Intermittent Fasting Instead of Insulin for Type 2 Diabetes

Written by Dr. Joseph Mercola

is fasting ok for diabetics

Story at-a-glance -

  • Type 2 diabetes is rooted in insulin resistance and faulty leptin signaling, caused by chronically elevated insulin and leptin levels. In other words, it’s a diet-derived condition
  • Treating Type 2 diabetes with insulin is one of the worst things you can do, and can even lead to the development of irreversible insulin-dependent diabetes in some cases
  • Diabetic patients who did 24-hour fasting three times a week or every other day were able to stop taking insulin within a month. They also lost 10 to 18 percent of their body weight
  • In another trial, Type 2 diabetics placed on a severely restricted calorie diet where they ate just 600 calories a day for eight weeks were disease-free by the end of the fasting program
  • A partial fasting diet has also been shown to regenerate the pancreas by promoting the generation of insulin-producing beta cells (cells that detect sugar in your blood and release insulin if blood sugar levels get too high)

Conventional medicine still has Type 2 diabetes pegged as a blood sugar problem. In reality, it's a disease rooted in insulin resistance1 and faulty leptin signaling, caused by chronically elevated insulin and leptin levels. In other words, it's a diet-derived condition.

Unfortunately, as noted by Dr. Abhinav Diwan, associate professor of medicine, cell biology and physiology at the Washington University School of Medicine in St. Louis,2 "In general, the concept of reversing or curing diabetes ... is not well-accepted in the medical field. It is not even a therapeutic goal when people start to treat diabetics."

This is why the medical community's approach to diabetes treatment, which typically involves the administration of insulin, is not getting anywhere. Treating Type 2 diabetes with insulin is actually one of the worst things you can do, and can even lead to the development of Type 1 (insulin-dependent) diabetes in some cases.

Conventionally trained doctors also continue to pass along seriously flawed nutritional information (such as recommending a high-carb diet and use of artificial sweeteners), which is yet another reason why Type 2 diabetes has ballooned to such epidemic proportions.

Most People Are on the Verge of Becoming Diabetic

An estimated 30.3 million Americans, nearly 1 in 10, have Type 2 diabetes.3 Another 84 million American adults — about 1 in 3 — are prediabetic. Prediabetes4 is defined as an elevation in blood glucose over 100 milligrams per deciliter (mg/dl) but lower than 125 mg/dl, at which point it formally becomes Type 2 diabetes.

However, any fasting blood sugar regularly over 90 mg/dl really suggests insulin resistance, and seminal work by the late Dr. Joseph Kraft suggests 80 percent — 8 in 10 — Americans are in fact insulin resistant,5 which means they're already well on their way toward developing diabetes.

That's the bad news. The good news is Type 2 diabetes is reversible, and the treatment doesn't cost you anything. In fact, it actually saves you loads of time and money. I'm talking about fasting. Both intermittent fasting and longer water-only fasting have been shown to reverse Type 2 diabetes.

Fasting — A Therapeutic Alternative to Insulin

A recent case series paper6,7 published in BMJ Case Reports by a friend, Dr. Jason Fung, details how fasting can be used as a therapeutic alternative for Type 2 diabetes. This exciting report actually made the front page of CNN online.8 As noted by the authors, their paper:

"… [D]emonstrates the effectiveness of therapeutic fasting to reverse insulin resistance, resulting in cessation of insulin therapy while maintaining control of blood sugars. In addition, these patients were able to lose significant amounts of body weight, reduce their waist circumference and also reduce their glycated hemoglobin levels."

A case series paper is not a controlled study; rather, it simply presents the case history of one or more patients and may propose a hypothesis for why a treatment did or did not work. In this case, three diabetic patients between the ages of 40 and 67 participated in a supervised fasting regimen to evaluate the effects on their insulin requirements. The patients had been diagnosed with Type 2 diabetes for 10, 20 and 25 years respectively, and were taking insulin daily.

Of the three patients, two did alternating-day 24-hour fasts, while one fasted for 24 hours three times a week over a period of several months. On fasting days, they were allowed to drink unlimited amounts of low-calorie fluids such as water, coffee, tea and bone broth, and to eat a low-calorie, low-carb dinner.

On nonfasting days, they were allowed both lunch and dinner, but all meals were low in sugar and refined carbohydrates throughout. The complete manual of the fasting regimen used is described in Fung's book, "The Complete Guide to Fasting."9

Two of the patients were able to discontinue all of their diabetes medications while the third was able to discontinue three of his four drugs. All three also lost between 10 and 18 percent of their body weight. As reported by the authors:

"In our study all three patients eliminated the need for insulin by initiating a therapeutic fasting regimen. All three patients succeeded within a month and one in as little as five days. Further, all patients improved in multiple other clinically significant health outcome measures, such as HbA1C, body mass index and waist circumference …

As such, patients with T2D can reverse their diseases without the worry of side effects and financial burden of many pharmaceuticals, as well as the unknown long-term risks and uncertainty of surgery, all by means of therapeutic fasting."

In another similar trial,10 Type 2 diabetics were placed on a severely restricted calorie diet where they ate just 600 calories a day for eight weeks. By the end of their fast, all were disease-free, and three months later, having returned to their regular diet, seven of the 11 participants remained free of diabetes.

Why Fasting Is Such a Powerful Intervention for Diabetes

Fung is a nephrologist (kidney specialist) with a practice in Toronto. Two years ago, I interviewed him about fasting, which is one of the most powerful interventions for Type 2 diabetes and insulin resistance I know of. Fung was also one of the experts who peer reviewed my book, "Fat for Fuel," which integrates some of his work.

Ultimately, diabetes is just one symptom of insulin resistance, which is the underlying problem. Insulin resistance, which results in mitochondrial dysfunction, is also at the heart of cancer, heart disease, Alzheimer's and other degenerative diseases, and it all starts because your body is unable to burn fat as a primary fuel.

When your body relies primarily on sugar, more reactive oxygen species (ROS) are generated, which damage the mitochondria in your cells. Fasting massively upregulates autophagy and mitophagy, and stimulates mitochondrial biosynthesis during the refeeding phase, which allows your body to naturally regenerate.

In fact, research11 published just last year demonstrated that partial fasting actually helps your pancreas to regenerate, by promoting the generation of insulin-producing beta cells. These are cells that detect sugar in your blood and release insulin if blood sugar levels get too high.

Through this restorative effect on the pancreas, the fasting-mimicking diet also reversed diabetes symptoms in mice. Valter Longo, Ph.D., professor of gerontology and biological sciences and director of the USC Longevity Institute, led the study, and explained the results:12

"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 …

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."

Type 2 Diabetes Is Predicated on Excess Sugar in Your Diet 

Once you understand what insulin resistance and Type 2 diabetes actually are, then you'll understand why something so simple as abstaining from food for a period of time can be such a powerful intervention. Contrary to infectious diseases, you cannot treat metabolic disease with a pill, because metabolic diseases such as diabetes are predicated on lifestyle, primarily diet. As previously explained by Fung:13

"You have to use metabolic treatments, which is why using fat for fuel is so important … Remember, the glucose goes into the cell, and insulin resistance is when the glucose doesn't go out of the cell. So, for years we've used this paradigm of lock and key.

That is, the cell is sort of gated off. Outside the cell there's blood, and when insulin comes around it turns the key, opens the gate and glucose goes in. So, if insulin is there, why is the glucose not going in? … You can measure the insulin and the insulin level is high. You can look at the insulin receptor, the gate is completely normal.

So, [conventional medicine] said something like, 'Well, maybe there's something gumming up the mechanism. It's stuck in the lock so it doesn't open properly, therefore the glucose can't get into the cell. There's a huge problem with this sort of paradigm, because if that is happening, the cell has no glucose and should be starving.

You should be losing lots of weight; you'd have a very thin liver. All your fat should just melt away, because if you think about untreated Type 1 diabetes, where you don't have enough insulin, that's exactly what happens. The cell literally starves and everything just wastes away … But that's not what's happening here.

In Type 2 diabetes you see that people are generally obese, they have large abdomens … What's happening instead is that it's actually an overflow syndrome. The cell can't accept any more glucose because it's jam packed full of glucose already.

That's the reason you have insulin resistance. Insulin is trying to move glucose into the cell but the cell is full … So, it's really an overflow mechanism …

That's also why your liver is full — it's a big fatty liver. The liver is busy trying to get rid of all this glucose by turning it into fat … Now, if Type 2 diabetes and insulin resistance are the same sort of thing, it's really about too much sugar. That's the bottom line.

And if you understand that the whole problem is too much sugar, then the solution is not to use more insulin to jam more glucose into an already full cell. The key is to get rid of it all. So, what you want to do is: 1) Don't put more sugar into your system, because you have too much sugar in already, and 2) burn it off."

Why Insulin Therapy May Do More Harm than Good

Now, when you take insulin, the added insulin allows your body to use more of that excess glucose, but it turns it into fat. This is why most diabetics who take insulin end up gaining weight, which is the exact opposite of a healthy development, as the more weight you gain, the worse your diabetes gets and the more insulin you require. As noted by Fung, this treatment doesn't make sense as diabetics already have high insulin.

"[Why give] more insulin in a situation where you have too much insulin already? If you have hyperthyroidism, you don't give more thyroid hormone.

If you have an alcoholic, you don't give more alcohol. It's the exact wrong thing to do. In fact, if your levels of insulin are too high and that's your disease, you need to lower insulin. By giving insulin, you're actually making the fundamental problem much worse," he says.

Research14 has also confirmed that insulin therapy fails to significantly add to your life expectancy and quality of life. As reported by Medical News Today:15

"[T]hey estimate that a person with Type 2 diabetes who begins insulin therapy at age 45 and lowers their hemoglobin A1c levels by 1 percent may experience an extra 10 months of healthy life.

But for a patient who starts treatment for Type 2 diabetes at age 75, they estimate the therapy may only gain them an additional three weeks of healthy life. The researchers say this prompts the question — Is 10 to 15 years of pills or injections with possible side effects worth it?"

In Some, Insulin Treatment Can Rapidly Induce Disease Progression

One really significant potential side effect of insulin therapy is disease progression from reversible to irreversible diabetes. This was demonstrated in a 2014 study16 published in the Journal of Clinical Endocrinology & Metabolism.

The study found that giving genetically engineered recombinant insulin — which is the type typically used — to Type 2 diabetics with certain genetic susceptibility can trigger their bodies to produce antibodies that destroy their insulin producing cells (pancreatic islet cells).

Basically, it triggers an autoimmune disease response, producing a condition in which you have both Type 1 and Type 2 diabetes simultaneously. The average time of Type 1 diabetes onset was 7.7 months. One study participant developed Type 1 diabetes in just over one month.

According to the authors, acute deterioration of blood glucose control after administering insulin is a warning sign of this problematic side effect. According to this study, the genes predisposing you to this autoimmune-type response to insulin are:

  • Type 1 diabetes high risk HLA class II (IDDM1), thought to play a role in about half of all Type 1 diabetes cases, and
  • VNTR genotype (IDDM2), which is believed to predispose you to Type 2 diabetes

Insulin Treatment Raises Risk of Several Health Complications

What's more, a 2013 study17 found that treating Type 2 diabetes with insulin more than doubled patients' risk of all-cause mortality. It also leads to:

Twice as many myocardial infarctions

1.4 times more strokes

2.1 times more neuropathy

1.4 times more cancer

1.7 times more major adverse cardiac events

3.5 times more renal complications

1.2 times more eye complications

2.2 times more deaths

A study published in Diabetologia18 in 2014 also found that diabetic cancer patients have a significantly elevated risk of death. Diabetic patients using insulin at the time of their cancer diagnosis had a four times higher mortality rate one year after cancer diagnosis compared to nondiabetic patients, or those who did not use insulin to control their diabetes. While this was an observational study, which means it cannot establish causality, the results are still noteworthy.

Other diabetic medications also have their risks. Avandia, for example, has been linked to a 43 percent increased risk of heart attack and a 64 percent higher risk of cardiovascular death, compared with other treatments.

So, it's really important to understand that Type 2 diabetes is best controlled by restoring your insulin and leptin sensitivities, and this is what fasting helps you do. You will also dramatically reduce your risk of diabetes by:

Limiting grains and sugars in your diet and getting plenty of healthy dietary fats, including animal-based omega-3

Exercising regularly19

Getting plenty of restorative sleep — In one 10-year-long study20 of 70,000 diabetes-free women, women who slept less than five hours or more than nine hours each night were 34 percent more likely to develop diabetes symptoms than those who slept seven to eight hours each night

Optimizing your vitamin D level to between 60 and 80 ng/mL

Optimizing your magnesium level — Magnesium plays an important role in glucose and insulin homeostasis21 and is required to activate tyrosine kinase, an enzyme required for the proper function of your insulin receptors.22

One 2013 study involving prediabetics found that most had inadequate magnesium intake, and those with the highest magnesium intake reduced their risk for blood sugar and metabolic problems by a whopping 71 percent23

Work With a Knowledgeable Physician if You're on Any Medications

While fasting is a profoundly effective intervention for Type 2 diabetes, you do need to use caution if you're diabetic. If you are taking medication, especially for your blood sugar, you have to make sure you talk to your doctor because there's a risk your blood sugar may end up dipping too low.

If you're taking insulin, and keep taking insulin while fasting, you could get into trouble. So, it's important to closely monitor your blood sugar and adjust your medication accordingly. As previously noted by Fung:

"Remember, the fasting is going to drive your blood sugars down, and your insulin or your medications will drive your blood sugars down, so you've got kind of two things driving your blood sugars down.

All of a sudden you go low, you can have seizures, you can wind up in the emergency room and you could absolutely die. And that's one of the things you have to be very careful of. So yes, you can do it, but you have to make sure you do it in a supervised setting with somebody who knows what they're doing."

Periodic Partial Fasting Is a Key to General Health and Wellness

By upregulating autophagy and mitophagy, stimulating mitochondrial biosynthesis and triggering the regeneration of stem cells, partial fasting (with days of 300 to 700 calories based on lean body mass) is not only beneficial for Type 2 diabetes and obesity, but also for health in general, and likely even longevity.

There's even evidence to suggest fasting can help prevent or even reverse dementia, as it helps your body clean out toxic debris. By lowering insulin, you also increase other important hormones, including growth hormone (aka the fitness hormone), which is important for muscle development and general vitality.

As previously noted by Fung, fasting is "fundamentally one of the keys of wellness." Other ailments that can benefit from fasting include polycystic ovaries, polycystic kidneys and fast growing cancer cells.

The reason for this is because when autophagy increases, your body starts breaking down old protein, including fast growing cells. Then, during the refeeding phase, growth hormone increases, boosting the rebuilding of new proteins and cells. In other words, it reactivates and speeds up your body's natural renewal cycle.