How to Lower Your Sodium-to-Potassium Ratio

The potassium content in greens is one of two ways they can improve artery function within minutes of consumption.

More than a thousand years ago, for the treatment of hypertension, an ancient Persian medical text advised lifestyle interventions, such as avoiding meat and pastries, and recommended eating spinach. A thousand years later, researchers discovered that a single meal containing spinach could indeed reduce blood pressure, thanks to its nitrate content. All green leafy vegetables are packed with nitrate, which our body can use to create nitric oxide that improves the flexibility and function of our arteries. This may be why eating our greens may be one of the most powerful things we can do to reduce our chronic disease risk.

As you can see at 0:54 in my video Lowering Our Sodium-to-Potassium Ratio to Reduce Stroke Risk, just switching from low-nitrate vegetables to high-nitrate vegetables for a week can lower blood pressure by about 4 points, and the higher the blood pressure people started out with, the greater benefit they got. Four points might not sound like a lot, but even a 2-point drop in blood pressure could prevent more than 10,000 fatal strokes every year in the United States.

Potassium-rich foods may also act via a similar mechanism. If we get even just the minimum recommended daily intake of potassium, we might prevent 150,000 strokes every year. Why? Potassium appears to increase the release of nitric oxide. One week of eating two bananas and a large baked potato every day significantly improved arterial function. Even a single high-potassium meal, containing the equivalent of two to three bananas’ worth of potassium, can improve the function of our arteries, whereas a high-sodium meal—that is, a meal with the amount of salt most people eat—can impair arterial function within 30 minutes. While potassium increases nitric oxide release, sodium reduces nitric oxide release. So, the health of our arteries may be determined by our sodium-to-potassium ratio.

As you can see at 2:30 in my video, after two bacon slices’ worth of sodium, our arteries take a significant hit within 30 minutes. However, if you add three bananas’ worth of potassium, you can counteract the effects of the sodium. As I show at 2:48 in my video, when we evolved, we were eating ten times more potassium than sodium. Now, the ratio is reversed, as we consume more sodium than potassium. These kinds of studies “provide additional evidence that increases in dietary potassium should be encouraged,” but what does that mean? We should eat more beans, sweet potatoes, and leafy greens, the latter of which is like giving you a double whammy, as they are high in potassium and nitrates. The recommendation from a thousand years ago to eat spinach is pretty impressive, though bloodletting and abstaining from sex were also encouraged, so we should probably take ancient wisdom with a grain of salt—but our meals should be added-salt free.

Why might abstaining from sex not be the best idea for cardiovascular health? Because the opposite may actually be true. See my video Do Men Who Have More Sex Live Longer?.


What else can we do about stroke risk? Check out:

For more on potassium, see in Potassium and Autoimmune Disease and 98% of American Diets Potassium-Deficient.

Interested in learning more about the dangers of sodium? See:

Sodium isn’t just bad for our arteries. Check out How to Treat Asthma with a Low-Salt Diet and Sodium and Autoimmune Disease: Rubbing Salt in the Wound?.

I further explore the wonders of nitrate-rich vegetables in:

Sweet potatoes are an excellent high-potassium, low-sodium choice, but what’s the best way to prepare them? Check out The Best Way to Cook Sweet Potatoes.

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:

 

What Exercise Authorities Don’t Tell You About Optimal Duration

Physical fitness authorities seem to have fallen into the same trap as the nutrition authorities, recommending what they think may be achievable, rather than simply informing us of what the science says and letting us make up our own minds.

Researchers who accept grants from The Coca-Cola Company may call physical inactivity “the biggest public health problem of the 21st century,” but, in actually, physical inactivity ranks down at number five in terms of risk factors for death in the United States and even lower in terms of risk factors for disability, as you can see at 0:17 in my video How Much Should You Exercise? What’s more, inactivity barely makes the top ten globally. As we’ve learned, diet is our greatest killer by far, followed by smoking.

Of course, that doesn’t mean you can just sit on the couch all day. Exercise can help with mental health, cognitive health, sleep quality, cancer prevention, immune function, high blood pressure, and life span extension, topics I cover in some of my other videos. If the U.S. population collectively exercised enough to shave just 1 percent off the national body mass index, 2 million cases of diabetes, one and a half million cases of heart disease and stroke, and 100,000 cases of cancer might be prevented.

Ideally, how much should we exercise? The latest official “Physical Activity Guidelines for Americans” recommends adults get at least 150 minutes a week of moderate aerobic exercise, which comes out to be a little more than 20 minutes a day. That is actually down from previous recommendations from the Surgeon General, as well as from the Centers for Disease Control and Prevention (CDC) and the American College of Sports Medicine, which jointly recommend at least 30 minutes each day. The exercise authorities seem to have fallen into the same trap as the nutrition authorities, recommending what they think may be achievable, rather than simply informing us what the science says and letting us make up our own minds. They already emphasize that “some” physical activity “is better than none,” so why not stop patronizing the public and just tell everyone the truth?

As you can see at 2:16 in my video, walking 150 minutes a week is better than walking 60 minutes a week, and following the current recommendations for 150 minutes appears to reduce your overall mortality rate by 7 percent compared with being sedentary. Walking for just 60 minutes a week only drops your mortality rate about 3 percent, but walking 300 minutes weekly lowers overall mortality by 14 percent. So, walking twice as long—40 minutes a day compared with the recommended 20 daily minutes—yields twice the benefit. And, an hour-long walk each day may reduce mortality by 24 percent. I use walking as an example because it’s an exercise nearly everyone can do, but the same applies to other moderate-intensity activities, such as gardening or cycling.

A meta-analysis of physical activity dose and longevity found that the equivalent of about an hour a day of brisk walking at four miles per hour was good, but 90 minutes was even better. What about more than 90 minutes? Unfortunately, so few people exercise that much every day that there weren’t enough studies to compile a higher category. If we know 90 minutes of exercise a day is better than 60 minutes, which is better than 30 minutes, why is the recommendation only 20 minutes? I understand that only about half of Americans even make the recommended 20 daily minutes, so the authorities are just hoping to nudge people in the right direction. It’s like the Dietary Guidelines for Americans advising us to “eat less…candy.” If only they’d just give it to us straight. That’s what I try to do with NutritionFacts.org.

Most of the content in my book How Not to Die came from my video research, but this particular video actually sprung from the book. I wanted to include exercise in my Daily Dozen list, but needed to do this research to see what was the best “serving size.”

I wish someone would start some kind of FitnessFacts.org website to review the exercise literature. I’ve got my brain full with the nutrition stuff—though there’s so much good information I don’t have time to review that there could be ten more sites just covering nutritional science!


For more on all that exercise can do for our bodies and minds, see

Some tips for maximizing the benefits:

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 Crowding Out Strategy to Eating Healthier

It may be more expedient politically to promote an increase in consumption of healthy items rather than a decrease in consumption of unhealthy items, but it may be far less effective.

The World Health Organization has estimated that more than a million deaths “worldwide are linked to low fruit and vegetable consumption.” What can be done about it? I explore this in my video Is it Better to Advise More Plants or Less Junk?

There’s always appealing to vanity. A daily smoothie can give you a golden glow as well as a rosy glow, both of which have been shown to “enhance healthy appearance” in Caucasian, Asian, and African skin tones, as you can see at 0:24 in my video.

What about giving it away for free?

A free school fruit scheme was introduced in Norway for grades 1 through 10. Fruit consumption is so powerfully beneficial that if kids ate only an additional 2.5 grams of fruit a day, the program would pay for itself in terms of saving the country money. How much is 2.5 grams? The weight of half of a single grape. However, that cost-benefit analysis assumed this minuscule increased fruit consumption would be retained through life. It certainly seemed to work while the program was going on, with a large increase in pupils eating fruit, but what about a year after the free fruit program ended? The students were still eating more fruit. They were hooked! Three years later? Same thing. Three years after they had stopped getting free fruit, they were still eating about a third of a serving more, which, if sustained, is considerably more than necessary for the program to pay for itself.

There were also some happy side effects, including a positive spillover effect where not only the kids were eating more fruit, but their parents started eating more, too. And, although the “intention of these programs was not to reduce unhealthy snack intakes,” that’s exactly what appeared to happen: The fruit replaced some of the junk. Increasing healthy choices to crowd out the unhealthy ones may be more effective than just telling kids not to eat junk, which could actually backfire. Indeed, when you tell kids not to eat something, they may start to want it even more, as you can see at 2:20 in my video.

Which do you think worked better? Telling families to increase plants or decrease junk? Families were randomly assigned to one of two groups, either receiving encouragement to get at least two servings of fruits and veggies a day, with no mention of decreasing junk, or being encouraged to get their junk food intake to less than ten servings a week, with no mention of eating more fruits and veggies. What do you think happened? The Increase Fruit and Vegetable intervention just naturally “reduced high-fat/high-sugar intake,” whereas those in the Decrease Fat and Sugar group cut back on junk but didn’t magically start eating more fruits and vegetables.

This crowding out effect may not work on adults, though. As you can see at 3:12 in my video, in a cross-section of over a thousand adults in Los Angeles and Louisiana, those who ate five or more servings of fruits and veggies a day did not consume significantly less alcohol, soda, candy, cookies, or chips. “This finding suggests that unless the excessive consumption of salty snacks, cookies, candy, and sugar-sweetened beverages”—that is, junk—“is curtailed, other interventions…[may] have a limited impact….It may be politically more expedient to promote an increase in consumption of healthy items rather than a decrease in consumption of unhealthy items, but it may be far less effective.” In most public health campaigns, “messages have been direct and explicit: don’t smoke, don’t drink, and don’t take drugs.” In contrast, food campaigns have focused on eat healthy foods rather than cut out the crap. “Explicit messages against soda and low-nutrient [junk] foods are rare.”

In the United States, “if one-half of the U.S. population were to increase fruit and vegetable consumption by one serving each per day, an estimated 20,000 cancer cases might be avoided each year.” That’s 20,000 people who would not have gotten cancer had they been eating their fruits and veggies. The U.S. Department of Agriculture recommends we “fill half [our] plate with colorful fruits and vegetables,” but less than 10 percent of Americans hit the recommended daily target. Given this sorry state of affairs, should we even bother telling people to strive for “5 a day,” or might just saying “get one more serving than you usually do” end up working better? Researchers thought that “the more realistic ‘just 1 more’ goal would be more effective than the very ambitious ‘5 a day’ goal,” but they were wrong.

As you can see at 4:56 in my video, those told to eat one more a day for a week, ate about one more a day for a week, and those told to eat five a day for a week did just that, eating five a day for a week. But here’s the critical piece: One week after the experiment was over, the group who had been told to eat “5 a day” was still eating about a serving more, whereas the “just 1 more” group went back to their miserable baseline. So, more ambitious eating goals may be more motivating. Perhaps this is why “in the US ‘5 a day’ was replaced by the ‘Fruits and Veggies—More Matters’ campaign…in which a daily consumption of 7–13 servings of fruits and vegetables – FVs –  is recommended.” However, if the recommendation is too challenging, people may just give up. So, instead of just sticking with the science, policy makers evidently need to ask themselves questions like “How many servings are regarded as threatening?”


For more on appealing to vanity to improve fruit and vegetable consumption, see my videos Eating Better to Look Better and Beauty Is More Than Skin Deep.

What does the science say about smoothies? See:

The flipside of free fruit programs is to tax instead of subsidize. Learn more by checking out my video Would Taxing Unhealthy Foods Improve Public Health?

For more on the paternalistic attitude that you don’t care enough about your health to be told the truth, see my videos Everything in Moderation? Even Heart Disease? and Optimal Diet: Just Give It to Me Straight, Doc.

I explore this same patronizing attitude when it comes to physical activity in How Much Should You Exercise?

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: