Fasting is one of the hottest health trends right now in Ontario and beyond. But is it just a trend or is there actually benefit to missing a few meals?
One of the most interesting aspects of fasting is that it’s a common practice among so many cultures and religions around the world. From Indigenous Canadians to devout Muslims, fasting is an important part of many traditions. But what are the health benefits?
But first- what is meant by fasting? In the low carb community fasting is usually defined as not eating for 24 hours or more. Some people call it fasting when skipping just breakfast or lunch, but most who study fasting call this time restricted eating. This also has benefits such as weight loss and increased insulin sensitivity, but without the anti-aging process of autophagy which is explained here later.
The main benefits of fasting.
1- Weight loss. It seems intuitive that not eating is helpful for weight loss. But studies show the benefit goes beyond calorie restriction. Traditional calorie restricted diets, popularized by groups like Weight Watchers, eventually lead to a decrease in basal metabolic rate. What this means is if you “diet” regularly by eating fewer calories than your body needs, eventually your body catches on and metabolism slows. With fasting however, when fasting for 3 days or less, metabolic rate does not slow. (There is some controversy when fasting longer than this. Some experts say metabolism may slow and some muscle may be lost. Other experts argue that this does not occur. For this reason, and for other health reasons, keeping a fast to a maximum of 2 or 3 days is probably best.)
2-Insulin sensitivity. This goes hand in hand with weight loss. It could be argued that some of the weight loss seen in fasting comes from lowering insulin levels. When we don’t eat, insulin levels drop. This gives the body a break from the continual insulin exposure our bodies experience, especially if we are eating snacks between meals. The opposite of insulin sensitivity is insulin resistance. This is important to our health because insulin resistance is the first step towards type 2 diabetes. It is also closely linked to heart disease, even before type 2 diabetes develops fully. A recent study found that only 12% of Americans are metabolically healthy. (Metabolic Syndrome and Related Disorders, Nov 28, 2018.) Essentially this means that 88% have some degree of insulin resistance. Fasting is one of the quickest and most effective ways to reverse this. (A low carb diet is the other way.)
3-Autophagy. Autophagy literally means “self eating” and this is what happens when you fast for more than 24 hours. At the cellular level, the cells take out the “garbage”, removing broken down components which improves cell health. Another amazing change at the cellular level is seen in the little cellular gizmo called telomeres. Telomeres are known to shorten as we age and it is generally a one way process. However, it has been observed that telomeres get longer with fasting, which is basically the fountain of youth at the cellular level. In some cases, the immune system is better able to attack some microorganisms when autophagy is occurring. Another cellular component that seems to recycle waste and improve function with autophogy are mitochondria. Since mitochondrial dysfunction is associated with many diseases, it is likely that there could be many applications for fasting in disease treatment. For example, there has been interest in using fasting for arthritis, cancer, and Parkinson’s disease, among others. From a non-disease perspective, at the full- body level, people see anti-aging changes such as color returning to grey hair, long standing scars fading and skin tags disappearing. In 2016 the Nobel Prize in Medicine was awarded to Japanese researcher Yoshinori Ohsumi for his work in discovering the mechanism of autophagy.
In the next blog post I will talk more about the “how-to’s” of fasting. There are definitely some good and bad approaches. Don’t try fasting without talking to your doctor and be sure to read up on how to do it safely first!