 What if just one lifestyle change could help you avoid getting cancer? Or diabetes? Or heart disease? Or high blood pressure? This one change could cut your risk of chronic disease and add years to your life. Well, the simple solution to so many of these problems is to eat a healthy diet. In other words, one centered around whole plant foods. Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Greger. There is a lot of demand for information about fasting, and as luck would have it, more and more research is released every day. Today we look at the practice of fasting to reverse type 2 diabetes. Currently, nearly half a billion adults have diabetes. That 50% increase is expected in another generation. I've got tons of videos on the best diets for diabetes, but what about no diet at all? More than a century ago, fasting was said to bring about the cure of diabetes, speedily arresting its development and causing complete disappearance of all its manifestations in several days or weeks. Even so, starvation is guaranteed to lead to the complete disappearance of you. If kept up long enough, what's the point of fasting it away? Diabetes is just going to come raging back as soon as you restart the diet that caused it in the first place. Might it be useful to kind of kickstart a healthier diet? Let's see what the science says. Type 2 diabetes has long been recognized as a disease of excess, a disease of the idle rich by which they mean anyone who doesn't practice sustained vigorous bodily exertion every day and earning enough to regularly eat more than they need. Diabetes is preventable, but then maybe it's also treatable. If we are dying of overeating, maybe we can be saved by under-eating. Remarkably, this was suggested about 2,000 years ago in an Ayurvedic text. Diabetics were encouraged to live like a saint, walk for 800 or 900 miles, dig a pond, or live only on cow dung and cow urine. That reminds me of the Rolo diet for diabetes proposed in 1797, composed of a diet of rancid meat that was on top of the Ipocac-like drugs he used to produce severe sickness and vomiting. Anything that produces sickness has a temporary effect in relieving diabetes by diminishing the quantity of food eaten, and his diet plan congealed blood for lunch and spoiled meat for dinner. Certainly had that effect. Similar benefits were seen in diabetics during the Siege of Paris in the Franco-Prussian War, leading to the advice to manger le moins possible, eat as little as possible. That was formalized into the Alan Starvation treatment considered to be the greatest medical advance in the treatment of diabetes prior to the discovery of insulin. Before insulin, there was the Alan Era. He noted reports in the clinical literature of even severe diabetics clearing up on wasting diseases like tuberculosis, so he decided to put it to the test. He found that even the most severe types of diabetes he could clear sugar from people's urine within 10 days. Of course, that's the easy part. It's maintaining it once you start eating again, for which he stuck to two principles, keeping them underweight, and restricting the quantity of fat. A severe diabetic can be symptom-free for days or weeks, but add some butter, or all the oil and the disease can come raging back. As I've covered before, diabetes is a disease of fat toxicity. Infuse fat in the people's veins through an IV, and by using a high-tech type of MRI scanner, you can show in real time to build up a fat in muscle cells within hours accompanied by an increase in insulin resistance. The same thing happens when you put people on a high-fat diet for three days, or even just one day, or even just a single meal can increase insulin resistance within six hours. Acute dietary fat intake rapidly increases insulin resistance, why do we care because insulin resistance in our muscles, in the context of too many calories, leads to the build-up of liver fat, which leads to the build-up of fat in the pancreas, which is eventually what causes diabetes. Type 2 diabetes can now be understood as a state of excess fat in the liver and pancreas, and remains reversible for at least 10 years in most individuals. Put people on a very low calorie diet, 700 calories a day, and fat can get sucked out of your muscle cells, and you get a corresponding boost in insulin sensitivity. Fat is then sucked out of your liver, and if you keep it up, the fat gets sucked out of your pancreas, and if you can catch it early enough, that can mean a reversal of your type 2 diabetes, meaning normal sugars on a normal diet. With a loss of 15% of body weight, nearly 90% of those who've had type 2 diabetes for less than four years can achieve remission, where it may only be reversible, and 50% of those who've lived with the disease for longer than 8 years. That's better than bariatric surgery, where those losing even more weight only got 62% and 26% remissions. Your forks are better than the surgeon's knives. Here's how much weight you have to lose to achieve various remission rates for those who've had diabetes for an average of three years. Lose about 30 pounds, and most newly diagnosed type 2 diabetes can reverse their disease. So an extended bout of physician-supervised water-only fasting could get you there, but you have to maintain the weight loss. One of the things we can say with certainty is that if you regain the weight, you regain your diabetes. To bring it full circle, the initial euphoria about medicine's greatest miracle that discovered Vinselin in 1921 soon gave way to the realization that while it was literally a lifesaver for type 1 diabetics, the use of Vinselin on its own in type 2 diabetics would not be enough to prevent the later onset of complications like kidney failure, blindness, stroke, amputation. So, as argued by one of the most famous diabetes pioneers, Elliot Joslin, self-discipline on diet and exercise, as it was in the days prior to Vinselin, should be central to the management of diabetes. Did you know that caloric restriction can boost levels of brain-derived neurotrophic factor, otherwise known as BDNF? In fact, I just wrote a chapter on it in my upcoming book, How Not to Age. Anyway, here's the story. For over a century, fasting has been espoused as a treatment of supposed great utility in the preservation of health, especially rejuvenating the body, but above all, the mind. But fast people, even just 18 hours, and they get all hungry and irritable. After one or two days, positive mood goes down, negative mood goes up, and by 72 hours, people can feel sad, self-blaming, and suffer a loss of libido. But then something strange starts to happen. After a few days, people experience a fasting-induced mood enhancement, decreased anxiety, depression, fatigue, and improved vigor. And that's what studies tend to show across the board. Once you get over the hump, fasters frequently experience an increased level of vigilance and mood improvement, a subjective feeling of well-being, and sometimes even euphoria. And no wonder, as by then your endorphin levels may shoot up nearly 50%. This enhancement of mood, alertness, and calm makes a certain amount of evolutionary sense. Yet, your body wants you to feel crappy initially, so you continue eating day-to-day when food is available. But if you go a couple of days without food, your body realizes it can't have you moping back in the cave, you've got to get motivated to get out there and find some calories. So, can fasting be used for mood disorders like depression? Yeah, it's great that you can get people to feel better after a few days of fasting. But the critical question revolves around the persistence of mood improvement over time once you start eating again. You don't know until you put it to the test. Interestingly, the little published evidence we have comes out of Japan and the former Soviet Union, and some of it is just ridiculous. Ten days of fasting, but they also kept them in bed all day, completely isolated with no contact with the outside world. So yeah, if people got better or worse, it'd be impossible to tease out the effects of just the fasting component. But they did apparently get better with efficacy, supposedly demonstrated in 31 out of 36 patients suffering from depression. They conclude that fasting therapy may provide an alternative to the use of antidepressant drugs, considering it a kind of shock therapy. People are so relieved to just be eating again to get out of solitary confinement, to even just get out of bed, they report feeling better. Yeah, but that was at the time of discharge. How did they feel the next day, the next week, the next month? Fasting is by definition unsustainable, so ideally what we want to see is some kind of longer lasting effects. So what the researchers did was follow up with a few hundred patients, not just a few months later, but a few years later. Of the 69 who were evidently suffering from depression, 90% reported feeling good or excellent results at the end of the 10-day fasts. And remarkably, years later, 87% of the 62 that replied claimed that they were still doing good. Now there was no control group, so we don't know if they would have done just as well or better without the fast. And it was just self-report, so maybe there was response bias, where you try to please the researcher. Or maybe they were afraid, otherwise they'd get sent back to the hole, and we have no idea. But we do have good evidence for the short-term mood benefits. The question is why? In addition to the endorphins when you fast, the surgeon serotonin circles happiness hormone. There is a bump in BDNF, brain-derived neurotropic factor, considered to play a crucial role in mood disorders. And it's not just because you perk up rodents with humans with major depression, have lower levels circulating in their bloodstream. Autopsy studies of suicide victims show only about half the BDNF in certain key brain regions compared to controls, suggesting they play an important role in suicidal behavior. You can boost BDNF with antidepressant drugs and electroshock, or with calorie restriction, a 70% boost in levels after three months cutting 25% of calories out of their daily diet. What effect does fasting and a plant-based diet have on traumatic brain injury and migraines? Let's find out. An uncontrolled and unpublished study purported to show a beneficial effect of fasting on migraine headaches, but fasting may be more likely to trigger a migraine than help it. In fact, skipped meals are among one of the most consistently identified dietary triggers of headaches in general. A review of hundreds of fasts at the True North Health Center in California, the incidence of headaches was nearly one in three. But True North also published a remarkable case report on post-traumatic headache. The CDC estimates that more than a million Americans sustain traumatic brain injuries every year, and chronic pain is a common complication. As in like three-quarters suffering such an injury, there are drugs, of course, to treat it there. Always drugs, and if that doesn't work, surgery, cutting the nerves to your head to stop the pain. What about fasting and plants? A highly debilitating condition, difficult to manage. A 52-year-old woman presents with unremitting chronic post-traumatic headache. And when I say chronic, I mean chronic pain for 16 years, but who then achieved long-term relief following fasting, followed by an exclusively plant-based diet free of added sugar, oil, or salt. Before then, she tried drug after drug, after drug after drug, after drug with no relief. Suffering in constant pain, her entire life started out in constant pain, but then after the fast, the intensity of her pain was cut in half. And though she was still having daily headaches, at least there were some pain-free periods. Six months later, she tried it again, and eventually her headaches were mild, under 10 minutes and infrequent, and she continued that way months and even years later. Now, of course, it's hard to disentangle the effects of the fasting, from the effects of the whole food plant-based diet she remained on, those ensuing years. You've heard of analgesics, pain killers? Well, there are some foods that may be pro-LG-sick, pain-promoting, such as foods high in arachidonic acid, which includes meats, dairy, and eggs. So, the lowering of arachidonic acid, from which your body makes a range of pro-inflammatory compounds, may be accomplished by eating a more plant-based diet. So, maybe that contributed to the benefit in the fasting case, whereas many plant foods are high in anti-inflammatory components. So, in terms of migraine headaches, more plant foods and less animal foods may help, but you don't know until you put it to the test. The researchers figured a plant-based diet may offer the best of both worlds, so they designed a randomized controlled crossover study, where those with recurrent migraines were randomized, due to strictly plant-based diet or to take a placebo pill. And then the groups switched. During the placebo phase, half said the pain got better, half said the pain remained the same or got worse, but during the dietary portion, they almost all got better. During that first blog, the diet group experienced significant improvements in headache number, pain intensity, days with headaches, and a reduction in the amount of painkillers they needed to take. In fact, it worked a little too good. Many individuals were unwilling to complete the study by returning to their previous diets. Remember, they're supposed to go back to the regular diets and take a pill instead, but they felt so much better that they were like, away Jose, and we've seen this with other trials, where those trying plant-based diets felt so good, they often refused to abandon them screwing up the study, so plant-based diets can sometimes work a little too well. We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to nutritionfacts.org slash testimonials. We may share it on our social media to help inspire others. To see any graphs, charts, graphics, images, or studies mentioned here, please go to the nutrition facts podcast landing page. There you'll find all the detailed information you need, plus links to all the sources we cite to each of these topics. My latest two books are How to Survive a Pandemic, available on ebook, audio book, or actual book, and the how not to diet cookbook, with more than 100 recipes for delicious and nutritious meals. All proceeds I receive from the sales of my books go to charity. NutritionFacts.org is a non-profit science-based public service where you can sign up for free daily updates on the latest in nutrition research via bite-sized videos and articles. Everything on the website is free. There's no ads, no corporate sponsorship. It's strictly non-commercial, not selling anything. I just put it up as a public service as a labor of love as a tribute to my grandmother, whose own life was saved with evidence-based nutrition.