Many people notice an belly fat Increases in abdominal fat as they reach middle age, and now science may finally have an explanation. A groundbreaking study published in Science by researchers at City of Hope and UCLA identifies a biological trigger responsible for age-related belly fat accumulation. The findings shed light on why maintaining weight becomes more difficult with age and open new doors for tackling obesity and metabolic diseases in older adults.
Dr. Qiong (Annabel) Wang, an associate professor at City of Hope’s Arthur Riggs Diabetes & Metabolism Research Institute, explained that as people age, the body activates a hidden mechanism that enhances fat production, particularly around the waistline. Even if overall weight remains stable, individuals often experience a shift in body composition—losing muscle and gaining fat, especially in the abdominal region. The team’s research zeroed in on white adipose tissue (WAT), the type of fat that typically expands with age.
Stem Cells Switch On Belly Fat Increases Production in Middle Age
The study found that aging doesn’t just cause existing fat cells to grow—it actually prompts the body to manufacture new fat cells. Researchers suspected this was due to changes in adipocyte progenitor cells (APCs), which are the precursors to fat cells. To explore this, they transplanted APCs from both young and middle-aged mice into young mice.
What they observed was striking: APCs taken from older mice rapidly generated new fat cells, even when placed in a young body. In contrast, APCs from younger mice produced very few new fat cells, regardless of environment. This showed that aging itself, not external factors, flips a biological switch in APCs, enabling them to aggressively create fat cells—especially in the abdominal area.
Dr. Wang emphasized that this internal transformation plays a crucial role in why fat becomes harder to lose with age. “It’s not just your metabolism slowing down,” she noted. “Your body is activating a new fat-building program that wasn’t active before.”
Discovery of a Dormant Stem Cell with Big Implications
Using advanced tools like single-cell RNA sequencing, the research team mapped the behavior of these APCs at a molecular level. They found that in young mice, these progenitor cells were mostly dormant. However, during middle age, they became significantly more active, leading to the creation of a distinct population of Belly Fat Increases cells that concentrated around the midsection.
This discovery marks the identification of a previously unknown adult stem cell type that appears to emerge in middle age with a strong drive to produce fat. The implications are significant—not only for understanding why belly fat is so persistent in later years, but also for developing targeted therapies to prevent or reverse this age-triggered fat buildup.
With further research, scientists hope to find ways to deactivate or block this fat-producing switch, potentially offering new strategies to combat middle-age weight gain and reduce the risk of diabetes and cardiovascular disease.
