Ketogenic diet improves mental and physical fitness - at least in mice

A lot of fat, hardly carbohydrates: The so-called ketogenic diet actually appears to work positively on the body and brain as two studies with mice suggest now. If the animals received high-fat low-carb diet, they did not only live longer, but also remained strong and mentally fitter, as the researchers report. Why the ketogenic diet has these effects is, however, only partially clarified.

Healthier through much fat and hardly carbohydrates? The ketogenic diet actually seems to have positive effects. © Top photo / thinkstock

Today nutrition seems almost to be a matter of faith: one swears by Low-Carb, others on Fasting, Mediterranean Diet or Stone Age Diet. Which of these dietary methods is healthier or better at losing weight, however, there is disagreement. Studies show that the method is less important than the calorie quantity, at least for weight loss.

However, the results are contradictory in terms of health effects. For example, some studies suggest that a healthy Mediterranean diet could help particularly against the mental breakdown. A fat-rich diet, on the other hand, should interfere with the energy supply of the brain and hinder muscle function.

What happens in the ketogenic diet?

Now, however, two studies with mice suggest that greasy food might be better than its reputation - at least when you relinquish carbohydrates. In this so-called ketogenic diet 80 to 90 percent of the calories are from fat. This causes the body to change the metabolism in the same way as fasting: it now burns fat for energy production instead of sugar and carbohydrates.

The liver produces so-called ketone bodies, chemical compounds, which can be decomposed in the organs and brain by certain enzymes into the energy carrier Acetyl-CoA. The ketones appear to have initial positive effects on health by, among other things, they have an anti-inflammatory effect. But what exact effect ketogenic diet has on the body is so far hardly known.

Mice on a Keto diet

At this point the new studies began. In them, two research teams have investigated how a ketogenic diet affects the longevity, strength and mental fitness of mice. Three groups of mice with the same caloric intake received either a diet of 80 to 90 percent of fats, normal diet, more carbohydrate food, or a moderate low-carb diet.

After a few months, the team around Megan Roberts from the University of California in Davis tested the strength and skill of the animals in running wheels, balancing and holding on a rope. They also tested heart function, gene activity and blood levels. The team around John Newman from the University of California in San Francisco focused on tests of memory and mental fitness. The lifetime of the mice was also determined.

Fitter in body and spirit

The result: The ketogenic diet showed clearly positive effects in both studies. The fat-fed mice cut significantly better in the cognitive tests than their otherwise fed cohorts.

The older mice with the ketogenic diet even had better memory than normal-fed younger mice, says Eric's colleague Eric Verdin. This effect is really exciting.

The effects on the physical fitness and longevity of the mice were similar: the keto-fed animals had more strength and endurance than their peers and lived longer.

We expected a few differences, but the scale surprised me, says Jon Ramsey from the Roberts team. Mice lived an average of 13 percent longer - transferred to humans this corresponds to seven to ten years.

Transferable to humans?

But as positive as these results are - they can only be transferred to humans in a limited way. One problem: The ketogenic diet is extremely unbalanced. In order for it to work, you have to avoid virtually any carbohydrate - which for most people in everyday life would hardly be feasible.

In addition, care must be taken that not too many calories come together with the many fat - and that there is no lack of vital nutrients and vitamins. The scientists therefore emphasize that it is not advisable to begin this drastic dietary change without consultation with a doctor and accompanying investigations.

Another problem is that not all effects and side effects of this extreme diet have long been sufficiently investigated.

If we were to have a better idea of ​​the mechanisms involved in the ketogenic diet, we could open up a way to achieve the same effects with less restrictive agents, says Ramsey.

However, further studies are necessary.

Source: Cell Metabolism, 2017; doi: 10.1016 / j.cmet.2017.08.004; doi: 10.1016 / j.cmet.2017.08.005