Monthly cycles of a fasting-mimicking diet (FMD) may slow metabolic and immune system aging and reduce the risk for metabolic disease, a US study has found.

 

In two clinical trials conducted at the Leonard Davis School of Gerontology, University of Southern California, Los Angeles and the Yale School of Medicine, Conneticut, monthly five-day cycles of an FMD (a proprietary line of plant-based, low-calorie and low-protein food products) showed lower body weight, body fat and blood pressure at three months.

 

Researchers assessed secondary outcomes for the impact of the diet on risk factors for metabolic syndrome and biomarkers associated with aging and age-related diseases.

 

This study looked at data from nearly half of the original 184 participants (aged 18-70 years) from the two clinical trials who went through three to four monthly cycles, adhering to five days of an FMD in either a crossover design compared with a normal diet or an intervention group compared to people following a Mediterranean diet.

 

Abdominal fat and hepatic fat were measured using an MRI in a subset of representative participants. The study also assessed metabolic blood markers and lipids and lymphoid-to-myeloid ratios (for immune aging).

 

Biological age estimation was calculated from seven clinical chemistry measures, and life expectancy and mortality risk estimates and a simulation of continued FMD cycles were based on the National Health and Nutrition Examination Survey.

 

In 15 volunteers measured by MRI, the BMI (p = .0002), total body fat (p = .002), subcutaneous adipose tissue (p = .008), visceral adipose tissue (p = .002), and hepatic fat fraction (p = .049) reduced after the third FMD cycle, with a 50% reduction in liver fat for the five people with hepatic steatosis.

 

In 11 participants with prediabetes, insulin resistance (measured by homeostatic model assessment) reduced from 1.473 to 1.209 (p = .046), while A1c levels dropped from 5.8 to 5.43 (p = .032) after the third FMD cycle.

 

The lymphoid-to-myeloid ratio improved (p = .005) in all study participants receiving three FMD cycles, indicating an immune aging reversal.

 

The estimated median biological age of the 86 participants who completed three FMD cycles in both trials decreased by nearly 2.5 years, independent of weight loss.

 

The study was published in Nature Communications.