“The results surprised me a little,” said nutritionist Jon Ramsey, senior author of the paper that appears in the September issue of Cell Metabolism. “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. In humans, that would be seven to 10 years. But equally important, those mice retained quality of health in later life.”

One of the high fat diets that has gained grounds in recent times is the Ketogenic diets with many claiming it has helped them not only lose weight  but also helped boost their fertility.

However scientists are finding out what happens during Ketosis, when carbohydrate intake is so low that the body shifts from using glucose as the main fuel source to fat burning and producing ketones for energy.

The study split the test mice into three groups: a regular rodent high-carb diet, a low carb/high fat diet, and a ketogenic diet (89-90 percent of total calorie intake). Originally concerned that the high fat diet would increase weight and decrease life span, the researchers kept the calorie count of each diet the same.

At the end of the study, it was discovered that the high fat diet significantly increased the median life span of mice in the study.

The ketogenic diet also increased memory and motor function (strength and coordination) of the mice as well as prevented an increase in age-related markers of inflammation. It had an impact on the incidence of tumors as well.

“In this case, many of the things we’re looking at aren’t much different from humans,” Ramsey said. “At a fundamental level, humans follow similar changes and experience a decrease in overall function of organs during aging. This study indicates that a ketogenic diet can have a major impact on life and health span without major weight loss or restriction of intake. It also opens a new avenue for possible dietary interventions that have an impact on aging.”