01/21/2023
Can fasting help you live longer?
What does the scientific evidence say?
More than a century of research has shown that calorie restriction (20 to 40 %) extends the lives of animals, including worms, flies, mice, rats, and monkeys, as long as they get the nutrients they need. No other antiaging intervention comes close. These studies also demonstrate that extremely low-calorie diets significantly reduce the incidence of age-related diseases, especially cancer.
In 2022, scientists at the University of Texas Southwestern Medical Center reported the results of an elaborate four-year experiment tracking hundreds of mice over their whole lives. Calorie restriction alone increased the lifespan of the animals by 10 percent. Coupled with limiting chow time to two hours at night, and peak activity time for mice, the diet extended their lifespan by 35 percent. That would translate into about 25 years, on average, for humans.
A 2019 study followed 2,001 heart patients and found those who routinely fasted were much more likely to be alive four years after a common procedure, cardiac catheterization, compared with patients who never fasted, did it briefly or stopped many years earlier.
A review of clinical trials of intermittent fasting concluded that there is enough evidence of the health benefits of fasting. Of course, what we eat matters, too.
A study published in 2022 estimated that a 20-year-old who cuts out hamburgers, hot dogs, white bread, and other staples of the Western diet, and makes a habit of eating beans, lentils, whole grains, nuts, fruits, and vegetables could increase their life expectancy by up to 13 years. And as with exercise, it’s never too late to start and reap the benefits.
A 60-year-old could gain more than eight years, and an 80-year-old could add more than three years, the study concluded.
There doesn’t seem to be a downside to following a 12- to 16-hour food-free interval nightly. In 2022, Panda and his colleagues published a study of 137 San Diego firefighters, half of whom agreed to eat only within a 10-hour daily window for 12 weeks. Overall, the fasting group showed improvements in cholesterol, mental health, alcohol-use reduction, blood pressure, and blood sugar.
In my practice, I prescribe a fasting-mimicking diet (FMD). It works by activating blood stem cells, which strengthen the body’s ability to produce infection-fighting white blood cells. The regimen also promotes a cellular cleansing process called autophagy: Cells devour their own damaged parts, which are replaced by functional components. Clinical trials have found that FMD switches the body from a sugar-burning mode to a fat-burning mode by reprogramming metabolism, which the modern Western diet has thrown out of whack.
No antiaging intervention has had stronger, more consistent effects than calorie restriction. In one study, researchers slashed the daily calorie intake of rhesus monkeys by 30 percent for their entire adult lives, without skimping on nutrients. Those animals not only lived longer than monkeys fed standard fare, but they also were less likely to develop diabetes, heart disease, cancer, and brain shrinkage that often comes with old age.
Ask me about a fast-mimicking diet (FMD), which includes both intermittent fasting and calorie restriction. FMD is the simplest and most effective anti-aging therapy, based on solid scientific evidence. Have a great weekend!
Dr. O.
Reference:
Caprara, Greta. ‘Diet and Longevity: The Effects of Traditional Eating Habits on Human Lifespan Extension’. 1 Jan. 2018: 261 – 294.
Acosta-Rodríguez V, Rijo-Ferreira F, Izumo M, Xu P, Wight-Carter M, Green CB, Takahashi JS. Circadian alignment of early onset caloric restriction promotes longevity in male C57BL/6J mice. Science. 2022 Jun 10;376(6598):1192-1202. DOI: 10.1126/science.abk0297. Epub 2022 May 5. PMID: 35511946; PMCID: PMC9262309.
Abstract 11123: Intermittent Fasting Lifestyle and Human Longevity in Cardiac Catheterization Populations. Benjamin D Horne, Ciera Bartholomew, Jeffrey L Anderson, Heidi T May, Kirk U Knowlton, Tami L Bair, Viet T LE, Bruce W Bailey and Joseph B Muhlestein 11 Nov 2019. Circulation. 2019;140:A11123
Effects of Intermittent Fasting on Health, Aging, and Disease. Rafael de Cabo, Ph.D., Mark P. Mattson, Ph.D. December 26, 2019 N Engl J Med 2019; 381:2541-2551 DOI: 10.1056/NEJMra1905136
Estimating impact of food choices on life expectancy: A modeling study. Lars T. Fadnes, Jan-Magnus Økland Øystein A. Haaland, Kjell Arne Johansson. February 8, 2022. https://doi.org/10.1371/journal.pmed.1003889
Pifferi, F., Terrien, J., Marchal, J. et al. Caloric restriction increases lifespan but affects brain integrity in grey mouse lemur primates. Commun Biol 1, 30 (2018). https://doi.org/10.1038/s42003-018-0024-8