How does alcohol cause hangovers? | Judy Grisel

0:00This is the TED Health Podcast. I'm Dr. Shoshana Ungerleider. Today, psychology professor Judy Griselle walks us through the anatomy of a hangover by exploring the surprising ways alcohol affects our bodies. We also discover which alcohols cause the worst hangovers. After the talk, I'll get deeper into the unique health risks associated with drinking alcohol for women, and how we might resist the social and cultural pressures that often lead to drinking. I'll even share why I decided to cut back. All this and more after the talk.

0:45In a 1973 study, 20 volunteers got drunk. Once a week, for eight consecutive weeks. Each time on a different alcoholic beverage and each time with precisely the same dosage. This was science, after all. The goal of this experiment was to find out which alcoholic drinks cause worse hangovers. Of course, it takes much more than one small study to answer such a question. Since then, science has learned a lot about hangovers, though some mysteries remain. The molecule responsible for hangovers is ethanol, which we colloquially refer to as alcohol. Ethanol is present in all alcoholic beverages, and generally speaking, the more ethanol, the greater the potential for a hangover.

1:30The symptoms and severity can vary depending on weight, age, genetics, and other factors. But still, hangovers generally share some common and unpleasant features. So how exactly does alcohol cause a hangover? And is there any way to reliably prevent one? Alcohol slows down the communication between neural cells. After someone has had their last drink, as the concentration of alcohol in the blood drops back to zero, the brain rebounds from sedation and swings in the other direction, entering a hyperactive state. This may lead to the tremors or rapid heartbeat associated with hangovers. It also makes sleep shorter and less restful than normal.

2:14But these effects are just the beginning. Alcohol impacts so many of the body's processes, throwing delicate balances off kilter. And even the most familiar hangover symptoms have surprising contributors. For example, alcohol disrupts levels of many hormones. One of those hormones is cortisol. Normally, fluctuating cortisol levels help regulate wakefulness throughout the day and night. So the disruption in cortisol during a hangover may cause people to feel groggy or disoriented. Another hormone alcohol interferes with is vasopressin, which normally decreases the volume of urine made by the kidneys.

2:52By decreasing levels of vasopressin, alcohol causes people to pee more and become dehydrated. Dehydration can lead to thirst, dry mouth, weakness, lightheadedness, and headache, one of the most common hangover symptoms. In addition to dehydration, hangover headaches can result from alcohol's influence on chemical signaling in the brain, especially on neurotransmitters involved in pain signaling. Alcohol can also damage mitochondria, which are responsible for producing the ATP that gives us energy. This may contribute to the fatigue, weakness, and mood disturbances experienced during a hangover.

3:31Meanwhile, alcohol stimulates the immune system, leading to inflammation that can damage cells within the brain, affect mood, and impair memory. And it can irritate the gastrointestinal tract and inflame the lining of the stomach and intestines. Alcohol may also slow down stomach emptying, which could lead to increased production of gastric acid. This is why alcohol can cause stomach pain, nausea, and vomiting. Alcoholic drinks also contain other substances that are produced during the fermentation process that give the drink its specific flavor. Some evidence suggests that one of these, methanol, is particularly bad for hangovers.

4:11The body doesn't start metabolizing methanol until it's done processing ethanol. And when it does, the toxic metabolites of methanol may potentially worsen hangover symptoms. Beverages that are closer to pure ethanol, such as gin and vodka, may cause fewer hangover effects. Meanwhile, the presence of flavor ingredients in beverages like whiskey, brandy, and red wine may make these kinds of alcohol cause more hangover symptoms. So, the choice of alcoholic beverage matters. But any of them can cause hangovers simply because they all contain alcohol. So do common hangover remedies actually work? Drinking water and electrolyte beverages can help reduce symptoms related to dehydration.

4:57And eating, especially carbs, can help replenish the glucose levels alcohol reduces. But ultimately, the only sure way to prevent a hangover is to drink alcohol in moderation. Or not at all. Hey there, it's Dr. Shoshana. So we just heard all about the science of hangovers. And chances are, you've experienced a hangover at one point or another. That's how common they are. Or more precisely, that's how common it is to drink. In America, we live in an alcohol-centric society. Our social events seem to naturally involve drinking, whether we're catching up with friends and family, celebrating important milestones, cheering for our favorite team, or just unwinding from a long day.

5:43And while we may think that celebrating an achievement with a toast of champagne or having a glass of wine with dinner is one thing, binge drinking can pose even more serious health risks. Sadly, it's a widespread occurrence on college campuses, claiming too many young lives each year. Given how much alcohol is a part of the average American's life, it seems almost surprising to consider that alcohol is technically a poison to our bodies. According to the World Health Organization, alcohol is a carcinogen that's linked to seven types of cancer. It's one of the few substances that not only causes a release of chemicals in your body, it also has a poisonous effect on cells and can cause cellular damage.

6:27The toxicity of alcohol kills cells and damages proteins and DNA. It's no wonder that it's linked to all sorts of health conditions like high blood pressure, heart disease, liver disease, disorders of the nervous system, digestive problems, and more. For women, the risk of developing alcohol-related health issues is even higher. It also affects us differently. For example, in general, women weigh less than men, so it doesn't take as much alcohol to cause damage. And because women have less water in their bodies than men, they tend to have a more concentrated blood alcohol level and a greater potential for harm.

7:04According to a 2015 study, women who drink excessively are more susceptible to alcohol-related heart disease than men, even if they consume less alcohol. And lastly, research shows that women who have just one drink a day have an increased risk for breast cancer compared to women who don't drink at all. So while we often focus on the dangers of binge drinking, even consuming alcohol in smaller doses can pose a risk to your health. There's a lot of good reasons not to drink, especially if you're a woman. I'm lucky that in my life, I've never felt too drawn to alcohol. I mean, I drank with my friends socially, but usually not too much.

7:44And if I did have one too many, I definitely felt hungover the next day. And that was enough of a deterrent to keep me from making that mistake too many times. I'm now comfortable simply ordering sparkling water or a mocktail at a bar or restaurant, even while everyone else is drinking. There's no shame in being sober. But understandably, it can be really hard for people to resist drinking alcohol, especially given the social and cultural pressures in this country that encourage it. And certainly, for people who have an alcohol addiction, this is much more complicated. But it looks like acceptance for not drinking is growing.

8:20Today, there's even a new wave of sober bars sweeping the country. Sober bars first appeared in the 19th century during the temperance movement, but they're now enjoying somewhat of a modern-day remake and resurgence, catering to people who want to socialize without the booze. And not drinking means I end up being the designated driver for a lot of outings. But the truth is, I really don't mind, and I get to use all of those calories I didn't spend on alcohol for the one vice that really matters. Dessert. The reality is, because alcohol is toxic, it's pretty impossible to call any amount of it truly safe.

8:58And despite some recent reports linking light drinking to a slightly longer lifespan, there's still no hard data that any amount of alcohol is better than none at all. Everything in moderation seems like a reasonable adage, but in the case of alcohol, the data shows it's best avoided altogether.

9:21Thanks so much for listening today. This episode was produced by Joanne DeLuna and fact-checked by TED. And special thanks to Anna Phelan, Sammy Case, Maria Lajas, Michelle Quint, and Colin Helms. I'm Dr. Shoshana Ungerleiter. Stay well, and I'll talk to you next week.