Glycans

What are glycans and why do they matter for aging?

Glycans are complex carbohydrate molecules made of sugar units linked in branching chains. They attach to proteins and lipids throughout your body, forming a molecular code that regulates how cells communicate, how proteins function, and how your immune system responds to threats. This attachment process—called glycosylation—is the most common chemical modification of proteins in human cells, with over half of all secreted and cell surface proteins carrying glycan structures ^[1].

The specific patterns of these sugar molecules change as you age. Unlike genetic mutations, which are fixed, glycan patterns are dynamic and responsive to your environment, lifestyle, and health status. This makes them exceptionally valuable as biomarkers—they reflect not just how old you are, but how old your biology actually acts.

How IgG glycans predict biological age

In 2014, researchers analyzing over 5,000 individuals from four European populations discovered something remarkable: specific glycan structures attached to immunoglobulin G (IgG) antibodies could predict chronological age with surprising accuracy. Just three glycan structures—FA2B, FA2G2, and FA2BG2—explained up to 58% of the variance in age, outperforming traditional biomarkers like telomere length ^[1].

But these glycans track more than just calendar years. The remaining variance in glycan patterns correlates strongly with physiological parameters of biological age, including markers of inflammation, cardiovascular health, and metabolic function. As you age, your IgG glycome—the complete set of glycans on your antibodies—shifts progressively toward pro-inflammatory structures. This shift reflects what immunologists call "inflammaging," the chronic low-grade inflammation that underlies most age-related diseases ^[2].

Glycans as modifiable aging markers

Perhaps the most important finding in glycobiology research is that glycan patterns are not destiny. Unlike DNA sequence, glycosylation changes in response to your behaviors. Studies have shown that intensive lifestyle interventions—combining exercise, improved nutrition, stress reduction, and better sleep—can reverse age-related glycan shifts, effectively making your immune system appear younger at the molecular level ^[3].

This reversibility makes glycans unique among aging biomarkers. Telomeres shorten with age and are difficult to lengthen. Epigenetic clocks change slowly. But glycan patterns can shift measurably within months of lifestyle modification, providing real-time feedback on whether your interventions are working.

The GlycanAge test and clinical applications

The commercial GlycanAge test analyzes 24 specific glycan structures from a blood sample to calculate your biological age. The test has been validated in over 350 scientific publications and is used by research institutions including Harvard, Cambridge, and Johns Hopkins ^[4].

From a clinical perspective, glycan testing offers several advantages. First, it detects inflammation years before symptoms appear. Second, it provides a single integrated measure of immune health that reflects the combined effects of diet, exercise, stress, sleep, and environmental exposures. Third, it offers objective feedback on whether your health interventions are producing measurable biological changes.