A study has found evidence that brain changes associated with aging can be seen at a much younger age than would be expected, in the late 40s. However, this process may be prevented or reversed based on dietary changes that involve minimizing the consumption of simple carbohydrates.

It’s suggested that, as people get older, their brains start to lose the ability to metabolize glucose efficiently, causing neurons to slowly starve, and brain networks to destabilize.

The evidence came from two large-scale brain neuroimaging datasets involving nearly 1,000 individuals (age 18-88). This data revealed that functional communication between brain regions destabilizes with age, typically in the late 40's, and that destabilization correlates with poorer cognition and accelerates with Type 2 diabetes.

The researchers then selected an additional 42 adults under the age of 50, to test whether giving the brain a more efficient fuel source, in the form of ketones, either by following a low-carb diet or drinking ketone supplements, could provide the brain with greater energy. It was found that even in younger individuals, this added energy further stabilized brain networks.

Brain network stability was tested after participants had spent one week on a standard (unrestricted) vs. low carb diet (e.g., meat or fish with salad, but no sugar, grains, rice, starchy vegetables).

To pinpoint whether glucose vs. ketones was the crucial difference, another group was scanned before and after drinking a small dose of glucose on one day, and ketones on the other. The same result was found, confirming that the crucial difference between the diets was the type of fuel they provide to the brain.

A mouse study also found that a ketogenic diet significantly improved memory in aging mice.

Different groups of mice were given carefully designed diets that were matched in every way except fat and carbohydrate content: a normal high-carbohydrate diet, a zero-carbohydrate ketogenic diet, and a high-fat, low-carbohydrate diet that was not ketogenic. Mice were fed the ketogenic diet intermittently to prevent them from becoming obese, starting at one year old - middle age for mice.

Mice that had been eating a ketogenic diet performed at least as well on memory tests at old age as they did at middle age, while mice eating the normal diet showed an expected age-associated decline. Mice who ate the ketogenic diet also explored more, and their improved memory was confirmed with another test a few months later.

All the mice ate a normal diet during the actual memory testing, suggesting the effects of the ketogenic diet were lasting.

People shouldn’t get carried away with these findings. Ketogenic diets are used clinically for life-threatening conditions, and many experts say such a diet is dangerous. People should consult a health care professional before trying it on their own. A better way of getting the effects may be through exercise, which also creates ketone bodies.