Written By Michael Greger M.D. FACLM on February 14th, 2019
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.
