In recent years, several promising studies came out, suggesting that a fasting diet can have remarkable benefits, down to the cellular level. But studies on humans were always scarce and challenging to conduct.

USC Professor Valter Longo is one of the pioneers of this study and now, Longo has come in with a potentially groundbreaking study on humans. Along with his colleagues, Longo showed that a fasting-mimicking diet (FMD) lowers risk factors for disease and reduces biological age in humans.

“I showed 30 years ago that fasting could triple the lifespan of unicellular organisms, then in the past 10 years we showed that FMD cycles could extend the lifespan, cognitive performance and function of mice while cutting cancer in nearly half, in part by activating stem cells and reprogramming damaged cells so that they become younger or more functional. So, the human studies were the obvious next step,” the researcher told ZME Science.

“Now this publication representing 2 different clinical trials done in Los Angeles and Tennessee on 184 participants is beginning to provide conclusive evidence for the safety and efficacy of FMD cycles against aging and disease risk factors.”

This is essentially the first study to show that a food-based intervention without chronic dietary or other lifestyle changes can make people biologically younger.

Mimicking fasting

Fasting diets have been shown to provide a number of benefits, ranging from stem cell regeneration to improving dementia and reducing biological age. But most of those studies were done using animal models. Now, it’s been tested in humans.

It starts with what researchers call the FMD — the fasting mimicking diet. Longo explained in an email that this FMD is a fairly complex plant-based composition of low protein, low sugar, high fat foods. It comprises plant-based soups, energy bars, energy drinks, chip snacks and tea. These are taken alongside a supplement providing high levels of minerals, vitamins, and essential fatty acids.

The idea behind the diet is to match the effects of true fasting on several blood markers by using ingredients that are both healthy and nutritious.

Half of the study participants were assigned this diet 5 days a month — the other 25 days they would eat normally. The other half of the participants were told to eat either a normal or Mediterranean-style diet.

The results showed that for people on the FMD their biological age (a measure of how well one’s cells and tissues are functioning, as opposed to chronological age) reduced by 2.5 years on average. Participants on FMD also had lower insulin resistance and reduced blood sugar levels. They also showed improvements in their lymphoid-to-myeloid ratio — an indicator of a more youthful immune system. Remarkably, participants only underwent 3-4 months on this diet to see these notable results.

Should we all try a fasting-mimicking diet?

Speaking to Longo, it seems like the answer should probably be “yes”. It’s not that expensive. It’s a bit tricky (but not very) to manage in the beginning, and you only need to do it from time to time. In fact, Longo suggests that a government subsidy for something like this won’t even be that bad.

“Since it needs to be done only 2-3 times a year and the cost of 2 cycles is about 300 euros, I think the great majority of people can afford it until it is hopefully reimbursed by governments, also keeping in mind that someone doing 2 cycles of FMD per year would not have to buy any food or drinks during the 10 days of the FMD (2 x 5 days).”

The researcher says there’s something else going for this diet: people seemed to adhere to it pretty well during the research.

How do you suggest individuals prepare for and adapt to the FMD, particularly if they are accustomed to a standard Western diet? What strategies can help improve adherence to the diet during the 5-day cycles?

“In the clinical trials we usually see 80-90% compliance even after many FMD cycles. So, I think most people can do it, but it may help to do it when someone feels it is the right time to do it, maybe during 5 days that are not very mentally and physically demanding.”

In fact, this type of diet already has its proponents. Doctors in the US and Europe have been prescribing this type of diet in some instances and protocols for it are already being developed.

“Although many doctors are already recommending the FMD in the United States and Europe, these findings should encourage many more healthcare professionals to recommend FMD cycles to patients with higher than desired levels of disease risk factors as well as to the general population that may be interested in increased function and younger age,” Longo said.

In fact, Longo sees the diet becoming an important tool in our arsenal for prevention and treatment. First, for diabetes, pre-diabetes, and obesity — where it is already being used with success — then, for the prevention of many diseases.

After all, if you can have a diet that does all that, why not use it?

The study was published in Nature Communications.