Immune Ageing May Move in Waves, Not a Straight Line

New research analysing 3.8 million immune cells suggests that immune ageing involves periods of accelerated change around the 40s and again after 60. For men over 35, the findings offer a new perspective on healthy ageing—but they are not a personal forecast or a reason to order an unvalidated immune-age test.

KEY BENEFITS

Understand why immune ageing may not follow a steady, linear decline.

Learn what researchers observed around ages 40 and 60.

Discover how immune-cell changes differed between men and women.

Separate population-level research from personal health predictions.

Identify practical priorities for healthy ageing without chasing unproven tests.

𝗧𝗛𝗘 𝗡𝗘𝗪 𝗣𝗜𝗖𝗧𝗨𝗥𝗘 𝗢𝗙 𝗜𝗠𝗠𝗨𝗡𝗘 𝗔𝗚𝗘𝗜𝗡𝗚

Ageing is often described as a gradual process. But the immune system may change in a less predictable way.

A study published in Nature Communications and highlighted by Duke-NUS Medical School on October 1, 2026, analysed approximately 3.8 million immune cells from 1,828 healthy people aged 19–97.

The researchers found prominent waves of gene-activity changes around age 40 and again after 60. These results suggest that some aspects of immune ageing may accelerate during particular periods rather than decline at a constant rate.

𝗪𝗛𝗔𝗧 𝗛𝗔𝗣𝗣𝗘𝗡𝗦 𝗔𝗥𝗢𝗨𝗡𝗗 𝟰𝟬 𝗔𝗡𝗗 𝟲𝟬?

The researchers found that different types of T cells were prominent during the two periods.

Around age 40: Changes were especially notable in CD4 T cells, which help coordinate immune responses.

After age 60: CD8 T cells were major contributors to another wave of gene-activity changes. These cells help identify and destroy infected or abnormal cells.

The study also identified age-related changes in the cellular systems responsible for maintaining RNA and protein balance—processes essential for normal cell function.

These are population-level patterns, not fixed biological deadlines. They do not mean every man experiences a sudden immune decline at 40 or 60.

𝗪𝗛𝗬 𝗦𝗘𝗫 𝗠𝗔𝗬 𝗠𝗔𝗧𝗧𝗘𝗥

The study identified different immune-ageing patterns in men and women.

Women showed sustained patterns of CD8 T-cell activation and additional late-life changes involving CD4 T cells, natural killer cells and B cells. Men showed different, earlier fluctuations in CD4 T-cell metabolism.

These differences may help researchers understand why some immune-related and autoimmune conditions affect men and women differently. However, the study does not establish a simple formula for predicting an individual's future health or disease risk.

𝗪𝗛𝗔𝗧 𝗜𝗧 𝗠𝗘𝗔𝗡𝗦 𝗔𝗙𝗧𝗘𝗥 𝟯𝟱

For men entering midlife, the key message is that chronological age does not tell the whole story of biological ageing.

The research provides a detailed map of changes in immune-cell gene activity. It does not show that a particular supplement, diet or treatment can reverse these patterns, prevent infections or extend lifespan.

The researchers also developed sex-specific biological-age prediction models. These are research tools, not automatically validated clinical tests for consumers.

Practical MEN35 guidance:

Keep recommended vaccinations up to date according to your age, health and local guidance.

Maintain regular physical activity and a balanced diet.

Prioritise adequate sleep and avoid smoking.

Discuss persistent or recurrent infections with a healthcare professional.

Do not buy an “immune-age” test simply because this study identified age-related patterns.

𝗠𝗘𝗡𝟯𝟱 𝗧𝗔𝗞𝗘𝗔𝗪𝗔𝗬

Immune ageing may happen in waves, with notable changes around the 40s and again after 60. The findings reveal important differences in how immune cells change across the lifespan—and between men and women. They do not tell you exactly how fast your own immune system is ageing.

𝗕𝗢𝗧𝗧𝗢𝗠 𝗟𝗜𝗡𝗘

Understand the science, but don't mistake a population trend for your personal forecast. For men over 35, established preventive care and sustainable health habits remain more useful than chasing an unvalidated biological-age score.