Imagine for a minute that the mythical scales held by blindfolded Lady Justice are really the scales of nutrition. On one side place all the high-sodium prepared foods you eat on a regular basis–a can of chicken soup, a sandwich of deli turkey and white bread, chips, crackers, a frozen dinner, low-fat salad dressing. You should add to that side of the balance every meal you eat from a restaurant or take-out counter. On the other side, place all potassium-rich fruits and vegetables you eat regularly--bananas, apricots, oranges, spinach, acorn squash, and cantaloupe. Whole grain breads and cereals also belong on this side.
At this point, if you’re at all typical, your scales are heavily weighted in favor of sodium. To even things out a bit, you can add potatoes to the potassium side. Unfortunately, fast food fries come with so much salt and are so heavily processed that they belong on the other side of the scale. Sodium and potassium are out of balance in the American diet, and, as a result, one of every three adults has high blood pressure, a major risk factor for stroke, heart attack and heart failure.
If you’re worried about high blood pressure–and you should be, whether you’re diagnosed with it or not–one look at the imaginary scales above will give you a very simple solution: you need to eat more fresh fruits and vegetables and less processed convenience foods.
Working in Opposition
Sodium and potassium are minerals that the body needs, and they basically work in opposition to each other to maintain a proper fluid balance in cells and control blood pressure. Our ancestors centuries ago, who subsisted on foods they could hunt or gather–fresh fruits and vegetables, nuts, seeds, fish and meat–ate a diet providing 5 to 10 times as much potassium as sodium–a healthy ratio. Dietary guidelines today, bowing to reality, recommend a potassium/sodium ratio of 2:1 to 3:1; yet the typical American diet actually has those ratios reversed.
The upper limit of sodium intake, according to the American Heart Association, should be 2,300 milligrams a day–equal to about a teaspoon of table salt. The average American eats three or four times that much–most of it from prepared foods.
The minimum requirement for potassium is 4,700 milligrams a day– and should be much higher for those with an excessive intake of sodium. Yet the average American, skimping on fresh produce, gets only about 2,300 milligrams a day.
The kidneys correct the imbalance...but at a price. Fluid retention, an increase in blood pressure, calcium loss and a risk of heart disease, osteoporosis and other chronic diseases results from imbalances of sodium and potassium.
The answer to potassium/sodium imbalance is not supplementation. Because of substantial risks of side effects and interactions, potassium supplements should be taken only under the supervision of a doctor. When blood pressure is being treated with diuretics, the risk of potassium supplementation may be even greater. Potassium restriction is also important in people with kidney disease. Otherwise, there’s no harm and a lot to be gained from adding potassium-rich foods to your diet while subtracting sodium.
Sodium restriction, of course, is an important part of treatment and prevention of high blood pressure and should be a priority for all Americans. The Institute of Medicine recommends an even lower intake–1,500 milligrams a day for healthy adults. Given the large proportion of packaged foods in the diet, that’s a formidable task.
As a preservative, salt is used generously in canned vegetables, beans and soups. And the sodium content of deli turkey is similar to that of ham. Sausages, olives and pickles are extremely high in sodium. Salty snack foods are also popular. Finally, those who cook your food in restaurants and take-away counters know that an extra dash or two of salt is bound to make the dish more appealing to customers.
Supermarket shopping requires vigilant label reading. In addition to salt, look for hydrolyzed vegetable protein, baking powder, sodium nitrate, sodium benzoate, sodium bicarbonate, soy sauce, sodium ascorbate, whey solids and monosodium glutamate. All of these add sodium.
When you’re eating out, inquire about how food is marinated and prepared. But the only way to really be assured of getting a low sodium diet is to eat as many meals at home as possible. Prepare food from scratch and use herbs, spices, pepper, lemon and garlic for seasoning.
Potassium
In addition to the added sodium, food processing tends to destroy whatever potassium was in the food originally. Potassium levels are highest in fresh foods. The effectiveness of the DASH (Dietary Approaches to Stop Hypertension) diet can be attributed in part to its high potassium content. The diet calls for five servings a day of both fruits and vegetables–most of which are high not only in potassium but calcium, magnesium and other essential vitamins and minerals. A baked sweet potato provides 694 milligrams of potassium; a half cup of winter squash has 448. Green, leafy vegetables, citrus fruits, apricots, peaches, bananas and canteloupe are all rich in potassium.
DASH calls for generous portions of whole grains, nuts and legumes. A half cup of white beans will give you 595 milligrams of potassium. A quarter of a cup of cooked whole grain cereal provides 140 milligrams of potassium...and no sodium.
And finally, the DASH diet calls for liberal quantities of low-fat dairy products, such as non-fat yogurt (595 milligrams per 8 ounces) or skim milk (382 milligrams per cup).
Studies have found that the DASH diet is more effective than sodium restriction alone in lowering blood pressure. A combination of the DASH diet and sodium restriction is even more effective, particularly in persons already diagnosed with hypertension.
In addition, several large population-based studies have found that persons eating a potassium-rich diet had a substantially reduced risk of stroke. High blood pressure is a major cause of strokes, but the protective effect of potassium was independent of its ability to lower blood pressure.
Getting enough potassium should not be difficult because the mineral is prevalent in many foods, even red meat, fish and poultry. Too much cooking and too much processing tends to destroy it, however. And too much sodium tends to deplete the body’s supply. The answer is simple: to keep the nutrition scales in a healthy balance, choose foods that are fresh, whole and natural.
Michelle Herbert, PharmD, CDE
Clinical Director, Richmond Apothecaries, Inc.
