The high-fat, low-carb ketogenic diet often sparks debate, but new research in mice indicates it may offer health benefits in specific situations, particularly when paired with exercise.
Researchers from various US institutions discovered that mice with elevated blood sugar (hyperglycemia) experienced normalized blood sugar levels after being placed on a strict ketogenic diet.
Moreover, when these mice engaged in exercise following eight weeks on the diet, their physical activity appeared to enhance the diet’s effects. The mice’s aerobic capacity, or VO2peak—an indicator of how effectively oxygen is utilized during exercise—increased, and their muscles became more resistant to fatigue and richer in oxygen.
“After one week on the ketogenic diet, their blood sugar was completely normal, as though they didn’t have diabetes at all,” says physiologist Sarah Lessard from Virginia Tech Carilion.
“Over time, the diet caused remodeling of the mice’s muscles, making them more oxidative and making them react better to aerobic exercise.”
frameborder=”0″ allow=”accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share” referrerpolicy=”strict-origin-when-cross-origin” allowfullscreen>These findings build on previous research, which led to this new study. Some of the same researchers had previously discovered that hyperglycemia disrupted muscle adaptations in exercising mice and diminished their aerobic capacity improvements.
This prompted researchers to investigate whether the keto diet, which has been associated with better blood sugar management, could help recover the lost exercise response in these animals.
The results suggest that the diet could indeed reverse both high blood sugar and exercise inefficiencies, but with some limitations: these effects have only been observed in mice, and the exercise benefits were not seen in animals with normal blood sugar levels.
One limitation is that the mice with restored VO2peak did not show improvements in actual exercise performance, likely due to a lack of carbohydrates. When carbohydrates were reintroduced into their diet, performance levels increased.
The researchers also examined the blood vessel and muscle signaling changes induced by ketosis, suggesting that this metabolic state actively influences the body rather than passively.
“What we’re really finding from this study and from our other studies is that diet and exercise aren’t simply working in isolation,” says Lessard.
“There are a lot of combined effects, and so we can get the most benefits from exercise if we eat a healthy diet at the same time.”
Previous studies have shown that maintaining a high aerobic capacity can reduce the risk of further complications for people with diabetes, and these findings suggest another potential strategy for mitigating those risks.
For those with high blood sugar, the study implies that varied dietary and exercise strategies might be necessary to sustain health and aerobic performance, which future research could explore.
Human trials are already planned to obtain more applicable data. While animal studies are informative, they do not always provide a complete picture. Notably, the keto diet administered to the mice was an extremely stringent version.
Related: Keto Diet May Slow Down Alzheimer’s, Mouse Study Reveals
It is crucial to recognize that this is not a one-size-fits-all solution. The researchers emphasize that the keto diet is notoriously challenging to adhere to, and alternatives like the Mediterranean diet may be preferable for those aiming to reduce blood sugar levels.
“Our previous studies have shown that any strategy you and your doctor have arrived at to reduce your blood sugar could work,” says Lessard.
The research has been published in Nature Communications.
