Can fasting reduce disease risk and slow aging in people

A nutritious diet that mimics the biological effects of fasting was associated with reduced disease risk factors and slowed biological aging in healthy adults, according to an NIA-funded study. The findings, published in Nature Communications, suggest this diet may hold promise as a dietary intervention for promoting metabolic health, reducing disease risk, and extending healthy lifespan.

Past research suggests that calorie restriction without malnutrition may promote healthy aging and increase longevity. However, as calorie restriction is difficult to maintain and may not be a practical or safe long-term dietary pattern, scientists are exploring alternatives. A team of researchers, led by scientists at the University of Southern California and Yale School of Medicine, studied the effects of a short-term, fasting-like diet to determine potential health benefits.

To understand how this special diet affects health markers related to aging and diseases, the researchers analyzed blood samples from participants in two clinical trials. These trials both were studying the effects of a plant-based, low-calorie, low-protein diet that mimics the effects of fasting while still providing nutrients. The fast-mimicking diet studied is one that's adhered to periodically, followed by a typical eating pattern. Each monthly five-day cycle of fast-mimicking involves eating a special diet high in unsaturated fats (such as those found in nuts, seeds, and olive oil) and low in overall calories, protein, and carbohydrates.

The first trial involved 100 participants who were randomly assigned to either follow their regular eating patterns (48 participants) or the fast-mimicking diet (52 participants). After three months, 43 participants in the regular diet group were moved to the other group. A second independent trial included 44 participants instructed to follow the fast-mimicking diet for four months, and 40 who followed the Mediterranean diet. In both trials, the fast-mimicking diet was associated with reduced risk of diabetes, decreased fat in the liver, and an enhanced immune system. Additionally, study participants following the fast-mimicking diet appeared biologically younger than they did at the beginning of the study. Other research has shown that reductions in biological age are associated with an increase in predicted life expectancy and a decrease in the risk of dying from age-related diseases such as heart disease, cancer, and diabetes.

Importantly, the improvements in health markers and biological age persisted after accounting for weight loss caused by the diet.

Overall, the findings suggest that a diet that mimics fasting without associated nutritional deficits has potential benefits for improving health and longevity by slowing down the aging process and reducing the risk of age-related diseases. However, more research is needed to fully understand the long-term effects and ensure these findings are consistent across different populations.

This research was supported in part by NIA grants 4R00AG052604-02, 1R01AG060110-01, and P30AG021342.

Reference: Brandhorst S, et al. Fasting-mimicking diet causes hepatic and blood markers changes indicating reduced biological age and disease risk. Nature Communications. 2024;15(1):1309. doi:10.1038/s41467-024-45260-9.