158: Sitting Is the New Smoking with Dr. Keith Diaz
In this episode, we are joined by Dr. Keith Diaz to discuss the significant health risks associated with prolonged sitting, likening it to smoking in terms of its dangers.
He emphasizes the importance of regular movement, introducing the concept of 'movement snacks'—short bursts of activity that can mitigate the negative effects of sitting.
We also cover the physiological mechanisms behind how movement affects blood sugar levels and inflammation, as well as insights from blue zones where people naturally incorporate more movement into their daily lives.
Dr. Diaz advocates for personalized movement recommendations to help individuals improve their health outcomes.
Learn more about Dr. Keith Diaz:
https://www.columbiacardiology.org/profile/keith-diaz-phd
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Download Dr. Buck Joffrey's FREE ebook, Living Longer for Busy People: https://ru01tne2.pages.infusionsoft.net/?affiliate=0
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Transcript
Disclaimer: This transcript was generated by AI and may not be 100% accurate. If you notice any errors or corrections, please email us at phil@longevityroadmap.com.
For your muscles to regulate blood sugar, help regulate blood sugar, they have to be contracted.
Welcome everybody. This is Buck Joffrey with Longevity Roadmap. Uh, back in the saddle here. I've been, uh, in Europe for a bit. It was actually a football game in London actually. So that was cool. And one of the things that I noticed about people in Europe and in London and stuff is we walk around. You walk around a lot, there's not a lot of sitting going on there.
Um, and interestingly, that is what today's show is about. Um, my guest today, uh, Dr. Keith Diaz, he's an expert on the, uh, evils of sitting. And, uh, this is a really fascinating, fascinating interview. Um, one of the things that I, uh, uh, think is what was one of the most mind blowing things about this is the, uh, comparison of basically doing, you know, simple movements during the day versus somebody who.
Does like a full workout and then sits for the next 12 hours, which is probably describing a lot of the American population today. Right? As it turns out, you may be able to throw away the gym and, and just do the simple movements when it comes to at least Cardiometabolic health, but obviously there's other benefits to the gym like the.
Weights and things like that as well. But at any rate, a fascinating interview. I think, um, and I think it's very relevant and it is something that, you know, a lot of us who are working, I mean, I, I don't get up and move every 30 minutes, uh, when I'm working and stuff like that. Um, but if you hear what the enormous benefits are of not being completely sedentary, you may change your mind about how you might like to work.
Anyway, fascinating interview and we will have it right after these messages. Hey, longevity enthusiast. It's time to take it to the next level. I've been fine tuning my longevity regimen for years, and I look better and feel better than I did a decade ago. In fact, my blood work is even better than it was back then, and it's all because of my data-driven regimen.
And it's inspired me to create a course and community just for you. It's called the Longevity Roadmap, and I urge you to check it out. If you're tired of your belly fat, tired of being tired, or just wanna optimize yourself for the next 50 years, visit longevity roadmap.com. That's longevity roadmap.com.
Welcome back to the show today. My guest is Dr. Keith Diaz. Uh, Florence Irving, associate Professor of Behavioral Medicine at Columbia University. Uh, he's earned his PhD in integrative exercise physiology from Temple. He certified exercise physiologist. Dr. Diaz directs Columbia's exercise testing laboratory and wearable device reading center.
His research explorers how prolonged sitting damages our health. Uh, welcome Dr. Diaz. How are you? I'm doing good. Thanks for having me on the show. You know, this is, uh, this is a topic a lot of people are not gonna wanna hear about, um, in part because it's sort of somewhat unavoidable these days, but it's sitting and you've called it the new smoking, right?
So what research, uh, what does the research actually show about how harmful prolonged sitting is compared to other well-known risks like smoking? Yeah, so I think, let's get one caveat outta the way. Do I think sitting is as harmful as smoking? No. Because if it is, it's something we've been doing since we were born pretty much, and we'd all have cancer, heart disease, you know, by our forties.
Right? So why I think that phrase is really effective is because, you know, doctors used to smoke in the office, right? But it was this, this hidden risk factor that they didn't know was bad. You know, when the early 19th century and it, it wasn't until the signs came out that it was like, oh my gosh, smoking is really this toxic behavior.
And I think sitting is, this is in the same fashion that it's just something that was. It's so just part of our everyday lifestyle that we didn't realize and we're learning now like, oh, actually sitting for 12 hours a day really isn't good for our health. And so that's where I think kind of this, this notion idea that sitting is new smoking.
Now the research doesn't show that it's as harmful as smoking, but it's still, um, a harmful risk factor that in increase your risk for most chronic diseases, diabetes, many types of cancers, heart disease, and early death. Well, uh, you know, one of the things that um, I think is interesting is that a lot of people out there are good about getting their exercise right.
They're, they're, you know, they wake up in the morning, uh, they go to the gym, maybe they do cardio, maybe they do their weights. Um, and that might take an hour, right? It might take whatever. Uh, but then. If they go to work and they gotta sit there all day long. So I guess the question is, is sitting, uh, most of the day, regardless of that exercise, is it, is it still as bad?
Unfortunately, yes, it is not enough to just check off that to-do list. I exercised this morning and I'm done and I don't have to worry about my movement the rest of the day. The science is showing us that sitting can increase your risk for most chronic diseases independent of or irrespective of your exercise habits, and it makes sense.
So if you're that person who meets physical activity guidelines that we recommend for all Americans. That 30 minutes to 60 minutes, that's only 2% of your day, and is that 2% of your day really enough to offset what you do the other 98% of the day? And what we're learning is that yes, exercise is good for you and that 2% is something you should still be doing.
But what matters is what you do the rest of the day is well. And there's been a lot of really interesting laboratory studies where they'll have people come in one day and they'll sit all day. Another day, they'll exercise for an hour vigorously before they sit all day. And then the third condition, they'll have a person just kinda just move throughout the day.
They don't do any exercise, just stand up light activity. And there's actually no difference in a person's kind of glucose, sugar level response. From sitting all day to exercising and sitting all day that there was no difference throughout the day in their blood sugar levels that the only condition where you actually saw improvements in your blood sugar levels is when a person was just perpetually moving throughout the day.
Um, so there's a lot of good, I think, laboratory evidence to show that there's really is something to this sitting outside of whether you exercise or not, um, and in fact, that sitting in some ways could potentially offset some of the good that comes from exercise. So, um, you know, there's this trial, uh, that you guys did.
Five minutes of light walking every 30 minutes. Tell us a little bit about that study. Yeah, so really the, the goal of the study was what's the least amount of movement that you have to do to offset the harms of sitting? And so we had people come into our lab and sit for eight hours straight. We measured their, their blood glucose levels of sugar levels.
We measured their blood pressure, we, their mood, their fatigue levels. And then we had them come back on four different days where they tried a different we'll call movement dose. But so one day they came and, and back and moved every half hour for five minutes. Another day they came back and moved every hour for one minute.
And we tried a couple different doses to see what is the least amount of movement Yeah. That you have to do. And when I say the movement, we threw 'em on a treadmill and they walked for two mile at two miles an hour. It is a slow walk, slower than most people's typical walking pace. So nothing vigorous by any means or shape or form.
Um. And the, the findings were just off the charts. So the blood glucose response, if you moved every half hour for five minutes lightly, your blood sugar surge after eating a meal was reduced by almost 60%. And I mean, those are reductions that are equivalent to if you give a person medication for diabetes, like that's the level of control that you got just by moving every half hour for five minutes.
They also reduce their blood pressure by four to five points, which is similar to if I got a person to exercise train every day, they had never exercised before in day in life, and then they exercise, you know, 30 minutes a day, five days a week for six months. That's about the reduction you'd be expect to see.
So these were clinically meaningful reductions. Was that cumulative or like immediate? Like what? I mean in terms of blood, the blood sugar, was that over a period of time where they were doing it or was it immediate effect? Immediate. So we saw, like just, we just looked at that breakfast. We, as soon as they had breakfast, um, we measured their blood sugar levels in the period after they ate breakfast.
And we saw the change immediately in their blood sugar levels. Like the spike was dramatically reduced just at breakfast. And then we saw it throughout the day as well. But I mean, it was instantaneous. You know, it's, it's also interesting too just to, you know. Kind of double click on the idea of, you know, eating, you know, taking a walk after eating.
I mean, it is sort of a common thing in the past. I think fewer of fewer people do that now. But I mean, I think you, you've sort of, uh, you've just brought that to light again where there's a significant potential value in taking that, you know, light walk after, uh, after a meal. Oh, yeah, absolutely. I think there's a lot of re coming out now that the timing of your movement around your meals is really important.
For controlling your blood glucose levels. Blood sugar levels. I think the best thing you can, I mean our, our results show it. I mean, we're not telling you to go walk for 30 minutes after you eat dinner, like five minutes was enough. Just get some movement in so that your muscles are gonna take up that blood sugar and it's not going to continue staying and circulating in your bloodstream.
That's harmful. That's incredible. So, okay, so, you know, in the trial it was like five minutes of light walking every 30 minutes right now. It sounds it, it sounds like, well, that's not a lot, but for people who can't do that in the office, you know, what's sort of the second best option you'd recommend? Yeah, so move every half hour for five minutes was like the best, but we found that moving every hour, even for just one minute, still reduce blood pressure by four to five points.
It didn't, it didn't impact blood glucose like the every half hour did. Um, but you still saw some benefits, um, for blood pressure. And then the other important thing was people's mood levels and their fatigue levels. I mean, they plummet when you sit for eight hours straight. And just that move one minute every hour was enough to prevent that kind of just slow decline into just feeling like disgusting and filthy and terrible by the end of it.
Um, so for those people or the every half hour or five minutes, it can't do it. And there's the feedback we often get from people when we bring this kind of to the public. Um, and my response is always like. Just, you know, if you could just do an hour, every hour, one minute, you're still gonna get some health benefits.
You know, is the type of movement important, for example, slow walking enough or, uh, is it, or is there evidence that slightly more intensity gives a bigger benefit, that kind of thing? Yeah. So that's still kind of, I think the science is still emerging in that area. There's been a handful of studies to suggest that.
Yeah, I think in theory, moderate intensity would be better than light if you can't do. Every half hour, maybe you do every hour more vigorous or every two hours, but there's not enough evidence right now to say that, that it seems logical to me. And I think it's one of the things we're gonna test in future work.
Um, but yeah, I, I think what do you do when you can't do every half hour is still kind of a gap that we need to fill. I, I will say that when we did, we did actually a study where we took it into the real world and. We said, you know, here's what the science says in the laboratory. Move every half hour for five minutes.
Try and do that in your everyday life. And we measured things like mood and fatigue. Um, and people took, on average about five or six breaks over two weeks a day, which is nowhere near, I mean, if you're trying to do every half hour, they should be taking 16 breaks a day. Um, we're talking only about five to six, and we still saw about 25% reduction in people's feelings of fatigue.
So really robust, even though they didn't even come close to meeting what the prescription that we said, they still saw tremendous benefit for their, at least their kind of mental health, their overall just mood. Um, so I think we're still gonna try to figure out do we need, actually, do you have to have perfect adherence to that every half hour for five minutes?
I don't think so. You know, do it when you can. When it makes sense for you. 'cause I know I can't, I can't do it myself. I can't take a, a break every half hour. But the more breaks that you can integrate, I think the better. Don't see it as like, I must meet this all the time. Now. Is the issue sitting or just even being still, I mean like, you know, if you're, some people stand, some people prefer to stand.
Is it, I mean, does that make a difference? Could you just stand. Yeah, we should dig into that one a little bit. 'cause I mean, the sit the stand desks are out there. I mean, that's big breathiness there. So I mean there, those are making millions of dollars a year of those companies when we sit the stand desks.
Is the scientific evidence then to support that standing is any better than sitting? It's still not. It's mixed. It's mixed. There's some studies that suggest that the more that you stand in a day, the greater your risk for things like heart disease, um, varicose veins. Um, so, and there's other studies that suggest that maybe is good.
Um, there's a couple lab studies that show is good for like managing your blood sugar levels, but if, yeah, it's not as clear cut as we know, movement is beneficial. I mean, I would think the walking desks are sort of a no-brainer and those are incredible. Right, right. But yeah, I, I think. I think the standing desk manufacturers just capitalize on a lot of the news headlines that sitting is bad and convince the public that standing is a healthier alternative.
Um, and it might be, but it's, it's not as, as robust of a health protector that movement is. And so if people ask me, should I get a standing desk? I say, well, it's probably better than just sitting all day, but if you're gonna do something, I'd want you to move. That would be my guidance. We also have to keep in the fine my mind that that standing still for hours at a time also is not healthy, right?
Like blood pools in your legs, uh, when you stand still for hours at a time. And that's not good. Um, so I don't necessarily think just standing eight hours is good either. And so the saying that I often use is the best postures and the next posture, you should always just be switching up from sitting to standing and above all integrating movements smirked in throughout your deck.
Do you think that the, um, the movement, you know, the, I guess the movement snacks, if you wanna call 'em, right? Yeah. What you call 'em and, uh, do they primarily, you know, are they primarily working through immediate glucose disposal and muscle or is it something else, you know, about vascular tone or nitric oxide or something like that?
What do you, what do you think is going on there? Yeah, so there's a couple thoughts that people have about what is it, and, and also like how is exercise not helping independent of, you know, the sitting, um, one is, has to do with glucose, so at the muscle cellular level. Um, they're called glute four receptors, that they go to the cell surface and help bring blood sugar into the, into the muscle.
That for the, for those glute four receptors, to get to the cell surface, you have to be contracting your muscle. So part of it is muscle physiology that for your muscles to regulate blood sugar, help regulate blood sugar, they have to be contracted. If they're not contracted, they don't do the work that they're supposed to do in helping to mitigate or manage blood sugar levels.
So that's one pathway. The other has to do with lipids. So, um, there's an enzyme, LPL, lipoprotein lipase, which is responsible for the breakdown of lipids in the bloodstream. Um, one of the rate limiting steps for breaking for that enzyme is muscle contraction. So if that, if you're not contracting your muscle, that enzyme that helps break down the lipids or fats in your bloodstream is, it's not at optimal levels.
It's not helping to break down. So again, it's muscle physiology again. So. One thought is why is sitting so bad, it has to do with the muscles and they need regular contraction to help regulate some of these key processes that are important for things like heart disease. Um, but the other has to do with the posture itself.
So when you sit, um, what essentially you're doing to your leg vessels is you're putting a kink in the hose. All right? So you're sitting, you put that kink. What happens is that there's a lot of blood pooling in your lower limbs Now. In your lower legs and it's also causing like turbulent blood flow right around where your band is.
And that turbulent blood flow, that blood pooling can cause damage to your blood vessels if you expose to your vessels to that day in and day out for long periods at a time. So the whole has to come just it's, it's blood flow, blood hemodynamics, and. That's where I think sometimes the, the standing may have some benefit that you are restoring typical normal blood flow just by standing and whether the sitting and posture itself may be particularly hazardous.
Um, so, so it's a combination of posture and just muscle inactivity that I think drives why sitting is thought to be really bad. So, you know, we've talked a bit a bit about glucose, uh, control, glycemic control and blood pressure. Have you seen effects on things like inflammation? End endothelial function, vascular aging, things like that, that could, you know, tie a little bit more even into the longevity picture.
Yeah, absolutely. And I think, going back to the thing I was talking about, blood flow, blood hemodynamics, that the thought is that that kind of bend in your artery legs or your blood vessel legs. Um, ultimately what that leads to is damage to the endothelium and what you see in the scientific studies that have tested this, that the, the ability of the endothelium to help vasodilate.
Um, is dramatically reduced with just like an hour or two of sitting. Yeah. Is that localized to that area where you're talking about the increased turbulence or, yeah, so it is localized. So if you, if you were to look at like the arm, if we tested your endothelial function in your arm, you wouldn't see those effects.
So it is localized to the leg vasculature, but the problem that you get is that when you have that damage happening in your lower limbs. That releases these microparticles. Mm-hmm. Endothelial, microparticle cytokines. Yep. And they can circulate and then cause and trigger inflammation elsewhere in the body.
Right? So it's not localized, it's the damage to the endothelium is localized, but then the signal can then gets kind of delivered and dispersed throughout the body and can create this kind of inflammatory response. Um, so that's how it started to ultimately can be linked to heart disease, even though it's.
In theory starts at the lakes. So does that, would that affect, uh, high sensitivity CRP for example? That, that that's a, a major way we often look at, uh, blood vessel inflammation. Is it, is that the way you track that? Yeah, so I think we look at CRP is probably the, the key indicator, but we look, you know, you can look at other cytokines.
T and alpha is one that comes up that you often see can be elevated with, you know, when we expose people to acute periods of prolonged sitting. So, um, and we also tend to see people just. Who, who, who virtually sit for long periods of day. They, they tend to have higher or, or, or more worse inflammatory profiles.
Yeah. I bring the hs, uh, you know, the H-S-C-R-P up because of its, you know, um, you know, I, I think cardiologists these days talk more and more about, you know, following those inflammatory markers, not just, you know, lipid profiles and that kind of thing. So it kind of makes sense, um, you know, if you link it to that, uh, as well.
So, um, in your. Your adaptive dose finding studies. Are you seeing signs that different movement prescription sort of will, will need to be tailored by age, metabolic health or cardiovascular risk profile? True to tell. I think we're still kind of looking through. Oh, we actually can't even look at the data yet.
We have to wait until the trial finishes. Well, will you describe those a little bit more? Those are just sort of like the different types of, you know, you're, you're basically trying to titrate the different movements and timing and stuff like that, right? So you can't really, do you think there's a difference between individuals?
Oh yeah, a hundred percent. I think any study that we've done, there are what we report, the average response, but I mean, there are people who are what we'd consider to be like extreme responders. They have just this tremendous response to the movement breaks, and there's others who the movement breaks didn't really move the needle a lot.
So you know, when we have people come to our lab, we give them their results and tell them like, here's how your body reacted to sitting all day versus moving throughout the day. Some of them are disappointed to see like, oh, I didn't see that great of a benefit. Um, what predicts whether a person's, what we call a responder or a non-responder, I don't think we know yet.
Um, and something that we hopeful we'll be looking at in the next trial. You know, there's these studies, I think, um, longevity type things when they look at populations that sit less. Um, you know, blue Zones traditional, I mean, I'm, I'm sure you've probably looked into that. What, what, what do you find there?
Yeah, I mean, it's just logical, right? Like Yeah. Right. Well, it's also hard to pull it all apart, right? 'cause they're doing a lot of things right. But, you know, like, these are places, a lot of these places, like they don't have gyms Yeah. Don't have a Planet Fitness. They go to, um, their days are spent moving.
Like there, a lot of these places, there is a lot of just kind of their work in the land, right? There's manual labor going on. So this notion or idea that I would sit at a chair in front of a computer all day, um, that doesn't happen. Um, and many of these, not all of them. Um, so I mean obviously there's, there's a lot of pieces to what makes a.
Place a blue zone. And it's not just their activity habits, but to me that always stands out as one of the striking features. Oh, every time they talk about what's a new blue zone, it's like, yeah, of course. It's something that's characterized by like lots of movement throughout the day and they don't have gyms, which strikes me as like, you know, when you look at, actually, sorry, I'm gonna go on a tangent here, but the first study to establish that movement was good for you.
It's called the London Double Decker bus study. It was done in the 19, I think it was the 1950s. Um, and that was the first study that ever like indicated that like physical activity is good. And what they found was that the, they compared the, the drivers of the bus to the conductors on the bus. Like the people were like checking the tickets and stuff.
And the driver's risk for heart disease was dramatically higher than those folks who were going around like collecting tickets on the bus. So that was, that kind of helped shift the field, or at least the, the profession towards rec or science and recognizing like, oh, movement actually is beneficial. But we went all the way into this direction of like exercise in leisure time.
But that study, the London Double Decker bus study, this is about workplace sitting, right? Like it was just about people, like those people walking all day, collecting tickets, they weren't doing exercise. So to bring us back to Blue Zones again, like this was just about moving throughout the day, but I, I feel like sometimes exercise came up from, came from like this fast food culture of like, well, like we have to sit eight to 10 hours a day for work.
So like, go exercise for 30 minutes afterwards and that should be enough to offset it. And I think we're learning that maybe that wasn't while still good, um, is not the, the, the full answer here. Are you surprised that there's really, I mean, there's. When you talk about like physical activity guidelines today, you know, federal stuff, you don't really, you don't really hear about the movement, you know, getting up every once in a while and walking around you, you don't hear that.
Are you surprised by that? Why is that? I mean, if it seems pretty obvious here and, and in some regards, what you said earlier is sort of profound. I mean, if some people are simply not gonna go to the gym or not gonna do things, if they are just kind of moving around a little bit more every day, there is some evidence that basically.
From a cardiometabolic standpoint, they're getting the same benefit as somebody who does that one hour workout, I would say stay tuned. Um, the guidelines, the last set from the US were published in 2018, and they did modify the guidelines to say, in addition to 150 minutes of exercise a week, everybody should sit less, move more.
And, and those are. Great. They acknowledge that it's not just about exercise, but sit less. Move more is a terrible guideline to give people. 'cause then the obvious question is, well, like how much sitting is too much? What should I do to offset it? And like, like it gave nobody, it's, but it's not like they didn't want to, it's just there wasn't enough evidence at the time to give a definitive recommendation.
This is what you should do to offset the harms of sitting. I think the field itself has progressed enough that I think in the next set of guidelines. You should be seeing a little bit more in terms of like actual quantitative, very specific guidance. We, yeah. We just didn't have enough evidence at the time to, to suggest it.
But to your point, I think where we're starting ahead is more of these personalized recommendations where it's, you know, I work in a job, I'm a truck driver, I am a, a cab driver. Like I literally can't move for my job, but I can get at some exercise when I'm off my job. I have to get enough of that exercise or enough of that movement outside of my work hours to offset and get it to, maybe I'm not gonna get to the greatest place I can get, but I'm gonna offset some of my risks and that's good enough for me.
And there's gonna be the other people who say like, I have caregiver responsibilities after work. I can't possibly get to a gym, but I have a job where like I could like sprinkle in movement throughout the day. That might be good enough and, and we can get them to a better healthy movement profile than if they could do anything at all.
And then obviously the ideal is someone moves throughout the day and exercises that's, it's a mover plus an exercise or is the ideal. But I think there's good, this gives us options to work with people and personalize their, their movement kind of profile that fits what they want to do, what they're capable of doing.
Um, and it helps them kind of get to a place where they're happy with, you know, their health risks or, or health behaviors. Yeah. Fantastic. Well, uh, Dr. Diaz, I wanna thank you for being on the show today. Where can people learn more about some of the research you're doing? Yeah, I mean, you know, I think just Google my name, you'll, you'll see, you know, we try to make sure and make efforts to, to, to get this to media outlets whenever we publish something that is important for people to find out about.
But yeah, I have a LinkedIn profile. I have a website. You can follow me and, and see the, our latest e efforts and, and trying to help our world become less sedentary. Yeah. Fantastic. Thanks so much for being on the show. My pleasure. Thanks for having me. Thanks for listening. A quick reminder that while I am in fact a surgeon, nothing I say should be construed as medical advice.
Now, make sure to include your physician in any medical decisions you make, and also, if you're enjoying the show, please make sure to show your support with the like, share, or subscribe.
