is fantastic."

— Dr. Joseph Raffaele, MD, Founder, Raffaele Medical

For clinicians, this makes GlycanAge a practical tool for baselining patients, monitoring intervention effectiveness, and detecting biological change before symptoms emerge.

If you are ready to measure your own chronic inflammation and find out whether your lifestyle and health interventions are working at a biological level, order a GlycanAge test kit, shipped to 65+ countries, with a 1:1 Result Interpretation Call included.

Order your GlycanAge test → Shop now

Healthcare providers looking to integrate GlycanAge into clinical workflows can learn more on our Healthcare Providers page.

External sources

• https://pubmed.ncbi.nlm.nih.gov/36599349/ — López-Otín C, Blasco MA, Partridge L, Serrano M, Kroemer G. Hallmarks of aging: An expanding universe. Cell. 2023;186(2):243–278.

• https://pubmed.ncbi.nlm.nih.gov/24325898/ —Krištić J, Vučković F, Menni C, Klarić L, Keser T, Beceheli I, et al. Glycans are a novel biomarker of chronological and biological ages. J Gerontol A Biol Sci Med Sci. 2014;69(7):779–789.

• https://pubmed.ncbi.nlm.nih.gov/24833586/ — Franceschi C, Campisi J. Chronic inflammation (inflammaging) and its potential contribution to age-associated diseases. J Gerontol A Biol Sci Med Sci. 2014;69(Suppl 1):S4–S9.