A Potassium-Rich Diet Can Lower Your Risk of High Blood Pressure

By Barbara Day, M.S., R.D., C.N

Recently theInstituteofMedicineof the National Academies of Science issued their sixth report in a series updating nutrient recommendations.  The report indicated that Americans need to get more potassium in their diet to help lower the risk of high blood pressure, kidney stones, osteoporosis, and stroke.  The recommendation is to include at least 4.7 grams or 4700 milligrams per day for all adults.  Since Americans are reportedly eating too much salt in their diet, eating adequate amounts of potassium each day may  actually help to blunt the effects of high salt intakes on blood pressure, according the report. Researchers have reported that American women consume only about half of their daily recommended amount of potassium whereas men consume more potassium but their levels are still lower than the recommendation.

The Body Contains Potassium 

            Potassium, a mineral which is referred to as an electrolyte, is about two times more plentiful in the body than salt.  An average man contains about 270 milligrams.  Most of the potassium is found inside the cells and is the major cation in the intracellular fluid.  However, a small amount is found in the extracellular (outside the cell) but this potassium source plays a significant role in muscle activity, especially the heart muscle.  Potassium is responsible for maintaining the electrical stability of the cells of heart and nervous system.

Potassium a Metabolic Workhorse

Potassium’s major role is to maintain fluid and electrolyte balance.  Potassium functions in a balance with extracellular sodium to maintain normal osmotic pressure and the water balance in the cellular fluid.  During muscle contraction, potassium and sodium briefly exchange places across the cell membrane and then the process is quickly reversed. It’s this sodium-potassium pump that regulates the water in and out of the cell which can therefore influence one’s blood pressure.

In addition to regulating the fluid-electrolyte balance, potassium also influences muscle activity, particularly the heart (cardiac) muscle.  Potassium functions with sodium and calcium ions to regulate the neuromuscular excitability and stimulation, transmission of the electrochemical impulses and contraction of heart and other muscle fibers.  Small variations in serum potassium can be seen on an electrocardiogram (ECG).

Too much serum potassium, hyperkalemia, causes muscle irritability and can be life threatening.   If the one experiences hyperkalemia the heart can hypertrophy and the heart rate is therefore slowed down.  Whereas too little serum potassium, hypokalemia, causes muscle weakness and can potentially cause paralysis. The heart muscle can then develop an increased rhythm known as tachycardia which can lead to cardiac arrest. But fortunately for us, the kidney is responsible for maintaining this sensitive balance.

Potassium’s Role in Glycogen Storage and Protein Metabolism

In addition to regulating fluid – electrolyte balance and nerve transmission, potassium is also needed to convert blood glucose to glycogen for storage and is also required for the storage of nitrogen in muscle protein.  When tissue is broken down, potassium is lost together with nitrogen.  Research has also suggested that a pound of sweat contains between 80 – 100 milligrams of potassium.  During a 2 – 3 hour bout of exercise, you might lose 300 – 800 milligrams of potassium (see Table 1. Potassium Found in Foods).  People who are active may need to concentrate on choosing potassium rich foods for recovery.

Because foods that are typically high in potassium come from fruits and vegetables,  you will also be getting a wide variety of nutrients and phytochemicals as well. Check out Table 1. Potassium Found in Food and try to incorporate adequate amounts for potassium daily.   Potassium rich foods may not only help to control your blood pressure but they may also help prevent the development of other disease processes as well.

Table 1. Potassium Found in Food

 

Bread, cereal, rice pasta

Food                                                    Portion                          Potassium (mg)

Bran flakes                                          ¾ cup                          184

Bread, whole wheat                            1 slice                          44

Bran muffin, homemade                     1                                  99

Oatmeal (cooked)                               ¾ cup                          99

Pasta, enriched (cooked)                     1 cup                           85

 

Vegetables

Food                                                    Portion                             Potassium (mg)

Artichoke (boiled)                               1 med                          316

Asparagus (boiled)                              ½ cup (6 spears)          279

Avocado (raw)                                    1 med                          1097

Broccoli (raw)                                     ½ cup, chopped           143

Brussel sprouts (boiled)                      ½ cup, (4 sprouts)       247

Carrot (raw)                                        1 med                          233

Corn, yellow (boiled)                          ½ cup                          204

Mushrooms (boiled)                            ½ cup, pieces               277

Potato (baked, with skin)                    1 med                          844

Spinach (boiled)                                  ½ cup                          419

Sweet potato (baked)                          1 med                          397

Tomato                                                1 med                          254

 

Fruits

Food                                                    Portion                             Potassium (mg)

Apple (raw, with skin)                        1 med                          159

Banana                                                            1 med                          451

Cantaloupe                                          1 cup, pieces                494

Dates (dried)                                       10 dates                       451

Figs                                                     10 figs                         1332

Orange juice (fresh)                            8 fl oz                          486

Orange, navel                                      1 med                          250

Prunes (dried)                                     10 prunes                     626

Prune juice (canned)                           8 fl oz                          706

Raisins, seedless                                  2/3 cup                                    751

 

Meats

Beef top round, lean (broiled)      3.5 oz                          442

Black eyed peas                                  1 cup                           476

Chicken, dark meat, no skin               3.5 oz                          240

Chicken white meat, no skin               3.5 oz                          247

Ground beef, regular                           3.5 oz                          292

Ham, canned (lean)                             3.5 oz                          364

Sirloin steak, lean (broiled)                 2.5 oz                          403

 

Seafood

Food                                                    Portion                          Potassium (mg)

Halibut (baked)                                   3 oz                             490

Lobster (steamed)                               3 oz                             299

Mackerel (baked)                                3 oz                             341

Oysters (steamed)                               3 oz (12 med)              389

Salmon (baked)                                   3 oz                             319

Clams (steamed)                                 3 oz (9 small)               534

Crab, blue (steamed)                           3 oz                             275

Trout, rainbow (baked)                       3 oz                             539

Tuna, light canned in water                3 oz                             267

 

Miscellaneous

Food                                                    Portion                           Potassium (mg)

Almonds                                             1 oz (22 nuts)              219

Peanuts, dry roasted                           1 oz                             184

Lentils (broiled)                                  1 cup                           731

Limabeans (boiled)                            1 cup                           955

Peanut butter, creamy                         1 tbsp                          110

Pinto beans (boiled)                            1 cup                           800

Soybeans (boiled)                               1 cup                           886

Egg, whole                                          1 large                         65

Coffee, brewed                                   6 fl oz                          96

Tea, black brewed 3 min                     6 fl oz                          66

 

Milk

Food                                                    Portion                             Potassium (mg)

Cottage cheese, creamed                    1 cup                           177

Milk, skim                                           8 fl oz                          406

Milk, whole                                         8 fl oz                          368

Yogurt, whole                                     8 fl oz                          351

 

Sugar

Food                                                    Portion                             Potassium (mg)

Molasses, black strap                          1 tbsp                          585

Sugar, brown                                       1 cup                           499

 

Source: Bowes & Church’s Food Values Commonly Used.  Jean A. T. Pennington. 18th edition.  2005.

Image from: www.howshealth.com

Barbara Day, M.S., R.D., C.N., is a registered dietitian with a Master’s Degree in clinical nutrition.  The former publisher of Kentuckiana HealthFitness Magazine, Kentuckiana Healthy Woman magazine and radio show host of Health News You Can Use, Barbara has over 30 years of experience in promoting healthy lifestyles to consumers.  Barbara worked as Nutrition Consultant to the Navy SEALs (8 years) and the University of Louisville Athletic Department (10 years). Barbara has private practice, DayByDay Nutrition, www.DayByDayNutrition.com, where she counsels clients on weight loss, cholesterol management, performance nutrition and an array of other medical issues.  Visit Barbara’s new website which is an on-line health & wellness magazine, www.KentuckianaHEALTHWellness.com. Barbara writes nutrition and health columns for www.LiveStrong.com as well as a weekly nutrition column for the Southeast Outlook. She also designs and presents employee wellness programs to small and large businesses. Barbara is a runner, cyclist, hiker and a mother and grandmother to 11 grandchildren.    

 

 

 

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