Salt Consumption in Ancient Polynesia

SALT CONSUMPTION IN ANCIENT POLYNESIA SCOTT A. NORTON* Introduction The dietary habits of technologically primitive societies are assuming new importance in the industrialized world. Diet may partly account for the high prevalence of chronic diseases in Western societies and the relative unimportance of these diseases in unacculturated societies [1—3]. Evidence for a nutritional determinant of chronic disease is shown by the epidemiologic link between dietary sodium and hypertension . Western diets, typically high in sodium, may promote hypertension and related conditions (e.g., heart disease and stroke [4—7]), among the most important causes of mortality in developed nations [8]. In contrast, traditional societies whose diets lack supplemental sodium are characterized by the absence of both hypertension and age-associated elevations in blood pressure [9-17]. Comparisons of diets and health of traditional societies with those of ethnically similar populations that have adopted Western dietary habits show that acculturating populations consume more salt than their unacculturated relatives [15—23] and that they acquire health problems associated with high blood pressures [2, 15, 16, 22—25]. Accordingly, the consumption of large amounts of salt [3—7, 10, 12-14, 16, 20-22, 25-29], the rise of blood pressure with advancing age [10-15, 21, 23, 30, 31], and the presence of hypertension [3, 12, 15, 18, 24, 30, 32] are considered Western traits, atypical of unacculturated societies. Polynesia (fig. 1), with its mix of traditional and modernized populations , has been the location of several studies on the relationships between salt and hypertension [22, 33, 34]. Cumulative Western influences The author thanks Drs. Ann M. Cowgill, James E. Fitzpatrick, Michael T. McDermott, and Stephen G. Reich for comments on the manuscript; Sue Coldren and Beth Knapke for help in obtaining materials on and by Pacific explorers; and Judy Grubaugh for preparation of the map. The opinions or assertions contained herein are not to be considered as reflecting the views of the Department of Defense. *Dermatology Service, Department of Medicine, Fitzsimons Army Medical Center, Aurora , Colorado 80045-5000. Copyright is not claimed for this article. 160 Scott A. Norton ¦ Salt Consumption nw* ima Fig. 1.—Pacific islands and island groups. The three ethnogeographic regions of the Pacific are Polynesia, Melanesia, and Micronesia. The Polynesian triangle is hounded by the Hawaiian Islands to the north, New Zealand to the southwest, and Easter Island to the east. Polynesian Islands mentioned in the text include: 1—Hawaiian Islands; 2—Society Islands; 3—New Zealand; 4—Easter Island; 5—Marquesas Islands; 6—Tuamotu Archipelago ; 7—Tokelau Islands; 8—Tuvalu (formerly Ellice Islands); 9—Phoenix Islands; 10—Tonga; 11—Samoa; 12—Cook Islands; 13—Wallis Island; and 14—Niue. Melanesian Islands include: 15—Solomon Islands; and 16—Fiji [33]. make it unlikely that any modern-day Polynesian society fully retains its authentic culinary traditions, including habits of salt consumption [31, 35, 36]. This article addresses the relationship between salt and hypertension in Polynesia before acculturation, at the time of first contact with Europeans. Patterns of salt consumption and estimated sodium content ofancient Polynesian diets are proposed. The salt habits of early Polynesians are compared to those of modern-day unacculturated societies. Anthropologic, historical, and physiologic evidence is used to answer the questions: did hypertension afflict the ancient Polynesians, and, if so, what were its manifestations? Primary Sources on Salt in Early Polynesian Diets The diets of polynesians at the time of European discovery were reconstructed from the writings of nearly 200 early Pacific explorers. The accounts range from the first recorded European contact with Polynesians in 1595, when Mendaña and Quiros arrived on Magdalena Island (now Fatu Hiva) of the Marquesas Islands [37, 38], to the mid-1800s Perspectives in Biology and Medicine, 35, 2 · Winter 1992 161 when Wilkes first described islands in the Tuamotu Archipelago, Tokelau Islands, Ellice Islands (now Tuvalu), and Phoenix Islands [38, 39]. Their accounts give considerable attention to the diseases and diets of the Pacific islanders and identify salt as an important component of aboriginal diets throughout much of Polynesia. The pursuits of early European voyagers in the Pacific were principally economic or geopolitical [38, 40]. Nevertheless, many expeditions, notably those from France and Great Britain, made significant contributions to...