Story at-a-glance

• Research involving lab mice shows a fasting-mimicking diet not only can help your pancreas regenerate itself, but it can also reverse diabetes symptoms
• Other animal studies suggest restricting calories to a six-hour window can significantly reduce levels of a particular mutant protein known to play a role in Huntington's disease
• Fasting has been shown to be beneficial in lowering your risk of cancer, cardiovascular disease and diabetes; it also boosts your body’s immune system and antiaging potential
• Three fasting methods I encourage you to consider are: the fasting-mimicking diet, intermittent fasting or water-only fasting
• I personally have experienced great results with both intermittent fasting and water-only fasting, and I believe fasting is one of the best tools you can use in the fight against chronic disease

Fasting is a powerful tool nearly anyone can use to take control of their health. Animal research indicates a fasting-mimicking diet not only can help your pancreas regenerate itself, but it can also reverse diabetes symptoms. In another study, also involving lab mice, restricting daily calories to a six-hour window significantly reduced levels of a particular mutant protein known to play a role in Huntington's disease.

Given these results, as well as other research, the tremendous benefits of fasting continue to emerge. If you haven't yet considered how fasting can make a positive difference to your health, I encourage you to keep reading and also consider one of three methods: the fasting-mimicking diet, intermittent fasting or water-only fasting. Fasting is one of the best tools you can use in the fight against chronic disease.

Fasting-Mimicking Regenerates Pancreas, Eliminates Diabetes in Lab Mice

In a study published in the journal Cell,1 a group of U.S. researchers, most of whom were affiliated with the University of Southern California (USC), suggest your pancreas may be able to regenerate itself through a fasting-mimicking diet.

In animal experiments, the scientists, led by Valter Longo, Ph.D., professor of gerontology and biological sciences and director of the USC Longevity Institute, were able to restore pancreatic function using a modified version of the fasting-mimicking diet. This diet is characterized by periods of feast and famine.

Longo notes the diet promoted the "generation of insulin-producing beta cells, resembling that observed during pancreatic development."2 (Beta cells detect sugar in your blood and release insulin if blood sugar levels get too high.) Given its restorative effects on the pancreas, the fasting-mimicking diet also reversed diabetes symptoms in lab mice.

Said Longo, "Our conclusion is by pushing the mice into an extreme state and then bringing them back — by starving them and then feeding them again —the cells in the pancreas are triggered to use some kind of developmental reprogramming that rebuilds the part of the organ that's no longer functioning."3 The experiments reflected noticeable benefits for mice with diabetes: Fasting-mimicking diet cycles restored insulin secretion and glucose homeostasis in both Type 1 and Type 2 diabetes mouse models. Longo stated:4

"Medically, these findings have the potential to be very important because we've shown — at least in mouse models — that you can use diet to reverse the symptoms of diabetes. Scientifically, the findings are perhaps even more important because we've shown you can use diet to reprogram cells without having to make any genetic alterations."

How Does the Fasting-Mimicking Approach Work?

Unlike traditional fasting centered on abstinence from all food for a period of time, a fasting-mimicking diet allows you to consume a greatly reduced number of calories, usually for a five-day period, in a way that allows you to realize some of the same therapeutic benefits of traditional foodless fasting.

Longo's fasting-mimicking diet involves restricting your calories to 800 to 1,100 calories per day for five days each month. This approach greatly improves compliance, as many would find a five-day water-only fast to be too difficult. The low-calorie strategy provides many benefits while also reducing your likelihood of suffering adverse side effects.

The five days of calorie restriction come in the form of choosing foods low in carbohydrates, low in protein and high in healthy fats. The rest of the month, you are free to eat whatever you want. The goal is to mimic periods of feast and famine. While all of this sounds simple, Longo is quick to suggest the diet is best undertaken with medical guidance. "It boils down to: Do not try this at home." Longo says, "This [diet] is so much more sophisticated than people realize."5

Calorie Restriction Also Shows Promise for Huntington's Disease

New research by Canadian scientists, published in the journal Acta Neuropathologica Communications,6 indicates restricting food intake to a specific daily time period could benefit sufferers of Huntington's disease. More than 30,000 Americans are affected by this progressive neurological condition, which typically appears between the ages of 30 and 50.7

Symptoms of Huntington's include cognitive impairment, involuntary movements (chorea) and mobility problems. Most conventional approaches involve taking drugs such as tetrabenazine to manage symptoms like chorea. Using lab mice, the researchers found that limiting calorie intake to the same daily six-hour period improved mouse models of Huntington's disease.8

Specifically, this strict eating schedule, which involved fasting for the remaining 18 hours a day, resulted in significant reductions in the levels of a particular mutant protein that plays a role in Huntington's disease. The disease is caused by an inherited mutation in the huntingtin (HTT) gene known to pass from parent to child. The mutant form of HTT is referred to as mHTT; it is thought to work with other bodily proteins to accelerate progression of the disease.

The study revealed food restriction triggered a process in the mice called autophagy — a cell self-cleaning process known to remove damaged or unnecessary components. Researchers noticed fasting-induced autophagy reduced levels of mHTT in the rodents' brains.9 About the research, lead study author Dagmar Ehrnhoefer, Ph.D., principal investigator at BioMed X Innovation Center in Heidelberg, Germany, stated:10

"We know specific aspects of autophagy don't work properly in patients with Huntington's disease. Our findings suggest, at least in mice, when you fast, or eat at certain very regulated times without snacking in between meals, your body starts to increase an alternative, still functional, autophagy mechanism, which could help lower levels of the mutant huntingtin protein in the brain."

Study coauthor Dale Martin, Ph.D., assistant professor, department of biology, Waterloo University, Waterloo, Ontario, Canada, said, "More studies are needed, but perhaps something as simple as a modified dietary schedule could provide some benefit for [Huntington's disease] patients and could be complementary to some treatments currently in clinical trials."11

Multiday Water Fasting Is Another Great Metabolic Intervention

After some initial hesitations, I am now embracing multiday water fasting as one of the best metabolic interventions available. I say that because this type of fasting switches your cells to a protected "antiaging mode." It also promotes autophagy, the cell self-cleaning process mentioned earlier, thanks to the activation of stem cells.

I have completed several five-day water-only fasts in recent months and highly recommend this as a regular practice. Assuming you are properly prepared, if you are dealing with insulin resistance, I believe you could benefit from monthly water-only fasts. Provided you're not anorexic, old and frail, pregnant or dealing with a serious health issue, fasting for three to seven days will likely be beneficial; a short fast certainly won't kill you, nor will it cause significant muscle loss. With respect to water-only fasts, ABC Science states:12

"After two or three days of fasting, you get your energy from two different sources simultaneously. A very small part of your energy comes from breaking down your muscles — but you can avoid this by doing some resistance training … The majority of your energy comes from breaking down fat.

But very soon, you move into getting all your energy from the breakdown of fat. The fat molecules break down into two separate chemicals — glycerol (which can be converted into glucose) and free fatty acids (which can be converted into other chemicals called ketones). Your body, including your brain, can run on this glucose and ketones until you finally run out of fat.

In humans, fasting seems to have health benefits for high blood pressure, diabetes, asthma and epilepsy in children. In animals, fasting seems to reduce the cognitive decline that happens in conditions such as Parkinson's disease and Alzheimer's disease."

You may find that starting with intermittent fasting first can prepare your body (and your mind) for a water-only fast. Simply by lengthening the number of hours you go without food can condition your body for completely foodless days. My habit of intermittently fasting 20 hours a day definitely made water-only fasting easier for me. Even if you intermittently fast short of 20 hours, you will be helping your body begin using fat for fuel.

I recommend you take a high-quality multimineral supplement any time you do a water-only fast, and you should continue taking your regular nutritional supplements, too. If you supplement with magnesium, be aware it may cause severely loose stools during foodless fasts. You also need to consume high-quality salt.

Health Benefits of a Fasting-Mimicking Style of Eating

In his book "The Longevity Diet: Discover the New Science Behind Stem Cell Activation and Regeneration to Slow Aging, Fight Disease and Optimize Weight," Longo suggests the fasting-mimicking protocol supports your overall health and well-being because it helps you maintain healthy levels of:

• C-reactive protein, a marker of inflammation
• Fasting glucose
• Insulin-like growth factor 1, a marker associated with increased mortality and DNA damage
• Stem cells and regenerative markers

Beyond that, according to Longo, the fasting-mimicking diet both protects and rejuvenates your body by going after multiple body systems and causing regeneration and improved performance in those systems. Among the health benefits, Longo says the fasting-mimicking diet:

• Reduces cancers by nearly 50 percent
• Delays cancer onset and results in more benign tumors than malignant ones
• Improves your cognition and markers for aging
• Strengthens your immune system, which is transformed to a more youthful state
• Lowers risk factors associated with cardiovascular disease, cancer and diabetes

Fasting-Mimicking Boosts the Effectiveness of Treatment for Malignant Disease

Given his years of research and experience, Longo strongly recommends actively incorporating the fasting-mimicking diet with cancer treatment. Not only will it radically improve the effectiveness of your cancer therapy, he says, but it will also decrease some of the unpleasant side effects. Longo states:

"This has been a difficult battle. We work with the top oncology hospitals in the world: MD Anderson, Mayo Clinic [and] USC Norris Cancer Center … we really didn't want to be the rebels …  We fought very hard, but also, we wanted them to agree with us. We wanted the oncologists to basically say, 'Yes. This [diet] is a good way to do it.'

The safety concerns … are really minimal and the potential benefits are very high … In mice, we consistently see cancer-free survival even in the metastatic models."

Longo believes fasting-mimicking diets are particularly beneficial in cases of more advanced cancers that have metastasized, leaving the patient with very few options. In those instances, he has encouraged oncologists to seriously consider integrating the fasting-mimicking diet with standard cancer care. To date, Longo and his team have demonstrated the effectiveness of the fasting-mimicking diet for kinase inhibitors, chemotherapy and all kinds of cancers.

He says hundreds of clinical trials are underway that involve the fasting-mimicking diet, and new data comes in regularly about new therapies. One of the new therapies, Longo suggests, is immunotherapy. It makes cancer visible to your immune system so it can be attacked by your immune system.

Whatever your situation with respect to cancer treatment, Longo recommends you bring the fasting-mimicking diet to the attention of your oncologist. For starters, you might suggest he or she "at least … read the clinical trials that are already published," said Longo. He adds, "I think it's important to talk to [cancer] patients about this [diet], and give them an opportunity, particularly where they don't have any other viable options."

Important Cautions About Fasting

Certain health conditions require more stringent medical supervision to ensure the safety of fasting. Regardless of your health, be sure to talk to your doctor before undertaking any fasting program. If you have a chronic disease, your doctor will need to closely monitor your condition and any potential complications related to fasting. I advise you avoid, or at least cautiously evaluate, fasting if you are:

Anorexic or seriously underweight

Pregnant or breastfeeding

Fragile or in ill health

Taking medication, especially if it must be taken with food

Have liver or kidney disease

Taking an antihypertensive or hypoglycemic medication, due to the risk of overdosing

More than 70 years of age, unless you're exceptionally healthy

Cycling Is Vital for Success With the Fasting-Mimicking Protocol

If you are in good physical health, you may be able to realize benefits from adopting a fasting-mimicking diet for five days every 90 days. However, if you are facing health challenges such as high blood pressure, high cholesterol or obesity, you may have more success by cycling on and off the diet monthly, at least until you see improvement in your health.

Longo underscores the need for some form of cycling on and off the diet because the cycling is vitally important to your success. The episodic fasting and refeeding is one of the keys that unlocks the many benefits of this diet. Notably, cycling also helps circumvent the negative effects associated with continuous fasting or chronic underfeeding.

If the information presented in this article has stimulated your thinking about fasting, you may be ready to take your diet to the next level. The potential benefits of fasting make each type of intervention worth checking out, mainly because your body was designed to: 1) run on fat as its primary fuel and 2) cycle through periods of feast and famine. As a means of taking control of your health, I encourage you — under the guidance of your doctor — to seriously consider one or more of the following types of fasting:

• Intermittent fasting
• Water-only fasting
• Fasting-mimicking diet