Subcutaneous grease protects the female brain

What is the mechanism that triggers inflammation in the brain, which can lead to dementia or strokes? 

A team of researchers who have been studying the impact of obesity on the brain for several years show that abdominal fat promotes brain inflammation in male mice, while subcutaneous fat transplantation reduces their brain inflammation.

The differential distribution of fat between men and women would offer a considerable advantage to the latter. According to a study published in the journal Diabetes, their propensity to deposit more fat in places such as the hips, buttocks and back of the arms, called subcutaneous fat, protects them against inflammation of the brain until menopause. On the contrary, men generally have a much higher risk of inflammation-related problems (from heart attack to stroke) because of the abdominal distribution of their fatty tissue.

To test the hypothesis that localizing fat in women would protect them from inflammation, male and female mice on a high-fat diet underwent subcutaneous fat surgery (liposuction-like), aimed at eliminating it. ” When we took subcutaneous fat out of the equation, all of a sudden women’s brains started showing inflammation the same way men’s brains did, and women gained more visceral fat. “, explains Alexis M. Stranahan, doctor of neuroscience and co-author of the study.

Brain protection until menopause

” In comparison, it was only after menopause that women who had not had subcutaneous fat removed, but who had been on a high-fat diet, experienced levels of brain inflammation similar to those of men “, she continues. However, removing subcutaneous fat at an early age in mice on a low-fat diet did not induce signs of inflammation in the brain. It therefore appears that a high-fat diet and liposuction are risk factors for brain inflammation.