What Alcohol Does to Your Body Brain Health by Personal Gym Trainer in Dubai Abhinav Malhotra AbhiFit UAE - Part 3

What Alcohol Does to Your Body, Brain & Health – Part 3

In this third and final part of the article “What Alcohol Does to Your Body, Brain & Health”, we cover

  • Gut-Liver-Brain Axis, Gut Microbiome, Inflammation & Leaky Gut
  • Improving / Replenishing Gut Microbiome
  • Reducing Alcohol Consumption & Stress
  • Hangover, Anxiety, Sleep, Headache
  • Hangover Recovery, Deliberate Cold Exposure & Adrenaline
  • Hangover Recovery, Dehydration & Electrolytes
  • Hangover Severity, Types of Alcohol & Congeners

For the first part of the article, please click here

For the second part of the article, please click here

Gut-Liver-Brain Axis: Alcohol, Gut Microbiome, Inflammation & Leaky Gut

One of the more serious effects that we should think about is the impact on the gut-brain axis, or for sake of discussion, the gut-liver-brain axis.

You have a brain. You have a gut. The gut runs from your throat down to the end of the intestine. The gut and the brain communicate by way of nerve cells, neurons and nerve connections, the vagus nerve in particular, and by way of chemical signalling. The gut also communicates by way of chemical signalling and, neural signalling to the liver. And, the liver is the first site in which alcohol is broken down or metabolized into its component parts. The liver is also communicating with the brain through chemical signalling and neural signalling, so we have the gut-liver-brain axis.

And what you find is that people who ingest alcohol, any amount, are inducing a disruption in the gut microbiome, the trillions of little micro bacteria that are resident in the gut and that help support immune system and literally signal by way of electrical signals and chemical signals to the brain to increase the release of things like serotonin and dopamine and regulate your mood generally in positive ways.

As alcohol kills bacteria and it is indiscriminate with respect to which bacteria it kills, so when we ingest alcohol and it goes into our gut, it kills a lot of the healthy gut microbiota. At the same time, the metabolism of alcohol in the liver, which you now understand, that pathway involving NAD, acetaldehyde, and acetate, that pathway is proinflammatory, so it’s increasing the release of inflammatory cytokines, things like IL-6, et cetera, tumour necrosis factor alpha.

You’ve now got disruption of the gut microbiota. As a consequence, the lining of the gut is disrupted, and you develop, at least transiently, leaky gut. That is, bacteria that exists in the gut which are bad bacteria can now pass out of the gut into the bloodstream. So, now you’ve got bad bacteria from partially broken-down food moving out of the gut, the good bacteria in the gut have been killed.

You might say, why doesn’t the alcohol kill the bad bacteria in the gut? Well, the bad bacteria that are from partially digested food oftentimes escape the gut before the alcohol can disrupt them, and so now you’ve got leaks in the gut wall, you’ve got the release of this bad bacteria, you’ve got inflammatory cytokines and other things being released from the liver, and they are able to get into the brain through what’s called a neuroimmune signalling.

You take in something that disrupts two systems, the gut microbiota, and it disrupts in two ways, it’s killing the good gut microbiota and it’s allowing the bad bacteria to move from the gut into the bloodstream, you’ve also got proinflammatory cytokines coming from the liver, and those converge or arrive in the brain and create a system in which the neural circuits cause more drinking. So, this is just terrible.

That’s a bad situation. And this is why people who drink regularly end up with a situation in which they have inflammation in multiple places in the brain and body and the desire to drink even more and to further exacerbate that inflammation and the gut leakiness.

Improving / Replenishing Gut Microbiome

There are ways to improve/replenish gut microbiome, there’s at least some promise for the ability for this system to repair itself. What are ways to improve the gut microbiota, in particular, to reduce the production of inflammatory cytokines and to adjust what’s called the inflammatome. The inflammatome is the total array or at least the near-total array of genes and proteins that control inflammation. How can you reduce inflammation and make that inflammatome healthier? Well, two to four servings of fermented foods per day, and here, we’re not referring to fermented alcohol. I’m talking about low-sugar fermented foods, things like kimchi, sauerkraut, natto. There are others like kefir or things like yogurts that have a lot of active bacteria, again, low-sugar varieties. Those are terrific at reducing inflammatory markers and at improving the gut microbiome.

A huge component of the negative effects of alcohol use disorder are based in this gut-liver-brain axis and disruption of the gut microbiome and the inflammatory cytokines. It stands to reason that things that are well-established to improve inflammation status, in other words, reduce inflammation, such as ingesting two to four servings of low-sugar fermented foods per day, makes sense in terms of trying to repair or replenish the system. One could also imagine taking probiotics or prebiotics. Certainly, that would work as well, although I’ve sort of favoured the discussion around fermented foods and replenishment of the gut microbiome mostly because there are more studies that have examined that in humans and because of the direct relationship that’s been established between doing that and reducing negative markers within the inflammatome.

Reducing Alcohol Consumption & Stress

Many people ask the question, well, if I drank a lot previously, am I doomed? Can I reverse the negative effects? Or, I’m trying to drink less and I’m trying to improve my health as I do that. What should I do? Well, certainly focusing a bit on the gut microbiome ought to be useful.

As people wean themselves off alcohol, even if they’re not full-blown alcoholics or have alcohol use disorder, they should understand that that increase in cortisol that we talked about earlier leads to lower stress threshold and greater feelings of anxiety and stress, that’s going to be present and it’s going to take some time to dissipate. So, for some people, it might even just be helpful to realize that as you try and wean yourself off alcohol or maybe you even go cold turkey, that increased anxiety and feelings of stress should be expected. You can find a ton of behavioural, nutritional, supplementation-based, exercise-based tools to help in this.

Hangover, Anxiety, Sleep, Headache

Now about a fairly common phenomenon, which is post-alcohol consumption malaise, also referred to as hangover. Hangover is a constellation of effects ranging from headache to nausea to what’s sometimes called hangxiety, which is anxiety that follows a day of drinking.

Hangxiety, I think we can understand physiologically if we think about that process of alcohol intake increasing the amount of cortisol and the ratio of cortisol to some other stress hormones. That well explains why some people wake up the day after or even the day the day after a night drinking and feel anxious and not well and stressed for reasons they don’t understand. So, if you’re somebody who experiences hangxiety, then, use the tools to deal with anxiety, tools to deal with stress, ranging, again, from behavioural to nutritional and supplement-based, et cetera. That, of course, is not justification for going out and drinking so much that you get hangxiety-induced hangover.

The sleep that one gets after even just one glass of wine or a beer is not the same sleep that you get when you don’t have alcohol circulating in your system. Dr. Matthew Walker from UC, certainly supported by lots and lots of quality peer-reviewed studies in animals and in humans, says that when alcohol is present in the brain and bloodstream the architecture of sleep is disrupted. Slow-wave sleep, deep sleep, and rapid eye movement sleep, all of which are essential for getting a restorative night’s sleep, are all disrupted. So, for those of you that are drinking a glass or two of wine or having a hard liquor drink or a beer in order to fall asleep, the sleep you’re getting is certainly not as high-quality as the sleep you’d be getting if you did not have alcohol in your system.

When we’re talking about hangover, we’re talking generally about the consumption of more than just one or two drinks. Of course, for some people, one or two drinks is probably sufficient to induce hangover. When one ingests too much alcohol, one of the reasons they feel terrible the next day is because their sleep isn’t really good sleep. In fact, it’s not even sleep. It’s often considered pseudosleep because people are in kind of a low-level, hypnotic kind of trance, it’s not real sleep, there are multiple bouts of waking up, they may not even realize they’re waking up multiple times.

In terms of headache, we know that that’s caused by vasoconstriction, the constriction of blood vessels that tends to occur as a rebound after a night of drinking. Alcohol can act as a vasodilator; it can dilate the blood vessels. Part of that is associated with the increase in so-called parasympathetic tone. We have an autonomic nervous system and it’s got a sympathetic component. These are neurons that make us more alert, and if they’re very active, they make us very stressed. There’s also the parasympathetic aspect of the autonomic nervous system.

This is all just fancy geek speak for the parts of your brain and body, the nerve cells that make you very relaxed. When you’re very relaxed, there tends to be vasodilation. It allows for more movement of blood and other things through the bloodstream, and alcohol tends to induce some vasodilation, at least in some of the capillary beds. And then when the alcohol wears off, there’s vasoconstriction and people get brutal headaches. That’s why some people will take aspirin or Tylenol or Advil or things like that, the sort of non-steroid anti-inflammatories.

So, I’m not one to tell you what medications to take or not take, but you certainly would want to do a quick web search of effects of non-steroid anti-inflammatories and aspirin before you start taking those, or stop taking those, for that matter. Generally, they will alleviate headache, but they can often have other issues, including liver issues.

There’s the lore that to avoid hangover one should simply ingest more alcohol. What terrible advice that is. That’s just going to delay an even worse hangover. However, I’d be remiss if I didn’t say that the reason that myth came to be, or that, I should say, that truth came to be, because indeed ingesting more alcohol will alleviate a hangover but then a worse hangover will show up, the reason that came to be is because ingestion of more alcohol will cause those constricted vessels that are giving the headache to dilate again. But, of course, ingesting more alcohol to relieve a hangover is simply a bad idea. Just don’t do it.

Hangover Recovery, Deliberate Cold Exposure & Adrenaline

One thing that you’ll hear out there is that deliberate cold exposure, for instance, taking a cold shower, might relieve hangover. How to use deliberate cold exposure for sake of treating hangover?

There is some evidence that increasing levels of epinephrine in the bloodstream can actually help with alcohol clearance. There’s some evidence pointing to the fact that when levels of epinephrine, adrenaline, are raised in the brain and bloodstream, that some of the components of alcohol metabolism can be accelerated and some of the inebriating effects of alcohol can be reduced. So, maybe this old school lore of taking a cold shower actually has something to it.

The way to do that is to understand that alcohol lowers core body temperature. It can make people slightly hypothermic. So, if you were inebriated and you went and got into a body of water, a pool or a lake or something, first of all, that’s extremely dangerous to do while you’re inebriated, right? People drown and die, so please don’t do that. Moreover, if it’s very cold water, your core body temperature is going to drop even further. Now, when people are not ingesting alcohol, they get into an ice bath or a cold shower and their body temperature initially dips but then it rebounds and increases. That’s a process that’s going to occur when people do not have alcohol in their system.

But when you have alcohol in your system, one of the reasons that you become hypothermic is because there’s a disruption in those hypothalamic brain areas, in particular, the brain area called the medial preoptic area that regulates core body temperature. So, it’s not so much that alcohol makes you cold, it’s that alcohol disrupts the central command centres of the brain that control temperature regulation, and that leads you to be slightly hypothermic. So, if you then go get into a cold shower or an ice bath, there’s the possibility of you going very, very far down the ladder into very hypothermic territory and that can be very dangerous.

Therefore, in terms of dealing with hangover, when the alcohol has been largely cleared from your system, well, that’s where if you can spike adrenaline, and certainly getting into an ice bath or getting into a cold shower will sharply increase your adrenaline and, your dopamine. You get these long, extended increases, several hours of increases in dopamine from deliberate cold exposure. It’s well-documented in humans.

So, one could use deliberate cold exposure as a way to accelerate the recovery from hangover provided that’s done safely.

Hangover Recovery, Dehydration & Electrolytes

Is dehydration associated with alcohol? Alcohol is a diuretic. For multiple reasons, it causes people to excrete not only water but also sodium. Sodium is an electrolyte critical for the function of neurons, so making sure that you have enough sodium, potassium, and magnesium, so-called electrolytes, is going to be important for proper brain function, bodily organ function. Even for people that have just had one or two drinks the night before, it’s likely that your electrolyte balance and your fluid balance is going to be disrupted, and that’s because alcohol also disrupts the so-called vasopressin pathway. Vasopressin interacts with and controls different aspects of water retention and water release from the body in the form of urine.

Having electrolytes at the proper levels before you drink is ideal. Some people will say for every glass of alcohol that you drink, you should drink one glass of water. I would say better would be two glasses of water given the dehydrating effects of alcohol, and even better would be water with electrolytes. That certainly would set you up for a better day the next day. The next day you could take some electrolytes upon waking, maybe even some before you go to sleep the night of drinking.

Hangover Severity, Types of Alcohol & Congeners

There have been studies of which types of alcohol lead to the greatest hangovers. There’s actually a lot of legend and lore about this as well. Some people have said, for instance, that drinks that have a high sugar content lead to greater hangovers. Turns out that’s not the case, or at least that’s not what the science points to. If you look at the expected hangover severity, what you find is that at the bottom end of the scale, or near it is, for instance, beer. The consumption of beer, provided it is not overconsumption, right, it’s not far beyond the tolerance of the individual, so it’s one or two beers, is less likely to cause a hangover than, say, whiskey. And a glass of whiskey, or, you know, not as much whiskey as beer, of course, but a glass of whiskey, for instance, is more likely to cause hangover than gin, as it turns out. And yet a glass of rum or red wine is more likely to cause a hangover than any of the other things mentioned so far. At the top, top, top of the list of drinks that induce hangover is brandy.

And one could then say, “Well, doesn’t brandy have a lot of sugar? Maybe it’s the sugar that’s causing hangovers.” And this is something that’s been, again, discussed over and over, that people say, “Oh, it’s the high-sugar drinks that cause hangover.” If it were sugar that’s causing hangover, well, then the ethanol diluted in orange juice would probably be at the top of the list in terms of inducing hangover. But it’s not, it’s at the bottom of the list, and brandy is at the top of the list. So, what you find is that what scales from ethanol diluted in orange juice to beer to vodka to gin, in the ascending hierarchy of things that cause hangover, gin, white wine, whiskey, rum, red wine, and then brandy at the peak, what’s increasing are congeners within those drinks.

Congeners are things like nitrites and other substances that give alcohol its distinctive flavour and that also lead to some of the inebriating effects of alcohol. Now, then you ask, “Okay, well, what is it that these congeners are doing? And what are these nitrites doing?” And guess what? While they do have effects on the brain and on other tissues, their main effects are to disrupt the gut microbiome.

So, what this points to again is that having a healthy gut microbiome and perhaps ensuring that you bolster your gut microbiome the day after drinking is going to be especially important for warding off hangover or at least reducing the effects of hangover or the symptoms of hangover or both.


Hangover is made worse by disturbed sleep, made worse by disrupted gut microbiome, made worse by disrupted electrolytes, and made worse by the depletion of epinephrine and dopamine. That’s why replenishing the microbiome with low-sugar fermented foods, using safe, deliberate cold exposure for spiking adrenaline and increasing dopamine, and consuming electrolytes are all going to be beneficial.

Please contact me Abhinav Malhotra to learn what I and my team AbhiFit can do for you through personal training and nutrition services. We train kids, teens, adults, elders, athletes and models in Dubai and online across the UAE and around the world. We help our clients achieve their fat loss, weight loss, muscle gain, strength gain, rehab, figure / physique transformation & healthy living goals.

Many female and male clients including kids, teens, adults and elderly people have greatly benefited from Abhinav’s strong experience as the best personal trainer and nutritionist in Dubai, UAE. You can see some of our client transformations here here.

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1. Link

Client Transformations - Best Personal Training and Trainers in Dubai, UAE – Abhinav Malhotra, Team AbhiFit - 8 August 2022
Boosting Immunity through Diet and Exercise - Dubai UAE Best Personal Fitness Trainer Abhinav Malhotra

About Author

Abhinav Malhotra

Abhinav Malhotra is an award-winning personal trainer, coach and sports nutritionist in Dubai, UAE. He also offers online services to clients around the world. A personal trainer par excellence, Abhi has worked with the world’s leading fitness chains, supplement brands and founded his own fitness academy in India. He has achieved successes for many clients from all backgrounds and has trained the Indian Army Rugby Team. He is the first International Kettlebell Sport athlete from India.

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