Quick summary: Long term monitoring of abdominal visceral fat reveals that maintaining low levels is associated with slower brain atrophy and improved cognitive performance in late midlife regardless of overall weight loss. These findings indicate that glucose control and insulin sensitivity serve as the primary pathways for preserving hippocampal volume and grey matter, suggesting that metabolic health is a more critical marker for brain ageing than body mass index. Public policy and healthcare practice should prioritize targeted reductions in visceral fat through lifestyle interventions to support long term mental well being and move towards more effective strategies for preventing cognitive decline.
A major long-term study using repeated MRI scans has found that maintaining low levels of abdominal visceral fat over many years is associated with slower brain atrophy, better preservation of key brain structures, and improved cognitive performance in late midlife. The benefits appear largely independent of overall weight loss and are mainly linked to improved glucose control and insulin sensitivity.
Published in Nature Communications, the study is the first to examine cumulative exposure to visceral fat, measured repeatedly over time, in relation to long-term brain ageing and cognitive outcomes.
Study design and participants
Researchers followed 533 men and women in late midlife who had participated in 4 large dietary trials: DIRECT, CASCADE, CENTRAL, and DIRECT-PLUS. The trials were led by Professor Iris Shai of Ben-Gurion University of the Negev, Dean of the School of Sustainability at Reichman University, and an adjunct professor at Harvard University.
Participants underwent repeated MRI scans of the brain and abdomen, along with cognitive testing using the Montreal Cognitive Assessment (MoCA), over follow-up periods ranging from 5–16 years.
Key findings on visceral fat and brain health
Lower accumulation of visceral fat over time was associated with higher MoCA scores and better preservation of total brain volume, grey matter volume, and the hippocampal occupancy score, a marker linked to brain ageing and memory function.
Researchers also observed slower enlargement of the brain ventricles, which is a recognised sign of brain atrophy.
In a subgroup with 3 brain MRI scans over 5 years, persistently higher visceral fat levels were linked to faster loss of brain volume, especially in the hippocampus, and faster ventricular enlargement.
These associations were specific to visceral fat. They were not observed with subcutaneous fat, whether superficial or deep, nor with body mass index.
Reductions in visceral fat achieved during an initial 18-month dietary intervention predicted better preservation of brain structure 5 and 10 years later, even after adjusting for overall weight loss and other factors. The findings suggest that reductions in abdominal fat itself, rather than weight loss alone, are most strongly associated with long-term brain benefits.
Glucose control as the main pathway
The study found that the link between visceral fat and brain ageing was primarily driven by glycaemic control. Fasting glucose and HbA1c levels were the strongest predictors of structural brain changes over time, while blood lipid levels and inflammatory markers showed no similar association.
The results support the idea that insulin resistance and chronic glucose dysregulation may reduce cerebral blood flow, weaken the blood-brain barrier, and accelerate degeneration in grey matter and the hippocampus.
Professor Iris Shai said: “The findings point to glucose control and reduction of visceral abdominal fat as measurable, modifiable, and achievable targets in midlife, with real potential to slow brain degeneration and reduce the risk of cognitive decline.”
Dr Dafna Pachter, the study’s first author, said: “Weight alone is not a sensitive marker of the profound metabolic changes occurring in the body. We found that even when weight loss is modest, sustained reductions in visceral fat – as measured across the entire period – are associated with preservation of brain structure and a slower rate of atrophy.”
The research, conducted at Ben-Gurion University of the Negev in collaboration with Harvard University, Leipzig University, and Tulane University, was funded by the German Research Foundation and the ERA-4-Health initiative.
It is the largest and longest-running study to date linking repeated measures of visceral fat with brain structure and cognitive outcomes. The authors conclude that targeting visceral fat through diet and lifestyle in midlife may offer a specific and modifiable strategy for supporting long-term brain health, with glucose regulation playing a central role.