Liquid Truth: What Alcohol Does to Your Body and Brain
Episode Notes

May 1, 2025 -- How much alcohol is actually safe – and are there any true health benefits? We speak with David Nutt, MD, author of Drink? The New Science of Alcohol and Your Health, to explore what alcohol really does to your brain and body. From fertility to gut health, mental health to emotional health, we break down the risks, debunk common myths, and discuss how to better understand and counsel others around alcohol use.

Transcript

Neha Pathak, MD, FACP, DipABLM: Welcome to the WebMD Health Discovered Podcast. I'm Dr Neha Pathak, WebMD's Chief Physician Editor for Health and Lifestyle Medicine. Have you ever wondered what's really happening in our brains and our bodies when we reach for that second or third glass of alcohol? Maybe you've heard alcohol described as good for your heart or safe in moderation, but what does the latest science say about drinking alcohol?

In today's episode, we'll take a step-by-step approach to alcohol consumption and risk. We'll discuss the latest research and how alcohol affects everything from anxiety and sleep to our gut microbiomes and cancer risk. And we'll answer the important questions you've been asking — things like, how exactly does alcohol affect my brain and body?

Why do many of us turn to alcohol to ease anxiety and depression, and can that habit actually make those conditions worse over time? Is there really a safe amount to drink, or is the idea of moderate drinking actually putting us at greater risk for conditions like breast cancer, liver disease, and cognitive decline?

Are there healthier alternatives to alcohol that still help us unwind and socialize without the harmful side effects? We will also explore why our society often ignores the risks associated with alcohol and how emerging trends — like the rise of being "sober curious" — are changing the way we think about drinking.

We will also dig into what we should ask our healthcare providers if we're concerned about how much we're drinking. Whether you're curious about cutting back, completely abstaining, or just want a clearer understanding of alcohol's complex role in your health, this conversation will give you the clarity and practical insights you need.

But first, let me introduce my guest, Dr David Nutt. Dr Nutt is a psychiatrist and the Edmond J. Safra Professor of Neuropsychopharmacology and Director of the Neuropsychopharmacology Unit in the Division of Brain Sciences at Imperial College London.

He's the author of the book Drink? The New Science of Alcohol and Your Health.

Welcome to the WebMD Health Discovered Podcast, Dr Nutt.

David Nutt, MD: Well, thank you for having me.

Pathak: Before we jump into our chat for today, I'd love to just ask about your own personal health discovery and your own sort of aha moment in your research as a psychopharmacologist — someone who studies and explores how drugs affect the brain and behavior. What made you hone in on alcohol?

Nutt: As a doctor — as almost every doctor — sees problems with alcohol from the very first day they go to medical school, and I was no different. But I suppose the aha moment came for me when I was doing my PhD. I was working on the way in which GABA, the GABA neurotransmitter, controls brain function. I was studying things like seizures and antidepressants on GABA.

One day I studied the effects of alcohol on GABA. I discovered that I could reverse intoxication in a rodent with a GABA blocker. And I thought, wow, I have an alcohol antagonist — an antidote. And I went running off to my professor. I think I said, "I've got an antidote! You know, we're gonna get the Nobel Prize!"

And he said, "Well, what's the point of that?" And I said, "Uh, well, you know, people could sober up and they could drive home safely and, you know, all sorts of positives." And he just said, "Well, yeah, but wouldn’t they just carry on drinking more?"

Yeah. I never got the Nobel Prize. Went back to the bench. But it made me realize that you could approach alcohol from a receptor function.

Up to that point, people had thought alcohol was a solvent — it just dissolved the brain. Now we know it very much isn't — at least in the concentrations that most people get when they're drinking. It's targeting neurotransmitters and receptors, and that gives us the opportunity to intervene — and also replace it, which is what I'm trying to do.

Pathak: So you've described alcohol as the most harmful drug in the United Kingdom, and there's a lot of strong, growing scientific evidence about the risks of alcohol. What do you think fuels society's ongoing acceptance of alcohol despite all of the scientific evidence about its harmful potential?

Nutt: The first thing is, we are very familiar with alcohol, and that familiarity breeds contempt, as the sort of English saying goes. So every family in Britain, I would contest, has someone who's been damaged by alcohol — either by drinking too much, or getting into trouble when they're drunk, or being damaged by someone who was drunk. But they still drink.

And the reason for that is that alcohol is the best drug for socializing. The reason alcohol exists in human society is because it allows us to overcome the innate anxiety we have when we meet other people. As I like to say, humans are a very social species. The reason we are the absolute dominant species on the planet is because we socialize. We put all our brain powers together and we achieve amazing things.

So we love socializing — but we're not very good at it. And alcohol makes us socialize better than no alcohol, which is why it exists.

Pathak: So can you talk a little bit then about what is going on in our brains when we take in alcohol?

Nutt: So alcohol has a very complex pharmacology. It's a very, very simple molecule — and that’s the problem. Because it's so simple, it can get into very many different enzymes and proteins and receptors, and it does it in a stepwise ladder fashion.

So the first drink of alcohol begins to turn on the system in the brain I was working on back in the 1970s with my PhD — the GABA system.

GABA is the main calming neurotransmitter in the brain. If you reduce levels of GABA, you are anxious — and anxiety is associated with low levels of GABA or GABA function. Alcohol restores GABA function to normal. So it takes away anxiety. That’s why it relaxes you, makes you more sociable, more convivial — first drink.

But then, when you continue to drink, you move up this stepwise fashion. You begin to get to alcohol doing other things, like releasing dopamine. And if you release dopamine, you are doing something rather similar to cocaine. Dopamine is a very activating transmitter — it gives you a lot of drive and energy. Also makes you happy — but also irritable. And it also begins to get you into the process of dependence.

And then, if you carry on drinking, you also begin to release endorphins. Endorphins — the endogenous opioids — are very strongly related to addiction, to liking, and to desiring.

And if you keep on drinking, you release some serotonin. That is one of the reasons alcohol is a sort of bonding drug.

But then, when you get to about 150 milligrams percent of alcohol — sort of twice or three times the driving limit in different countries — then you get into a serious problem, because then alcohol blocks glutamate.

Now, glutamate is the on switch of the brain. And if you block the on switch, your brain switches off. That’s why people start to get blackouts — because to lay down any memory requires glutamate activity. And if you block it, you can’t lay down a memory. So you have a blackout.

And then, of course, if you keep pushing the glutamate blockade, you end up becoming anesthetized — and then eventually, you stop breathing and die.

Pathak: As you're speaking, it resonates with that initial question, which is, for a lot of us, we think of risky alcohol use as potentially someone else — someone who's doing this every single day, or taking in alcohol every day or at certain amounts — and that if we're staying within certain limits, then we're drinking safely. And then there's also this question about potential health benefits that folks may have heard about.
So can you talk a little bit about dispelling some of those myths?

Nutt: One of the reasons it's taken a long time to have a proper public discourse on the harms of alcohol is because we don't want it to be harmful. The majority of adults in America, in the UK, and in Western countries drink alcohol. So we don't want it to be harmful. So we're always looking for excuses to believe it's good for us.

And one remarkable story that was told — and has only recently just been properly disowned — is the idea that small amounts of alcohol are good for your cardiovascular system. The so-called French Paradox: you know, if you drink red wine, you have antioxidants in the red wine, and that protects your heart. And there was data supposedly showing a J-shaped curve — that particularly in men over the age of 50, a bit of alcohol reduced cardiovascular risk.

Now we know that that may be true, but it's only true if you live in Provence. If you live in Belfast or Scotland, alcohol doesn't seem to have any protective effect on the cardiovascular system. In fact, it's very hard to find any evidence that alcohol is helpful on any bodily system.

And now, that's why countries are beginning to revalidate or essentially dial down their recommendations. In the UK, we recommend no more than 14 units, which is about 140–160 mL of pure, absolute alcohol a week. In Canada, they've recommended no drinking. And the truth is, if you want to have no risk for anything, you don't do it at all.

My take is different, though. My take is that the risks of alcohol to most people are relatively low — if they don't drink more than a couple of drinks a day.

Pathak: So can you help us break down this concept of alcohol and its risk to various medical conditions?

Nutt: Just in the way alcohol has different effects on different transmitters at different doses in the brain, it has different effects on the body in different doses. The risk — it's become more clear in the last 20 years. Hence the Surgeon General's report, hence the Canadian government's revision of guidelines — is that there is a real risk of alcohol and cancer.

For instance, alcohol is, I think, the only known causative factor in breast cancer that women can do anything about. You know, if you've got the BRCA gene, then drinking alcohol — almost any level of alcohol — will put you at risk.

In fact, if we put alcohol through the safety toxicology testing you'd have to do to make it a food or a medicine, it would fail. The safe, maximum recommended limit of alcohol consumption per year is about a medium glass of wine.

Now the reality is — unless you are, I think, very vulnerable to cancer risks, as some women are — most people aren't going to be at risk if they're drinking at relatively low levels.

So, for instance, if you're concerned about liver cirrhosis, liver disease, then a drink a day is very unlikely to cause liver disease. But once you go over two drinks a day, then the level goes up.

And there's one other aspect we mustn't forget, which is that the problem — as we all know with alcohol — is that in some people, they lose control. And we now know that binge drinking — getting really drunk twice a week — is more damaging to your body and your brain than using the same amount spread out over the week. So less is better, and not bingeing is better.

Pathak: Folks might not necessarily understand their risks for long-term health concerns with that type of drinking pattern.

Nutt: Yes. Binge drinking is particularly problematic for the brain. It also is the kind of drinking that tends to lead to people being very vulnerable to accidents, because they're clearly drunk or doing stupid things like walking off a sidewalk into a car.

So, a lot of the brain damage from alcohol comes from people being drunk and then getting head injuries. It's not just the toxicity of alcohol or the toxicity of a hangover — it's the fact that they damage their brain because they're intoxicated and fall over and get hit, etc.

Pathak: Can you talk a little bit about what happens to our mental health if we do start self-medicating with alcohol because we have anxiety or we might have some level of depression?
So what's happening in the long term with alcohol?

Nutt: Yes. Well, of course, there are two main drivers to people becoming alcohol dependent. One of them is young people — young men often — who have a genetic vulnerability. Sons of alcoholics have a much higher risk of becoming alcoholics.

But the majority of people who are alcohol dependent are people who develop alcohol dependence in their twenties and thirties because they're using alcohol to deal with problems — such as anxiety, such as depression, such as trauma. We know a lot of veterans who've got PTSD — they turn to alcohol just to numb the memories.

And the alcohol does numb — there is no doubt. But the problem is, the numbing itself damages your ability to get control of those emotions. And then, when you stop drinking, you're going to withdraw — and they come back even worse.

I mean, withdrawal is a state of hyper-anxiety. For depressed people, withdrawal is often associated with increased depression, and the traumatic memories can come back as well.

So then you get dependent. You have another trauma. In fact, we've done work on people who are basically co-dependent. Very many of them had an initial trauma, but then the traumas that come from drinking and messing up the rest of your life — destroying your family, destroying your relationships, destroying your job — you get a vicious circle of worse trauma.

So, the message is very clear: alcohol is not a medicine for any psychiatric disorder.

Pathak: How should we think about counseling people — personalizing this recommendation for their individual risk?

Nutt: Well, I say: know your number. People should know some facts about themselves. They should know their weight, they should know their waist circumference, and they should know their blood pressure. They should know their cholesterol, and they should know how much they drink.

And with all those measures, for most people, you should always be trying to reduce them. So, know what you're doing. Then think about how you can deal with it now.

And then, if you can go two, three days a week without any alcohol, that is particularly good — because that gives your liver optimal time to recover.

Pathak: So, we've been talking about some of the health harms of alcohol on our physical health, and research shows that alcohol can harm the body on multiple fronts. So, can you talk a little bit about the harms on our gut health, potentially our fertility, or things that people don't necessarily know so much about?

Nutt: Alcohol, particularly spirits, are not very good for the mouth, they're not very good for the esophagus—the gullet—and they're not very good for the stomach. They tend to damage the lining of the intestines. When I was training in medicine, you know, drinking and smoking were causing vast numbers of stomach ulcers.

We now have, obviously, medicines that can help people reduce that risk, but it's still there as a risk. But the more interesting thing now is we're understanding that alcohol can have a negative effect on the microbiome. We clearly know, you know, the bugs in your gut—you need a lot of good bugs in your gut. Alcohol can get in the way of the good bugs, but also, by eroding and interfering with the stomach lining and the small intestine lining, it can also predispose for the absorption of toxins from the bad bugs.

And actually, the other thing I should mention is alcohol does suppress immune function. So you've got a sort of double whammy—you're actually making toxins more easily enter the body, and then your immune system is suppressed so it can't kill them.

So, there's a growing interest in seeing if we can promote the microbiome to protect against the toxicity in people who are drinking. That's some research we're doing ourselves. And in terms—yes, in terms of fertility—drinking is clearly anti-fertile. So if you want to have children, it's best not to drink when you're trying to conceive.

Pathak: So, for the person who's listening, if they are sort of thinking about their own alcohol use or a loved one's alcohol use, and they want to, at their next appointment with the healthcare professional, talk about reducing their intake—what are some of your suggestions about bringing up this topic and communicating with their healthcare professional that this is something that they're interested in doing?

Nutt: Well, in the UK, it is a measure of necessary competence that people have to be asked about their drinking. So it's used the other way around—people denying their drinking rather than presenting and asking. But it is a very important question.

So, I think the answer is to go in and, if you're concerned, specify why you're concerned. For instance, one of the most important messages anyone can have is someone saying, "You drank too much last night." If someone says that to you, you really should take it on board because it's a difficult thing to say—particularly for a friend to say it. And if they're concerned about your drinking, you should be concerned.

So that would be a way of introducing the concept: "People—my friends—are worried I'm drinking too much. Doctor, can you help me evaluate that?"

Pathak: I also just kind of wanted to take us down the path of societal costs, societal expectations. As you were talking about, in certain societies, drinking alcohol is part of the culture. And I do definitely see a shift in some of my social circles, where people sort of felt like, “Okay, yes, I want to actually stop. I don’t want to drink at all. I really want to be what they're calling ‘sober curious.’” So, can you talk to us a little bit about how you're seeing some of this shift in society? What should we be doing as healthcare professionals to assist or be part of this type of conversation?

Nutt: We should be celebrating—particularly that younger people are beginning to turn away from alcohol. And we don't know why that is. I think there are several factors. One of them is that they're becoming more health-conscious. The second is that they're actually not so well-off as they were.

And alcohol can be quite an inexpensive way of having fun. And I know we can make functional alternatives—herbal alternatives—which will give people some of that relaxation that will allow them to socialize without the complications and the potential harms from drinking alcohol.

Pathak: So, can you talk a little bit more about that research? Tell us a little bit about what you're working on and some of the potential benefits.

Nutt: Well, all my professional career—dating back really to the 1970s, when I finished my training in medicine—I’ve been working in the field of addiction and alcoholism. And the first 20 years, I was trying to find antidotes, as I told you my story.

And about 20 years ago, I was working for the British government on a sort of foresight program. How could we use brain science to help people who've got addictions? We had a year’s brainstorming, and during that, I suddenly realized alcohol is far too complicated and promiscuous a drug. We cannot find an antidote to all the effects of alcohol—it's just not possible. And I thought, "Well, why don't we just replace it? Why don't we find a small molecule which will do the good things about alcohol—make you sociable and relaxed—and not do all the bad things?"

And I’ve been working on that for the last 20 years, and we’re making significant progress. So currently, we do have on the market—in the UK, in Europe, and in America—a herbal drink called Sentia, which contains a range of herbs which are known in some countries for centuries to be relaxing. And they work through GABA—they enhance GABA in a similar way to alcohol enhancing GABA.

They give you the effect of like half a glass of wine or half a pint of beer, and that's enough for most people. It relaxes them, and it doesn't mess with their sleep, and they don’t get hangovers. So, it's become quite popular with people who are trying to minimize the risk of alcohol—and particularly minimize hangovers, which is another reason we didn’t talk about. Why young, professional people—hangovers really get in the way of your productivity. So, if you could avoid that and still have fun, you know, that’s a real incentive.

Pathak: So, talk about how alternative GABA enhancers hit you.

Nutt: Well, we call it a GABA spirit. You've got alcohol here. You've got non-alcoholic drinks, which often smell the same as alcohol—you know, you've got gins which are just water and juniper smell—which give you some of the flavor, but very little of the effect. But in the middle, we and a number of other companies are developing these functional drinks which give people enough relaxation to really get in a relationship with others, but not enough to get them drunk.

It's an alternative, and some people find it very helpful. And some people deliberately mix the two—they have a glass of alcohol and they have a glass of Sentia—because they know they can still maintain the benefits, like alcohol, without the harms.

Pathak: Thank you so much for being with us today. We've talked with Dr David Nutt about alcohol consumption and risk. My key takeaways from this discussion are:

Number one, we have a roadmap of how alcohol affects our brain with each sip—starting with anxiety relief and escalating to dopamine release, endorphin release, and, when we consume too much, potential blackouts.

There’s no clear health benefit for consuming any amount of alcohol. Although moderate consumption was once thought to be protective or supportive of our overall health, the latest evidence challenges the idea that any amount of alcohol has any definitive health benefit.

In fact, alcohol use is linked to increased risks of serious health conditions like breast cancer, liver disease, high blood pressure, gut health issues, and fertility problems.

We also talked about how alcohol is not a mental health solution. While alcohol temporarily masks feelings of anxiety, depression, or trauma, it can worsen these mental health conditions in the long term, leading to dependence and a cycle of deeper emotional distress when sober.

Binge drinking is especially dangerous. Drinking heavily on a single occasion can be more damaging than drinking the same amount spread out over time. Binge drinking patterns raise the likelihood of accidents, head injuries, and acute damage to organs like our liver, as well as contribute to the risk of dependence over time.

There are an incredible and growing number of swaps for alcohol when it comes to drinking—from functional alcohol-free beverages to simply limiting intake and spacing out drinking days. There are many ways to reduce alcohol-related harm.

Talking openly with your healthcare provider about your concerns is also essential to find healthier ways to manage alcohol consumption.

To find out more information about Dr Nutt and his work, make sure to check out our show notes. Thank you so much for listening. Please take a moment to follow, rate, and review this podcast on your favorite listening platform.

If you'd like to send me an email about topics you are interested in or questions for future guests, please send me a note at [email protected]. This is Dr Neha Pathak for the WebMD Health Discovered Podcast.