Fasting is as old as humanity itself. While our ancestors were naturally forced to endure long periods without food due to scarcity, in today's society, fasting is usually motivated by cultural, spiritual, or medical reasons. But is fasting also worthwhile from a longevity perspective?
Let's first look at the different types of fasting. In Western culture, there is Lent, in the Orient, Ramadan, Islam abstains from pork, as does the Torah in Judaism, and among Hindus, it depends on the deity one worships whether one abstains from citrus fruits, certain roots, or meat. Moses fasted before receiving the stone tablets, Muhammad received the Quran while fasting in a cave, and Buddha almost fasted himself to death before attaining enlightenment. In all religions, fasting is practiced to purify body and mind.
Medical fasting is usually about gut health. The most popular forms of fasting are therapeutic fasting according to FX Mayr or Buchinger, both of which aim to cleanse and detoxify the intestines. Then there are also fasting-mimicking diets, water fasts, and various juice cleanses. The goal is always a significant calorie reduction over several days. Anyone who has undergone such a regimen reports invigorating effects that can be observed after a few days of abstinence. One feels more energetic than in a long time, and unusual bowel movements suggest that detoxification is taking place.
In contrast to these fasting methods that last for days, there is also fasting for just a few hours, known as intermittent fasting. The originator of intermittent fasting is Buddha. And he was by no means fat, as all those cute Buddha figures would have you believe, but rather slim. Siddhartha Gautama, also called Buddha, which means "The Awakened One," was an ascetic. His teachings, the Dharma, with over 20,000 pages, regulate Buddhist monastic life in detail and is quite a comprehensive work compared to the Bible, which has 1,000 pages. However, it contains no instructions about non-conforming foods or fasting periods, but solely the instruction to eat only from sunrise until noon and nothing more after that. This is strictly forbidden for the monks. Siddhartha, if the records are to be believed, lived to be 80 years old. In 500 BC, that was a biblical age. So the originator of intermittent fasting lived to a very old age. Is that enough to prove that intermittent fasting is a longevity method? Certainly not.
First, it's important to note that there are at least as many types of intermittent fasting as there are of traditional fasting. There's day-by-day intermittent fasting, for example, on two consecutive days each week. Or there's alternate-day fasting, where you alternate between fasting and eating normally on different days. And there's hour-by-hour intermittent fasting, such as "One Meal a Day," "Dinner Cancelling," or the 16:8 method. Intermittent fasting isn't about temporarily reducing calories, but rather about a time-limited zero-calorie diet in which eating is prohibited and drinking low-calorie beverages is permitted. Intermittent fasting generally offers the possibility of making fasting a part of everyday life. Only then does it become a potential longevity strategy.
But let's take a closer look at the effects of intermittent fasting. Consulting the science quickly reveals that there is a general consensus that intermittent fasting is healthy and possibly even life-extending, but a large-scale study providing irrefutable proof is lacking. However, there is plenty of evidence, all of which suggests that intermittent fasting has a positive effect at the cellular level.
The latest wave of intermittent fasting was initiated in the USA by a 2018 study from the Massachusetts Institute of Technology (MIT). With age, the ability of humans to regenerate stem cells in the gut steadily declines. In animal experiments with fasting mice, MIT scientists demonstrated a significant improvement in stem cell regeneration at the cellular level. They described this as a "dramatically improved" effect, also with regard to fighting cancer cells and other infections in the gut.
The Max Planck Institute for Biology of Ageing in Cologne took an even closer look. They discovered that fasting stimulates an enzyme that could be a key to longevity. The molecular biologists used fish that typically live for only six months and divided them into two groups. One group fasted, while the other was fed a normal diet. The fish that fasted intermittently lived a third longer than those in the well-fed control group. In their genetic analyses, the scientists found that fasting stimulates the AMPK enzyme. AMPK stands for AMP-activated protein kinase. During fasting, the AMPK gene detects an energy deficit and activates survival mode. In this phase of external deprivation, the cell searches for "internal nourishment" and begins to consume parts of itself. This process is also known as autophagy. Autophagy is a self-cleaning mechanism of cells and is apparently further stimulated by fasting. Harmful or unusable proteins and cell organelles are increasingly removed from the cells and broken down into amino acids, which are then available to the body again.
Current scientific findings support the assumption that intermittent fasting can extend lifespan and positively influence our health in many aspects. This longevity method also seems to be about leaving one's comfort zone and then reaping the resulting benefits. Once intermittent fasting is integrated into one's life, it is a relatively simple method for extending one's healthspan in old age.
The 16:8 formula—fasting for sixteen hours a day and consuming two meals within the remaining eight hours—appears to produce the desired effect. It doesn't matter whether, as with Buddha, one eats in the first or second half of the day. For the sociable, less ascetic person, it's advisable to eat in the second half of the day and skip breakfast. After all, breakfast also means breaking the fast, and dinner is the more significant meal in our society. People come together to review the day over a shared meal and to take their time enjoying it.
Start your day unburdened, enjoy the feeling of hunger until lunchtime, and take pleasure in the thought of doing something positive for your health and longevity every day.
