Modernisation, Migration and Nutritional Health of Pacific Island Populations

Transcription

1 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek 167 MYU Tokyo ES591 Modernisation, Migration and Nutritional Health of Pacific Island Populations Stanley J. Ulijaszek * School of Anthropology, University of Oxford, 51 Banbury Road, Oxford OX2 6PF, UK (Received February 7, 2005; accepted March 2, 2005) Key words: obesity, diet, Pacific Islanders, population, economic change The emergence of obesity and fatness across the second part of the 20th century has been documented for a number of Pacific Island populations. While dietary change and reduced physical activity levels associated with economic modernisation have been identified as the key factors fuelling the emergence of obesity, it is argued here that increasing numbers of Pacific Island migrants in the United States, New Zealand, France and Australia have provided the basis for the acceleration of the modernisation process by way of remittances, and the transmission of ideas of economic opportunity and change. Potential for migration for the Pacific Island nations is estimated from available data on population growth, total fertility rates and total mortality rates. Pacific Islander migrants form approximately one quarter of the total global Pacific Islander population, the majority of whom are from Tonga, Fiji, French Polynesia, and the Federated States of Micronesia. Per capita energy and fats and meat intake for the period 1961 to 2000 is described for five Pacific Island nations, showing that, in general, energy intakes have increased, as have the energy densities of the diets consumed. Thus the increase in mean body mass index observed in Pacific Islanders in the second half of the twentieth century can in general be attributed to dietary change associated with greater food and energy intake, and with increased consumption of fatty foods and meat, most of which are imports. 1. Introduction Fatness and obesity emerged among Pacific Islander populations during the second part of the 20th century, alongside great increases in population size in many of the Pacific Island nations and migration from the Pacific Islands to urban centres, especially in the United States, France, New Zealand, and Australia. Among Pacific Islander populations, there is good documentation of increasing obesity and fatness among adults in Western Samoa, (1,2) the Cook Islands, (3,4) the Tokelau Islands, (5) Tuvalu, (6) the Marquesas Islands, (7) and American Samoa, (2) and of migrants to New Zealand (8) and Hawaii. (9) Of the measures of economic modernisation investigated in relation to obesity and fatness in Pacific Island nations, * stanley.ulijaszek@bioanth.ox.ac.uk 167

2 168 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek changes in diet and patterns of physical activity associated with levels of education, occupational status, and urban residence have been put forward as key factors. (2 4,10 12) Another important factor for emergence of obesity and fatness in Pacific Island nations is the extent to which migrants send resources back to relatives on the Pacific Islands. This influence has certainly increased across the 20th century. Migrations of significant numbers of Pacific Islanders have taken place since the 1920s, when Samoans and Tongans began to migrate to Hawaii in large numbers. The greatest influx of Samoans to Hawaii came in the 1950s with the end of United States naval administration in American Samoa, but migration has continued at a steady rate to the present day. In New Zealand, Pacific Islanders have a more recent demographic history. In 1945, there were just over 2,000 people of Pacific origin in this country; by 2001, the number of Pacific Islanders in New Zealand was 232,000, about 6% of the total resident population, Migration of Pacific Islanders to Australia was already in place prior to 1950, but increased greatly in the early 1980s. Between 1971 and 1991, the Pacific Islander population of Australia had more than trebled from a 1971 value of 23,000. In France, Pacific Islander migration from French colonies has taken place since the beginning of the 20th century. However, the number and proportion of Pacific Islanders living in France cannot be obtained from census data, because there is no enumeration on the basis of ethnicity in that country. In this article, changes in population sizes of Pacific Islander nations are described for the period from 1961 to 2000, and estimates of migrant Pacific Islander populations in the United States, France, New Zealand and Australia are given. The potential for migration for individual Pacific Island nations, calculated from known population growth, total fertility rates (TFR) and total mortality rates, is also estimated. From this, the extent to which migrants may be fuelling the process of economic modernisation in the Pacific Islands is commented on. Dietary change and the emergence of obesity and fatness in the context of the expanding world food system is described, and it is argued that increasing Pacific Islander migrant numbers, now at approximately one quarter of the total global Pacific Islander population, have accelerated the process of dietary change and increased prevalence of obesity in the Pacific Islands, both directly through remittances, and indirectly through the introduction to new foods from industrialised nations. 2. Pacific Islander Demography Table 1 shows population sizes of the Pacific Island nations between 1961 and These data are compiled from census and survey data of the various nations by the Food and Agriculture Organization (13) and are of varying quality. However, the data indicate that the populations have more than doubled across this period, although the increase is not distributed evenly (Table 1). Population size appears to have more than doubled in this period for the Mariana Islands, American Samoa, Vanuatu, French Polynesia, Western Samoa, Palau, the Marshall Islands, the Federated States of Micronesia, New Caledonia, Nauru and Guam. Natural disasters have resulted in out-migration and greatly reduced population size in Tokelau and Niue, respectively, while Tonga, the Cook Islands, and the Wallis and Fortuna Islands have seen population increases which are considerably less than two-fold across this period.

3 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek 169 Table 1 Population of Pacific Island nations and their potential for migration for the period Population (1000s) Population increase Potential for (%) %/decade migration (1000s) Tonga Fiji French Polynesia Micronesia Western Samoa New Caledonia Vanuatu Marshall Islands Cook Islands Guam Wallis and Fortuna Kiribati Niue Nauru Tokelau Tuvalu Palau American Samoa Mariana Islands Total Source: Food and Agriculture Organisation. (13) Figure 1 shows the relationship between TFRs prior to 1980 (14) and the rate of population increase per decade for various Pacific Island nations for the period (13) Again, caution must be used in the interpretation of this data set. The hatched line represents the expected population growth rate at different TFRs, acknowledging a steady decline in total mortality rates across this time. While most nations lie reasonably close to this line, eight have much lower population growth rates than might be expected on the basis of TFR and declining total mortality rate. While Tokelau and Niue became depopulated because of natural disasters, Tonga, Fiji, the Cook Islands, Wallis and Fortuna, Nauru, the Marshall Islands and the Federated States of Micronesia are likely to have experienced lower than expected population growth because of high levels of out-migration. By comparing the expected population growth at the average TFRs and average total mortality rates with known population growth of different Pacific Island states across the period , the potential migrant population was calculated, as given in the final column of Table 1. This is a crude calculation, but one which gives some indication of the extent of the out-migrant Pacific Islander populations outside the Pacific Island nations. While there were 2,318,000 Pacific Islanders living in their nation states in the year 2000, there may be a further 815,000 living elsewhere, predominantly in the United States, France, New Zealand and Australia. The most numerous of these are likely to be Tongans, Fijians and French Polynesians. The potential migrant Pacific Islander population values estimated

4 170 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek Fig. 1. Potential for population migration of Pacific Island nations for the period , based on pre-1980 total fertility rate (TFR) (14) against population growth in terms of percent per decade. (l3) Nations with TFR above the line of expected population growth rate are likely to cope with population growth by out-migration. in this way are very similar to those obtained from census data for Pacific Islander populations in the United States, New Zealand and Australia (Table 2). The estimates of potential migrant Pacific islander populations of the United States, New Zealand and Australia obtained by this method is 583,000, while the value obtained from census enumeration is 577,000, indicating that the procedure used here gives reasonably accurate estimates. Of Pacific Islanders living abroad, most are in the United States. The nations next most populated by Pacific Islanders are New Zealand and France, although the latter value can only be estimated from the calculation carried out using data presented in Table 1 and Fig. 1, since there is no enumeration on the basis of ethnicity in France. In most major official classifications of people resident in France there are only two categories: national or foreigner. Most Pacific Islanders in France are classified as nationals. New Zealand also has a Pacific Islander population of 232,000. (16) In 1945, there were only 2,000 people of Pacific origin in this country. While there was a period of high immigration in the early 1970s, this inflow slowed in the late 1970s, as social, economic and labour market conditions in New Zealand became less favourable. In the early 1980s, the flow reversed as return migration to the Pacific region and chain migration to Australia combined and exceeded immigration from the region. Immigration increased again by the end of the decade. In Australia, migration of Pacific Islanders was already in place prior to 1950 but increased greatly in the early 1980s. In 1996, Australia was estimated to have a Pacific Islander population of 96,000.

5 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek 171 Table 2 Pacific Islander populations outside Pacific Island nations. Nation Population Source United States of America 249,000 United States 2000 Ceneus (15) France 233,000 Estimated from model New Zealand 232,000 Statistics New Zealand (l6) Australia 96,000 Australian Bureau of Statistics (l7) Total 809, Obesity and Fatness, Modernization and the World Food System Table 3 shows mean body mass index (BMI, [body weight (kg)] / [stature (m)] 2 ) of adult Pacific Islanders living in their Pacific Island nations, and of Pacific Island migrants to industrialised nations. In all cases, mean BMI is high when compared with values for industrialised nations. In general, mean BMI is higher among more modernised Pacific Islanders living on Pacific Island nations than among those leading traditional lifestyles. For example, a survey carried out in 1966 in the Cook Islands showed adults living on the more modernised island of Rarotonga to be taller, heavier with greater BMI than those observed on the less modernised island of Pukapuka. (14) Furthermore, Katoh et al. (20) observed the adult population of Rarotonga to have higher prevalence of obesity than the population of the less modernised island of Mangaia. Increased prevalence of obesity and fatness across time has been documented for adults in Western Samoa, (1,2) the Cook Islands, (12) the Tokelau Islands, (5) Tuvalu, (6) the Marquesas islands, (7) and American Samoa, (2) in association with increased economic modernisation. (2,10 12) Mean BMIs of migrants to industrialised nations are generally greater than those of non-migrants. Changing diet has been implicated in this pattern of emerging obesity. Historically, traditional diets of Pacific Islanders have been uniformly very low in fat and high in complex carbohydrates and dietary fibre from foods of plant origin in particular, (24) consisting largely of bananas, yams, taro, coconut and animal foods obtained from reefs. (25) However, modernization of the Samoan diet through the increased consumption of imported items is not just a recent phenomenon, but has taken place across most of the 20th century, (26) perhaps beginning with the earliest large-scale migrations of Samoans to Hawaii in the 1920s. In 1952, the typical rural diet of Cook Islanders on Rarotonga was largely comprised of taro, banana, breadfruit, fresh fish and coconut, although significant amounts of bread and tea or coffee with sugar were also consumed. (21,27) Thus, food imports were clearly important on Rarotonga 50 years ago. Dietary change with modernization and migration in the Pacific region has been documented by other authors, showing modernising populations to have a higher proportion of fat and protein in their total energy intake than among those practicing traditional subsistence. (28 31) Modernisation must be considered in terms of interlocking global economic interdependence of societies and nations, (32) dietary change being a useful marker of behavioural change, reflecting the interdependence of local and global economies. The world food system increasingly reflects the economic interdependence of nations and global regions,

6 172 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek Table 3 Mean BMI of adults in Pacific Island nations and migrants to the United States, New Zealand and Australia. Males Females N BMI N BMI Reference (A) Pacific nation Tokelau Islands Traditional Prior et a1. (5) Traditional Ramirez (18) Marquesas Islands Traditional Darlu et a1. (7) Westernised Darlu et a1. (7) Nauru Zimmet and Whitehouse (19) Western Samoa Urban Jackson et a1. (1) Rural Bindon (9) American Samoa McGarvey (11) American Samoa McGarvey (11) American Samoa Bindon (9) Cook Islands Atiu and Mitiaro Hunter (3) Pukapuka Evans and Prior (4) Mangaia Katoha et a1. (20) Rarotonga Fry (21) Rarotonga Hunter (3) Rarotonga Evans and Prior (4) Rarotonga Katoh et a1. (20) Rarotonga Ulijaszek (12) (B) Destination United States Samoans Pawson (22) Samoans Bindon (9) New Zealand Rural (Maori) Prior et a1. (23) Tokelau Islanders Baker (8) Tokelau Islanders Ramirez (18) Australia Cook Islanders Ulijaszek (unpublished) with the proportion of global food production being traded internationally increasing enormously during the last three decades of the 20th century, (33) increasing availability of high energy density foods, many of which are less favoured in the exporting and industrialised nations, has extended to some of the remotest places on earth, including the Pacific Islands. In addition, generally declining food prices globally have also contributed to the expansion of food imports into remote places. (33)

7 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek 173 Food imports to the least developed nations of the Pacific region, including Tuvalu, the Solomon Islands and Kiribati, increased more than six-fold in the period from 1961 to 2000; the increase across the same time-frame was more than four-fold for Western Samoa and more than two-fold for the Cook Islands. (13) Hanna et al. (26) observed that the proportion of dietary energy from imported foods varied according to the degree of modernization, being highest among Samoans on Hawaii, lowest among those in Western Samoa and at an intermediate level in American Samoa. Galanis et al. (34) found substantial differences between the diets of residents of American Samoa and of those of the less modernized nation of Western Samoa. American Samoans consumed significantly more energy as carbohydrate and protein and less as total fat and saturated fat than Western Samoans. Hanna et a1. (26) reported greater dietary diversity with greater extent of modernization and with migration among Samoans, speculating that this greater diversity may be associated with increased food consumption. This author drew similar conclusions for adults on Rarotonga in the Cook Islands. (35) In a comparison of urban and rural populations in Fiji, Kiribati and Vanuatu, Taylor et al. (36) found that the urban diet contained more protein and fat than the rural diet, with the exception of Kiribati, where rural communities consumed large amounts of coconut. In Kiribati, however, imported food constituted a lower proportion of the daily energy intake of the rural population compared to the urban population. (37) The suggestion that obesity has emerged with increased food availability is borne out in large part by the increased per capita daily energy availability between 1961 and 2000, as observed in four of the five nations for which such data are available on the Food and Agriculture Organisation s FAOSTAT food balance database (12) (Table 4). With the exception of Kiribati, where increased energy intake is accompanied by reduced energy density, the proportion of dietary energy from fat has increased, indicating that the diet has increased in energy density. The proportion of dietary energy from protein has also increased between 1961 and 2000 in four of the five Pacific Island nations reported in Table 4. In general, the increased energy density of Pacific Islanders diets is reflected in the increase in per capita consumption of imported fats, oils and meat. The per capita daily availability of meat has increased for all Pacific Island nations between 1961 and 2000, while the per capita daily availability of vegetable oils has increased in French Polynesia, Kiribati and Vanuatu, but decreased in Fiji. This is reflected in total fat intake, which has declined in Fiji and increased in French Polynesia, Kiribati, Vanuatu and New Caledonia. The overall decline in availability of dietary fats and oils in Fiji occurs largely because of a decline in availability of coconut oil in this country. However, this was more than compensated for by the increased consumption of fatty meat. 4. Dietary Change, Transnationalism and Obesity While it might be expected that families with members working for wages and/or receiving significant remittances in cash would be more likely to be involved in the global economy (38) and have greater access to imported foods, Pelletier (39) found that the proportion of imported foods in the diet of Samoans in Western Samoa was similar, regardless of the presence of wage earners in the household. However, remittances from family members overseas may have more importance than the presence of wage earners. Although the population of the Cook Islands has shown little increase between 1950 and

8 174 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek Table 4 Daily per capita availability of dietary energy, fats, mean and protein among Pacific Island nations in the years 1961 and Energy Fat (g) Meat %Energy from (kcal) Vegetable Animal Total (g) Fat Protein 1961 Fiji French Polynesia Kiribati New Caledonia Vanuatu Fiji French Polynesia Kiribati New Caledonia Vanuatu Source: Food and Agriculture Organisation. (13) 2000, (40) this does not reflect the true extent of the Cook Island population at home and abroad. An estimate of migrant numbers based on known resident population and population in excess of replacement level calculated from TFRs of 7.3 in 1955 (14) and 3.3 in 1991 (assuming a linear decline in TFR across this period), (40) suggests that in the year 2000, migrants are likely to outnumber residents by about 2 to 1. The vast majority of Cook Islander migrants Iive in New Zealand and Australia. In the early 1970s, first the Niuean and then the Cook Island populations in New Zealand exceeded those of their home island populations. (41) Links between migrants and relatives on their island nations of origin strongly operate to generate tastes for imported foods and to provide remittances which can be used to buy foods among those living on the home islands. Other Pacific Island nations where migrants are likely to outnumber island residents include Tonga, Wallis and Fortuna, Tokelau and Niue. In these nations, too, remittances are likely to support the use of imported foods. 5. Summary and Conclusions The increase in mean BMI observed in Pacific Islanders in the second half of the 20th century can, in general, be attributed to dietary change, typically seen in greater food and energy intake, associated with increased consumption of fatty foods and meat, most of which are imports. Economic modernization on the Pacific Islands has been identified as consisting of a common nexus of factors fuelling dietary change and the emergence of obesity. However, the modernizing influence of migrants on their home populations and communities is largely left out of this nexus. The existence of significant and increasing Pacific Islander migrant populations in the United States, New Zealand, France and Australia must provide considerable impetus for economic modernization on the Pacific

9 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek 175 Islands. As migrant populations continue to increase in size, this impetus may increase, accelerating the pace of dietary change on the Islands. References 1 Jackson, L.R., Taylor, S., Faaiuso, S., Ainuu, S.P., Whitehouse, S. and Zimmet, P. (1981): Hyperuricaemia and gout in Western Samoans. J. Chron. Dis. 34: Bindon, J.R. and Baker, P.T. (1985): Modernization, migration and obesity among Samoan adults. Ann. Hum. Biol. 12: Hunter, J.D. (1962): Diet, body build, blood pressure and serum cholesterol levels in coconut eating Polynesians. Federation Proceedings 21: Evans, J.G. and Prior, I.A.M. (1 969): Indices of obesity derived from height and weight in two Polynesian populations. Br. J. Prev. SOC. Med. 23: Prior, I.A.M., Stanhope, J.M., Evans, J.G. and Salmond, C.E. (1974): The Tokelau Island migrant study. Int. J. Epidemiol. 3: Zimmet, P., Seluka, A., Collins, J., Currie, P., Wicking, J. and Deboer, W. (1977): Diabetes mellitus in an urbanized isolated Polynesian population: the Funafuti survey. Diabetes 26: Darlu, P., Couilliot, M.G. and Drupt, F. (1984): Ecological and cultural differences in the relationships between diet, obesity and serum lipid concentrations in a Polynesian population. Ecol. Food Nutr. 14: Baker, P.T. (1984): Migrations, genetics and the degenerative diseases of South Pacific Islanders. In: Boyce, A. Ed.: Migration and Mobility: Biologicol Aspects of Human Movement. Taylor and Francis, London, pp Bindon, J.R. (1995): Polynesian responses to modernization: overweight and obesity in the South Pacific. In: de Garine, I. and Pollock, N.J. Eds.: Social Aspects of Obesity. Gordon and Breach, Amsterdam, pp Prior, I.A.M. (1971): The origins of civilisation. Nutr. Today 6: McGarvey, S.T. (1991): Obesity in Samoans and a perspective on its etiology in Polynesians. Am. J. Clin. Nutr. 53: 1586S 1594S. 12 Ulijaszek, S.J. (2001): Increasing body size and obesity among Cook Islanders between 1966 and Ann. Hum. Biol. 28: Food and Agriculture Organisation (2002): FAOSTAT Database < default.htm> (accessed June-September 2002). 14 South Pacific Commission (1998): Pacific Island Populations. South Pacific Commission, Noumea. 15 United States Census 2000 (2000): < (accessed July-September 2002). 16 Statistics New Zealand (2002): 2001 Census of Population and Dwellings. < (accessed September 2002). 17 Australian Bureau of Statistics (2002): Intercensal Data < (accessed July-September 2002). 18 Ramirez, M.E. (1987): Biological variability in a migrating isolate: Tokelau effects of migration of fat patterning adults. Hum. Biol. 59: Zimmet, P. and Whitehouse, S. (1981): Pacific islands of Nauru, Tuvalu and Western Samoa. In: Trowel1 H.C. and Burkitt, D.P. Eds.: Western Diseases: Their Emergence and Prevention. Edward Arnold, London, pp Katoh, K., Yamauchi, T. and Hiraiwa, K. (1990): Blood pressure, obesity and urine cation excretion in two populations of the Cook Islands. Tohoku J. Exp. Med. 160:

10 176 Environmental Sciences, 12, 3 (2005) S. J. Ulijaszek 21 Fry, P.C. (1957): Dietary survey on Rarotonga, Cook Islands. I. General description, methods and food habits. Am. J. Clin. Nutr. 5: Pawson, I.G. (1 986): The morphological characteristics of Samoan adults. In: Baker, P.T., Hanna, J.M. and Baker, T.S. Eds.: The Changing Samoans: Behavior and Health in Transition. Oxford University Press, New York. 23 Prior, I.A.M., Rose, B.S. and Davidson, F. (1964): Metabolic maladies in New Zealand Maoris. Br. Med. J. 1: Shintani, T.T. and Hughes, C.K. (1994): Traditional diets of the Pacific and coronary heart disease. J. Cardiovas. Risk 1: Bindon, J.R. (1982): Breadfruit, banana, beef and beer: modernisation of the Samoan diet. Ecol. Food Nutr. 12: Hanna, J.M., Pelletier, D.L. and Brown, V.J. (1986): The diet and nutrition of contemporary Samoans. In: Baker, P.T., Hanna, J.M. and Baker, T.S. Eds.: The Changing Samoans: Behavior and Health in Transition. Oxford University Press, New York, pp Fry, P.C. (1957): Dietary survey on Rarotonga, Cook Islands. 11. Food consumption in two villages. Am. J. Clin. Nutr. 5: Ringrose, H. and Zimmet, P. (1979): Nutrient intakes in an urbanized Micronesian population with a high diabetes prevalence. Am. J. Clin. Nutr. 32: Prior I. and Tasman-Jones, C. (1981): New Zealand Maori and Pacific Polynesians. In: Trowell, H.C. and Burkitt, D.P. Eds.: Western Diseases: Their Emergence and Prevention. Edward Arnold, London, pp Schendel, D.E. (1988): Daily activity, energy intake and body composition among Western Samoans. Am. J. Phys. Anthropol. 75: Hezel, F.X.S.J. (1992): Expensive taste for modernity: Caroline and Marshall Islands. In: Robillard, A.B. Ed.: Social Change in the Pacific Islands. Kegan Paul International, London, pp Dressler, W.W., dos Santos, J.E. and Viteri, F.E. (1993): Social and cultural influences in the risk of cardiovascular disease in urban Brazil. In Schell, L.M., Smith, M.T. and Bilsborough, A. Eds.: Urban Ecology and Health in the Third World. Cambridge University Press, Cambridge, pp Dyson, T. (1996): Population and Food. Routledge, London. 34 Galanis, D.J., McGarvey, S.T., Quested,C., Sio, B. and Afele Fa amuli, S.A. (1999): Dietary intake of modernizing Samoans: Implications for risk of cardiovascular disease. J. Am. Diet. Assoc. 99: Ulijaszek, S.J. (2002): Modernization and the diet of adults on Rarotonga, the Cook Islands. Ecol. Food Nutr. 41: Taylor, R., Badcock, J., King, H., Pargeter, K., Zimmet, P., Fred, T., Lund, M., Ringrose, H., Bach F. and Wang, R.L. (1992): Dietary intake, exercise, obesity and noncommunicable disease in rural and urban populations of three Pacific Island countries. J. Am. Coll. Nutr. 11: King, H., Zimmet, P., Bennett, P., Taylor, R. and Raper, L.R. (1984): Glucose tolerance and ancestral genetic admixture in six semitraditional Pacific populations. Genet. Epidemiol. 1: Lockwood, B.A. (1971): Samoan Village Economy. Oxford University Press, Melbourne. 39 Pelletier, D.L. (1 984): Diet, activity, and cardiovascular disease risk factors in Western Samoan men. Unpublished Ph.D. Thesis, Pennsylvania State University, University Park, Pennsylvania. 40 National Statistical Office (2001): Cook Islands Annual Statistical Bulletin. National Statistical Office, Rarotonga. 41 Hau ofa, E. (1994): Our sea of Islands. Contem. Pacific 6: