This 5-Day Diet That Mimics Fasting Slows Down Aging

LOS ANGELES — Forget the fountain of youth, new research out of California suggests the fast of youth may be upon us. Scientists at the University of Southern California say short cycles of a diet that mimics fasting, or the fasting-mimicking diet (FMD), appears capable of reducing signs of immune system aging, in addition to insulin resistance and liver fat in humans, ultimately resulting in a lower biological age.

All in all, researchers from the USC Leonard Davis School of Gerontology say their work contributes mightily to the growing pile of evidence in support of the benefits of the fasting-mimicking diet.

So what exactly is the FMD? Study authors explain it is a five-day eating plan high in unsaturated fats and low in overall calories, protein, and carbohydrates. The FMD mimics the same effects of a water-only fast while still providing people with the nutrients they need, thus making it much easier to complete the routine. The diet was put together originally by the laboratory of USC Leonard Davis School Professor Valter Longo, the senior author of the new study.

“This is the first study to show that a food-based intervention that does not require chronic dietary or other lifestyle changes can make people biologically younger, based on both changes in risk factors for aging and disease and on a validated method developed by the Levine group to assess biological age,” Prof. Longo says in a media release.

FMD Advantages

Prior studies conducted by Prof. Longo already indicate that brief, periodic cycles spent engaging in the FMD show an association with numerous health benefits. Examples include:

• The promotion of stem cell regeneration
• Lessening chemotherapy side effects
• Reducing signs of dementia in mice

Moreover, FMD cycles can lower risk factors connected to cancer, diabetes, heart disease and other age-related diseases in humans.

The Longo lab has also shown that one or two cycles of the fasting-mimicking diet for five days per month can increase the healthspan and lifespan of mice adhering to either a normal or Western diet. That being said, the influence of the FMD on aging and biological age, liver fat, and immune system aging in humans had remained unknown up until now.

Methodology

Researchers analyzed the diet’s impact across two clinical trial populations. Both groups featured men and women ages 18 through 70. Patients randomly assigned to the fasting-mimicking diet underwent 3-4 monthly cycles, adhering to the FMD for five days, then went on eat a normal diet for 25 days.

The FMD mostly features plant-based soups, energy bars, energy drinks, chip snacks, and tea rationed out across five days. The group was also given a supplement that provides high levels of minerals, vitamins, and essential fatty acids. Those placed in a control group ate either a normal or Mediterranean-style diet.

When the research team performed an analysis on blood samples taken from trial participants, it showed that those in the FMD group had lower diabetes risk factors, such as less insulin resistance and lower HbA1c results. Magnetic resonance imaging, meanwhile, showed a drop off in abdominal fat as well as fat within the liver. Those improvements signify a reduced risk of metabolic syndrome. Researchers add the FMD cycles also appeared to boost the lymphoid-to-myeloid ratio – considered an indicator of a youthful immune system.

Results also indicate that FMD participants had reduced their biological age (in other words, how well one’s cells and tissues are functioning, as opposed to chronological age) by an average of 2.5 years. “This study shows for the first time evidence for biological age reduction from two different clinical trials, accompanied by evidence of rejuvenation of metabolic and immune function,” Prof. Longo adds.

In conclusion, study authors say their work lends more support to the fasting-mimicking diet’s potential as a short-term periodic, easier dietary intervention capable of helping people lower their disease risk and improve their health while avoiding dramatic, extensive lifestyle changes.

“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,” Prof. Longo concludes.

The study is published in Nature Communications.