Intermittent Fasting as a Cure for Disease

 

Dr. Alan Goldhammer is a pioneering physician who has spent 40 years helping thousands of people reverse chronic disease, eliminate medication, and reclaim their health using one of the most ancient healing tools known to humanity – fasting.

Fasting is the most effective treatment that's ever been shown in treating the leading cause of death and disability, which is high blood pressure. It also reduces insulin resistance. It can enhance cognitive capacities. And you also see it affecting things like depression and anxiety.

Fasting introduces not just a chance to lose weight. It also mobilizes visceral fat, which is the fat around the belly and the organs, which is giving off inflammatory products that are causing heart disease, cancer, and diabetes. All human beings have the capacity to fast. People that have not been successful resolving their conditions with medications, have been profoundly affected by water fasting. You should be fasting intermittently every day for optimal health.

Today, we live in a world designed to make you fat, sick, and miserable, where 76% of people are overweight or obese, and where people think that health comes from pills, potions, and powders. And yet, most of us are ignorant of the proven health benefits of fasting. In fact, if you look at all the chemical changes that happen with exercise, they also happen with fasting.

I studied with a guy named Alec Burton who was the world's leading expert in the use of medically supervised water-only fasting and I saw things there that weren't supposed to be happening. People were getting better. I saw people with chronic diseases like high blood pressure resolving their hypertension and getting off the medications. And so we began to carefully evaluate patients with hypertension. In this study, 174 out of 174 patients with high blood pressure normalized their blood pressure without the need for medication. Fasting helps the body do what it really does best, which is heal itself if you get out of the way.

Fasting is the complete abstinence of all substances in an environment of complete rest. That means that you're actually resting while you're fasting in order for it to be most effective. The reason is if you're very active when you're fasting, your body has to produce more glucose in order to carry on the extramuscular and brain activity. The only way that it does that after glycogen reserves are depleted is through a process called gluconeogenesis where the body breaks down lean tissue. So when you're fasting, if your goal is to maximize fat loss and minimize lean tissue loss, it's important that resting be a part of the protocol.

So what happens to the body during fasting? It's a really interesting, fairly well-studied and complex physiological adaptation that human beings make to fasting. Normally your brain burns glucose which is what I get if I have a piece of bread or a bar of chocolate or if you break down protein, which can also break down into glucose... which is what happens after 24 hours of fasting.

You've depleted your glycogen stores - the sugar stores in your muscles - and so then the body, in order to get the glucose it needs, has to either convert to burning fat or break down muscle in order to form glucose.

What the human being does is it converts its main user of glucose, which is the brain, from burning sugar to burning fat. Now, if it didn't do that, you could fast about a week. You'd enter starvation, deplete your protein stores, and you'd starve to death.

Because you can convert your brain to burning fat instead of sugar, a 150-pound male can fast about 70 days. That doesn't mean they should fast 70 days, but they could fast up to 70 days because your main burner of glucose, your brain, will convert to burning a completely different fuel, which is fat.

If I stop eating the glucose, my body has this sort of evolutionary switch where it's going to start burning my fat and turning that into this thing called ketones, which my brain can run on as well.

You have about 24 hours of glycogen stores or sugar stores in your muscles and your liver. So when you stop eating, for the first 24 hours, you're still able to produce glucose from your glycogen stores. But once you've depleted your glycogen stores, now you're you're stuck. You either burn fat or you break down lean tissue.

Because the human brain is so ridiculously large - it's two and a half times a chimp's brain - it's a huge glucose burning machine - you have to have a way of being able to use some other fuel. Otherwise, the first time spring comes late, all the human beings would have died.

And so this biological adaptation was clearly important for our survival in large part because we have disproportionately large brains that burn ridiculous amounts of glucose. Just because the body does it as a survival mechanism doesn't posit that it's necessarily healthy, though. What we've done is we've taken this biological adaptation which by definition would be something the body's capable of doing safely and efficiently and utilizing it in a very unusual situation and that's where people have consistently been exposed to dietary excess.

In the world of our ancient ancestors, getting enough to eat and not getting eaten was the biological imperative of life. It was difficult to get enough to eat. In fact, most human beings that were born probably didn't live to reproduce. They didn't pass on their DNA. We're the results of the winners. For most early humans it was a world of starvation and predation, with all kinds of challenges that would prevent people from reaching reproductive age.

Today we're taking a biological adaptation, something that's natural to the body, and applying it in a situation where people have consistent exposure to dietary excess - too many calories.

The diseases that we suffer today - the heart disease, the diabetes, the autoimmune diseases, some of the cancers - these used to be rare conditions that were called the diseases of kings. It was only royalty that could consistently overeat and get gout or get heart disease. These weren't common conditions that were present for the peasants. These were rarified conditions.

They've become common conditions because now people are consistently being exposed to dietary excess. And more importantly, we're fooling our brain satiety mechanisms into overeating by putting chemicals in our food. And as a consequence, we have a situation today where 76% of people are overweight or obese. And the extra fat comes with something called visceral fat. It's the fat that tends to accumulate around the belly and the organs. And it's pro-inflammatory, hyper-metabolic, hypertrophic. It acts like a tumor.

You have people walking around, maybe they have 20 pounds of extra adipose tissue. They have 2 pounds of visceral fat and that visceral fat is giving off inflammatory products that's causing heart disease, cancer, diabetes, or autoimmune diseases. And what's weird is these conditions are treated as if they're completely independent, unrelated conditions.

You have to go to a different kind of doctor to be even diagnosed and treated with these conditions. And yet, they all seem to be associated with dietary excess, excess fat, excess visceral fat, and the inflammation that's associated with that visceral fat.

Let's run through what happens inside the body when I start fasting. And then I want to talk about fasting a little bit more specifically.

After the first 24 hours, my body is going to switch from using glucose as a fuel source to ketones. It's going to predominantly shift the brain and liver. It's a progression depending on your glycogen stores. You'll be going from burning almost exclusively glucose in the brain to burning predominantly byproducts of fat metabolism, ketones, and specifically beta hydroxybutic acid.

Ketones break down into different components. Beta hydroxybuturic acid becomes the predominant fuel of the brain. It's a byproduct of fat metabolism. And the higher your beta hydroxybutic acid is, the more BDNF is produced. BDNF, Brain Drive Neurotrophic Factor is a neurochemical that's thought to protect the brain from oxidative damage that can result in things like Alzheimer's disease and dementia.

When they do rat studies, they give half the rats a wheel. The rats with the wheel will run on the wheel and they don't get Alzheimer's disease. And they said, "Why? What is it about the exercise that's preventing these rats from getting oxidative damage in their brain that results in dementia or Alzheimer's type disease?" And they found it was BDNF. It's dramatically higher with exercise. It also goes up with fasting.

It's interesting that if you look at all the improvements that happen with exercise, the same chemical changes happen with fasting. And that's not intuitively obvious because in fasting, you're resting, while in exercise, you're vigorous.

You might say, "What do these two seemingly unrelated uh phenomena have in common?" What I think is going on is that both exercise and fasting undo the consequences of dietary excess. They reduce the fat, specifically the visceral fat and the inflammation that leads to all these different diseases. And so, every time you look at the benefits of exercise, you often times see these corollaries with fasting.

At some point in this fasting process, your brain and your body move into a state of autophagy. Autophasia or autophagy is how the body gets rid of senescent cells as well as waste products and cancer cells. It kind of eats up all the debris and does the housekeeping.

There's some things that increase autophagy and one of those things is fasting.

If you take rats, for example, and you let them eat as much as they want, they will live a certain amount of time. If you take rats and you periodically fast them you can increase their lifespan from 30% to 100%, even though the diet's the same, just with periodic fasting or with systematic underfeeding.

If you limit instead of giving them as much to eat as they want, you feed them at 60% of what they would eat if they ate unlimited amounts and you can dramatically increase their lifespan. It's and it's an interesting way of looking at it, but it's not that fasting doubles your lifespan. It's overfeeding that cuts it in half. By overfeeding the rats, they're developing fat - visceral fat. They get inflammation and you cut their lifespan in half.

What fasting is doing is allowing them live their full life span by getting rid of the consequences of dietary excess.

The game here is either to not eat as much or fasting. The idea is to avoid excess intake that results in excess fat that results in excess visceral fat. The problem is it's very difficult to do that when they are putting chemicals in your food that fool your satiety mechanisms and lead to overeating... satiety mechanisms being mechanisms that tell you whether you're hungry or not... whether your brain signals you accurately about the amount of calories you have eaten.

If you, for example, just sit down and and eat your fill of whole plant foods, you eat a certain amount and then you feel full. But if you put certain chemicals in the feed, you'll eat significantly more before you trigger those satiety mechanisms and feel full.

Those chemicals that we put in our food are salt, oil, and sugar. Salt, oil, and sugar are not food. They're hyper-concentrated components derived from food that are put back into food. And we put them into food to make food taste better.

And what tasting better actually means is it results in more stimulation of dopamine in your brain. Dopamine is the neurochemical associated with pleasure. The more dopamine, the more pleasure, the more you like it. And so it turns out that higher caloric density foods or foods that have chemicals like salt, oil, and sugar in the food will stimulate more dopamine in the brain.

And that's because your brain evolved in an environment of scarcity. It involved surviving where it was difficult to get enough to eat and avoid being eaten. And so richer foods had more value. Early humans that recognized the value of more concentrated foods tended to live and to reproduce and pass on their DNA.

Today we live in a world where we've corrupted the whole system. And so now we have unlimited amounts of hyper-concentrated foods with additional chemicals like salt, oil, and sugar. So when you eat those foods, you will overeat. The only question is how much and what are the consequences.

Should we be intermittent fasting or should we just be restricting our calories? Are they the same thing?

There are different approaches that allow us to eat ad libitum but still meet optimum nutritional intake. One tool is intermittent fasting... or time-restricted feeding which we've practiced for 40 years... which is basically don't eat three to four hours before you go to bed at night.

So instead of eating right up till the time you go to sleep, you withhold calories after the last meal so that you have three to four hours of fasting every day. That gives you a 12-hour fast every day. And if you're trying to lose weight, some people believe you could extend that fasting period another four hours in the morning... with some exercise in the morning, preferentially burning fat.

And so that would give you a 16-hour fast and limit your feeding window to 8 hours.

So what's the benefit of that?

Some people find that by limiting the feeding window, they can limit some of the overeating... that a lot of eating is being done for reasons other than being hungry. Sometimes people have had a big dinner and then they eat additional food before bed, not necessarily because they're hungry, but because they're bored, they're tired, or they're fatigued.

Sometimes when they're fatigued and they eat and they think, "Oh, they must have been hungry"... when in reality, they were just tired.

Our suggestion is when you're tired, go to sleep.

When you're bored, engage in productive activities.

And when you're hungry, then you eat.

And if you limit your feeding window to 8 hours, some people find that it's a helpful tool at minimizing some of the overeating.

Now, it's not going to work for everybody. If you have very high caloric needs, you know, you're a competitive athlete, an 8-hour feeding window, particularly on high nutrient density, low caloric density foods, may not give you enough of a feeding window to get the calories that you need. When you're trying to burn 3500 or 4000 calories in a day on very low caloric density foods, you may need to have a 12-hour feeding window in order to be able to get the calorie density need.

But for most of us that are trying to maintain or lose weight, having a narrow feeding window may prove to be of of some benefit.

When I'm in a ketogenic diet, or when I am fasting my cognitive performance seems to be significantly better. When I'm eating a normal western diet my ability to articulate myself and think and be creative seems to be diminished. Whereas when I'm avoiding carbohydrates and sugar, I seem to be able to think and talk better.

It may not be that the ketones are helping you think better. It may be that the sugar vacillations are interfering with your cognitive function. For example, when people eat particularly refined carbohydrates, their insulin levels go up, driving the sugar down, resulting in low blood sugar levels which can interfere with cognitive function as a consequence of this vacillation that's taking place with their blood sugar levels between insulin and glucose. When you go on a ketogenic type of an approach or you're in a fasting state, everything's very stable as far as glucose and insulin are concerned. You don't want to be on the sugar roller coaster if you you're doing important work. Being stable seems to help people in their cognitive function.

People talk a lot about juice fasting. What is it and is juice fasting advisable?

Juice fasting isn't technically fasting because fasting is the complete abstinence of all substances. It's a modified form of eating. It's a diet that's high in sugar and very low in fiber. Where it can be helpful is with people who are trying to make dietary changes who may be addicted to the artificial stimulation of dopamine in their brain that comes from the use of highly refined diets. They're trying to make a change. They're trying to make a break. And because it's sweet and very appealing, they'll drink the juices, they'll get their 600 or 800 calories, they'll feel relatively satiated, and it allows them to avoid the greasy, fatty, processed foods that sometimes they're trying to get away from.

Personally, I think that water fasting has advantages over juice fasting in terms of the magnitude of the detoxifying effect, the impact that it has. But the advantages of juice fasting are that it can be done without modifying medications. You're still in a feeding physiology. It could be done safely by people without having to be in a controlled setting like you would for water fasting.

So there's advantages to the intermittent or modified fasting approaches. It's not the basis of the research that we've published, however, which is actually water only fasting. We're fasting people on water only from 5 to 40 days.

Patients that are fasting in our facility are on fractionally steamed distilled water only. That's the only thing they take. They're not taking supplements or medications. This is highly purified water.

Not everybody's a good candidate for that type of fasting. In order to determine if you're a good candidate, you have to take a look at what people are doing in terms of their medical treatment, with basic laboratory testing to make sure kidney and liver function are intact or capable of adapting to fasting.

When people fast, they need to rest. If people are active, we've already mentioned they'll increase their weight loss, but that weight will be derived from breaking down lean tissue. We want to minimize lean tissue, maximize fat, particularly visceral fat.

It's also important that they be monitored because people do have issues that can be aggravated by fasting. Fasting presents a dehydration response. There's a physiological dehydration that occurs with fasting. There's changes in electrolytes. So, you need to make sure that people are being monitored appropriately.

And then the most important part probably is they need to return to eating very slowly after the fast. If they go back to eating too rapid they can get into problem with post-fasting edema which could be a very serious or even potentially fatal problem that can be completely avoided by following a reasonable protocol of a realmentation after fasting... which is the reason why we encourage patients that are doing fasting to do it either in a controlled setting or under some supervision so that they don't make catastrophic error.

So you want to make sure the person's a good candidate, that they're fasting in a controlled setting, that they rest, and they re-feed properly. So a person that has, say, a 20-day fast would have 10 days of controlled re-feeding. It'll take about half the length of the fast to properly return to normal after the fast, so that you're ready to go back to hopefully a whole plant food diet, free of sugar, salt, and oil.

Dr. Alan Goldhammer interview with Steven Bartlett @TheDiary Of A CEO on YouTube on September 1, 2025