Photo: WLADIMIR BULGAR/SCIENCE PHOTO LI
To get the best health benefits from a keto diet take a "vacation", US scientist Professor David Gius says.
Gius conducted a trial involving mice on the keto diet which revealed significantly higher senescent cells, or ageing cells, in their organs compared with those on a standard diet.
These findings suggest the keto diet might accelerate organ ageing, which would raise the risk of conditions like heart disease, cancer and type 2 diabetes.
However, switching mice back to a standard diet decreased senescent cells.
The key is to take a "keto vacation," Gius said.
Gius is a prominent figure in cancer research, and the genetics of ageing, and is currently associate cancer director of translational research, and assistant dean for research at the University of South Texas.
"I think what the study really shows is, like any kind of medical intervention or nutrient intervention, the question is not whether it works or not," he told Sunday Morning.
"The question is, who it works in, who it doesn't work in and who it might potentially not benefit. And I think that's the real story of our trial on ketogenic diet and ageing cells in mice."
Taking regular breaks from the Keto Diet may be the key
If you take a ketogenic break, senescent, or ageing, cells go away, he said.
"A cycling ketogenic diet, and there seem to be a lot of definitions of that, but I think a common one is four or five days on a ketogenic diet, and two or three days off, doesn't see the accumulation of the cells.
"So, I think the important finding in our study is not just that we find these senescence cells, these cells that have an ageing phenotype, I think the real discovery is that you shouldn't be on a ketogenic diet indefinitely."
When you first embark on a ketogenic diet, you go into ketosis, and ketone bodies get excreted from the liver into the serum, he said.
"That's responsible very likely for the positive health related effects like diabetes, anti-ageing effects, in some neurodegenerative diseases that people have published on.
"Those are due to the ketone bodies. But what happens, and this has been shown in several other studies, is after a week or two, the fat, the lipids, become so high, that the beneficial effects of the ketone bodies are overwhelmed by the detrimental effects of the high lipid concentrations in your blood."
The results seen in mice may apply to humans, he said, with certain caveats, as the person's physiological state will be a factor.
"A bodybuilder who's on a ketogenic diet to decrease his fat levels, as long as he's losing weight, and not over consuming lipids, a long-term ketogenic diet probably wouldn't suffer from the accumulation of these senescent cells.
"If you're losing weight, or exercising very heavily, while you're on a ketogenic diet these lipids, what I would call toxic lipids most likely won't accumulate."
Getting to a sweet spot if you are on a keto diet is the key, he says.
"There's this interplay between ketone bodies, which are probably very helpful, and the idea that the lipids become so high in your blood, that it causes a pro-inflammatory state. So, it's this kind of Yin Yang."