The Benefits of Slow Breathing

There are all manner of purported hiccup “cures,” which include everything from chewing on a lemon, inhaling pepper, or, our dog’s favorite, eating a spoonful of peanut butter. In my video How to Strengthen the Mind-Body Connection, I talk about the technique I’m excited to try the next time I get hiccups: “supra-supramaximal inspiration,” where you take a very deep breath, hold for ten seconds, then, without exhaling, breathe in even more and hold for another five seconds, and then take one final, tiny breath in and hold for five last seconds to achieve “an immediate and permanent termination to hiccups…”

When I was a kid, I taught myself to control my own hiccups using slow-paced breathing, and, as an adult, was so excited to see there was finally a case report written up on it.

There’s a nerve—the vagus nerve—that goes directly from our brain, to our chest, and to our stomach, connecting our brain back and forth to our heart and our gut, and even to our immune system. The vagus nerve is like the “‘hard-wired’ connection” that allows our brain to turn down inflammation within our body. When you hear about the mind-body connection, that’s what the vagus nerve is and does. “There has been increasing interest in treating a wide range of disorders with implanted pacemaker-like devices for stimulating the vagal afferent [vagus nerve] pathways,” but certain Eastern traditions like Yoga, QiGong, and Zen figured a way to do it without having electrodes implanted into your body.  

“A healthy heart is not a metronome,” as a study titled exactly that explains. “Your heart rate goes up and down with your breathing. When you breathe in, your heart rate tends to go up. When you breathe out, your heart rate tends to go down.” Test this out on yourself right now by feeling your pulse change as you breathe in and out.

Isn’t that remarkable?

That heart-rate variability is a measure of vagal tone—the activity of your vagus nerve. Next time you’re bored, try to make your heart rate speed up and slow down as much as possible within each breath. This can be done because there’s an entirely other oscillating cycle going on at the same time, as you can see at 2:08 in my video, which is the speeding up and then slowing down of your heart rate, based on moment-to-moment changes in your blood pressure. And, as any physics student can tell you, “all oscillating feedback systems with a constant delay have the characteristic of resonance,” meaning you can boost the amplitude if you get the cycles in sync. It’s like pushing your kid on a swing: If you get the timing just right, you can boost them higher and higher. Similarly, if you breathe in and out at just the right frequency, you can force the cycles in sync and boost your heart rate variability, as you can see at 2:36 in my video.

And what’s the benefit again? According to the neurophysiologic model postulation it allows us to affect the function of our autonomic nervous system via vagal afferents to brainstem nuclei like the locus coeruleus, activating hypothalamic vigilance areas.

Huh?

In other words, it’s not just about curing hiccups. Practicing slow breathing a few minutes a day may have lasting beneficial effects on a number of medical and emotional disorders, including asthma, irritable bowel syndrome, fibromyalgia, and depression. In the United States, we’ve also put it to use to improve batting performance in baseball.

To date, most studies have lacked proper controls and have used fancy biofeedback machines to determine each person’s resonant frequency, but, for most people, it comes out to be about five and a half breaths per minute, which is a full breath in and out about every 11 seconds. You can see the graph at 3:34 in my video. When musicians were randomized into slow-breathing groups with or without biofeedback, slow breathing helped regardless. It’s the same with high blood pressure. As you can see at 3:52 in my video, you can use this technique to significantly drop your blood pressure within minutes. The hope is if you practice this a few minutes every day, you can have long-lasting effects the rest of the day breathing normally.

Practice what exactly? Slow breathing—taking five or six breaths per minute, split equally between breathing in and breathing out. So, that’s five seconds in, then five seconds out, all the while breathing “shallowly and naturally.” You don’t want to hyperventilate, so just take natural, shallow breaths, but be sure to simply breathe really slowly. Try it the next time you get hiccups. Works for me every time!


For more tips, watch my video on How to Stop Hiccups.

And, because slowing down our pulse in general may also have beneficial effects, I encourage you to check out:

Every time I’m amazed by ancient wisdom, I have to remind myself of the video I did on toxic heavy metals—Get the Lead Out. So, though traditional healing methods may offer a plethora of insights, they still need to be put to the test.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

The Best Food to Slowing Your Resting Heart Rate

Monitoring resting heart rate has strong advantages. Taking your pulse is cheap, takes little time, is understandable to people, and is something everyone can do at home to measure their progress to become an active participant in their own health management. “The accumulated weight of evidence linking elevated [resting] heart rate to cardiovascular and all-cause mortality”—that is, to a shortened lifespan—“even in apparently healthy individuals, makes a strong case for it to be considered in the assessment of cardiovascular risk.” 

Every ten-beat-per-minute increase is associated with a 10 to 20 percent increase in the risk of premature death. “There seems to be a continuous increase in risk with increasing heart rate,” at least for values above a beat a second. So, we can simply look at our watch or the timer on our smartphone, and, if our heart is beating faster than the seconds going by, especially when we’re sitting quietly, then we have to do something about it. This is particularly important when we start getting up to around 80 or 90 beats per minute. As I discuss in my video Slow Your Beating Heart: Beans vs. Exercise, men with no apparent evidence of heart disease who have a pulse of 90 may have five times higher risk of sudden cardiac death compared to those in the safety zone. To put it bluntly, their first symptom is their last. Indeed, resting heart rates around 90 beats per minute increase heart disease risk at a level similar to smoking.

If you ask most doctors, though, 90 is considered normal: The accepted limits of heart rate have long been set at 60 to 100 beats per minute. Where did that range come from? It was adopted as a matter of convenience simply based on the scale of the squares on EKG paper. It was an historical accident like the QWERTY keyboard that just became the norm. A heart rate of 60 to 100 doesn’t even represent the bell curve.

A group of cardiologists measured the heart rate of 500 people and concluded that 45 to 95 beats per minute was a better definition of normal, rounding to 50 to 90, which a survey of leading cardiologists concurred with. Now, we know that normal doesn’t necessarily mean optimal, but doctors shouldn’t be telling people with heart rates in the 50s that their heart rate is too low. In fact, these people may be right where they should be.

Certainly, a “heart rate higher than 80 beats per minute should ring an alarm bell,” but what can we do about it? Exercise is one obvious possibility. Ironically, we make our heart go faster so, the rest of the time, it beats slower.

“The public health benefits of physical exercise, especially for [heart] protection, are widely accepted.…Among the many biological mechanisms proposed to account for this risk-reducing effect is autonomic nervous system regulation of the heart”—that is, our brain’s ability to slow down the resting beat of our heart. If you put people through a 12-week aerobic conditioning program of cycling, StairMaster, and running on a treadmill, their resting heart rate can drop from around 69 to about 66—about a three-beat-per-minute drop. Of course, they have to keep it up. Stop exercising and resting heart rate goes right back up.

Exercise is only one way to drop our heart rate, though. The way to our heart may also be through our stomach. What if instead of three months of exercise, we did three months of beans, like a cup a day of beans, chickpeas, or lentils? The first randomized controlled trial of beans for the treatment of diabetes showed they did indeed successfully improve blood sugar control, dropping subjects’ average A1C level from 7.4 to 6.9. This study was “also the first to assess the effect of bean consumption on heart rate and indeed one of the few to determine the effect [on heart rate] of any dietary intervention.” This is particularly important in diabetics, since having a higher resting heart rate not only increases their risk of death as it does for everybody, but it also appears to predict greater risk of diabetic complications, such as damage to the nerves and eyes.

So, how did beans do in the study? They produced a 3.4 beat drop in heart rate—just as much as the 250 hours on a treadmill. We’re not sure why beans are as powerful as exercise in bringing down one’s resting heart rate. “In addition to the potential direct beneficial effects of vegetable protein and fiber”—all the good stuff in legumes—“there is also the potential displacement value of vegetable protein foods in reducing animal protein foods, which are higher in saturated fat and cholesterol.”

Regardless, we should consider eating pulses for our pulse.


What is that about a shortened lifespan? See my Finger on the Pulse of Longevity video.

Having “normal” risk factor values in a society where it’s normal to drop dead of preventable diseases like heart disease is not necessarily a good thing. Learn more with:

For more on the musical fruit, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

One Heartbeat per Second to Beat the Clock

Immanuel Kant, the famed 18th century philosopher, described the chemistry of his day as a science, but not really science, as it wasn’t grounded in mathematics—at least not until a century later. The same could be said for biology, the study of life.

In math, physics, and quantum physics, there are constants: physical quantities thought to be both universal and unchanging. Biology, though, was considered too complex and too messy to be governed by simple, natural laws. In 1997, however, a theoretical high-energy physicist from Los Alamos joined two biologists to describe universal scaling laws that appear to apply across the board. Are there any clinical implications of these types of theories?

A fascinating observation was published. As I discuss in my video Finger on the Pulse of Longevity, the number of heartbeats per lifetime is remarkably similar whether you’re a hamster all the way up to a whale. So, mice, who typically live less than two years, have a heart rate of about 500 to 600 beats a minute—up to 10 beats a second. In contrast, the heart of a Galapagos tortoise beats 100 times slower, but they live about 100 times longer. There’s such a remarkable consistency in the number of heartbeats animals get in their lifetimes that a provocative question was asked: “Can human life be extended by cardiac slowing?” In other words, if humans are predetermined to have about three billion heartbeats in a lifetime, then would a reduction in average heart rate extend life? This is not just some academic question. If that’s how it works, then one might estimate that a reduction in heart rate from an average of more than 70 beats per minute down to what many athletes have, 60 beats per minute, could theoretically increase life span by more than a decade.

This reasoning may seem a bit off the wall, but that’s how the scientific method works: We start out with an observation, such as this striking heartbeat data, and then make an educated guess (or hypothesis) that is then put to the test. How might one demonstrate “a life-prolonging effect of cardiac slowing in humans”? Perhaps a first attempt would be to see if people with slower heart rates live longer lives. Unfortunately, researchers couldn’t just give subjects drugs that only lower heart rate. Drugs like beta blockers at the time lowered both heart rate and blood pressure, so they weren’t ideal for testing the question at hand. We can, however, do that first part and look at whether people with slower heart rates live longer.

“From the evidence accumulated so far, we know that a high resting heart rate,” meaning how fast our heart beats when we’re just sitting at rest, “is associated with an increase in…mortality in the general population,” as well as in those with chronic disease. A faster heart rate may lead to a faster death rate. Indeed, faster resting heart rates are associated with shorter life expectancies and are considered a strong independent risk factor for heart disease and heart failure. Researchers found that those with higher heart rates were about twice as likely over the next 15 years to experience heart failure. This was seen in middle-aged people, as well as observed in older people. It was also found in men and women. What’s critical is that this link between how fast our heart goes and how fast our life goes is independent of physical activity.

At first, I thought this was painfully obvious. Of course lower resting heart rates are associated with a longer lifespan. Who has a really slow pulse? Athletes. The more physically fit we are, the lower our resting pulse. But, no: Researchers “found that irrespective of level of physical fitness subjects with higher resting heart rates fare worse than people with lower heart rates,” so it appears a high resting heart rate is not just a marker of risk, but a bona-fide risk factor independent of how fit we are or how much we exercise.

Why? If our heart rate is up 24 hours a day, even when we’re sleeping, all that pulsatile stress may break some of the elastic fibers within the arterial wall, causing our arteries to become stiff. It doesn’t allow enough time for our arteries to relax between beats, so the faster our heart, the stiffer our arteries. There are all sorts of theories about how an increased resting heart rate can decrease our time on Earth. Regardless, this relationship is now well recognized.

It is not just a marker of an underlying pathology nor can it be said to be merely a marker of inflammation. The reason it’s important to distinguish a risk factor from a risk marker is that if you control the risk factor, you control the risk. But, if it were just a risk marker, it wouldn’t matter if we brought down our heart rate. We now have evidence from drug trials—indeed, there are now medications that just affect heart rate—that lowering our heart rate lowers our death rate.

It’s been shown in at least a dozen trials so far. Basically, we don’t want our heart to be beating more than about one beat per second at rest. (Measure your pulse right now!) For the maximum lifespan, the target is about one beat a second to beat the clock. Don’t worry if your heart’s beating too fast: Heart rate is a modifiable risk factor. Yes, there are drugs, but there are also lifestyle regimens, like eating beans, that can bring down our resting pulse. See Slow Your Beating Heart: Beans vs. Exercise.


Other lifespan-expanding strategies are detailed in:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: