Intermittent Fasting: Reset Your Clock, Cut Inflammation, Boost Mood

Hey there everybody, and welcome to this presentation on intermittent fasting and its impact on circadian rhythms, chronic pain, mental health and more. I'm your host, Dr. Donnellice Snipes. In this video, we're going to define what is meant by intermittent fasting. We'll explore the impact of intermittent fasting on the body and the brain. We'll review some diseases and conditions that are currently being addressed with intermittent fasting. Finish up by talking about some contraindications or who shouldn't use intermittent fasting. Of course, it's important to remember that any changes to your diet or exercise routine should always be reviewed with your doctor. So let's talk about intermittent fasting. It has become a very common phrase among people these days. But what does it mean and why? Why did it come to be of such prominence? Well, during evolution, people whose brains and bodies functioned well in a fasted state were more successful in acquiring food for survival and reproduction. So think about those cavemen. The ones who were able to successfully hunt and do what they needed to do in a fasted state were the ones that survived. The ones that sort of lost all ability to do anything when they were hungry. They didn't do so well. With fasting, our blood sugar reserves are reduced and ketones are produced from fat. A lot of people are familiar with the term ketones because of the ketogenic diets that are out there. Intermittent fasting is not necessarily a ketogenic diet, but during the fasting phase, ketones are produced. When the ketones are produced from fat, the body can switch to a cellular fuel source of the ketones instead of using glucose, which causes adaptations in the body and brain that they found enhance the body's resistance to stress, injury and disease and even enhances cognitive and physical performance in the fasted state state. Wow. Who knew? There are two basic varieties of the intermittent fasting diet. The tf, or time restricted feeding type is when people restrict their feeding to a particular number of hours per day. So they may fast for 16 hours and eat during an eight hour window. Or they may fast, fast for 18 hours and eat during a six hour window. You see where we're going? Ultimately, the research has indicated that for intermittent fasting to be effective for most people, the fasting window should be at least 14 hours. The fasting window can be planned during nighttime to help people maintain their circadian rhythm and make it easier to comply. I know I find it really hard, but to fast all day long. Sometimes people do it especially for religious reasons. And there are certain benefits to fasting during the day. However, I personally find it more difficult not to eat during the day. Another variety of intermittent fasting is called alternative day fast, alternate day fasting, 24 hour fasting periods which are characterized by eating 25% of your caloric needs. So if you Normally eat, require 2000 calories to maintain your weight, you're only going to ingest 500 calories during that on that fasting day. The next day you're going to eat as normal. And this can be repeated two or three times a week. During intermittent fasting, there are marked metabolic changes which are is really kind of cool to see how our body adapts to the stressors of not having food, but also how it adapts and how fasting actually impacts our circadian rhythms and our hormones. When we go into a fasting glucose levels, our blood sugar levels are elevated during feeding. So after you eat, your body uses some of that blood sugar, it stores what it needs to and then your blood sugar levels remain high for about six hours after your feeding period ends. Once fasting begins, the available glucose decreases as your body goes through it. And insulin and IGF1, the insulin like growth factor 1 levels are also reduced. Eventually the glucose stores are exhausted, your blood sugar stores are exhausted. We've all been to that place, place where we don't have any blood sugar left. We feel like our blood sugar is really low. And this is usually after about 10 to 14 non exercising hours. It's fewer hours if the person is exercising. But if they're not exercising after about 10 to 14 hours of fasting, then the body switches over to using ketones as a primary source of food. Fuel, fatty acids and ketones become the main source of energy for the cells. The transition is called intermittent metabolic switching or glucose to ketone switchover. So what we see here is basically switching fuel sources. And for a lot of us, our bodies are not used to that. So this when it does switch over, when our blood sugar gets low, it's really hard for our body to switch over to ketones because it's not used to doing intermittent fasting. Strengthens our ability or makes our body more effective and efficient at switching over fuel sources. So after somebody is engaged in intermittent fasting for a while, a lot of times they find it's much easier to do. They don't even notice the switch from glucose to ketones. How does intermittent fasting impact the body? In a lot of ways, blood pressure improvement is seen during the period of the intermittent fasting. If the person practices intermittent fasting for a month or two months or whatever, and they are maintaining those windows of fasting and eating. Blood pressure stays down. If they stop doing the intermittent fasting and they go back to eating kind of willy nilly whenever and they don't have those fasting windows and then blood pressure resumes where it was prior to the intermittent fasting. So this isn't something that somebody can do for a month or even three months and then go back to their old habits and have the changes persist. It's something that we're really looking at as a lifestyle. Not everybody's willing to commit to it, but some people are. So I figured we'd talk about it a little bit more. During intermittent fasting, brain health is also improved. During that fasting state, we see the release of brain derived neutrophic factor, which is a hormone that promotes neurogenesis and neuroprotection. So it's going in there and it's starting to protect all those neurons. Remember we've talked in other videos about how we're under stress and the glutamate levels and the excitatory neurochemical can get too high, and when those chemicals get too high, we see neuronal destruction. Well, BDNF actually helps protect or buffer against those excitatory neurochemicals, so we see neuroprotection instead. Cognition is actually improved. Glucose, blood sugar, or ketones can be used by the brain for energy. Intermittent fasting improves the switch between the energy sources. So when your blood sugar gets low, especially if you're not used to intermittent fasting, your brain has a hard time switching over and going, oh, I can pull from the fat resources for energy. Once you've done it for a while, it switches over sort of seamlessly. Fat is a much denser source of energy at about 9 calories per gram. So with all the fat that we have in our bodies, even people who are quite lean, you've got some fat that can go a long way to supporting thinking and supporting cognition. Circadian rhythms are also altered in accordance with the feedback feeding schedule. They find that when the fast is broken, when the person starts to eat, is when their circadian rhythms are altered. And so the feeding itself serves to help set the circadian rhythms. If you watched my video on circadian rhythms, you know that activities, daylight and internal and external temperature all help set our circadian rhythms. When we eat, what happens? Our internal body temperature goes up a little bit. Cholesterol, total cholesterol and low density cholesterol levels are improved in Intermittent fasting, collagen. Interestingly enough, wound healing is also improved in intermittent fasting. If the body is in a fasted state state it tends to be able to heal much more efficiently. And I didn't really understand all the neurochemical aspects of that, but the study was, the studies that I looked at were very clear that certain hormones and chemicals were released that supported the healing of skin based wounds. Energy and motivation is also increased. Increased alertness, arousal and increased mental acuity. And we're going to talk about why this might be when we get down to the impact on mood heart disease. With intermittent fasting. The studies have shown a reduction in atherosclerosis, which is the inflammation and narrowing of arteries due to that's kind of when we talk about getting those clogged arteries. Intermittent fasting has been shown to help reduce some of that inflammation and reduce the buildup of those plaques and insulin levels. Intermittent fasting has been shown to reduce fasting insulin, which is a known contributor, interestingly enough, to cartilage degeneration in osteoarthritis. So people who have high levels of fasting insulin evidently have increased cartilage degeneration, which eventually leads to arthritis. So it's another one of those buffer things that can be really helpful in terms of inflammation. There's a reduction in generalized pro inflammatory Factors, including homocysteine, interleukin 6 and C reactive proteins in people when they are engaging in intermittent fasting. When they're switching back and forth and they're giving their body that break from constantly having insulin levels elevated, they find that inflammation goes down. And in the microbiome, intermittent fasting positively modulates the microbiome and has more beneficial effects than a water only fast fast. So one of the studies that I looked at looked at a water only fast or a intermittent fasting like we talked about that has on the fasting day, the person consumes up to 25% of their needed calories. And they found that in terms of the microbiome, the gut seemed to heal itself better and it balanced out the microbiome more effectively if it did have some nutrients even on the fasting day. Now, I told you we would talk about what intermittent fasting is being looked at or researched for. And it's a bunch of stuff in terms of Alzheimer's and dementias. Intermittent fasting has been shown to be helpful partly because it reduces inflammation, but partly also because it improves the brain's ability to, to use glucose and switch over to ketones when needed. Autoimmune disorders including Crohn's colitis, rheumatoid arthritis, ankylosing spondylitis, asthma and diabetes have all been shown to show some improvement under intermittent fasting. Now, is it going to be the be all, end all treatment? No, but it is another tool in your toolbox. In people with intestinal disorders like Crohn's and colitis, intermittent fasting may promote intestinal regeneration, partly because during part of the day, part of the 24 hour cycle, the intestines have a break and they're able to heal, but also because the inflammatory factors are reduced, so they don't have as much inflammation going on, which means there's not as much stress. And we know when the body senses stress, whether it's physical or emotional, it alters the microbiome. And that stress microbiome can contribute to intestinal inflammation and flare ups. In terms of cancer, there's been a lot of research on intermittent fasting with cancer. When people engage in intermittent fasting, it increases adiponectin levels and upregulates downstream signaling pathways, which may be useful as an anti cancer agent. So this adiponectin is a really interesting chemical that they're looking at for helping reduce tumor proliferation. The use of the intermittent fasting diet increases adiponectin levels even if there's no change in weight. So we talk about intermittent fasting and I keep using the word diet and I'm just using that term as a method for ingesting food. I'm not talking about necessarily weight loss, but they found that the adiponectin levels, this chemical is increased in the body when the body becomes more effective at responding to insulin, more effective at switching over to ketones, even if the person doesn't lose weight, even if they are still, quote, clinically obese. Although they found that people that are in a normal weight range, which is a BMI of 18.5 to 25, and y' all know I don't like BMI measurements because they don't capture the whole picture. But in terms of the studies, they still use bmi. So that's what we're going to use for a point of reference here. But people with a BMI of 18.5 to 25 tend to have better adiponectin levels. And if they have a, if they're within that normal, normal weight range and then they also begin using intermittent fasting, there's an increased improvement in their adiponectin levels. Some studies have found reduced cancer activity when fasting during activity periods. So a couple of the studies I looked at were studies in which the people ate before daylight, they fasted all day long, and then they ate again at sundown and repeated the cycle. And they found that this tended to be super helpful for addressing cancer in some people. Now, they don't quite understand why fasting at different times and for different periods. The timing and amount of fasting impacts different cancers in different people. So it's something definitely to discuss with your oncologist. However, the research is somewhat promising for people who are trying to prevent cancer that if they engage in intermittent fasting, that it might help increase those adiponectin levels and serve as a protective factor. Is it going to completely prevent it? Probably not, but it's again, another tool in the toolbox. We already talked about intermittent fasting to help lower cholesterol levels. It's not just oats that lower cholesterol or statins. Intermittent fasting has been shown to be very, very helpful at reducing cholesterol levels in people of all ages. It's been shown to be helpful at reducing blood pressure and atherosclerosis. I don't know why I can't say that today. And we talked about that one already. And intermittent fasting has also been looked at in terms of chronic pain. And it's not just because intermittent fasting is associated with a reduction in inflammatory cytokines. It's also associated with an increase in our natural, our endogenous endorphins, our natural painkillers, as well as neurotransmitter mediated volume control. In other videos I've talked about serotonin, for example, as a neurotransmitter that's associated with pain perception. When people's serotonin levels are too low, their pain tolerance is also a lot lower. When their serotonin levels are in normal range for them, their pain tolerance tends to be a lot higher. When people engage in intermittent fasting, one of the effects, and one of the most promising effects in my field is the fact that it's been shown to increase levels of serotonin, norepinephrine and dopamine. Again, these are systemic levels, not necessarily just in the brain. But it is encouraging to note that the levels of these monoamines, these chemicals increase in response to intermittent fasting. When serotonin goes up, for example, especially in the brain, there is the ability to basically turn down the volume of the pain. It increases the person's pain threshold, however you want to put it. But the increases in serotonin, norepinephrine, and dopamine also are significantly correlated with people's mood. What do we look at when we talk about antidepressant medications? Selective serotonin, norepinephrine and dopamine reuptake inhibitors. What those medications do is make those neurochemicals more available. Well, intermittent fasting does that. Intermittent fasting in a couple of studies was shown to increase mood and perceptions of well being within seven to 10 days of starting the intermittent fasting protocol, as opposed to antidepressants, which can take up to six weeks. Can antidepressants be taken in conjunction with intermittent fasting? Sure, probably. It's something to discuss with your treatment team whether that might be a useful component of your of your regimen. It is important to note that short term fasting may have negative effects. When people select a fasting window that is too long or for the initial couple of days, especially if they're fasting during the day, they may experience a significant amount of frustration and irritability. Especially if those people were using food to self medicate their depression to increase their serotonin and dopamine, then being blocked from that can actually make them feel worse in the short term. This is another one of those times where you've got to weigh the costs and benefits, but also consider the timing. Some people who find that the short term fasting, they get cranky and much more irritable and maybe even more depressed in the short term find that if they do the fasting overnight, they stop eating at 4 or 5 in the afternoon, then they go to bed, they sleep, they get up and then they begin eating at 8 or 9 the next day. It's not nearly as distressful to them. Epilepsy and fibromyalgia have also been shown to be positively impacted by intermittent fasting. And polycystic ovarian syndrome has also been positively affected by intermittent fasting. Because during the intermittent fasting periods, testosterone is reduced and ovarian inflammation is also reduced. So both of those work together to improve the hormonal and ovarian health profile of people with pcos. In a lot of the subjects that were studied, their hormonal cycles actually returned to normal and they resumed menstruation once they began intermittent fasting. Parkinson's disease is another condition for which intermittent fasting has been shown to be somewhat helpful as well as sleep phase disorders, since intermittent fasting alters when cortisols peak and it can help the body set its circadian rhythms. Remember, your cortisol levels are supposed to Peak first thing in the morning and then decline throughout the day. Well, when people are engaging in intermittent fasting, if they are sort of manually setting when those cortisol levels peak, then they are better able to set their sleep phase. They're better able to time when their body is going to start releasing melatonin because it's a gradual decline, the cortisol, until the release of melatonin. They also have shown, though, that for people who are engaging in intermittent fasting, there is an increase in REM sleep. So people with sleep disorders that involve a lack of REM sleep may find that this helps improve their sleep quality. In terms of contraindications, there's not a lot. Obviously, you need to talk with your doctor if you've got diabetes or cardiovascular disease or if you're on medications to make sure that you do it in a way that is helpful. Likewise, if you have any mood disorders, definitely talk it over with your treatment providers to make sure that you don't trigger something. There was one study that I looked at in which people with bipolar disorder were able to trigger a relapse in their in their cycling or trigger to relapse in their cycling with intermittent fasting. But then there were other articles that talked about an improvement in the bipolar symptoms in, in people with bipolar disorder. So the evidence is kind of mixed for people with bipolar disorder, likewise for people with schizophrenia. Remember that schizophrenia is associated with too much dopamine. So intermittent fasting may trigger a relapse of psychotic symptoms or a worsening of psychotic symptoms, because part of what it does is increase dopamine levels. So there was an article that cautioned against intermittent fasting, especially unsupervised in people with schizophrenia. In people who are pregnant, intermittent fasting is something to be seriously discussed with your obstetrician because it may have negative effects on the fetus. And for people with eating disorders, it's kind of dicey here because people with eating disorders tend to become very focused on what they're eating and sometimes obsessive about eating schedules and eating regimens. So this can actually feed into those symptoms and exacerbate or trigger a relapse in people who have a history of eating disorders, which is again, the reason that it's important to talk to your medical team prior to starting intermittent fasting or any other dietary change. Intermittent fasting promotes a regular cycle of feeding and fasting, which helps set your circadian rhythms and including hormones like cortisol, ghrelin and leptin, your hunger and satiation hormones and testosterone. Intermittent fasting has been associated with positive changes in mood, sleep quality energy partly because of an improved sleep quality, cardiovascular risk Factors, inflammatory markers A1C or blood sugar levels, pain perception and wound healing. The timing and size of the Eat Fast window should be discussed with your medical team to optimize the beneficial effects for you.