Obesity may leave a long-lasting biological imprint on the immune system, potentially keeping some health risks elevated for years after weight loss. A 10-year study published in EMBO Reports suggests that people who have lived with obesity can retain a molecular "memory" of that state in important immune cells.
The European research team, led by Professor Claudio Mauro at the University of Birmingham and supported by the National Institute for Health and Care Research (NIHR) Biomedical Research Centre: Birmingham, found that helper T cells (or CD4+ lymphocytes) can retain signs of past obesity long after body weight has been reduced.
Obesity May Leave Long-Lasting DNA Marks
The researchers focused on a process called DNA methylation, in which chemical tags or markers attach to DNA inside immune cells. Their findings suggest that these changes may persist for 5-10 years following successful weight loss.
This lingering "memory" of obesity in helper T cells could interfere with normal immune functions. Among the processes that may be affected are the removal of cellular waste and the 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 even after returning to a normal weight.
