Obesity leaves lasting memory in immune cells, study finds

September 1, 2026 at 05:00 AM2 min

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A 10-year study published in EMBO Reports found that obesity leaves a lasting molecular imprint on immune cells. Researchers led by Professor Claudio Mauro at the University of Birmingham identified persistent DNA methylation changes in helper T cells that may remain for 5-10 years after weight loss. The findings suggest that weight loss alone may not immediately reverse obesity-related immune dysfunction.

Key Facts

The study was published in EMBO Reports and involved a 10-year investigation.
DNA methylation changes in helper T cells may persist for 5-10 years after successful weight loss.
The research was led by Professor Claudio Mauro at the University of Birmingham and supported by the NIHR Biomedical Research Centre: Birmingham.
The study analyzed immune cells from four groups, including patients receiving weight loss injections and those with Alstrom Syndrome.
Professor Mauro stated that ongoing weight management may be needed for several years to fully reverse the effects on T cells.

Study Design

Researchers analyzed immune cells from four distinct human cohorts. The cohorts included patients with obesity receiving weight loss injections, patients with Alstrom Syndrome, participants in a 10-week exercise intervention, and osteoarthritis patients undergoing joint replacement surgery. The team also examined cells from mice fed a high-fat diet and blood donations from healthy human volunteers. These additional models helped investigate cellular mechanisms contributing to immune dysregulation in obesity.

Molecular Memory

The researchers focused on DNA methylation, a process where chemical tags attach to DNA inside immune cells. Their findings suggest these changes may persist for 5-10 years following successful weight loss. This lingering memory in helper T cells could interfere with normal immune functions, including removal of cellular waste and regulation of immune aging. According to the researchers, these lasting changes may help explain why people who lose weight can remain at increased risk for obesity-related diseases.

Clinical Implications

Professor Claudio Mauro from the Department of Inflammation and Ageing at the University of Birmingham is co-lead author of the study. He said that short-term weight loss may not immediately reduce the risk of some disease conditions associated with obesity, including type 2 diabetes and some cancers. Instead, ongoing weight management following loss will see the obesity memory slowly fade. This may take several years of sustained weight loss maintenance, likely 5-10 years, though this requires further study.