Why can I handle tequila but not rum?

[MUSIC PLAYING] JANE LINDHOLM: Hey, it’s Jane Lindholm, filling in for Ira and Flora. And you’re listening to Science Friday. We are on the precipice of summer right now, so that means the season for porch beers and happy hours is upon us. I myself am partial to a midweek near beer these days. We nerds here at Science Friday have been thinking a lot about the science of alcohol. More data is coming out that shows it’s not really good for us to drink, but a lot of us do it anyway. So what’s going on in the chemistry of our alcoholic bevies? And what are they doing to our brains and bodies?

Joining me now are Dr. Tom Shellhammer, a brewer and professor of fermentation science at Oregon State University– he’s the past president of the American Society of Brewing Chemists– and Dr. Jacqui Barker, who studies what alcohol does to our brains and our memories at Drexel University’s College of Medicine. Welcome to Science Friday to you both. It’s great to have you with us.

JACQUI BARKER: I’m delighted to be here.

TOM SHELLHAMMER: Yeah, likewise.

JANE LINDHOLM: Jacqui, start us off. How do you think about this tension, that we know drinking isn’t good for us, but we do it anyway?

JACQUI BARKER: Sure. Yeah, I mean, I think one of the challenges is being informed. And I think it’s really awesome that you’re starting this conversation because being able to have the information to make a smart choice about whether you want to enjoy a beer or two beers, or maybe you make that near beer decision, it starts with that information. And I think there’s a growing appreciation that even small amounts of alcohol do impact our brain, do impact behavior, but so do a lot of other things we do– eating lunch meat, sodas, living in a city where you have to rely on cars. And so we’re all making choices across our lives about which rewards are valuable enough to us to maybe take some risk alongside them.

JANE LINDHOLM: Jacqui, do you drink?

JACQUI BARKER: I do.

JANE LINDHOLM: Tom, do you drink?

TOM SHELLHAMMER: I do.

JANE LINDHOLM: Yeah, for me, it’s soft serve ice cream, which, in Vermont, we call creemees. And I know it’s not doing me any good physically, but mentally, it is crucial to my mental health.

TOM SHELLHAMMER: Oh, yeah. I think we need to do things that make us enjoy ourselves and happy. And alcohol is part of that. I think it’s been part of that for millennia.

JACQUI BARKER: Yes.

JANE LINDHOLM: We have a lot of listeners who have questions about alcohol and its effects on us and things that we’ve heard over the years maybe, but don’t really know what the science says. So let’s start with this call that we got about alcohol.

MIKE: Hi, my name is Mike, and I’m calling from Santa Barbara, California. I’ve always wondered if it’s just kind of a psychosomatic thing, but do different alcohols affect different people differently? So when I drink tequila, I feel really good and almost no hangover the next day. But when I drink gin or rum, I feel pretty bad. And am I just making this up because I want to tequila? Or does it really have different effects on different people’s physiologies? That’s it. Thank you.

JANE LINDHOLM: I love this question because I have heard that so many times over the years that certain alcohol will make you feel a certain way, and others won’t. Is that right, Jacqui, or is it all in our heads?

JACQUI BARKER: Well, I think that the answer to this is yes and no. So– and I hope Tom will weigh in as well– but I think part of this is that the way we drink different alcohol is often very different. Tequila shots might look like a very different night than red wine on your couch. And the speed that you consume that alcohol, whether you’re eating with your alcohol or having a night out dancing, whether you’re staying hydrated alongside that is going to have a variety of different effects on that next morning and on how you associate learned experiences and environmental outcomes with that particular alcohol.

And so I think a lot of people– I hear, also, I have a really fun time. We used to call it getting wheels when I was in college when I have tequila. Or I always feel really relaxed and want to read a book when I have red wine. That’s not necessarily the difference of the alcohol. It’s the context and how you’ve learned to consume those alcohols.

JANE LINDHOLM: Yeah, Tom, what about the chemistry here? Is alcohol just alcohol just alcohol? Or are there differences?

TOM SHELLHAMMER: It kind of depends. So the basic production process of making any alcoholic beverage starts with some sort of fermentable sugar and yeast, Saccharomyces cerevisiae mainly, in some other cases, some different Saccharomyces or non-Saccharomyces strains. But these organisms are converting these fermentable sugars into ethanol. And ethanol is the alcohol that we find in all alcoholic beverages.

The starting material varies. Grapes are fermented to wine. Mash, malted barley, is fermented into beer. Agave is fermented into pulque. And these have ethanol in them, but they all have these other components that come from the starting material. That’s what makes wine taste different than beer that tastes different than pulque.

And then if we’ve got a distillation on top of that, we end up concentrating the ethanol, and we concentrate some of these other flavorings that are coming from either the byproducts of the fermentation or from the starting materials. So you ferment wine, you get brandy. You ferment beer, you get whiskey. Ferment pulque, you get tequila.

So on one hand, the ethanol part is a common thread amongst all these, but it’s these other minor components that make brandy taste different than tequila, or certainly, wine tastes different than beer. And as Jacqui pointed out, it’s the combination of these things and, also, then, what you do with that beverage by itself. Are you drinking tequila straight, or are you making margaritas out of it? If you’re making margaritas, you’ve got both sugar and salt there that have an interplay with the alcohol. And the cumulative effect kind of impacts how you’re going to feel that evening or the next morning.

JANE LINDHOLM: While we’re talking about how we react to alcohol, let’s listen to another call that we got.

BOB: Hey, I’m Bob calling from Fort Wayne. I was wondering why alcohol does and does not sedate certain people. Because the other night, I had about 13 shots’ worth of alcohol over the course of four hours on nearly an empty stomach, and I did not black out. I went to sleep at about 2:00 AM, and I woke up at 8:00 AM the next day feeling completely fine, except I ran around my entire neighborhood about five times over and absolutely wrecked my house. So I’m just wondering if it metabolizes into something different or how that sedation works for different people. Thanks.

JANE LINDHOLM: OK, well, that’s quite a story. Jacqui, what do you make of it and how we process alcohol?

JACQUI BARKER: So whether alcohol is sedative at a given moment for a person is going to depend on a lot of things. That will depend on the dose, how much alcohol. Certainly, Bob, I believe it was, consumed a fairly high dose of alcohol here. And that would certainly be a sedative dose across a large range of conditions.

My first thought is that Bob may have woken up still intoxicated, which drove him to be motivated to run around and perhaps impact his home in unexpected ways. I mean, I will say that as we metabolize alcohol, our blood alcohol concentration will come back down. And so you may reach some of those less sedative doses on both ends. So you have an ascending side and then a descending side of this blood alcohol concentration, in this case, where he’s consuming and then metabolizing. And so depending on the exact timing of the runabout, he may have been in that stimulatory phase of intoxication at that time.

TOM SHELLHAMMER: Jacqui, what do you think about tolerance in terms of for a person who is a regular consumer of alcohol versus someone who isn’t. I think these effects can be very different.

JACQUI BARKER: Yes, I completely agree, Tom. Absolutely people who are regular consumers do develop tolerance. It is absolutely the case that people who regularly drink, especially if they drink with– instead of being a regular binge drinker, for example, where you drink a large amount of alcohol only on Friday night, for example, someone who is drinking frequently on repeated consecutive days is very likely to develop tolerance and be able to consume higher amounts of alcohol without experiencing as high sedative effects or potentially those deleterious, acute consequences.

JANE LINDHOLM: I mean, Tom, Bob also didn’t tell us what was in the shots. Do things that are added to alcohol sometimes change the way we feel and react to them? I mean, some shots might have a lot of sugar in them. Some could even have caffeine or other things.

TOM SHELLHAMMER: Yeah, exactly. That’s exactly where I was going to. If you’re mixing caffeine and ethanol, that’s– I won’t call it amplifying combination, but a catalyzing combination. And that’s one reason why we don’t see caffeinated alcoholic drinks anymore on the market because they can be potentially dangerous. If you don’t really realize the alcohol level you’re consuming or the caffeine that you’re consuming, you’re cranking both of those up, and you get yourself in a dangerous spot.

JANE LINDHOLM: Well, that actually brings us to our next call.

SADIE: Hi, my name is Sadie. I’m calling from Burlington, Vermont. I feel like I always hear people saying, oh, you’re going to get such a bad hangover if you drink really sugary drinks, because the alcohol and the sugar. Is it the alcohol that’s actually interacting with the sugar that’s causing the issue, or is it just the combination of drinking and also having a lot of added sugar in the body, and the two of them put together is just too much?

JANE LINDHOLM: Tom, I saw you nodding as Sadie was talking about sugary drinks and the interaction.

TOM SHELLHAMMER: Yeah, I’m thinking less about a biochemical interaction, but more of like a sort of physiological, maybe lifestyle interaction. Sugar is one of these molecules that, as humans, we love. We’re just primed. We’re like little hummingbirds in some respects. So we love sugar. It stimulates that “I like it” button.

So that can potentially move people into consuming more alcohol than they had realized, particularly if you’re drinking very sugary drinks. Alcohol itself is a diuretic, so it has a dehydrating effect. Sugar amplifies that as well. So you’re moving yourself into this area where you’re going to be very prone to the detoxification effects of alcohol. You got this ethanol detoxification, but you also have this dehydration that– and you can feel like you’re drinking a lot. And in fact, you are, but your body is not hydrating. It’s actually dehydrated. You’re just kind of turning into a little human raisin, so–

JANE LINDHOLM: [CHUCKLES] We have to take a quick break. And when we come back, we’re going to talk about shifts in people’s tastes for alcohol and why low ABV is having a moment. Stay with us.

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All right. Let’s take another listener question.

KRISTEN: Hi, this is Kristen from Ventura, California. And I am dying to know more about the relationship with drinking alcohol, specifically wine, and how much do you need to be drinking to where you are most likely going to cause harm to your body. And the reason I’m asking that is, we’ve swayed back and forth.

As a nurse, I’ve seen it, the information say, oh, drinking a glass of wine is good for you. Then now it’s like, no, don’t drink any. None of it is good for you. But my question for you is, then, what do people in Italy and France– how are they getting away with it, or are they not? I do enjoy a glass of wine with dinner. It’s part of my culture. But again, I don’t want to be causing any harm. All right, thank you so much. Bye.

JANE LINDHOLM: All right, there’s a lot in that question. So how are we to make sense of this when people have had cultures of drinking for generations, in some cases? Jacqui, what do you think?

JACQUI BARKER: Yeah, so I mean, I think part of what was mentioned in that call is this idea of consuming alcohol with a meal. I do think that this reflects, in part, a cultural difference that was hit on a little bit there in the US versus other places where, often, in other cultures, you are having a glass of wine with dinner, not having as prevalent of a binge-like relationship as is seen often in the US.

But to the science, I think that there are very clear, emerging data that any alcohol is potentially having negative health consequences. Even a single glass of alcohol can increase risk for various cancers, cardiovascular disease. And again, being informed of that means you can make the right choice for you. Is it worth it to increase your risk at whatever level it is? And people can make that decision.

But I think some of those early studies, there have been controversy around this idea that people who drink low amounts of alcohol are healthier than abstainers. Some of the data around that seem to suggest that, actually, there are a variety of confounds. People who completely abstain from alcohol often have other co-occurring health conditions.

And so it may reflect that they have shorter life expectancy, other things that may drive the abstention, not drinking at all. And then that can artificially make it seem like our low drinkers are a healthier population. So it’s not causative there. There’s a lot baked into the data set that I think created that false impression.

JANE LINDHOLM: We’ve been hearing a lot recently about the difference in how we metabolize alcohol as we age, and that that can also make a really big change in how you experience drinking and whether and how much you choose to drink. Do you know about that science, Jacqui?

JACQUI BARKER: So it is definitely the case that alcohol metabolism is altered, as a range of metabolic outcomes as we age. Some of this is related to if you have been a chronic drinker across your life, potentially accumulated effects on the liver, which can, in fact, impact metabolism.

It also may be related to a greater medical treatment burden as we age. You might be taking additional medications that are metabolized by similar processes. And so that might impact outcomes as well. But it is definitely the case that we see physiological changes that can facilitate ethanol impacts where the same doses can have greater impacts as we age.

JANE LINDHOLM: Of course, Tom, not everybody chooses to drink alcohol, and some people choose to drink things that are like alcohol, but do not contain alcohol. And we’re seeing a really large growth in no or low ABV beer, where the alcohol has either been taken out or wasn’t brewed into the process. Can you talk a little bit about how those drinks are being made and how you see that trend going?

TOM SHELLHAMMER: Yeah, you’re correct, Jane. There’s a huge growth category in low and non-alcoholic beverages– beer, wine, and spirits. The divide that you have to cross to get from a non-alcoholic spirit, like from a spirit to a non-alcoholic spirit, is huge. The brewers have to cross a much shorter divide. It’s like only 5%, and so I think that’s why you’re seeing a lot of activity in this non-alcoholic beer space.

And the way that brewers are making non-alcoholic beer fall into three categories. One is to take a normal fermentation and just arrest it, stop it prematurely. Those are first-generation non-alcoholic beers. They’re not terribly satisfying because they taste very worty, very sweet. They’re kind of cloying. They don’t mimic a full-on alcohol beer.

Another approach is to use techniques where you take a full-strength beer and just remove the alcohol. And so you can do this by distillation or by membrane separation. What happens there is that in addition to pulling alcohol out, you’re also pulling out a lot of these other flavors, like we talked at the beginning of the show around higher alcohols or esters or other things that will move like the ethanol away from the base beer. And so you get a very bland product. And so in that case, brewers will do flavor add-backs that will take higher alcohol ester materials that have left and add those back to try to replace that, minus the ethanol.

And then a third approach is to use yeast that don’t ferment maltose. So the main sugar in a brewery mash is maltose. There’s a little bit of glucose, tiny bit of fructose, but mainly maltoses from a fermentability perspective and something called maltotriose. If we hunt for yeast that don’t metabolize maltose, then we get a very small fermentation. But it doesn’t bring the alcohol level above 0.5, which is kind of like a threshold for low alcohol.

And what really successful brands are doing are blending these different approaches. But some brands are doing great with this. You look at Guinness 0. It’s just taken off. It’s way outperformed what they thought when they first started this. And that’s on a big scale. We got smaller brewers like Deschutes that a big part of their brand now is their non-alcoholic line. You have Athletic. It’s a whole brewery that is just around non-alcoholic beer. And that brewery itself is like the fifth largest brand of craft beer.

JANE LINDHOLM: Wow.

TOM SHELLHAMMER: And that’s interesting. And it’s the one that’s growing. And like many breweries and wineries and distilleries, everything’s in a declining stage right now because of the demographics of young drinkers moving away from alcohol– the discussions we’ve had around health, a focus on lifestyle changes, people wanting to either not have as much calorific intake and maybe not as much inebriation or intoxication. So that’s driving this interest in the non-alcoholic space.

JANE LINDHOLM: Jacqui, I mean, we’re especially seeing this in younger generations that are coming into legal age for drinking and are choosing not to or are choosing to drink much less. Is that related to some of what we’ve been hearing about alcohol being less healthy, or is there something else afoot that you think?

JACQUI BARKER: I mean, I do think part of it, I hope, is public health messaging. We’re actually effectively communicating to people that there is negative consequences to high levels of alcohol intake. I do think there’s also very real behavioral changes in how young people are spending their Friday nights compared to– I’m not going to make any guesses about anyone’s age, but compared to how I spent my Friday nights. And I think that people tend to socialize very differently.

There’s also, in certain states, I think, access to legal marijuana has changed alcohol consumption as well. So there’s been, in some places, a shift from one substance to another. And some of this is also, in that case, non-caloric. And so there may be a perception that being California sober is perhaps healthier than other intake patterns. And so I do think that it reflects both, I hope, some of the public health messaging, but also, broader changes in the way that young people are spending their Friday nights.

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JANE LINDHOLM: Jacqui Barker is an associate professor in the Department of Pharmacology and Physiology at Drexel University’s College of Medicine. And Tom Shellhammer is a brewer and professor of fermentation science at Oregon State University. Thank you both for being with us and sharing this really interesting knowledge. Appreciate it.

JACQUI BARKER: Yes, it was fun. Thank you.

TOM SHELLHAMMER: Yeah, fun discussion with you guys.

JANE LINDHOLM: And that’s it for today’s show. If hearing this made you thirsty for more science content, you can tune into the podcast anytime. And hey, why not give us a review on your favorite podcast platform? Five stars, please. We’ll catch you next time. I’m Jane Lindholm.

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