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What is Hypertension
Lifestyle Modification for Hypertension Sodium and Hypertension Whole Grains for Hypertension Article Review
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OBJECTIVES:
REFERENCES:
- Identify normal and abnormal blood pressure.
- Discuss the role of Lifestyle modification in Hypertension management.
- Understand the effect of sodium in hypertension.
- Describe the importance of Sodium-restricted and Whole food diet in managing hypertension.
REFERENCES:
- Nutrition Facts, Dr. Michael Greger
- Nutrition for Clinicians, Dr. Neal Barnard
What is Hypertension?
The most comprehensive and systematic analysis of the causes of death ever undertaken was published recently in the Lancet, one of the world's leading medical journals. Funded by the Bill & Melinda Gates Foundation, the Global Burden of Disease Study involved nearly five hundred researchers from more than three hundred institutions in fifty countries and examined nearly one hundred thousand data sources. The study noted which foods, if added to the diet, might save lives. Eating more whole grains could potentially save 1.7 million lives a year. More vegetables? 1.8 million lives. How about nuts and seeds? 2.5 million lives. The researchers didn't look at beans, but of the foods they considered, which does the world need most? Fruit. Worldwide, if humanity ate more fruit, we might save 4.9 million lives. That's nearly 5 million lives hanging in the balance, and their salvation isn't medication or a new vaccine-it may be just more fruit. The number-one risk factor for death in the world they identified is high blood pressure. Also known as hypertension, high blood pressure lays waste to nine million people worldwide every year. It kills so many people because it contributes to deaths from a variety of causes, including aneurysms, heart attacks, heart failure, kidney failure, and stroke.
You've probably had your blood pressure taken at the doctor's office. The nurse reads off two numbers, say, for example, "115 over 75." The first number (systolic") represents the pressure in your arteries as your blood pumps from the heart; the second number ("diastolic") is the pressure in your arteries while the heart is resting between beats. The American Heart Association defines "normal" blood pressure as a systolic pressure under 120 and a diastolic pressure under 80-or 120/80. Anything above 140/90 is considered hypertensive. Values in between are considered prehypertensive. Increased blood pressure puts a strain on the heart and can damage the sensitive blood vessels in your eyes and kidneys, cause bleeding in the brain, and even lead certain arteries to balloon and rupture. The fact that hypertension can damage so many organ systems and increase the risk of heart disease and stroke, two of our leading killers, explains why it is the number one killer risk factor worldwide.
In the United States, nearly seventy eight million people have high blood pressure-that's about one in three American adults. As you age, your blood pressure tends to get higher and higher. In fact, after age sixty, 65 percent of Americans can expect to be diagnosed with the condition. In the Philippines according to the Department of Health survey in 2017 it was found out that 1 in every 4 Filipinos are already hypertensive. And unfortunately, more than half of them are not aware of their condition. This has led many people, including doctors, to assume that high blood pressure, like wrinkles or gray hair, is just an inevitable consequence of getting older.
However, we've known for nearly a century that this isn't true. In the 1920s, researchers measured the blood pressure of a thousand native Kenyans who ate a low-sodium diet centered around whole plant foods-whole grains, beans, fruits, and dark, leafy greens, and other vegetables. Up until age forty, the blood pressure of the rural Africans was similar to that of Europeans and Americans, about 125/80. However, as Westerners aged, their blood pressure began to surge past the Kenyans. By age sixty, the average Westerner was hypertensive, With blood pressure exceeding 140/90. What about the Kenyans? By age sixty, their average blood pressure had actually improved to an average of about 110/70.
However, we've known for nearly a century that this isn't true. In the 1920s, researchers measured the blood pressure of a thousand native Kenyans who ate a low-sodium diet centered around whole plant foods-whole grains, beans, fruits, and dark, leafy greens, and other vegetables. Up until age forty, the blood pressure of the rural Africans was similar to that of Europeans and Americans, about 125/80. However, as Westerners aged, their blood pressure began to surge past the Kenyans. By age sixty, the average Westerner was hypertensive, With blood pressure exceeding 140/90. What about the Kenyans? By age sixty, their average blood pressure had actually improved to an average of about 110/70.
The 140/90 threshold for hypertension is considered an arbitrary cut off. Just like having too much cholesterol or body fat, there are benefits to having a blood pressure that is even lower than the "normal" range. So even people who start out with a so--called normal blood pressure of 120/80 appear to benefit from going down to 110/70.4 But is it possible to do that? Look at the Kenyans-not only is it possible, it appears typical for people who live healthy, plant-based lifestyles. Over a two-year period, 1,800 patients were admitted into a rural Kenyan hospital. How many cases of high blood pressure did they find? Zero. There also wasn't a single case found of America's number-one killer, atherosclerosis. High blood pressure, then, appears to be a choice. You can continue eating the artery-bursting Western diet, or you can choose to take off the pressure. The truth is that eliminating humanity's primary risk factor for death may be simple. No drugs, no scalpels. Just forks.
The American Heart Association and American Stroke Association released the new blood pressure categories with the goal of starting lifestyle change and medication to prevent complications the earliest possible. The Philippines and most Asian countries are still using the old categories.
Sodium and Hypertension
The two most prominent dietary risks for death and disability in the world may be not eating enough fruit and eating too much salt. Nearly five million people appear to die every year as a result of not eating enough fruit, while eating too much salt may kill up to four million. Salt is a compound made up of about 40 percent sodium and 60 percent chloride. Sodium is an essential nutrient, but vegetables and other natural foods provide the small amounts of sodium you need in your diet. If you consume too much, it can cause water retention, and your body may respond by raising your blood pressure to push the excess fluid and salt out of your system. For the first 90 percent of human evolution, we likely ate diets containing less than the equivalent of a quarter teaspoon of salt's worth of sodium a day. Why? Because we likely ate mostly plants. We went millions of years without saltshakers, so our bodies evolved into sodium-conserving machines.
That served us well until we discovered that salt could be used to preserve foods. It didn't matter that the addition of salt to our food resulted in a general rise in blood pressure the alternative was starving to death because all our food rotted away. But where does that leave us now? After all, we no longer have to live off pickles and jerky. Humans are genetically programmed to eat ten times less sodium than we do now. Many so-called low-salt diets can actually be considered high-salt diets. That's why it's critical to understand what the concept of "normal" is when it comes to sodium. Having a "normal" salt intake can lead to a "normal" blood pressure, which can contribute to us dying from all the "normal" causes, like heart attacks and strokes. The American Heart Association recommends everyone consume less than 1,500 mg of sodium daily that's about three-quarters of a teaspoon of salt. The average American adult consumes more than double that amount, about 3,500 mg daily.
Reducing sodium consumption by just 15 percent worldwide could save millions of lives every year. If we could cut our salt intake by about a half teaspoon a day, which is achievable by avoiding salty foods and not adding salt to our food, we might prevent 22 percent of stroke deaths and 16 percent of fatal heart attacks. That's potentially more lives saved than if we were able to successfully treat people with blood pressure pills. Simply put, reducing salt is an easy at-home intervention that may be more powerful than filling a prescription from the pharmacy. Up to ninety two thousand American lives could be saved each year simply by eating less salt. This is also true to other countries who also adopted the Western diet. The evidence that sodium raises blood pressure is clear, including double-blind, randomized trials dating back decades. If we take subjects with high blood pressure and put them on a sodium-restricted diet, their blood pressure drops. If we keep them on the low-salt diet and placebo, nothing happens.
However, if we instead give subjects salt in the form of a time-release sodium pill, their blood pressure goes back up again. The more sodium we give them secretly, the higher their blood pressure climbs. Even just a single meal can do it. If we take people with normal blood pressure and give them a bowl of soup containing the amount of salt that may be found in an average American meal, their blood pressure climbs over the next three hours compared to eating the same soup without any added salt. Over 33 dozens of similar studies demonstrate that if you reduce your salt intake, you reduce your blood pressure. And the greater the reduction, the greater the benefit. But if you don't cut down, chronic high salt intake can lead to a gradual increase in blood pressure throughout life.
Doctors used to be taught that a normal systolic blood pressure is approximately 100 plus age. Indeed that's about what you're born with. Babies start out with a blood pressure around 95/60. But, as you age, that 95 can go up to 120 by your twenties. By the time you're in your forties, it can be up to 140-the official cut off for high blood pressure--and then keep climbing as you get older. What would happen if, instead of consuming ten times more sodium than what your bodies were designed to handle, you just ate the natural amount found in whole foods? Is it possible your blood pressure would stay low your whole life? To test that theory, we'd have to find a population in modern times that doesn't use salt, eat processed food, or go out to eat. To find a no-salt culture, scientists had to go deep into the Amazon rainforest. Strangers to saltshakers, Cheetos, and KFC, the Yanomamo Indians were found to have the lowest sodium intake ever recorded which is to say the sodium intake we evolved eating. Lo and behold, researchers found that the blood pressures among older Yanomamo were the same as those of adolescents. In other words, they start out with an average blood pressure of about 100/60 and stay that way for life.
The researchers couldn't find a single case of high blood pressure. Why do we suspect it was the sodium? After all, the Yanomamos studied didn't drink alcohol, ate a high-fiber, plant-based diet, had lots of exercise, and were not obese. An interventional trial could prove that sodium was the culprit. Imagine if we took people literally dying from out-of-control high blood pressure (known as malignant hypertension), a condition from which you go blind from bleeding into your eyes, your kidneys shut down, and your heart eventually fails. What if you put these patients on a Yanomamo-level salt intake-in other words, a normal-for-the-human-species salt intake? Enter Dr. Walter Kempner and his rice and-fruit diet. Without drugs, he brought patients with eye-popping blood pressures like 240/150 down to 105/80 with dietary changes alone. How could he ethically withhold medication from such seriously ill patients? Modern high blood pressure pills hadn't been invented yet. Dr. Kempner conducted his work back in the 1940s. Back then, malignant hypertension was a death sentence, with a life expectancy of about six months.
Lifestyle Modification for Hypertension
Nevertheless, he was able to reverse the course of disease with diet in more than 70 percent of cases. Though the diet wasn't merely extremely low sodium-it was also strictly plant-based and low in fat and protein, Dr. Kempner is now recognized as the person who established, beyond any shadow of doubt, that high blood pressure can often be lowered by a low-sodium diet. In addition to high blood pressure, salty meals can significantly impair artery function, even among people whose blood pressure tends to be unresponsive to salt intake. In other words, salt itself can injure our arteries independent of its impact on blood pressure. And that harm begins within thirty minutes.
Using a technique called laser Doppler flowmetry, researchers are able to measure blood flow in the tiny vessels in the skin. After a high-sodium meal, there is significantly less blood flow unless vitamin C is injected into the skin, which appears to reverse much of the sodium induced suppression of blood vessel function. So, if an antioxidant helps block the sodium effect, then the mechanism by which salt impairs arterial function may be oxidative stress, the formation of free radicals in your bloodstream. It turns out that sodium intake appears to suppress the activity of a key antioxidant enzyme in the body called superoxide dismutase, which has the ability to detoxify a million free radicals per second. With the action of this workhorse of an enzyme stifled by sodium, artery crippling levels of oxidative stress can build up. After one salty meal, not only does blood pressure increase but the arteries actually begin to stiffen.
This may be how we figured out thousands of years ago that too much salt was bad for us. Quoting from a translation of The Yellow Emperor's Classic of Internal Medicine, an ancient Chinese medical text, "If too much salt is used in food, the pulse hardens..." It turns out that we may not need a double-blind trial; maybe we just have to feed someone a bag of potato chips and take his or her pulse. Unsurprisingly, the salt industry isn't thrilled about the idea of us cutting back on salt. Back in 2009, the American Heart Association quoted the chair of the U.S. Dietary Guidelines Advisory Committee as saying that Americans should reduce their sodium intake. The Salt Institute, a salt industry trade organization, accused her of having an "unhealthy prejudice" against salt, arguing that she had "pre-judged the salt issue." This is like the tobacco industry complaining that people at the American Lung Association are biased against smoking. Of course, the Salt Institute wasn't the only aggrieved party.
For adults over fifty, it's bread, but between the ages of twenty and fifty, the greatest contributor of sodium to the diet is chicken-not the canned soups, pretzels, or potato chips one might expect. How can you overcome your built-in craving for salt, sugar, and fat? Just give it a few weeks, and your taste buds will start to change. When researchers put people on a low-salt diet, over time, the research subjects increasingly enjoyed the taste of salt-free soup and became turned off by the salt-heavy soup they had previously craved. As the study progressed, when the participants were allowed to salt their own soup to taste, they preferred less and less salt as their taste buds became acclimated to healthier levels. The same may be true for sugar and fat. It's likely that humans actually taste fat, just like they taste sweet, sour, and salty flavors. People placed on low-fat diets start preferring low-fat foods over fatty options.
Your tongue may actually become more sensitive to fat, and the more sensitive your tongue becomes, the less butter, meat, dairy, and eggs you eat. On the flip side, if you eat too much of these foods, you may blunt your taste for fat, which can cause you to eat more calories and more fat, dairy, meat, and eggs and ultimately gain weight. This can all happen in just a matter of weeks. There are three things you can do to shake the salt habit. First, don't add salt at the table. Second, stop adding salt when cooking. The food may taste bland at first, but within two to four weeks, the salt-taste receptors in your mouth become more sensitive, and food tastes better.
Believe it or not, after two weeks, you may actually prefer the taste of food with less salt. Try any combination of such fantastic flavorings as pepper, onions, garlic, tomatoes, sweet peppers, basil, parsley, thyme, celery, lime, chili powder, rosemary, smoked paprika, curry, coriander, and lemon instead. Also, it's probably a good idea to avoid eating out as much as possible. Even non-fast-food restaurants tend to pile on the salt. Finally, do what you can to avoid processed foods. In most countries studied, processed foods provide only about half of people's sodium intake, but in the United States, we consume so much sodium from processed foods that even if we completely stopped adding salt in the kitchen and dining room, we'd still only reduce our salt intake by a small fraction. Try to buy foods with fewer milligrams of sodium on the label than there are grams in the serving size. For example, if it's a 100 g serving size, the product should have less than 100 mg of sodium." Alternatively, you can shoot for fewer milligrams of sodium per serving than there are calories.
Most people get around 2,200 calories a day, so if everything you ate had more calories than sodium, you would probably make it at least under the Dietary Guidelines for Americans upper limit of 2,300 mg of sodium a day. Ideally, though, you'd buy mostly food without any labels at all. It is considered almost impossible to come up with a diet consisting of unprocessed natural foods that exceeds the strict 1,500 mg a day American Heart Association guidelines for sodium reduction.
Whole Grains
On average, high blood pressure medications reduce the risk of heart attack by 15 percent and the risk of stroke by 25 percent. But in a randomized, controlled trial, three portions of whole grains a day were able to help people achieve this blood-pressure-lowering benefit too.
The study revealed that a diet rich in whole grains yields the same benefits without the adverse side effects commonly associated with antihypertensive drugs, such as electrolyte disturbances in those taking diuretics (also known as water pills); so increased breast cancer risk for those taking calcium-channel blockers (like Norvasc or Cardizem); lethargy and impotence for those on beta blockers (like Lopressor and Corgard); sudden, potentially life-threatening swelling for those taking ACE inhibitors (like Vasotec and Altace); and an increased risk of serious fall injuries for apparently any class of these blood pressure drugs. Whole grains do have side effects, though. Good ones! Whole-grain intake is associated with lower risks of type 2 diabetes, coronary heart disease, weight gain,85 and colon cancer. Take note of the whole, however.
While whole grains, such as oats, whole wheat, and brown rice, have been shown to reduce your risk of developing chronic disease, refined grains may actually increase your risk. Harvard University example, found that while regular consumption of brown rice was associated with a lower risk of type 2 diabetes, consuming white rice was associated with higher risk. Daily servings of white rice were associated with a 17 percent greater risk of diabetes, whereas replacing one-third of a serving a day of white rice for brown rice might lead to a 16 percent drop in risk. And it looks like replacing white rice with oats and barley may be an even more powerful step, associated with a 36 percent drop in diabetes risk. Researchers, for given the improvements in cardiac risk factors seen in interventional trials of whole grains, it's not surprising to see a reduction in the progression of arterial disease among those who regularly eat them.
In studies of two of the most important arteries in the body, the coronary arteries that feed the heart and the carotid arteries that feed the brain, people who ate the most whole grains had significantly slower narrowing of their arteries. Since atherosclerotic plaque in the arteries is our leading killer, ideally, you should not just slow down the process but actually stop or even reverse it altogether. This appears to require more than just whole grains; whole vegetables, whole fruits, whole beans, and other whole plant foods are needed, along with a significant reduction in your intake of trans fats, saturated fats, and cholesterol, the food components that contribute to clogging your arteries shut.
What About the DASH Diet?
What if you are among the seventy eight million Americans who already have high blood pressure? How can you bring it down? The American Heart Association (AHA), the American College of Cardiology (ACC), and the Centers for Disease Control and Prevention (CDC) all recommend that patients first try lifestyle modifications, such as reducing body weight, limiting sodium and alcohol intake, getting more exercise, and eating a healthier diet.
What if you are among the seventy eight million Americans who already have high blood pressure? How can you bring it down? The American Heart Association (AHA), the American College of Cardiology (ACC), and the Centers for Disease Control and Prevention (CDC) all recommend that patients first try lifestyle modifications, such as reducing body weight, limiting sodium and alcohol intake, getting more exercise, and eating a healthier diet.
However, if their recommended lifestyle changes don't work, then it's off to the pharmacy. First up is a diuretic (water pill), and before you can spell "pharmaceutical cocktail," the medications begin piling up until your blood pressure comes down. High blood pressure patients commonly end up on three different antihypertensive drugs at a time, yet only about half tend to stick to even the first-line drugs. (This is due in part to all their side effects, which can include erectile dysfunction, fatigue, and leg cramps.) At the end of all of this, the drugs still haven't gotten to the root cause of the problem. The cause of high blood pressure isn't medication deficiency.
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