Potassium is the yin to sodium's yang. Not only does supplementing with potassium lower blood pressure, but diets high in this mineral tend to be lower in sodium. Potassium is thought to act by increasing sodium excretion in the urine, which helps blood vessels dilate, and changing the interactions of hormones that affect blood pressure. In one analysis of several studies that looked at the ability of supplemental potassium to lower blood pressure, participants taking 2.3 to 4.7 grams a day of supplemental potassium had an average blood pressure reduction of 4.4/2.5 mmHg.
In the INTERSALT study all populations that consumed more salt than potassium saw their blood pressures rise, while those consuming more potassium than salt had no increase. And when Harvard researchers followed 43,738 men for eight years, they found a 38 percent reduced risk of stroke in those who got the most potassium. If you follow the DASH-Plus Plan, you're going to get plenty of potassium in your diet. If you find it difficult to stick to the eating plan, you might consider taking a potassium supplement or a multivitamin with extra potassium.
- Super foods: Bananas, orange juice, spinach, chard, mustard greens, zucchini, and button mushrooms.
If sodium and potassium are yin and yang, then potassium and magnesium are fraternal twins. If your diet is rich in potassium, chances are it's also rich in magnesium, since the two are often found together in food. It's clear that a diet high in magnesium benefits those with hypertension, most likely by contributing to the relaxation of the smooth muscles of the blood vessels. However, if vegetables and fruits grace your plate about as often as calf brains, you might want to consider taking a magnesium supplement. One study found that taking magnesium in amounts as low as 365 milligrams per day with beta-blockers significantly reduced blood pressure compared with taking the medication alone.
- Super foods: Whole grains, chard, spinach, sea vegetables, basil, dill, and squash. Avoid overcooking to minimize mineral loss.
Got milk? It could be the ticket to reducing your blood pressure. Numerous studies suggest that high intake of dietary calcium (whether from milk, cheese, yogurt, or ice cream) contributes to lower blood pressure. Because calcium is needed for smooth muscle relaxation and contraction, increased consumption can have a direct effect on blood vessels. It's best to get your calcium from your diet; studies have found that compared with supplements, dietary calcium has twice the benefits for blood pressure.
- Super foods: Low-fat or fat-free milk, cheese, and yogurt.
This powerful antioxidant has a significant effect on blood pressure. In one study, researchers found that people taking 500 milligrams of supplemental vitamin C a day for one month saw their systolic, diastolic, and mean blood pressures drop by about 9 percent, a pretty significant decline. One possible explanation: Vitamin C helps support the body’s production of nitric oxide, which is critical to normal functioning of blood vessels. The better your blood vessels work, the lower your risk of hypertension.
- Super foods: Chile peppers, parsley, broccoli, bell peppers, strawberries, oranges, lemon juice, papayas, cauliflower, kale, mustard greens, and Brussels sprouts.
Fiber—the indigestible part of plants—has long been the butt of late-night comedy routines. Now it's time to give it a little respect. Fiber is a powerhouse when it comes to health, reducing your risk of everything from colon cancer and heart disease to hypertension, and even helping you maintain or lose weight. When it comes to fiber, keep in mind that there are two kinds. Soluble fiber forms a kind of jelly in your stomach that helps slow the digestion of food, letting you feel full longer and consequently helping to slow the passage of food through the intestines, thus maintaining steadier blood sugar and insulin levels. Insoluble fiber acts as a giant vacuum cleaner, sweeping away toxins as it passes through the digestive system.
What does this have to do with blood pressure? Well, researchers suspect that fiber works its magic by improving your body's ability to use insulin and thus process glucose, both of which have a direct impact on blood pressure. Also, high amounts of fiber in your diet generally suggest an overall healthy diet, including more fruits and vegetables—which, as we've seen, makes a big difference when it comes to blood pressure control. There are also phytochemicals and antioxidants in whole grains (a great source of fiber) that may be partially responsible for some of fiber's beneficial effect on blood pressure.
Those benefits can be big. When researchers had 41 study participants double their soluble fiber intake and increase their protein intake with soy, their systolic blood pressures dropped by about 10.5 mmHg, and their diastolic readings declined by 3.5 mmHg. Even just increasing the fiber resulted in a drop of 2.4/1.9 mmHg.
Fiber can also help prevent the initial development of high blood pressure, which is particularly important if you fall into the prehypertension category. Harvard researchers found that volunteers who consumed more than 24 grams of fiber a day were 50 percent less likely to develop high blood pressure than those who consumed less than 12 grams a day. For the record, the average American consumes less than 15 grams a day.
- Super foods: Whole grains, fruits, and vegetables. For a major wallop, try oat cereal for breakfast. A small study at the University of Minnesota found that 73 percent of participants who ate oats every day were able to reduce the amount of blood pressure medication they took after 12 weeks.
You'd expect to see low blood pressures in people who follow vegetarian diets, but researchers were really surprised when they found that adding lean meat to a vegetarian regimen maintained the lower blood pressure. As it turns out, protein is critically important in maintaining healthy blood pressure. It contains two amino acids important to blood vessel health: l-arginine, a precursor of nitric oxide, which dilates blood vessels and lowers blood pressure, and taurine.
Several studies have found that restricting animals' ability to make nitric oxide results in hypertension. And when six healthy participants were randomly assigned to one of three diets for a week—a control diet, a natural-foods diet enriched with l-arginine, or a diet identical to the control diet but with the addition of l-arginine supplements—both groups receiving l-arginine saw their blood pressures drop.
The other amino acid, taurine, also has antihypertensive effects. When 19 study participants with borderline hypertension supplemented their diets with 6 grams of taurine daily for seven days, systolic blood pressure dropped an average of 9 mmHg, compared with a 2 mmHg decrease in patients treated with placebos, while diastolic pressure dropped an average of 4 mmHg, compared with 1 mmHg drop in the placebo group. Taurine seems to control levels of the stress hormone epinephrine, which have been found to be higher in people with hypertension. It also relaxes blood vessels by improving production of "feel good" hormones called endorphins, resulting in lower blood pressure.
- Super foods: Eggs, poultry, tofu, fish, and lean pork, beef, and lamb.
Omega-3 fatty acids
Found primarily in cold-water fish, this form of fat (yes, the "f" word), is like a winning lottery ticket for your heart, improving electrical activity and reducing risk of heart disease, stroke, and heart attack. In one well-designed study, participants who received 3 grams of an omega-3 fatty acid supplement a day showed significant improvement in something called systemic arterial compliance, which is really a fancy way of saying how well your larger artery works. The stiffer the artery, the higher your systolic and pulse pressure. But after seven weeks on this regimen, the participants’ arterial compliance rose 36 percent with one form of omega-3 fatty acid (EPA) and 27 percent with another (DHA). The best source of omega-3 fatty acids is fish, which would explain why an Australian study found that people who ate diets both high in fish and low in fat had significantly lower blood pressures than those who followed one or the other.
- Super foods: Mackerel, anchovies, salmon, tuna, and herring.
This crisp vegetable has traditionally been used as a blood pressure treatment in Asian medicine. More recent studies in rats have found that animals injected with celery extract (the equivalent of four stalks of the green roughage) had blood pressure reductions of 12 to 14 percent within a week. The key celery nutrient believed to fight hypertension is 3-n-butyl phthalide, which helps artery muscles dilate and reduces stress hormones in the blood. A bonus: Celery packs a whopping 8 grams of fiber in each large stalk.
If you're looking for a savory substitute for salt, try some minced garlic mixed into your food. Not only does it pack a seasoning punch with no sodium, but several clinical trials attest to its blood pressure–lowering properties. In fact, as little as one clove a day can significantly reduce your overall blood pressure. You can expect to see improvement in as little as three months.
There's a great deal of evidence that oxidative stress may be a contributing factor in hypertension. Oxidative stress occurs as a basic side effect of living—it's wear and tear on cells that in turn produces wear and tear on your body as a whole. Normally, we have defenses in place to arrest this damage in the form of antioxidants, which do just what their name implies—reverse or prevent oxidative damage.
Much of that antioxidant power comes from nutrients in food, including antioxidant vitamins E, C, and beta-carotene. Another important antioxidant is co-enzyme Q10 (CoQ10). It’s long been known to be critical for overall heart health, and several recent studies suggest that part of its benefit may stem from its effects on hypertension. An eight-week trial completed in 1999 on 59 men with hypertension found that those who received 120 milligrams per day of CoQ10 saw their blood pressures drop an average of 16/9 mmHg, while a group taking placebos had no change. A 2001 study of 46 men and 37 women with systolic hypertension found that taking 60 milligrams of CoQ10 twice a day resulted in an average reduction in systolic blood pressure of nearly 18 mmHg, with 55 percent of the patients showing a drop. Although we can get CoQ10 from food, people taking cholesterol-lowering statin drugs and those with diabetes may benefit from supplementing with this antioxidant.
- Super foods: Fresh sardines, mackerel, beef, pork, and eggs. Vegetable sources include spinach, broccoli, peanuts, wheat germ, and whole grains.