198. Dynorphins: This Brain Chemical Is Why You’re Addicted to Junk Food

We all know that our favorite fast foods or processed snacks are bad for us. But for some reason, we keep going back to them. It turns out there might be a small silent chemical reason for that. It's a special group of chemicals called dynorphins. We're going to explore these brain chemicals and see how they influence our eating habits, especially when it comes to tempting junk food and those addictive ultra processed snacks. Dynofins are powerful players in regulating when or how much we eat and how our bodies manage that energy. Some new research found that injecting specific dynorphin into the brain of mammals caused them to eat more. But it didn't mess with anything else. A dynofin's job is even more complicated than normal eating. It turns out they play a much bigger role in impulsive eating than you might think. So exactly what do dinorphins do? We all know that our favorite fast foods or processed snacks are bad for us, but for some reason, we keep going back to them. It turns out there might be a small silent chemical reason for that. These peptides are found in our daily diet and play a huge role in why we keep eating junk food. I'm Gary Breca and you're listening to the ultimate human podcast where we dig into the real science of human performance, longevity and disease prevention. Today, we're going over something quite fascinating. It's a special group of chemicals called dynorphins. Now, if you're wondering what dynorphins are, don't worry. We're going to explore these brain chemicals and see how they influence our eating habits, especially when it comes to tempting junk food and those addictive ultra processed snacks. Spoiler alert. It turns out they play a much bigger role in impulsive eating than you might think. So what exactly do dynofins do? They latch onto what are called kappa opioid receptors, or cores for short. These receptors are sprinkled all over the brain, including areas that are very involved in reward and feeding. These areas are control centers for when and why we eat. Dynofins aren't floating around aimlessly. They help regulate how much we want to eat and even how our body handles energy once that food gets inside. Some new research found that injecting specific dynorphin into the brain of mammals causes caused them to eat more, but it didn't mess with anything else they were doing, like moving around or resting. This told researchers that dynorphins play a targeted and specific role in triggering appetite without being Involved in other behaviors. They also found that various parts of the dynorphin molecule and different dynorphins can stimulate appetite. That revealed the brain as a backup system to make sure that your feeding behavior gets activated properly. But the research has gone even further. Scientists bred special mice that don't produce dynorphins at all, and then fed them high fat diets, the kind of diet that's much more popular nowadays with these highly processed options. These knockout mice ended up getting much heavier than the normal mice, despite eating the same amount or even less in some cases. This tells us that dinerfins are more involved than only making us hungry. They also play a part in how the body controls weight, metabolism, and how efficiently energy is used from food. Usually, if you burn more calories than you intake, you lose weight. That rule gets a little loose here. Without dynofins, the body loses some of its ability to balance energy intake and weight gain, Possibly because dynorphins affect how our cells produce and use energy. It's pretty striking, especially when you consider the environment we live in today, where junk food is everywhere and metabolic problems like obesity are on the rise. A dynofin's job is even more complicated than normal eating. It's also involved in some unique eating behaviors, like binge eating. This is the urge to eat way more than you intended, Driven by emotional states or cravings. Dynofins are right there in the mix. It works on those kappa opioid receptors to influence how rewarding food feels, Specifically how much we want or crave it. Animal studies have shown that when drugs block these receptors, big binge or compulsive eating drops, Especially in animals prone to obesity. This overlaps quite a bit with what we know about addiction, because the same brain circuits involved in drinking alcohol or using drugs Also respond to these signals. This supports the growing idea that some people develop food addictions, where hyper processed foods kick off cycles of craving, binging, and withdrawal. Like feelings. Blocking these dynorphin signals doesn't just reduce overeating, but it also calms the bad feelings. It breaks the cycle of needing food to feel better, Only to feel worse when it's not available. This makes the dynofin core system a promising target for new treatments Aimed at controlling impulsive, compulsive eating patterns. Speaking of impulsive eating, let's talk a bit more about impulsivity itself. Impulsivity is a personality trait. You might know people who tend to act without thinking much, or want rewards right away without waiting These traits are often linked to greater chances of food addiction and overeating impairment. Animal studies have shown us that those with higher impulsivity are much more likely to engage in rapid, uncontrollable eating binges. Now, dynofins and their receptors step in here as well. This system dampens the activity of brain areas responsible for self control, especially the prefrontal cortex, which is the same brain region you rely on. Say no when you want that extra cookie, but you know you probably shouldn't have it. We when dynofins are in high quantity, the brakes on these self control areas weaken, meaning the temptation to go back for seconds or thirds wins even more often. This creates a perfect storm for impulsive eating, especially fueled by ultra processed foods that are designed to be irresistible. So if you ever wonder why those chips, cookies or fast food grab your attention, dyno fins might play a part in making it harder to resist. Now if we dig even deeper, let's touch on brain chemistry and reward. Ultra processed foods are experts at hacking our reward system. They flood our brain with dopamine in the nucleus acubens, the feel good hub, making you want more and more. But here's where dynofins add another layer of complexity. They actually attach to the receptors in the brain, which then actually reduce dopamine release. You're brought down from that feel good state. This leads to feelings of dysphoria or a kind of mild negative mood or dissatisfaction. Because you feel a little off, you may be pushed to eat more ultra processed food to chase that dopamine hit again. As this happens over time, the brain adapts, so the negative feelings from dynafrins ramp up while dopamine's positive effect slows down. This relationship creates a cycle where you keep chasing that reward, but it feels less and less satisfying. Dynorphin influences other neurotransmitters like dopamine, acetylcholine and glutamate, which help regulate how rewards are processed and how impulses are controlled. These widespread effects mess with how your brain balances wanting food and managing cravings, ultimately contributing to binge eating and loss of control. So what are some real life solutions that are currently being developed to implement into daily life? Well, thanks to ongoing research, pharmacological blockade of kappa opioid receptors is starting to look like a promising approach to reduce compulsive eating behaviors. In animal studies, drugs that block these receptors reduce binge eating and seem to restore healthier reward balance. Genetic differences in how dynofins and core are expressed might explain why some people struggle with food addiction and why treatments might need to be tailored to individuals. Looking ahead, researchers want to better understand how lifelong consumption of ultra processed foods impacts dynofin systems in humans and how this relates to obesity risk and impulsive eating. Also, broadening our knowledge of how dynafrins interact with other brain chemicals involved in this reward and impulse control will help paint a fuller picture. All of this will be crucial to developing smarter, more effective treatments. Summing it up Dynofins are powerful players in regulating when or how much we eat and how our bodies manage that energy, especially in the context of today's high fat, ultra processed diets. They play a big part in why binge eating and compulsive eating happens. By influencing brain reward systems and impulse control. Ultra processed foods exploit this system, leading to cycles of craving and overeating that are hard to break. But with new research targeting dynorphin pathways, there's hope on the horizon for better interventions that address impulsive eating and food addiction, which could also help slow down rising obesity and metabolic disorders. If you're someone who loves learning about the science behind health and you want access to deeper dives like this but live, then I want to personally invite you to my VIP community. Every single month, I go live with our VIPs in an exclusive Q and A where you can ask me anything. No gatekeepers, no fluff, just real answers backed by real data. And the Best part? Our VIPs get to submit topics for podcast shorts just like the one you heard. If you want to be a part of that group, get exclusive content, join the monthly calls, and help shape what we cover on this show. Click the link below in the show notes and join us. 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