One study on the high-fat, low-carb diets was led by scientists from the Buck Institute for Research on Aging in Novato. The other came from UC Davis. Both appeared Tuesday in the journal Cell Metabolism.
The UC Davis study found that aged mice fed a ketogenic diet better preserved their motor function, memory, and muscle mass. The diet was calorie-limited to prevent obesity. Go to j.mp/ketoucd for the study.
The Buck Institute study found that a cyclic ketogenic diet, alternated weekly with a non-ketogenic control diet, worked best in promoting longevity, health and memory, while avoiding obesity. Go to j.mp/buckketo for the study.
“The results surprised me a little,” said Jon Ramsey, one of the UC Davis study authors, in a statement.
“We expected some differences, but I was impressed by the magnitude we observed — a 13 percent increase in median life span for the mice on a high-fat vs high-carb diet,” Ramsey said. “In humans, that would be seven to 10 years. But equally important, those mice retained quality of health in later life.”
The studies also confirmed earlier mouse research that found the diets produce genetic changes resembling those in fasting.
Ketogenic diets were originally developed nearly a century ago to manage epilepsy. These diets resemble the Atkins diet, but are stricter in limiting carbohydrates.
In recent years, ketogenic diets have found favor with people trying to lose weight and improve health. They challenge the widespread belief that eating fat makes one fat and produces heart disease. Instead, most of the harm is attributed to carbohydrate consumption.
Ketogenic diets are very controversial in the medical community. Those thinking of starting on such a diet are advised to talk it over first with a medical professional.
A number of organizations such as the American Heart Association say saturated fats are consumed to excess in Western diets.
However, a considerable body of research challenges this view. In particular, studies have found that:
Ketogenic diets stimulate production of ketone bodies, fatty acids which the body can use as fuel instead of carbohydrates. There’s evidence that some of these ketone bodies are beneficial in disease.
A ketogenic diet in mice was found to reverse diabetic kidney disease, according to a study published in 2011 in the journal PLoS One. The protective effect may have been caused by the ketone 3-beta-hydroxybutyric acid (3-OHB), the study said. The ketone is known to reduce response to glucose.
Some ketogenic dieters aim to increase the beneficial effects of ketones by consuming substances that the liver directly converts into ketones. These include butter and coconut oil, along with medium-chain triglycerides.
For further reading