When it comes to brain health, leaner may not be better.
In a new study published in the journal GeroScience, researchers from Toho University in Japan found that visceral fat, the deep fat that wraps around your internal organs, plays a critical role in maintaining brain health.
But it’s a fine line: Having some belly fat has brain benefits, but too much can be dangerous to your health for other reasons and even increase your risk of death.
The team focused on the relationship between visceral fat and BDNF (brain-derived neurotrophic factor), a protein vital for memory, learning and mood regulation.
BDNF encourages the growth, survival and connection of brain cells.
Low BDNF levels have been linked to conditions like depression and dementia, while high BDNF levels are directly related to higher brain function. As we age, BDNF levels decline, leading to memory loss and compromised cognitive functioning.
The study found that CX3CL1, a protein produced by visceral fat, actively contributes to maintaining healthy BDNF levels.
Researchers tracked male mice of different ages, roughly equivalent to young adults, middle-aged, and elderly humans.
In younger mice, their belly fat produced large quantities of the visceral fat protein, keeping their cognition top-notch. Quality production continued in the middle-aged contingent but dropped by roughly a third in the elderly population.
This decline mirrors the steep cognitive changes humans experience later in life.
To test the relationship between the fat protein and BDNF, scientists artificially lowered the protein in young mice and found the decrease mimicked the effects of aging. In contrast, when they gave the older mice an extra dose of the protein, their BDNF levels were restored.
While belly fat seems to be beneficial for brains, the key is not to have too much, which can contribute to other problems like heart issues.
Previous research has established that carrying extra fat around your midsection increases your risk for heart disease, high blood pressure, diabetes and sleep apnea.
Other research has linked excess abdominal fat to an increased risk of cancers of the womb, gallbladder, kidney, liver and breast.
A 2020 review of 72 studies found that people with an apple-shaped body — meaning a wider midsection and less defined waist — had a significantly higher risk of death from all causes than those with pear-shaped bodies.
While the negative consequences of excess visceral fat are well established, this latest research suggests that healthy visceral fat levels are critical to the production of enzymes, proteins, and molecules that support brain health.
And though the brain inevitably changes and shrinks with age, experts agree that prioritizing a nutrient-rich diet, regular physical activity, social connections, stress management, adequate sleep, and cognitive engagement can help protect and promote brain health.
