Recently, there has been a lot of talk about fasting for health benefits, and for good reason. As more and more research accumulates, the benefits of fasting are becoming undeniable.
Humans have been fasting since the beginning of civilization. Having food on demand 24/7 is a completely new phenomenon to human physiology and we’re surely not built to consume high-carbohydrate foods, refined sugars, or industrialized oils at the rates that most Americans do.
Instead, humans are hardwired, not only withstand regular periods without food, but actually thrive during these time. Fasting gives the body a chance to reboot several important systems and triggers deep cellular cleansing that otherwise would not happen.
When I work with patients that have chronic health challenges I often recommend fasting as a way to reset their health and relieve their chronic symptoms. I’ve personally seen my own health improve and have witness many patients make significant progress by following different types of fasts.
There are four systems of the body that seem to respond best from fasting. Studies show that fasting can dramatically improve the (1) the immune system, (2) blood sugar stability, (3) gut health and (4) brain health. Let’s go through these one by one.
Fasting Can Reboot The Immune System
Prolonged fasting (2-4 days) has been shown to reboot the immune system (i). This study found that prolonged fasting triggers stem-cell based regeneration of the immune system, clears out old, tired immune cells and replaces them with new cells that better protect the body from foreign invaders. The study also showed that prolonged fasting protects the body against the adverse affects of chemotherapy.
Another study shows that prolonged fasting can help reduce the cytokine storm and oxidative stress that makes COVID more harmful to some individuals (ii). The study concluded that fasting helps to optimize the immune system against COVID or any other invader.
When I start to feel under the weather, my first line of defense is to do a 2-3 day fast and this strategy has not let me down yet.
Fasting Can Improve Blood Sugar & Diabetes
One of the most common conditions I see with my functional medicine patients is what is know as metabolic syndrome. Metabolic syndrome occurs when insulin levels are elevated for a prolonged time. Insulin’s main function is to allow glucose to enter into cells to be used for energy. When blood sugar levels are chronically elevated (usually from eating high carbohydrate foods, refines sugars and late night snacks) insulin levels will rise. If insulin levels remain high for extended periods, the insulin receptors will “down-regulate” making insulin less effective. This is known as insulin resistance. When the body become resistant to insulin blood sugar levels will rise, cholesterol and triglycerides will rise, blood pressure will rise, body fat will rise, inflammation will rise and eventually type 2 diabetes will result.
Reversing this process of high insulin and high blood sugar can dramatically improve your health. And guess what has been shown to significantly lower both insulin and blood sugar? Yep, fasting.
A 2018 study found that time restricted fasting improved insulin sensitivity, lowered blood pressure and reduced oxidative stress after just 5 weeks (iii). Another study done on subjects with type 2 diabetes found that fasting reversed insulin resistance, eliminated the need for insulin, and resulted in significant weight loss (iv).
Fasting Can Improve Brainpower
One of biggest paradoxes in regards to fasting is the effects on the brain. Most people believe that they will feel sluggish, fatigued and mentally dull during a fast. However, just the opposite actually happens.
Humans, like all mammals, experience an increase in mental activity when hungry and a decrease when full. I’m sure you’ve experienced a “food coma” after a large meal. Think about how your brain feels. Is it sharp as a tack and ready to solve all the worlds problems? Probably not.
How about the opposite? When you are really hungry do you feel mentally sluggish or are you mentally alert with your senses hype focused? Most of my patients report an increase in mental clarity, better focus and more stable energy while fasting.
In fact, fasting has been used by all known religions to experience a deeper and more profound spiritual connection and by ancient philosophers to obtain a heightened state of mental awareness.
The brain boosting effects are believed to come from increased levels of brain-derived neurotropic factor (BDNF). As we age, our levels of BDNF naturally decline leading to reduced neuroplasticity, failing memory, slower learning and increased risk for cognitive decline and Alzheimer’s disease. Yep, fasting has been shown to dramatically improve BDNF levels (v).
Fasting Can Improve Gut Function
The connection between gut health and chronic disease can no longer be argued. Imbalances in the microbiome (too many bad bugs and too few beneficial bugs) and increased permeability of the gut lining (leaky gut) are two important mechanisms that, if left untreated, will lead to chronic disease. Once again, fasting has been shown to restore a more health balance in the microbiome and improve the integrity of the gut lining (vi).
Fasting Is Not For Everyone
By now, I hope you’re exited about the potential health benefits from fasting. However, fasting is not for everyone. There is generally an adaptation period when you first begin, but once you are adapted, fasting should make you feel better, not worse.
Below are some situations where fasting may be a negative instead of a positive.
- Hypoglycemia (Chronic Low Blood Sugar)
- Adrenal Fatigue (Chronic Stress)
- Uncontrolled Diabetes & Insulin Use
- History of Eating Disorder
- Underweight and/or Malnourished
- Pregnant or Breastfeeding
About Dr. Garcia
Dr. Garcia is a chiropractic physician and the owner of the Idaho Center For Functional Medicine. He sees patients from across the country and around the world who are suffering from challenging autoimmune, endocrine and neurological disorders. Dr. Garcia uses a natural, science-base approach to help his patients overcome chronic disease.