Like calorie restriction, the practice of intermittent fasting has been shown to improve measures of health in humans and extend healthy life spans in mice. One research group has in recent years been working on taking a specific implementation of intermittent fasting and running it through the expensive hurdles needed for FDA approval, for instance as an adjuvant therapy for cancer patients. Needless to say, this involves commercialization of a medical diet and industry participation, as otherwise where else will the funding come from for all this work? Arguably despite the long history of calorie restriction research there has been little effort to push approaches like this through the regulatory gauntlet because it requires some ingenuity to link "just eat less" with "some entity can charge lots of money for this." Here is an update on some of that work:
In a new study, researchers show that cycles of a four-day low-calorie diet that mimics fasting (FMD) cut visceral belly fat and elevated the number of progenitor and stem cells in several organs of old mice - including the brain, where it boosted neural regeneration and improved learning and memory. The mouse tests were part of a three-tiered study on periodic fasting's effects - testing yeast, mice and humans. Mice, which have relatively short life spans, provided details about fasting's lifelong effects. Yeast, which are simpler organisms, allowed researchers to uncover the biological mechanisms that fasting triggers at a cellular level. And a pilot study in humans found evidence that the mouse and yeast studies were, indeed, applicable to humans.
Bimonthly cycles that lasted four days of an FMD which started at middle age extended life span, reduced the incidence of cancer, boosted the immune system, reduced inflammatory diseases, slowed bone mineral density loss and improved the cognitive abilities of older mice tracked in the study. The total monthly calorie intake was the same for the FMD and control diet groups, indicating that the effects were not the result of an overall dietary restriction. In a pilot human trial, three cycles of a similar diet given to 19 subjects once a month for five days decreased risk factors and biomarkers for aging, diabetes, cardiovascular disease and cancer with no major adverse side effects.
The diet slashed the individual's caloric intake down to 34 to 54 percent of normal, with a specific composition of proteins, carbohydrates, fats and micronutrients. It decreased amounts of the hormone IGF-I, which is required during development to grow, but it is a promoter of aging and has been linked to cancer susceptibility. It also increased the amount of the hormone IGFBP, and reduced biomarkers/risk factors linked to diabetes and cardiovascular disease, including glucose, trunk fat and C-reactive protein without negatively affecting muscle and bone mass.