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Immune & Inflammation

Lymphocyte Percentage

Lymphocyte percentage is the share of white blood cells that are lymphocytes — the T-cells, B-cells, and natural killer cells that drive adaptive immunity. It is reported alongside absolute lymphocyte count on a standard full blood count. In the Levine PhenoAge composite, a declining lymphocyte percentage is one of the strongest signals of immunosenescence — the age-related erosion of immune function.

Optimal Ranges

Clinical (NHS) Range

20-45 %

%

Performance-Optimised Range

30-45 %

%

The clinical range defines what is considered medically “normal” — broad enough to cover 95% of the population. The performance range reflects where research and clinical experience suggest most people feel and function at their best.

Why It Matters

Why Lymphocyte % matters for performance

Lymphocyte percentage falls naturally with age as the thymus involutes and naive T-cell production slows. A higher-than-typical-for-age percentage suggests a younger immune profile, better vaccine response, and lower infection risk. Persistently low lymphocyte percentage (often paired with high neutrophil percentage) is a marker of chronic stress, chronic inflammation, or undiagnosed infection. A neutrophil-to-lymphocyte ratio above 3 is a recognised inflammation signal independent of CRP.

Symptoms

Signs your levels may be off

Low / Deficiency

  • Frequent or prolonged infections
  • Slower recovery from common viruses
  • Poor wound healing
  • Persistent fatigue

High / Excess

  • Usually reactive to viral infection or stress
  • Can flag chronic infection or rare immune conditions if sustained

Dietary Sources

Foods that support Lymphocyte % levels

Lymphocytes are produced internally — diet supports their functionZinc (oysters, beef, pumpkin seeds) for thymus functionVitamin D (oily fish, fortified foods, sunlight)Selenium (Brazil nuts, eggs, sardines)Polyphenol-rich foods (berries, green tea, olive oil)

Supplementation

Evidence-based supplementation

Address the upstream drivers: chronic sleep debt, sustained psychological stress, and gut inflammation all suppress lymphocyte function. Zinc (15-30 mg with copper), vitamin D (to a 25-OH level above 100 nmol/L), and adequate protein intake support normal lymphocyte production. Direct supplementation is not appropriate.

Research

Key study

An epigenetic biomarker of aging for lifespan and healthspan

Levine ME, Lu AT, Quach A, et al.

Aging (Albany NY) (2018)

DOI: 10.18632/aging.101414

Related Biomarkers

Inflammation

hs-CRP (High-Sensitivity C-Reactive Protein)

Optimal: Below 1.0 mg/L

Vitamins & Minerals

Vitamin D (25-OH)

Optimal: 100-150 nmol/L

Inflammation

Ferritin (Iron Stores)

Optimal: 80-150 ng/mL

Related Guides

Explore Lymphocyte % in depth

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UK guide to understanding results

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Always Tired? The Blood Tests That Reveal Why

8 biomarkers behind fatigue

Test your Lymphocyte % levels

Lymphocyte % is included in the Helvy 50+ biomarker panel. Get your results in 5 days with a personalised protocol.

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This content is for educational purposes only and does not constitute medical advice. Your data suggests areas for optimisation, but any concerns should be discussed with a qualified healthcare professional. If your results flag values outside safe ranges, we recommend consulting your GP.