A new study by researchers at the University of Southern California shows that a diet which mimics fasting can reverse biological age, on an average by two and half years, with adherents of the diet showing reduced signs of immune system aging, as well as insulin resistance and liver fat.
The study adds to increasing evidence supporting the beneficial effects of the fasting-mimicking diet (FMD). The FMD is a five-day-a-month diet high in unsaturated fats and low in overall calories, protein, and carbohydrates. The diet is designed to mimic the effects of a water-only fast — drinking only water for 48 to 72 hours — while still providing necessary nutrients and making it much easier for people to complete the fast.
Fasting or restricting calories appears to induce ‘autophagy’, which is the body’s process of clearing out old, damaged cells to make space for new ones. Autophagy is initiated when cells are stressed or deprived of nutrients, or when cells naturally decrease in activity with age, In other words, autophagy plays a significant role in slowing aging,
The new study is the first one to show that a food-based intervention, which does not require extensive dietary or other lifestyle changes, can make people biologically younger, based on both changes in risk factors for aging as well as diseases. While chronological age refers to how many years someone has lived, biological age is a measure of how well cells and tissues in the body are functioning.
Biological age is usually assessed by the damage suffered by various cells due to the impact of genetic, nutritional, lifestyle and comorbidity factors. For their study, the researchers analyzed the FMD’s effects in two clinical trial populations, each with men and women between the ages of 18 and 70. The FMD consisted of plant-based soups, energy bars, energy drinks, chip snacks, and tea portioned out for five days, as well as a supplement providing high levels of minerals, vitamins, and essential fatty acids.
Patients who were randomized to the fasting-mimicking diet underwent 3-4 monthly cycles, adhering to the FMD for five days, then ate a normal diet for 25 days. Patients in the control groups were instructed to eat either a normal or Mediterranean-style diet. An analysis of blood samples from trial participants showed that patients in the FMD group had lower diabetes risk factors, including less insulin resistance and lower average blood sugar, as measured by HbA1c, the common test used to diagnose for prediabetes and diabetes.
Magnetic resonance imaging also revealed a decrease in abdominal fat as well as fat within the liver, improvements associated with a reduced risk of metabolic syndrome. In addition, the FMD appeared to increase the lymphoid-to-myeloid ratio — an indicator of a more youthful immune system. Statistical analysis of the results from both clinical studies showed that FMD participants had reduced their biological age by 2.5 years on average.
The study lends support to the FMD’s potential as a short-term periodic, achievable dietary intervention to help people lessen their disease risk and improve their health without extensive lifestyle changes. The findings could 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
