28 June 2004

Are You Getting The Right Amounts?

Tito Rolly sent me this morning an email about the health benefits of eating bananas. Being a doctor, I usually associate bananas with potassium. Potassium and sodium are electrolytes. As such, they are responsible for regulating the electrical activities of the body, including the heart, muscle and nerves. Potassium is usually found inside our cells, while sodium along with chloride are found mainly outside cells. These 3 have to be in proper balance with each other to assure normal metabolic and neuromuscular functioning. An imbalance of high sodium and chloride in relation to potassium is thought to be a major factor in several serious chronic ailments. That's why when you get confined to a hospital, one of the first things a doctor orders is to get your electrolyte profile.

During prehistoric times, early humans survived mainly on diets rich in potassium and very low in sodium. They ate more fruits and vegetables than meat. But modern-day diets, be it American or Filipino, are the reverse of what those early humans consumed --- being loaded with sodium and relatively poor in potassium. There is also a notable increase in processed food consumption, which has a similarly higher sodium than potassium content. The average Western man consumes only 2/3rds the recommended amount of potassium each day, and the average Western woman consumes even less --- half of the 4,700 milligrams a day considered to be an adult's adequate daily intake. In the Philippines, regardless of gender, the recommendation for potassium is even lesser at 2000mgs per day (see table below) --- which, really makes me suspect that the average Filipino isn't really getting the proper electrolyte balance in his body. Filipino adults are advised to consume 500mgs of sodium and 750mgs of chloride each day or about 2gms of salt to replace the amount lost daily on average through perspiration and urination. Elevated blood pressure, which may lead to stroke, coronary heart disease, and kidney disease, is associated with sodium intake. On average, blood pressure rises progressively as salt intake increases. A value known as the upper intake level (UL) is the maximum amount that people should not exceed --- is set at 5.8 grams of salt (2.3 grams of sodium) per day. Older individuals and people with chronic diseases including hypertension, diabetes, and kidney disease are especially sensitive to the blood pressure-raising effects of salt and should consume less than the UL.
FNRI data, 2002. DOST Philippines

To lower blood pressure and reduce the risk of kidney stones and bone loss, American health authorities recommend a consumption of 4.7 grams of potassium per day. I personally think that the 2-gram Filipino recommendation is a bit low. The potential consequences of a chronic potassium deficiency are often unrecognized, and this often escape the notice even of doctors. The problems include high blood pressure, heart attacks, strokes, kidney stones and a loss of bone minerals that can lead to osteoporosis. A low potassium consumption can also cause a sensitivity to salt, further raising the risk of hypertension. Most people have no warning of their potassium deficiencies. They may feel exhausted, weak, and irritable, but unable to pinpoint the cause.

Two weeks ago, I visited the mother of a classmate (she was in her mid-60s) in a hospital in our province. She was brought there when relatives noticed her unusual lethargy, weakness, and inability to speak. They thought she was having her second stroke attack. Initial laboratory results revealed a potassium value of 2 mEq (normal value is 3.5-5.5mEq). Doctors usually panic when they see low values like this! After infusing her intravenous fluid with potassium, she recovered very quickly. She is now back in her home. Elderly people especially those with chronic illnesses are very prone to electrolyte imbalances. Their diet and liquid intake and output should always be carefully monitored.

To prevent electrolyte imbalances, you should eat ample amounts of fresh fruits and vegetables. In processed foods, potassium is commonly lost and sodium substantially increased. Nearly all processed foods are sodium rich and potassium poor. According to Jane Brody of the NYT:
"Among the foods richest in potassium, are leafy greens like spinach, romaine and cabbage; vine-grown foods like tomatoes, cucumbers, zucchini, winter squash and pumpkin; root vegetables like carrots, radishes, turnips and onions; dried peas and beans, and green beans; fruits like apples, oranges, bananas, apricots and strawberries; and tubers like potatoes and sweet potatoes, as well as milk and yogurt. Lesser amounts are found in meats, nuts, eggs, cereals and cheese.

"In physically active people, potassium is important to sustaining good muscle function. But sports drinks, often consumed to restore the nutrients exhausted by vigorous exercise, are close to worthless when it comes to replacing potassium. An eight-ounce serving of a sports drink contains about 30 milligrams of potassium. You would have to drink 12 servings of a sports drink, 600 calories, to consume the amount of potassium in one 65-calorie banana, or consume 375 calories of the drink to get the potassium in 27 calories of a half-cup of cantaloupe.

"If you consumed 100 calories each of spinach, tomatoes, carrots, chickpeas, oranges and potatoes, you would easily take in a day's recommended amount of potassium and only 600 calories. A potassium-rich diet is also great for weight control."
Isn't it time we really consume more fruits and vegetables, and less meat?

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