#471 Ranking 100 Health Biomarkers (Most to Least Important)

Siim Land (0:00)

Over the last few years, I've measured hundreds of biomarkers, taken dozens of blood tests and read dozens of scientific studies on what truly predicts long-term health. And here's what I've learned. Not all biomarkers are equal. Some have a massive impact on your longevity, whereas others have a smaller effect. So in this video, I'm going to rank a hundred biomarkers from the most critical to your longevity all the way down to the least important, based on my reading of the literature and opinion. Timestamps for everything are down below. And to make it even easier, I've put together a free blood work cheat sheet that you can find in the description. All right, let's begin. The first marker is a resting heart rate. Now, obviously, your heart rate is the most critical biomarker you have, because if you don't have a heart rate, then you're dead. And when it comes to overall health and associations with heart disease mortality, overall all cause mortality, then resting heart rate does have a pretty significant effect. There is a pretty linear relationship between higher resting heart rate and increased risk of mortality. One meta-analysis of over 1.2 million people did find out that everything above 45 beats per minute was associated with increased risk of mortality. And usually, people with lower resting heart rates have better cardiovascular fitness, better cardiac function, they have less cardiac stress, etc. So a healthy heart doesn't beat super fast. That's just the truth to it. Now, of course, there are some situations where a low resting heart rate can predict mortality, but it usually coincides with also a low HRV. So if your heart rate is slow, and you also have a low HRV, so there is less interval between the heart beats, then that is typically a sign of, usually it's a sign of aging, but it can also be a sign of some comorbidities that predict future mortality. So a healthy heart goes with a slow resting heart rate, so something like less than 45 beats per minute, less than 50 beats per minute, and also a high HRV, so there is a high variation between those heartbeats. Resting heart rate and HRV are also a good indicator of your nervous system balance, your autonomic nervous system balance. So it's a good proxy of overall recovery and stress as well. So I'm gonna put it in the vital tier, because I do think that it's pretty reliable, and it can be a good indicator of overall fitness, cardiovascular fitness, and cardiac function. Next up, I'll take HSCRP, highly sensitive C-reactive protein. So this is a marker of systemic inflammation, and similar to resting heart rate, there is a linear relationship between higher CRP levels and all-cause mortality risk and heart disease risk as well. And I do think that it's pretty reliable as well. Of course, HSCRP can fluctuate if you get some infections, it doesn't have to be some serious illness, just a bacterial infection or something like that, your CRP levels can acutely rise, but generally speaking, it is a pretty good marker of overall systemic inflammation. If you're otherwise healthy person, then your CRP levels tend to be close to zero, something like 0.1, 0.2, 0.4, or something like that. And anything above 1 tends to be indication of unwanted inflammation that could be improved upon. So I'm gonna put it in the vitals here because it's a very, I guess universally you can find very strong associations with all different types of chronic diseases with high CRP levels. Next, VLDL. So this is a type of lipoprotein, and this is different from all these other types of cholesterol and lipoproteins. And VLDL tends to be more atherogenic than other types of cholesterol and lipoproteins. So I'm gonna put it in the vital tier. It has a stronger association. LDLP, so this refers to particle count. LDL, particle count, low density lipoprotein, particle count. And when it comes to atherosclerosis and heart disease, then the particle count is a much stronger predictor of risk than the amount of cholesterol, the amount of LDL, for example, alone. So the particle count generally is a much better predictor. Of course, there's gonna be some situations where people with high particle count necessarily don't develop heart disease, but in the vast majority of cases, you don't want to take the risk. So I'm gonna put it in the vital tier for that. Homocysteine. So this is a marker of inflammation as well. High homocysteine can increase endothelial dysfunction and cause endothelial inflammation. So it is associated with heart disease risk as well. It can be also a proxy of methylation. So if you have poorer methylation, then you tend to have higher homocysteine levels. But the association with heart disease, for example, is much weaker compared to some other markers like HHCRP and VLDL. So I do think it is important, but I wouldn't become very worrisome or very worried from slightly elevated homocysteine because it can also fluctuate quite a lot depending on if you've been infected with some virus recently or some bacterial infection or something like that. So yeah, it is quite important, but not in the vital tier. Respiratory rate. So this biomarker you can measure also during your sleep. For example, oaring measures your respiratory rate. Other sleep trackers can measure this. It essentially just refers to how fast you breathe during your sleep. And generally speaking, healthier bodies, healthier hearts, healthier humans, they tend to breathe slower in their sleep because it's about like oxygen efficiency. So you don't need to have a very fast heart rate. You don't need to breathe very fast. A lower respiratory rate is a sign of better overall health. And, you know, the association with mortality is not that researched. There are a few studies showing that a respiratory rate above 16 breaths per minute is associated with increased mortality, and a lower respiratory rate is associated with lower mortality. So I'm going to put it in the important tier just because of the limited amount of research in this biomarker. VO2max. So VO2max refers to your maximal oxygen consumption during exercise. And, you know, you've probably heard a lot that VO2max is one of the biggest predictors of longevity in humans. Which, to a certain extent, can be true, but it obviously has some limitations. So VO2max is a good umbrella marker of your overall cardiovascular fitness, as well as how your other organ systems are functioning. So to have a good VO2max, you not only need to have, you know, a fit heart, but you also need to have fit lungs, and a good circulatory system, and good metabolic health, generally speaking, because to achieve a high VO2max, you need to be exercising. You're not going to have a high VO2max by just sitting around and having a bad diet, et cetera. So if you have a high VO2max, that warrants that you are exercising or training your VO2max to some degree. Generally if you have high VO2max, then you're doing a lot of things right. So that's why I'll put it in the vital tier. Let's take something like a body fat. So body fat percentage, you know, everyone knows that if you're obese, then you're harming your health. I think we're past that phase by now. And body fat is interesting. It can tell you a lot about your metabolic health. If you just look at someone's body fat percentage, you can pretty much predict what their blood work is also going to be with quite good accuracy. You can predict their VO2max as well with their body fat percentage quite accurately. Other biomarkers as well. So it is a good, you know, rule of thumb to kind of this Occam's razor that, okay, if you just look at your body fat percentage, you can get a pretty good overview of someone's health. Now, it is more important for men. In women, there's a smaller association with body fat percentage and mortality risk. Unless you're in the severe obesity category, for men, it's anything above 15% body fat is associated with increased mortality. So men need to be slightly leaner with subcutaneous fat, so fat under the skin. For women, the subcutaneous fat matters a lot less, so there's a much weaker association with mortality. But regardless, body fat percentage alone can have its flaws. I'm going to be putting it in the important tier because of that reason, that it doesn't fully grasp the nuances of someone's metabolic health and overall health. You need to look at all the subtypes of body fat, mostly like visceral fat mass and subcutaneous fat mass, etc., liver fat, etc. You know, if someone has a high body fat percentage, then they also have high amounts of visceral fat. That's, you know, we can be pretty sure of that in most cases. But body fat alone can be misleading. What about BMI? So this notorious biomarker of body fatness or estimated body fatness. Now, of course, BMI has a lot of flaws. If you have a lot of muscle, then your BMI can be in the overweight category. So, for example, my BMI is 25.5. So I'm slightly over the limit for normal body weight, but my body fat percentage is 10%. My waist circumference is very low. My visceral fat is extremely low. My metabolic health is excellent. So I have a higher BMI because of my muscle mass. Now, some people take it too far. So they'll say, although my BMI is 31, I have muscle and therefore BMI is useless. Because I have muscle and I'm healthy. Well, to have a BMI of 31, you still have slightly too much body fat for your frame, for your height. Because even if you're muscular, to have a BMI of 31, you will need to be having too much body fat to reach that BMI to begin with. So you're probably something like, okay, 15% body fat, which isn't the end of the world, but it's not the most optimal as well for males especially. Now, if you're some sort of pro bodybuilder, then maybe you can have a BMI of 31, 32 with sub 10% body fat. But even in that scenario of being a pro bodybuilder, a mass monster with a BMI of 32, of leanness, of pure muscle, then it's still not healthy. I think that having that much mass is going to wear down your organs eventually. And just to maintain that amount of muscle mass, you need to be doing something, either anabolic steroids or just eating insane amounts of food or something like that. So even if you are sub 10% body fat, but your BMI is 31, then I would argue it's not healthy. So the BMI is more of like a population, like a tool to analyze populations, not individuals specifically. So I would put it in the not significant category. It has some validity. Like I said, if your BMI is 31, then you probably have too much body fat or you are just, you know, a mass monster, which is also not healthy. So I wouldn't ignore the BMI completely. But if your BMI is, let's say, 25.5, 26, maybe 27 at the most, then it might be that, yes, you have slightly more muscle than the average person, which increases your BMI. And that isn't necessarily a bad thing. But at some point, the insane BMI numbers, even with very leanness, a lot of leanness can be still harmful to overall health. HRV, so heart rate variability, I mentioned it in the context of the resting heart rate, that if you have low resting heart rate and high HRV, then that's a good sign of heart health. And it also tends to be a sign of lower biological age, because when you're younger, you have a lower resting heart rate and you have a higher HRV. With age, you see the opposite of that, that your heart rate increases and your HRV decreases. So if you have low heart rate and high HRV, then that can be a good sign of lower biological age. Now, the thing with HRV is that, at least with these commercial devices like the O-Ring, Whoop, other fitness trackers, people get a lot of different results with them. My average HRV is 100, 100 plus, where some other people might have a HRV of 40, 50, 60, 20, or something like that. And they are generally still healthy. They exercise regularly, they eat a good diet, they sleep, etc. So they follow all the things they need to do, but their HRV is still, let's say, 45 Doesn't matter what they do, it stays at 45 So there might be some just individual differences between people that some people just have a lower HRV. What matters more in the context of HRV is how does it fluctuate. If you see that your HRV is always the same, doesn't increase, doesn't decrease, then there's nothing, there's not that much to worry about, even if it's 45 or 35 What matters more is that, okay, is it increasing or is it decreasing? If you see a sudden drop in your HRV, then that can be a predictor of some infection. Usually, your HRV drops a few days before you get sick, or if you have some infection, you can pretty accurately predict getting future sickness with your HRV. But ideally, your HRV should slightly be increasing over time. If it stays the same, then it's not the end of the world. If it's slowly decreasing, then that could be something to be worried about. That, okay, maybe you're too stressed out, maybe you're not getting enough sleep, maybe you're not walking enough, you're not getting enough downtime, whatever the case may be. So I'm going to put it in the important tier, that HRV is important, but it has, again, limitations and a lot of individual differences. Let's take waist circumference. So waist circumference, just measuring the narrowest point of your waist, which is usually around your belly button. And waist circumference can be a good predictor of your visceral fat mass, so visceral fat around the organs, in between the muscles. If you have a very big waist circumference, you just have like this beer belly, this pot belly, that is usually a sign of high amounts of visceral fat. So that can be a useful tool to just assess your visceral fat mass. And there are studies finding an association between higher waist circumference and increased risk of mortality in a linear fashion. So lower waist circumference tends to be a sign of better metabolic health and better body composition that you have less visceral fat mass. But waist circumference can of course be influenced also by your height, your just genetics, where you store your fat, etc. So it is important, but it doesn't tell the full story. What tells the full story is the waist to hip ratio. So waist to hip ratio is a better marker than waist circumference, because you measure your waist and you measure your hip circumference. You divide your waist circumference with your hip circumference, and then you get a particular number. The lower the number, the better it is. So your waist should always be narrower than your hips because of that reason. So if your body stores fat around the hips, which is what females tend to do more, then that's a sign of better health. If your body stores a lot of fat around the belly and your hips don't have that much body fat, then that means your body is preferentially storing the body fat as visceral fat mass, which is worse for your health than the subcutaneous body fat. So while we're on the topic of fat mass, then visceral fat mass, I do think that it's vital. So visceral fat is both a cause and a driver of insulin resistance and diabetes. So visceral fat accumulates around the organs, in between muscles and around the liver, around the heart, et cetera. So it is quite bad that it increases the risk of heart disease and definitely drives metabolic syndrome, drives metabolic diseases like diabetes, insulin resistance, et cetera. So you want to have lower visceral fat, generally speaking. Now, of course, you probably won't be able to have zero visceral fat. Zero is probably going to be unhealthy, but on the lower end, less than average is what you want to aim for. So the average person might have 500 grams of visceral fat.