Michael Greger, MD is an American physician, world-renowned speaker, and an ardent advocate of a plant-based diet. Dr. Greger argues that adopting a plant-based diet can not only improve the quality of life but also prolong your life. His best-selling book “How Not To Die” is a guide to a better and longer life.
Here, Dr Greger tells us how we can improve our longevity.
“Finger on the Pulse of Longevity”
Immanuel Kant, the 18th century philosopher described the chemistry of his day as a science,but not really science,because 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, quantum physics, etc., there are constants: physical quantities thought to be both universal and unchanging. Biology, though, was considered too complex, too messy to be governed by simple, natural laws, but in 1999, a theoretical high energy physicist from Los Alamos joined up with two biologists to describe universal scaling laws that appear to apply across the board.
Are there any clinical implications of these types of theories?
Well, a fascinating observation was published.
The number of heartbeats per lifetime is remarkably similar, whether you’re a hamster all the way up to a whale.
So even though mice only live less than two years, their heart rate is like 5 to 600 beats a minute—up to ten beats a second, whereas the heart of a Galapagos tortoise beats 100 times slower, but they live about a 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 heart beats period,
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 worked, then one might estimate that a reduction in heart rate
from more of an average 70 beats per minute down to what many athletes have,
60 beats per minute could theoretically increase life span over a decade.
Seems a bit off the wall, but that’s how the scientific method works: you start out with an observation, like this striking heartbeat data, and then you make an educated guess, or hypothesis, that you can then put to the test.
How might one demonstrate a life-prolonging effect of cardiac slowing in humans?
Well perhaps a first attempt in this direction would be to see if people with slower hearts
live longer lives, lamenting the fact that there was no drug that just lowered heart rate they could give to people, since drugs like beta-blockers lower heart rate, but also lower blood pressure, so wouldn’t be ideal for testing the question at hand, but at least we can do that first part, about do people with slower heart live longer lives.
And indeed, from the evidence accumulated so far, we know that a high resting heart rate,
meaning how fast our heartbeats when we’re just sitting at rest, is associated with an increase in mortality in the general population, as well as those with disease.
A faster heart rate may lead to a faster death rate.
Faster resting heart rates, (RHRs) are associated with shorter life expectancies, considered a strong independent risk factor for heart disease and heart failure.
You can see how those with higher heart rates were about twice as likely over the next 15 years to experience heart failure in middle-aged people, and older people, in men, and women.
And 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 was like duh, of course lower resting heart rates are associated with a longer lifespan.
Who has a really slow pulse? Athletes.
As you can see, the more physically fit we are, the lower our resting pulse.
But no, they found that irrespective of the level of physical fitness people with high resting heart rates fare worse than people with lower heart rates, so it appears it’s not just a marker of risk, but a bona fide risk factor, independent of how fit we are or how much we exercise.
Well, 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, and so the faster our heart, the stiffer our arteries, but there are all sorts of theories on how an increased resting heart rate could decrease our time on Earth.
Regardless, this relationship is now well recognized.
It’s not just a marker of an underlying pathology…
It’s not 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’s just a risk marker, it wouldn’t matter if we brought our heart rate down.
But now we even have evidence from drug trials—now that there actually are medications that just affect heart rate, that lowering our heart rate lowers our death rate. It’s now 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.
You can measure your pulse right now!
For the maximum lifespan, the target is like one beat a second, to beat the clock.
But don’t worry if you’re too fast; heart rate is a modifiable risk factor.
Yes, there are drugs, but there are also lifestyle regimens that can bring our resting pulse down…which I’ll cover next.
“Slow Your Beating Heart: Beans vs. Exercise”
The accumulated weight of evidence linking elevated resting heart rate to a shortened lifespan—even in apparently healthy individuals, makes a strong case for it to be considered in the assessment of risk.
It’s got strong advantages. Taking one’s pulse is cheap, takes little time, it’s understandable to people, and it’s something everyone can do at home to measure their progress to become an active participant in their own health management.
Every ten beats per minute increase is associated with a 10 to 20% increase in the risk of death.
There seems to be a continuous increase in risk with increasing heart rate, at least for values above about a beat a second.
So we can just look at our watch and if our heart is beating faster than the seconds go by—even when we’re sitting quietly, then we have to do something about it, especially when we start getting up around 80 or 90.
Men with no apparent heart disease evidence with a pulse of 90 may have five times higher risk of sudden cardiac death—meaning their first symptom is their last—compared to those down the safety zone.
Living up around 90 increases heart disease risk at a level similar to smoking.
If you ask most doctors, though, 90 is considered normal.
The accepted limits of heartrate have long been set at 60 and 100 beats/min.
How did they come up with that?
It was adopted as a matter of convenience just based on the scale of the squares on EKG paper. A historical accident like the QWERTY keyboard that just became the norm.
60 to 100 doesn’t even represent the bell curve. These cardiologists measured the heart rate of 500 people and concluded that 45 to 95 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 50’s that they’re are too low; in fact, they may be right where they should be.
Certainly, a heart rate higher than 80 should ring an alarm bell, but what can we do about it?
Exercise is one obvious possibility. Ironically, you make the heart go faster so that that the rest of the time your heart beats slower.
The public health benefits of physical exercise, especially for heart protection, are widely accepted, and among the many biological mechanisms proposed is autonomic nervous system regulation of the heart. That’s your 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, you can drop their resting heart rate down from about 69 to about 66, so three beats per minute drop.
Of course, you have to keep it up; stop exercising and your resting heart rate goes right back up.
Exercise is just one way to drop our heartrate, though.
The way to our heart may also be through our stomach.
What if instead of three months of exercise, you did three months of beans?
A cup a day of beans, chickpeas, or lentils.
The first randomized controlled trial of beans for the treatment of diabetes. And indeed successfully improved blood sugar control dropping A1C levels from 7.4 to 6.9, but this was also the first study to ever 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 the risk of death just like everybody else but also appears to predict a greater risk of diabetic complications, such as damage to the nerves and eyes.
So how did beans do?
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 all the good stuff in legumes, there is also the potential displacement value of reducing some of the animal protein foods eating so many beans instead.
Regardless, we should consider eating pulses for our pulse.