Ka Wai Ola - Office of Hawaiian Affairs, 1 September 1983 — He Mau Ninau Ola Questions About Health [ARTICLE+ILLUSTRATION]

He Mau Ninau Ola Questions About Health

by Kekuni Blaisdell, M.D.

This fifth eolumn of He Mau Ninau Ola (Some Heakh Questions), like the previous ones, continues to respond to her readers' ninau ola, for whieh we mahalo ia 'oukou apau. 1. Q. Why is high blood pressure so eommon among us Hawaiians, and what should 1 do about it when 1 don't feel sick? A. High blood pressure or hypertension refers to excessive pressure within the arteries of the body. "Excessive" usually means repeated blood pressure measurements greater than "140/90" (pronounced "140 over 90") in an adult. The first, higher number is the "systolic" pressure — the pressure when the heart contracts and pushes blood into the arteries, as shown in the accompanying figure. The second, lower number is the "diastolic" pressure, when the heart is relaxed, and the pressure within the arteries is due to the resistance in the small arterioles in all the body tissues. Blood pressure tends to rise with age in our society, and values higher than 140/90 occur in about 30% or more or us adult po'e Hawai'i (Hawaiian people). In 1962, the death rate from high blood pressure was first shown to be greatest among us Hawaiians — twice the mortality rate of all racial groups in Hawai'i. Currently, a State of Hawai'i Hypertension Task Force is attempting to acquire more meaningful, standardized data on high blood pressure in our Islands so that persons at high risk ean be identified and helped before they die or develop serious complications. These serious consequences are: heart attack (myocardial infarction or fatal heart rythmn), heart failure, stroke, and kidney failure. The higher the blood pressure, the greater the risk of these complications. A person with high blood pressure, like you, may not feel sick before such complications strike. This is why high blood pressure is sometimes called "the silent killer." To understand why hypertension is so eommon among us po'e Hawai'i and what we ean and need to do about it, even when we do not feel sick, we should be familiar with the nature and

causes of high blood pressure. Hypertension is often spoken of as if it were a single disorder, but it is not. It may be due to a variety of kidney, hormonal, heart, blood vessel and brain abnormalities. These need to be eonsidered by your examining kauka (physician). ln many cases, however, the blood pressure remains high without any obvious explanation. In such instances, it is usually called "essential," or "primary." This is supposed to mean that the kauka does not know the cause. But even in these patients, there are usually clues as to casual factors. The five most important are: (1) Familial occurrence (2) Too mueh fat (obesity) (3) Too mueh pa'akai (sodium) (4) Stress (5) Physical inactivity. Familial occurrence may be due to heredity, or to similar lifestyle involving any of the other factors, such as eating too mueh pa'akai. Some authorities believe that 5 to 40% of people, depending upon heredity, are especially susceptible to high blood pressure. We po'e Hawai'i seem to be among those who are genetically more vulnerable, but this has yet to be proved. Fatness appears to be an independent casual factor among those who have the inherited tendency. That is, if such persons become too fat, their blood pressure goes up. lf they lose their excessive weight, the blood pressure goes away. Similarly, eating to mueh pa'akai (sodium) leads to hypertension in the hereditarily predisposed. When these po'e restrict their pa'akai intake, their high blood pressure appears to be "cured." Our Polynesian cousins on the isolated Western Pacific atolls of Tokelau do not have high blood pressure at all! Perhaps this is because they do not become fat and they do not eat pa'akai. In 1966. when a hurricane hit their islands, 2,000 Tokelauans were evacuated to New Zealand. Within 10 years, their average blood pressure values were higher with age and similar to those of the Maori and white city dwellers. Their average body weight

had increased and they now ate pa'akai. In contrast, those Tokelauans who stayed behind on the atolls and continued their old ways, had no high blood pressure. Eating salt is a culturally-acquired habit of ours, just like not eating salt is a culturally-acquired habit of the Tokelau islanders. Captain Cook's Journals of 1779 describe our kupuna Hawai'i (ancestors) eating "customary great quantity of salt with flesh and fish." For the maka'ainana (commoners) who worked and were vigorous in sport, mueh of the sodium whieh they ate may have been lost in sweat, so that hypertension may not have been prevalent among these po'e. However, the relative inactive and overeating po'e, such as some ali'i, probably had a high frequency of high blood pressure is discussed in Question No. 2 whieh follows. 2. Q. Why is pa'akai (salt) bad for us Hawaiians today when it was eonsidered good, and even medicine, for our kupuna (ancestors)? A. As with many things, a certain amount of pa'akai is not only good for us and our kupuna, but it is necessary. However, too mueh is harmful. Pa'akai is chemically sodium chloride. For our purpose, sodium is the key element, not chloride. And "salt" is too general a term. Sodium is an essential component in the cells and fluids of the human kino (body). The normal daily requirement of sodium in most adults is about Vi gram. If we ate only that mueh every day, high blood pressure would probably be unknown in our Islands, as it is on the Tokelau atolls, as described above. Also, if we ate only /2 gram of sodium everyday, we would not be able to taste it. lt would be "hidden," mainly in the animal and processed foods we consume. This means that whenever we ean taste salt, it is already too mueh sodium for our kino. It is estimated that most of us in Hawai'i eat 3 to 10 grams of sodium every day. That is 6 to 20 times the amount the average human kino needs daily! When we eat too mueh sodium, water is retained in our kino. This ean cause high blood pressure in some genetically susceptible po'e. lt ean cause pehu (swelling), such as in patients with

heart failure or kidney disease, or in hapai (pregnant) women. Sodium is lost from the kino in two main ways: in the mimi (urine) and in the hou (sweat). If one vomits or has diarrhea, sodium ean be lost in these ways also. In kahiko loa (ancient times), our kupuna did eat abundant pa'akai. However, those who worked and played vigorously, probably lost more sodium in hou, and thus remained in proper sodium halanee. Those who were sedentary and overate pa'akai may have had more high blood pressure, heart and kidney failure, as we see in ourselves today. In the days of old, many la'au (medicines) contained pa'akai. If such la'au were given for excessive sweating, vomiting or diarrhea, they may have been beneficial by replacing sodium lost from the kino. One main difference between the nutrition of kahiko loa and modern Hawai'i is that there were almost no processed and preserved foods, such as we have today. Long ago, some salted and dried fish, yes, but certainly not the supermarket canned foods, such as Spam, pastries, frozen foods, fast junk foods, such as "french fries," dairy products, sauces, and snacks, such as see moy, of today, whieh have high concentrations of sodium. Since eating pa'akai is a culturally acquired habit, learned in early childhood, cutting down on sodium intake must be a whole family affair. Children need to learn early in life to avoid highsodium foods. Because of nationwide eoneem for the harmful effects of sodium, the American Medical Association and the Food and Drug Administration are now promoting: — Labelling of all packaged foods for their sodium content. — Education of the public of the dangers of too mueh sodium intake. — Physician counseling of patients about sodium hazards. — Reduction of sodium content of processed foods by the food industry. Since we po'e Hawai'i are particularly sensitive to too mueh pa'akai, we must begin ourselves within our own families to eliminate adding this mineral to our mea 'ai (food) and aequire a new kind of 'ono without pa'akai, or continue to suffer the serious consequences of ill heahh.