Losing deep belly fat, rather than simply shedding overall body weight, is linked to slower brain ageing and better cognitive function years down the line. The research, published in Nature Communications, suggests that targeting this specific type of fat might help protect the brain from age-related decline. Lead authors Dafna Pachter and Hadar Klein, alongside corresponding author Iris Shai and colleagues from Ben-Gurion University of the Negev in Israel, led the study, which utilised long-running trial data to probe whether sustained reductions in particular fat depots can preserve brain health.
Visceral fat sits deep around internal organs, while subcutaneous fat lies just beneath the skin and is more visible. Visceral fat is highly metabolically active and frequently releases inflammatory molecules that can travel through the body and reach the brain. While previous research linked high visceral fat to cognitive decline, it remained unclear whether actively losing this fat could confer lasting neurological benefits.
The researchers began with 533 adults who had taken part in four dietary and lifestyle trials five to sixteen years earlier. These participants, mostly male and in their early sixties, underwent magnetic resonance imaging to measure brain volume and abdominal fat, and completed the Montreal Cognitive Assessment, a standard test for detecting cognitive impairment.
They found that individuals with lower visceral fat levels scored consistently higher on cognitive tests. This relationship was driven by brain volume, with the negative association between visceral fat and cognitive scores most evident in people who already had relatively preserved brain structures. Body mass index did not show the same relationships with cognitive performance or brain structure, indicating that BMI alone may not capture the neurodegenerative risks posed by deep abdominal fat.
A subset of 295 participants had complete abdominal fat data across three time points—at the start of the original trial, at eighteen months, and at a final follow-up several years later. The researchers calculated each person’s cumulative exposure to abdominal fat over the years and found that long-term exposure to high visceral fat predicted lower cognitive test scores. In contrast, cumulative exposure to subcutaneous fat did not show this negative relationship, underscoring the distinct metabolic risks of visceral fat compared with fat stored under the skin.
The team then assessed whether the initial fat lost during the eighteen-month trials could predict later brain health. For 297 participants, they compared fat changes during the intervention with brain scans taken five to ten years later. A greater reduction in visceral fat during the trial forecasted higher total brain volume at the long-term follow-up and a larger grey matter volume. Reductions in visceral fat were also linked to a healthier hippocampus, a region central to learning and memory. By contrast, reductions in superficial and deep subcutaneous fat during the intervention did not relate to later brain structure, and changes in BMI during the intervention did not predict long-term brain volume either.
In a further analysis, 188 participants underwent repeated brain scans at baseline, eighteen months and five years. The researchers found that higher cumulative visceral fat exposure was associated with a faster rate of brain atrophy across multiple regions and with quicker ventricles expansion, the fluid-filled spaces that widen as surrounding tissue shrinks.
To explore potential biological pathways, the team examined a range of blood markers. They found that only baseline fasting blood sugar and a marker of long-term glycemic control related to the observed long-term brain changes; lipid and inflammatory markers did not. This points to the possibility that visceral fat’s impact on brain health operates through disruptions to blood sugar regulation and insulin sensitivity, with improvements in glycemic control potentially easing stress on brain tissue when visceral fat declines.
The authors cautioned that the study population was eighty-six per cent male and predominantly overweight or obese, which may limit applicability to women or those with lower body weight. While fat loss occurred during the randomised trials, the long-term follow-up was observational. Post-trial lifestyle choices were not strictly controlled, so the study cannot definitively prove causation for the long-term data. Additionally, the researchers did not measure fat accumulation in organs such as the liver and pancreas, which could also influence brain health.
Future research incorporating measurements of organ fat and specific biomarkers for neurodegenerative diseases will help clarify the biological pathways linking abdominal fat to brain ageing. The study identifies visceral fat as a distinct, modifiable risk factor for neurodegeneration and highlights the potential cognitive benefits of reducing this fat depot beyond general weight loss.
The study, “Sustained visceral fat loss is associated with attenuated brain atrophy and improved cognitive function in late midlife,” was authored by Dafna Pachter, Hadar Klein, Omer Kamer, Dana Tamar Goldberg Toren, Liav Alufer, Noa Ebstein Karamani, Tomer Atlas, Amit Yaary, Idan Hagbi, Yoash Chassidim, Ilan Shelef, Moti Salti, Frauke Beyer, Veronica Witte, Assaf Rudich, Uri Yoel, Gal Ben-Arie, Anat Yaskolka Meir, Alon Kaplan, Gal Tsaban, Hila Zelicha, Carmi Bartal, Lu Qi, Matthias Blüher, Michael Stumvoll, Uta Ceglarek, Berend Isermann, Dong D. Wang, Meir J. Stampfer, Frank B. Hu, Galia Avidan, and Iris Shai.
