A low-fat diet may protect the aging brain against inflammation-related activation of microglia, according to a new study of, naturally, mice. It’s always mice.
Microglia are key cells in overall brain maintenance—they are constantly scavenging the CNS for plaques, damaged or unnecessary neurons and synapses, and infectious agents. As we age, some regions of the brain become inflamed because of microglia activity. But what is not clear is how this process responds to diet and lifestyle.
A study was led by the University Medical Center Groningen (UMCG) (in the Netherlands) and published in the journal Frontiers in Molecular Neuroscience — discovered that exercise was far less effective than restricting calorie intake at preventing the inflammatory activation of microglia brought on by aging. Prof. Eggen and his colleagues examined the effect of high-fat and low-fat diets on markers of inflammation and microglia activity in the hypothalami of mice aged 6 months. At this age, mice are adult but not elderly.
They also investigated the impact of high-fat and low-fat diets on the microglia of two groups of elderly 2-year-old mice. One group had been raised on a lifelong regime of exercise (they could voluntarily use an exercise wheel), while the other had been raised on a lifelong regime of 40 percent calorie restriction but with no exercise.
The findings revealed that only a low-fat diet combined with calorie restriction prevented microglia-driven inflammation brought on by aging.
“A low-fat diet per se was not sufficient to prevent these changes,” Prof. Eggen observes.
The study authors point out that there are still many questions to be answered before we can understand what these findings mean. Take, for example, the fact that the mice were only fed one type of diet for their whole lives. This means that the findings cannot address questions about changes in diet. Could a low-fat diet with calorie restriction undo any potential damage that might be inflicted by a high-fat, unrestricted diet? If so, how early in life should the switch take place for the consequences to be significant?
So, there is more research to be done before we all go out and start buying up a lot of kale and carrots and starving ourselves. There is more research to be done. But healthy eating — low fat and reasonable portions — is a good idea any time in your life.