A higher level of the fat that gathers around organs has been linked to faster brain aging in a new study, with glucose and insulin the likely mediators.
The study, led by a team from Ben-Gurion University of the Negev (BGU) in Israel, suggests that reducing visceral fat can protect against brain atrophy.
Like other parts of the body, the brain doesn’t necessarily age at a consistent rate: wear and tear can increase or decrease, depending on numerous factors. Faster brain aging typically means a faster decline in mental performance, and a higher risk of brain diseases.
Crucially, this new research shows that brain aging can be indirectly influenced by visceral fat in particular. Meanwhile, the subcutaneous fat that gathers around most of the body – and is the biggest influence on how much we weigh – was not found to be related to brain health.
“Our findings demonstrate that long-term exposure to higher visceral adiposity is associated with both accelerated brain atrophy and lower cognitive performance, while sustained visceral fat reduction, achieved through lifestyle interventions, predicts preserved brain structure and cognition in late mid-life,” write the researchers in their published paper.
The study data is based on MRI scans taken of 533 adults (mostly men), who were followed for a variety of periods from 5 to 16 years, after going through one of four different dietary clinical trials.
As well as the visceral fat and brain volume data obtained from the scans, the researchers also used cognitive assessment tests to measure the mental ability of the study participants over time, and took blood samples to measure a variety of biomarkers.
Across the follow-up periods, a lower level of visceral fat was associated with better cognitive test scores, higher brain volume and gray matter volume, and better results on the Hippocampal Occupancy Score – a metric specifically designed to assess brain atrophy.
The researchers also found that more visceral fat was linked to a faster expansion of brain ventricles, a marker of brain aging. Subcutaneous fat, meanwhile, showed none of these relationships.
So, why might this association exist? The blood tests revealed that elevated blood sugar levels were linked to brain atrophy over time, suggesting that an imbalance in blood sugars played a role in the damage being done. Visceral fat has previously been linked to insulin resistance and dementia.
There is some good news: the participants who lost the most visceral fat in the original dietary trials had the best-preserved brain volumes in later life. Add in the blood sugar link, and it seems good old diet and exercise could help your head as much as your belly.
“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,” says epidemiologist Iris Shai from BGU.
While the study doesn’t prove that reducing visceral fat can slow brain aging, it makes a strong case. Another point to note is that the study participants were mostly male, and mostly overweight – so more work will need to be done to see how generally this applies.
Given everything we already know about brain aging and visceral fat, however, it’s another reason to think about eating well and staying active. The researchers also want to see a greater awareness of how targeting visceral fat in particular, rather than simply measuring weight loss, can lead to health benefits.
Related: Hidden Patterns of Body Fat Could Be Shrinking Your Brain, Study Finds
“Weight alone is not a sensitive marker of the profound metabolic changes occurring in the body,” says epidemiologist Dafna Pachter from BGU.
“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 has been published in Nature Communications.
