Cold Plunges: What the Science Shows

Summary

Chasing Life — "Cold Plunges: What the Science Shows"

Host: Dr. Sanjay Gupta (CNN Podcasts)
Date: January 20, 2026

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Episode Overview

In this episode, Dr. Sanjay Gupta responds to listener questions on health, focusing first on the increasingly popular trend of cold plunges—full-body immersion in cold water—and examines what the current science says about their claims, benefits, and risks. Dr. Gupta also addresses a second listener question about the science of itching and how to effectively manage it. The episode maintains a conversational, approachable tone, rich with practical advice, scientific insight, and personal perspective.

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Key Discussion Points & Insights

1. Are Cold Plunges Actually Good for Reducing Inflammation?

[00:27–09:01]

• The Popularity & Promise

  • Cold plunges, or cold water immersion (CWI), have become a global wellness trend, especially prominent in Nordic countries ("winter bathing").
  • Proponents claim a range of benefits: stronger immune system, cardiovascular improvements, quicker muscle recovery, reduced inflammation, calmer nervous system, and better mental health.

• Scientific Evidence: Mixed and Limited

  • Small, Recent Studies
    • Research is recent, largely small-scale, and results are inconsistent; no regulatory requirement for rigorous evidence collection in wellness fads.
  • Meta-Analysis (2025)
    • Out of 11 studies on CWI, immediate and 1-hour post-exposure showed a significant increase in inflammation markers—contrary to claims.

      "Inflammation actually went up in the immediate time of the cold plunge and continued that way for one hour post exposure."
      — Dr. Sanjay Gupta [03:48]

  • Ironman Athlete Study (2021)
    • With 29 participants, CWI had no effect on inflammatory markers or athlete recovery.
  • Netherlands Study (2022)
    • 48 healthy men tested breathing exercises, cold plunges, or both.
    • Breathing exercises reduced inflammation; cold exposure alone did not. However, combining them enhanced the effect.
    • Conclusion: Cold plunges alone do not demonstrably reduce inflammation, but may amplify other anti-inflammatory interventions (like breathing exercises).

• Cautions & Risks

  • Immediate Physical Effects
    • Cold shock response triggers "fight or flight," rapidly increasing heart rate and blood pressure.
  • Dangerous for Certain Conditions
    • Risks for those with heart conditions, those on beta blockers, people with diabetes, peripheral neuropathy, poor circulation, and certain autoimmune diseases.
    • Potential for hypothermia, nerve or skin damage, difficulty breathing, and fainting (especially when alone).
    • Cleveland Clinic and other institutions have issued warnings.
  • Dr. Gupta’s Emphasis:

    “There are a lot of cold water evangelists out there, and their personal anecdotes are pretty compelling. ... But before you dive in, you should know that this isn’t always just a harmless health fad.”
    — Dr. Sanjay Gupta [06:06]

• Practical Tips if You Try Cold Plunges

  • Consult your doctor, especially for underlying or unknown medical conditions.
  • Try other remedies for inflammation or pain first (e.g., localized ice packs).
  • If proceeding: start slow, use partial immersion, limit exposure to 30–60 seconds, check water temperature (avoid under 50°F), and never plunge alone.

    “Don’t try to plunge your entire body in at once. Maybe start with an arm or a leg before getting to the whole body.”
    — Dr. Sanjay Gupta [08:17]

• Summary Judgment

  • Current evidence does not support cold plunges as a definitive way to reduce inflammation.
  • Risks are real; personal anecdotes are not a substitute for data.
  • Localized ice packs remain useful for spot injuries or inflammation (always use a towel barrier; limit to 10-minute intervals).

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Notable Quotes

• On Evidence and Anecdote:

  “That doesn’t mean cold plunges don’t necessarily make you feel better, even if there’s not a lot of evidence behind it. But it does mean we want to think through the benefits and the risks a little bit more carefully.”
  — Dr. Sanjay Gupta [01:38]

• On Scientific Uncertainty:

  “There is no conclusive, obvious benefit to cold plunges alone when it comes to reducing inflammation. ... The evidence and the science around this is still new, it is still limited.”
  — Dr. Sanjay Gupta [05:37]

• On Risk:

  “When you plunge into cold water, you’re essentially triggering what is called a cold shock response, rapidly increasing heart rate and blood pressure.”
  — Dr. Sanjay Gupta [06:26]

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2. What’s Really Going on When You Can’t Stop Scratching an Itch?

[10:29–15:20]

• Physiology of Itching

  • Caused by complex interactions of skin, immune, and nervous system signals.
  • Signals from skin are carried to the brain, which interprets the sensation as itch.

• Common Causes

  • Dry skin, bug bites, allergies, hives, certain medications, and psychological factors (stress, anxiety).
  • Neuropathic itch is caused by nerve dysfunction, sometimes related to arthritis or shingles.

• Why Scratching Feels Good (But Can Make It Worse)

  • Scratching releases pain-fighting molecules (like serotonin) in spinal cord, temporarily dampening itch.
  • Scratching also reduces activity in the brain's anterior cingulate cortex, lessening focus on the itch.
  • Vicious cycle: Scratching can release more itch-inducing chemicals (histamine), making it even more intense.
  • Brain’s reward system gets activated when scratching—explaining why it is so compulsive/addictive.

• Relief Strategies

  • Over-the-counter creams: hydrocortisone, antihistamines, anesthetics (lidocaine), menthol, camphor.
  • Moisturize to prevent dry skin.
  • Use a cool compress/ice pack (wrapped, for 5–10 minutes).
  • Try “habit reversal”—engage hands with another task during likely scratching triggers.
  • If psychological in origin, consult a mental health professional.

• Notable Moments

  • Dr. Gupta acknowledges that “just don’t scratch” is unrealistic for most people, given the neurological basis behind scratching urges.

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Section Timestamps

• Cold Plunges Discussion: [00:27–09:01]

  • Evidence review: [02:30–05:37]
  • Risks: [06:06–07:56]
  • Practical advice: [08:17–08:56]

• Itching Science & Advice: [10:29–15:20]

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Memorable Moments

• Dr. Gupta’s summary on the limits of current evidence:

  “Maybe one day we’re gonna have a deeper understanding of cold water immersion, cold plunges. But at this moment, the evidence is mixed and the risks are real."
  — [08:43]

• On the frustration of itching:

  “You shouldn’t feel bad about not being able to stop scratching. It’s a powerful force for that very reason.”
  — [12:48]

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Tone & Language

Dr. Gupta maintains an empathetic, scientifically rigorous, but accessible and conversational tone. He emphasizes evidence-based medicine while acknowledging the emotional and psychological realities behind health behaviors.

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Summary Conclusion

This episode of Chasing Life delivers a careful and grounded exploration of cold plunges: while culturally intriguing and anecdotally appealing, current science offers no solid support for inflammation reduction and underscores the risks, especially for those with underlying health issues. Dr. Gupta’s advice: assess your personal health risks, proceed cautiously, and consult with your doctor. The segment on itching similarly peels back the biological and psychological complexity behind common impulses, offering both understanding and practical guidance.

Transcript

[Dr. Sanjay Gupta]

Foreign. Welcome to Paging Dr. Gupta. Thank you so much for joining us. This is one of my favorite parts of the week. I get to connect with you. I get to hear from you and hopefully answer your questions. Jesse's back with us today to help us go through the questions. Who do we have first? Hey, Sanjay. The first caller didn't leave a name, but their question is a great one that I think a lot of people can relate to. Check it out.

[Caller (e.g., Stephanie or unnamed caller)]

I have arthritis in my C5 and a ruptured disc in my C6. So I'm dealing with quite a bit of inflammation and discomfort there. I've read conflicting information on whether cold plunges can be helpful to reduce inflammation. So I'm just wondering if you have any insight into the benefits or potential risks of cold plunges. Thanks so much. Bye.

[Dr. Sanjay Gupta]

Okay, well, first of all, I'm sorry you're dealing with arthritis and a disc issue in your cervical spine in your neck, and I hope you're getting good care for that. First things first, sometimes there are all sorts of different treatment options, possibly even surgery. I'm a neurosurgeon. These are the types of operations I do. So I do want to make sure you're getting all the best care that you can possibly get. Your question, though, about cold plunges, Great question. I know a lot of people who love them. You see about these cold plunges in videos and podcasts, and, you know, I just got back from Denmark in places like Finland and Iceland and Denmark, this is a big deal. In fact, they call it winter bathing. But I think the question you're really asking is, does this wellness trend have the evidence to back it up? So let's go through it right after the break. Okay, so first of all, no surprise that you're seeing conflicting information. That's because the scientific evidence is mixed and it's limited. One thing I'll just say about limited evidence when it comes to things like this, sometimes this evidence is hard to collect. And when we're talking about something like cold plunges, there is no requirement for that evidence to be collected. So that doesn't mean cold plunges don't necessarily make you feel better, even if there's not a lot of evidence behind it. But it does mean we want to think through the benefits and the risks a little bit more carefully. First, we'll touch on what the believers often say about cold plunges. Then we will talk about what evidence does exist to understand the effects that cold shock actually has on our body. And. And then we'll go over some practical things to consider to decide if cold plunges might be right for you. So first of all, proponents argue that cold plunges offer a whole menu of wellness benefits. Stronger immune system, improved cardiovascular health, better muscle recovery. That's a big one. Calmer nervous system, improved mental health. And what we're primarily talking about here, reduced inflammation. And what's the rationale? How do they think it works? Well, they think the shock of the cold water causes your blood vessels to constrict. And proponents say that can help flush out toxins and reduce inflammation in the body. And if you've been on social media, you hear folks talking about their success stories. But let's move on to the next part. Is there evidence to support that? I've decided to pull a few studies. There was a 2025 meta analysis of 11 studies on the physiological effects of cold water immersion CWI cold plunges essentially. And what they found was interesting actually significant increases in inflammation immediately and 1 hour post exposure during a cold plunge. Okay, so inflammation actually went up in the immediate time of the cold plunge and continued that way for one hour post exposure. Another study from 2021 looked at the effects of CWI. Again, that's cold water immersion. That's what they call it in these papers. They were looking at 29 participants at the Ironman World Championships and in that case they found that CWI had no effect on inflammatory markers. CWI did not seem to be improving the athlete's recovery in any demonstrable way. And then Another interesting study, 2022 study out of the Netherlands looked at a group of 48 healthy men and how their inflammatory were affected by breathing exercises, cold plunges or a combination of both. And they found that breathing exercises were associated with reduced inflammation. Cold exposure had no impact on inflammatory responses. But when combined, cold exposure did seem to enhance the anti inflammatory effects of the breathing exercises. So what does that mean? By itself, cold plunges did not seem to make a difference, but they could serve as a great amplifier to things that did make a difference. Again, in this case, breathing exercises. Now notice a couple of commonalities about all these studies. First of all, there is no conclusive obvious benefit to cold plunges alone when it comes to reducing inflammation. And second of all, again, take all of this with a grain of salt. The evidence and the science around this is still new, it is still limited. Most of the studies are pretty recent and pretty small. To really understand cold water immersion impacts, we're going to need more studies and they're going to need to be Larger studies, and they're going to need to be randomized, controlled trials. We'll see if we ever get data out there like that. Now, there are a lot of cold water evangelists out there, and their personal anecdotes are pretty compelling. I can see how they might intrigue you. But before you dive in, you should know that, that this isn't always just a harmless health fad. There are some risks. When you plunge into cold water, you're essentially triggering a fight or flight, what is called a cold shock response, rapidly increasing heart rate and blood pressure. Okay, so if you have a heart condition, for example, that could potentially be dangerous. People who take medications like beta blockers that already lower their blood pressure and reduce the heart rate, that make it more difficult, for example, for the body to adapt, adapt to the cold shock. And also keep in mind there may be people out there who have heart conditions and they don't know it. And this is not how you want to find out. Cleveland Clinic recently said as well that cold plunges could be dangerous for people with diabetes, peripheral neuropathy, poor circulation, and certain autoimmune diseases where cold temperatures can actually make your immune system attack your red blood cells. And look, if you don't have an underlying condition, you can still have hypothermia, you could still have skin and nerve damage, difficulty breathing, which could lead to dizziness or fainting, which obviously you don't want to do in cold water or any water. So there's a lot there, a lot that I've tried to get at. If you do decide to give cold water immersion cold plunges a try, here are some tips. Talk to your doctor about this. Make sure you don't have any conditions that might make it unsafe for you. And if you're trying to address a problem, see if there are other options as well. Some other ideas. Second of all, start slow. Don't try to plunge your entire body in at once. Maybe start with an arm or a leg before getting to the whole body. And start with short times, 30 seconds to a minute. Check the temperature before you get in. Water below 50 degrees Fahrenheit is going to significantly increase the risk of these adverse side effects. And finally, don't plunge alone. Do have someone nearby just in the off chance there is some sort of emergency. So maybe one day we're gonna have a deeper understanding of cold water immersion cold plunges. But at this moment, the evidence is mixed and the risks are real. So if you're considering it like you think about most things in life, look at the risks, look at the rewards and figure out the balance for you. I should note that when it comes to reducing inflammation, using an ice pack locally on problematic spots can help relieve pain and reduce inflammation. Be sure to protect your skin with a thin towel and apply the ice pack in 10 minute intervals. Hope that helps. After the break, we're going to switch gears to something I am really fascinated by, itching, that scratching, itching sort of feeling that you get. I'm going to explain what's actually happening in our brains when we feel the need to scratch. Stay with us.

[Audie Cornish]

This week on the Assignment with Me, Audie Cornish. I heard a rumor that one of the moms in this news story reached out to you. Ashley, you are the cause of this news story.

[Dr. Sanjay Gupta]

I was like, did I cause this?

[Audie Cornish]

You just heard me Talking to the Dr. Noel Santarelli about the Ashley Tisdale French toxic mom group chat drama and like, yeah, it's celebrity gossip, but this is a real thing. Mom friends and mom friendships. It can be difficult and you're vulnerable. Dr. Noel Santarelli is a clinical psychologist and a mom and she's going to break down to us exactly why the first viral story of the year is striking such a nerve. Listen to the Assignment with me, Audie Cornish. Streaming now on your favorite podcast, Apple.

[Michael Ian Black]

Tav. I got News for your ears. The podcast. I am your host, Michael Ian Black Streets aren't safe.

[Dr. Sanjay Gupta]

Kids can't go to school. Like they're.

[Michael Ian Black]

Yeah, they shut down schools.

[Audie Cornish]

Yeah.

[Michael Ian Black]

For at least a couple days last week because, you know, a block away they're tear. I've heard of a snow day, but an ice day?

[Dr. Sanjay Gupta]

Hey, that's why he's a panelist on this show. That's how he got the part. He's so excited to be on campus camera again.

[Michael Ian Black]

Have I GOT News for your Ears. Releases new episodes every Wednesday. Don't miss an episode. Follow us wherever you get your podcasts.

[Dr. Sanjay Gupta]

Okay, Jesse, who's up next? Okay, our next question is from Stephanie in California.

[Caller (e.g., Stephanie or unnamed caller)]

So my questions are about itching. Just the topic in general. I'd love to learn more about it. So I have had over the course of my life different experiences where I get like really intense itching and like a place in my arm and you can't see anything. But I scratch it so much that it becomes like a big rash. And everyone says just don't scratch it, don't scratch it. But it really itches. And I know that itching is bad, but I do it anyway. I'd like to understand more like how your body, like, responds to it. If different people are more susceptible to itching than others, just how that works. And also, like, understand what might be causing that and what could give some relief for that because, like, topical stuff doesn't seem to work in that case. Anyway, those are my questions. That's a really long, rambling message, but thank you for all the information you share. All right, bye. Bye.

[Dr. Sanjay Gupta]

Stephanie, thank you so much for sharing your question. As I said, I'm fascinated by this. I think a lot of people have wondered about this as well and also felt that frustration that I can sense from you on not being able to control the urge to scratch. So let's start with the basics. Why do we itch? Well, here's what we know. It's complicated. It's actually caused by a tremendous interaction of various cells and proteins and inflammatory mediators in our skin and our nervous system. Basically speaking, chemicals are released into the skin. They send messages to our spine, and then the messages go to the brain. And that essentially makes us feel itchy. Things like dry skin and bug bites, they tend to be the most common causes of itchy skin. No surprise. But there are other things that can cause the itch alarm to go off as well. Hives and allergies. Those can certainly cause an itchy rash. Some medications can cause itching by causing dry skin or because of the immune response they trigger, they essentially are releasing these itch signaling chemicals into our bodies. Then there is something known as a psychogenic itch, and that's an itch that's caused by psychological factors. Anxiety, stress, depression. Psychologists and dermatologists observe this condition all the time, but its mechanisms are not entirely known. There is something known as neuropathic itch, where there's nothing wrong with the skin. Instead, essentially think of it like your nervous system is misfiring, causing the brain to perceive an itch somewhere. It's caused by damage to our specialized itch sensing nerves. Those nerves can get pinched sometimes in people with arthritis. They can become inflamed after, for example, shingles, whatever it may be. You're essentially sending excessive itch signals to the brain, even though there isn't a problem with the skin. So, Stephanie, yes, some people are more susceptible to itching. Skin conditions can do that. Mental health conditions can do that. Possible nerve damage can do that. New medications. Now, there is this fascinating link I do want to tell you about. Between that itching feeling and scratching, our urge to scratch and itch, that's rooted in evolution. It's our body's defense mechanism, essentially letting us know there are potentially dangerous intruders, bed bugs, ticks, something that's irritating the skin. So why does scratching then bring relief, at least momentarily? Well, scratching, you're actually prompting the nerve endings in the spinal cord to. To release your body's painkilling molecules, which essentially dampen the itch. Neurons also send signals that quiet that region of the brain called the anterior cingulate cortex, which is a region that's important for attention, decision making, and impulse control. So interestingly, the anterior cingulate is strongly activated by itch. So when it quiets down, so does the itchy feeling. You're essentially not paying as much attention to that area anymore. Now, at the same time, I know what you're thinking. Scratching can sometimes make you itch even more. And why is that? Well, scratching can trigger the pain fighting chemicals I just mentioned, like serotonin. But then serotonin might make you feel itchier. And therein lies the vicious cycle. Scratching, especially in the case of allergies and hives, can also release more itching, Histamine and other itch inducing chemicals also perpetuating the itch cycle. Histamine is one of the causes of that itching. That's why so many of the medications people take for itching are antihistamine drugs. There was also a study from 2013 which found that when people scratch an acute itch, the brain's reward system lights up. That's likely why scratching can become addictive and. And we sometimes feel powerless to stop. You shouldn't feel bad about not being able to stop scratching. It's a powerful force for that very reason. I know the advice, don't scratch. It hasn't worked for you, Stephanie, and I'm sure plenty of other listeners have not been able to follow that rule either. It's hard. So here are some other thoughts. Apply an over the counter topical ointment designed to stop itching. Hydrocortisone creams. That's a type of topical steroid. That's gonna help. Almost certainly antihistamine creams, as I was just mentioning, they can offer relief from allergic reactions. In some cases, an anesthetic like lidocaine can numb the area. Or a cooling agent like menthol or camphor, that can help as well. Do make sure it's not a dry skin issue, so use moisturizer. Apply a cool compress or ice pack wrapped in cloth for about five to 10 minutes until the itch subsides. And you can also try and break your routine with a psychological tool called habit reversal. So think about the times you're most likely to scratch an itch. Let's say you do it a lot while watching television. Well, next time you're watching, have something else to do that keeps your hands busy, a stress ball or knitting, for example. If you think the itchiness might be psychological, talk to a mental health professional about your urges. Maybe that conversation can help you identify things that are happening in your life, maybe identify triggers and develop tools to sort of resist. So I hope that helps you, Stephanie. Again, a lot of people deal with this, this idea that there is this insatiable need to just keep scratching. But I hope some of these strategies work for you. Thanks for sharing your experiences, everyone. Thanks for sharing your questions. I try and listen to as many as I can. I enjoy the chance to go down these rabbit holes and learn with all of you. So keep sending the questions our way. Record a voice memo. Email it to paging.gupta.com that's paging Dr. Gupta.com or give us a call. 470-396-0832. Leave a message. Hope to talk soon. News cycle making your head spin. The have I Got News for you Crew is here to help with a comic take on the week's headlines. New episodes premiere January 24th on CNN. And next day on the CNN app.