Fasting for short periods as a way of cleansing and detoxifying your mind and body has a history going back millennia. Fasting exists in all cultures and religions, from western Christian mystics to eastern sages, as a way of achieving peace and physical and spiritual enlightenment.
While for most of our history the science behind fasting was barely understood, today we know that engaging in frequent, short fasts helps our bodies perform at optimal levels. Fasting has all kinds of benefits, from encouraging our bodies to switch fuel sources and work more efficiently, to cleaning out waste material, recycling amino acids, and even reducing the risk and spread of cancer cells.
THE SCIENCE OF INTERMITTENT FASTING EXPLAINED
Intermittent fasting isn’t about starving yourself, or even losing weight. Instead you limit the number of hours in a day during which you can eat in order to give your body enough time between meals to exhaust its supply of easy energy sources such as carbohydrates and sugars.
When we eat three meals a day plus snacks, we never get away from using our food as fuel. However, we didn’t evolve to rely on sugars for our energy all the time. When we prevent our bodies from using other fuel sources, we suppress key functions of our cells that help us live longer and be healthier. Specifically, our bodies are designed to switch to burning fats (ketones) when we’ve run out of sugars and carbs. This switch is known as “ketosis,” and it’s the trigger for a lot of important events to start taking place in your cells.
Getting into ketosis can be hard. Your body might not have run on ketones for months or even years, and it will send increasingly urgent signals telling you that you’re hungry. Ignoring a rumbling stomach can be difficult, but once your body accepts it needs another fuel source and switches to ketones, the hunger will go away. For most people these hunger pangs don’t last too long and are only a little bit uncomfortable. If you find yourself getting hangry instead of hungry, you might be feeding something else every time you eat carbs.
You don’t have to fast long to encourage your body to enter ketosis. Once you begin fasting and limit your carb intake, your body will start to use up your glycogen stores. Glycogen is the stored version of carbohydrates you have in reserves inside your cells. It can take up to a week for you to exhaust your glycogen supplies, after which your body will begin burning ketones.
That doesn’t mean you have to fast for a week! A common intermittent fasting diet is to fast for 16 hours, and eat for eight. What that means is you might only allow yourself food between 12 p.m. and 8 p.m. That means you skip breakfast, have a normal lunch and dinner, and then no snacking after 8 p.m. There are probably days you intermittent fast without even realizing! There are other variations of intermittent fasting, outlined below:
Before you even enter ketosis, you still get great benefits from intermittent fasting. Within 24 hours, the production of growth hormones is stimulated, increasing up to 1,500 percent. These hormones help repair our cells, keeping us looking and feeling younger and healthier. Fasting also helps your body to detox and regenerate cells through a process called autophagy. This term comes from the Greek and translates as “self-eating,” which might sound a bit scary, but it refers to the way your body breaks down and consumes or removes waste products.
As our cells age, they create waste. Bits of the cell break down and mingle with all the excess proteins left over as a cell performs its role and produces and uses energy. These can end up hanging around, hampering the cell’s function and clogging up your system. During autophagy, your body switches into cleaning mode and starts collecting and removing all the detritus that has collected. Over 90 percent of the waste inside cells gets recycled into amino acids, the building blocks of your body, which are used to repair existing cells and generate more. Just like a forest will repurpose the nutrients from fallen trees, so your body can reuse old cells and matter to keep you thriving.
When you enter ketosis, all that cellular waste gets released into your bloodstream, where it is carried to the liver and GI tract, where it is filtered, sorted, and flushed out of your body. Your body can’t complete this process if it’s always burning carbs, because all that quick, easy energy tells your system to engage in more intensive processes like building and growing. It’s only when we fast and switch metabolic gears that we can turn to maintenance processes like cleaning and repairing cells.
THE HEALTH BENEFITS OF INTERMITTENT FASTING
Now that you know some of the good things autophagy and ketosis do for your body, you can see how intermittent fasting can help you at a cellular level. What does it do for anti-aging and overall health? The short answer is, lots!
Regular detoxing through autophagy is a good way to maintain cell health and promote new cell growth. This is especially vital to brain health. While it’s not true our brain cells never regenerate, it is important that we give our bodies time to build and repair the neural connections that make our brains work. Neuron degeneration is a primary symptom of many age-related diseases, such as Alzheimer’s, Parkinson’s, and Huntington’s.
Intermittent fasting can also reduce the proliferation of cancer cells. In fact, a Ketogenic diet (high-fat/low-carb) is recommended as an adjuvant therapy in the treatment of many cancers.The diet works because cancer cells feed predominantly off glycogen, the stored carbohydrates in your cells. When you fast, you force your cells to use up those stores of glycogen, eliminating a vital food source for cancer cells. This starves some cancers out, because they are unable to metabolize ketones in the same way healthy cells can.
Ketosis also reduces the amount of insulin, and insulin-like growth factors (IGF) in your blood. This also has significant implications for fighting cancer because high levels of one particular growth factor, IGF-1, has been linked to elevated risk of certain cancers.
IGF-1 is a hormone that is found naturally in your body, and it controls your growth hormones. It’s especially important for the development of adolescents, but as we age it can become problematic if we produce too much of it. Intermittent fasting has been found in studies to reduce the levels of IGF-1 in the blood by up to 15 percent, even after the test subjects resumed their normal diets.
Intermittent fasting cannot cure cancer, but it can make it less likely that some cancers will develop, or inhibit the growth and spread of some existing cancer cells.
By allowing your body to do what it wants to do naturally, you can improve your chances of living a long, healthy life. Neuron degeneration and cancers are among the leading causes of death in the United States, and intermittent fasting has been shown to play a significant role in reducing the risk factors.
Intermittent fasting isn’t a weight-loss technique, although you may find that you lose some weight once you start. The goal of intermittent fasting is to promote healthy cellular function by encouraging ketosis. When fasting, it’s important to drink plenty of water (water is not regulated by fasting hours, so drink frequently) and avoid any activities that are too strenuous.
While ketosis is a natural condition and has a lot of health benefits, it can be dangerous if you have certain medical complaints, such as diabetes, hypoglycemia, or impaired liver function. Fasting releases cellular waste into the bloodstream, so it’s important your body is able to flush it out. Otherwise all those toxins end up becoming reused by your body, potentially causing harm rather than having beneficial effects.
While you’re fasting, you can reduce the number of toxins by controlling what you eat. Avoid processed, unhealthy foods high in carbs and sugars, as they generate more cellular waste which can put your immune system, GI tract, and liver under increased stress. Instead, try to eat a healthy, balanced diet of high-fiber vegetables, avocados, olive and coconut oil, and raw nuts.
It’s also a good idea to take supplements to protect and support your liver. Zinc, Vitamin B12, and glutathione all help improve liver function and keep your body healthy.