December 1992: 449-453

Nutritional Requirements of the Elderly: A Japanese View Yoshiaki Fujita, Ph.D.

Introduction

For hundreds, perhaps thousands, of years, rice, fish, soybean products, and green vegetables made up the traditional Japanese diet. However, after World War 11, Western habits penetrated Japanese life to an enormous extent, bringing important changes in dietary and eating practices. In particular, consumption of rice as a staple food declined sharply. By contrast, intake of animal foods, such as meat, eggs, milk, and dairy products, has markedly increased, resulting in an expanded intake of animal protein and fats and total fats. This change has greatly improved the nutritional status of the Japanese people. Results from the recent National Nutrition Survey’ showed that in comparison with the recommended dietary allowances (RDAs), the nation’s mean nutrient intake comes close to expectations, and nutritional status has been satisfactory, excluding calcium intake. The proportions of energy derived from protein, fats, and carbohydrates in a conventional Japanese diet were 15, 25, and 60%, respectively, of total energy. However, it should be noted that the average value encompasses large deviations, from under- to overconsumption. In the past, diseases associated with undernutrition, such as tuberculosis and other communicable infectious diseases, constituted the major causes of death in Japan. With changes in dietary habits the incidence of such diseases declined, and the noncommunicable, degenerative diseases of aging are now the leading causes of death.2 However, it is important to note that age-adjusted mortality rates, in which the population composition is expressed on an equalized age distribution basis, show that the number of those suffering from the chronic degenerative diseases has remained almost constant durDr. Fujita is at the Department of Nutrition, Division of Physiological Aging Research, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakecho, Itabashi-ku, Tokyo 173, Japan. Nutrition Reviews, Vol. 50, No. 12

ing the last three decades. This indicates that the rise in crude mortality rates from these diseases is mainly due to increases in the actual numbers of elderly persons, rather than to westernizing effects in dietary habits. Japan is moving toward an advanced-age society at a very high speed. In 1991, mean life expectancy of the Japanese was 75.86 years for males and 81.81 years for females. Twelve percent of the population is over 65, and statistical data indicate that by 2020 one out of every four Japanese will be at least 65 years old. In about 3300 facilities for the elderly, the meals are based on the RDA. However, these people have differences in eating habits, dietary customs, food preferences, chronological and physiological ages, and health conditions. Therefore, flexibility is essential when applying the RDAs to the elderly.

Nutritional Status

The leading causes of death in Japan are malignant neoplasms, heart disease, and cerebrovascular disease, followed by suicide and accidents for the middle-aged and malnutrition-related infectious diseases for older persons. In elderly Japanese, undernutrition is a serious problem, as is overnutrition (Table 1).

Activities of Daily Living (ADL) Among aged persons, the “dynamic elder,” who takes an active part in his or her community or household, generally has good-nutritional ~ t a t u s . ~ In contrast, housebound and bedridden elderly persons are often deficient in good quality protein, vi. ~ Table tamin A, riboflavin, iron, and ~ a l c i u m(See 2.) Nutritional needs in the elderly seem to be closely related to levels of ADL rather than to chronological age, but the present RDAs for elderly persons have been set on the basis of chronological age. 449

Table 1. Leading Causes of Death in Different Age Groups in Japan

45-49 79-84 85-89

Malignant neoplasms Malignant neoplasms Heart disease

Heart disease Heart disease Cerebrovascular disease

Cerebrovascular disease Cerebrovascular disease Pneumonia/ bronchitis

All ages

Malignant Heart disease Cerebrovascular neoplasms disease From report of the Ministry of Health and Welfare in Japan.’

Food Preferences Table 3 summarizes several reports on food preferences of elderly persons. As a group, the elderly in contrast to younger Japanese, prefer traditional dishes rather than Western foods. Moreover, they prefer dishes made with the best natural, fresh ingredients rather than highly processed foods. Results from the 1988 National Nutrition Survey’ show that mean daily intake of potatoes, legumes, fruits, and vegetables increased with the age of the head of a family, whereas daily intake of fat and oil, milk and dairy products, meats, and precooked foods decreased. There is no conclusive evidence on whether characteristic food preferences in older Japanese result from physiological changes, a desire to return to familiar foods, or an adaptation to changes in the living environment. Suyama et aL6 examined 422 elderly men and women (69-71 years old) living in an urban area, and found that the three leading factors determining the number and variety of foods consumed were the level of education; the level of the ADL; and, for males, the type of living arrangements and level of education, and for females, the level of the ADL and business experience. These findings suggest that characteristic food preferences and eating habits among elderly persons depend strongly on changes in their socioeconomic environment rather than on age-related changes in their physiological functioning.

Suicide

Accidents

Pneumonia/ bronchitis Malignant neoplasms

Nephritis

Pneumonia/ bronchitis

Accidents

Senility

Recommended Dietary Allowances

In consideration of the changes just described, and growing evidence from nutritional science, in Japan the RDAs have been revised every five years. The present RDAs,’ the 1989 revision, have been classified in detail according to gender and differences in physical condition, age (by decade), work intensity (four levels: light, moderate, light-heavy, and heavy), and pregnancy or lactation. In general, the RDAs have been established to evaluate the nutritional status of groups and populations; therefore, they should not be used as an index to assess the adequacy of individual nutrient intake. However, the current (1989) RDAs do contain figures that can be applied to individuals. The RDAs have been established for ten kinds of nutrients, as shown in Table 4: energy (fat and carbohydrate); protein; vitamins A, D, C, thiamin, riboflavin, and niacin; and the minerals iron and calcium. Except for the energy nutrients, intake tends to be low, given the daily dietary habits in Japan. Daily energy intake, on the other hand, has remained almost constant through four decades, while the intensity of physical work has decreased. As a result, there has been a relative increase in obesity, a major risk factor in various degenerative diseases. Moreover, increased intake of animal fats (as a result of accelerated westernizing of dietary

Table 2. Effects of Living Environment and Physical Activity on Some Nutrient Intakes in Japanese Elderly Persons Nutrient Intake (per day) Living Environment

Physical Activity

One’s home

High Bedridden High Bedridden

Institutions

(g)

Calcium (mg)

Iron (mg)

Vitamin A (IU)

Vitamin B, (mg)

58 36 56 43

378 226 449 419

9.7 6.8 10.2 8.5

594 563 978 846

0.56 0.40 0.68 0.68

Protein

n

Energy (kcal)

39 14 47 54

1647 1009 1560 1171

Cited from ref. 4. 450

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Table 3. Food Preferences in Japanese Elderly People Prefer

Rather than

Fish and shellfish Boiled rice and noodles Native vegetables Vegetable foods Seasoned by soy sauce soy paste vinegar Boiled foods Stewed foods

Meats Bread Imported vegetables Animal foods Seasoned by milk butter ketchup Fried Frizzled

and eating habits) is related to an increased incidence of some degenerative diseases, such as cardiovascular disorders. In the RDAs published after 1975, an adequate ratio of energy provided from dietary fats has been set at 2&30%. The recommended fat:energy ratio is 25-30% from one to 19 years; 2&25% (with light and moderate physical activity), and 25-30% (light-heavy and heavy activity) for 20 years old and above. The idea that the RDAs should be principally applied to healthy subjects has been widely accepted. However, most elderly people suffer from some age-related diseases. It is difficult to apply to elderly persons a standard based on data from healthy young adults. Protein Allowances Most Japanese elderly prefer food rich in carbohydrates, such as rice and noodles, to animal foods rich in protein. They are in the habit of eating rice at every meal, a practice that cuts down on their intake of other foods rich in protein, vitamins, and minerals. There is no consistent evidence on whether the aging process changes protein needs in human subjects. Protein requirements for the elderly, on the basis of nitrogen balance studies, range from 0.59-0.85 g/kg body weight.%" As a whole, the values for the aged are slightly higher than those for These young men: 0.49-0.74 g/kg body wide ranges for protein requirements in the two age

groups seem to be due mainly to differences in experimental design and conditions, including the health and nutritional status of the subjects, rather than to differences in age. In Japan, most of the RDAs for elderly persons have been established in accordance with those for young adults, because of the paucity of data available. In conformity with the general principles presented in the FAO/WHO/UNU report,14 the requirement for highly digestible good, quality protein for Japanese adults to maintain nitrogen balance is set at 0.64 g/kg body weight with an adequate energy intake. Recommended protein allowances are calculated in consideration of the relative utilization efficiency (bioavailability) of a habitual mixedprotein diet consisting of the usual Japanese food estimated at 85% as against high-quality reference protein; an additional 30% to cover individual variations in nitrogen balance; and a further 10% safety margin to deal with physiological stress, including light infections and external injuries. The recommended protein allowance (RPA) is calculated as follows: RPA

=

=

0.64 x 100/85 x 1.3 x 1 . 1 1.08 g/kg body weight.

In most tissues and organs, physiological functions decrease with age, whereas differences in agerelated changes in physiological functions increase. However, the value (1.08 g/kg body weight) for young adults has also been applied to persons above 60 years of age, since no basic difference is assumed between normal healthy elderly persons and younger adults with an adequate energy intake. The same value is recommended for those age 70 and above (although physiological functions decrease during aging), in view of individual differences in physiological function and variation in amount and type of daily activities. However, in estimates the practical value per day for elderly persons, broadly increased and rounded values have been adopted. These are almost comparable with those for the elderly in other countries, but may be slightly high, in view of the physique of elderly Japanese.

Table 4. Comparison of Recommended Dietary Allowances for Elderly Persons Between Japan and the United Statesa Vitamin B, (mg)

Niacin Vitamin C Vitamin D (mg) (mg) (IU)

0.8

1.2

14

50

100

1.2

1.4

15

60

200

Energy Protein Calcium Iron Vitamin A Vitamin B , (kcall (g) (mg) (mg) (IU) (mg) Japan 2100 70 600 10 2000 United 63 800 10 3300 States 2300 a With moderate level of physical activity. Japan: age: 60-65 years; body weight: 55 kg United States: age: 51 + years; body weight: 70 kg Nutrition Reviews, Vol. 50, No. 12

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Calcium Allowance Results from the recent National Nutrition Survey’ showed that calcium is the sole nutrient for which the national mean daily intake failed to meet the current RDA (600 mg/day, or 10 mg/kg body weight, for adults). Actual dietary calcium intake of the survey population was found to range from 7 to 10 mg/kg body eight.'^.'^ The calcium allowance for elderly persons is the same as that for young adults. However, there are reports”*’*that the daily intake necessary for the elderly to maintain calcium balance ranges from 10 to 18 mg/kg body weight per day. Although it is true that intake of animal foods has increased greatly in Japan over the last four decades, among the animal foods, milk and dairy products are the most efficient and convenient sources of calcium. By comparison with meats and eggs, milk and dairy products do not merge well into traditional Japanese dishes, and older Japanese prefer the traditional Japanese foods to Western dishes that are much richer in calcium. There are reports that an insufficient intake of calcium is one cause of osteoporosis, a typical agerelated disorder. Calcium intake has increased among the Japanese in the last four decades; however, by 1989, the mean calcium intake of the population as a whole was only 540 mg/day, or about 60-70% of that in Western countries.” On the other hand, the incidence of femoral neck fracture is significantly lower in Japanese females20321 than in women in Western c o ~ n t r i e s , irrespective ~~,~~ of age. In cross-cultural studies, there is no consistent evidence for a causal relationship among dietary calcium intake, osteoporosis, and bone fractures. In Western countries such as the United States, about 70-80% of dietary calcium is provided by milk and dairy products, as compared to only 25% in Japan.’ This indicates that the appearance and development of osteoporosis and the incidence of bone fractures may be closely related not only to differences in dietary calcium intake, genetic background, and life style, but also to differences in a variety of dietary calcium sources and food patterns. Nutrition and Drugs

In Japan, expenditures for medical care have continued to grow. The ratio of pharmaceutical expense to total medical expenditure is over 30%. Use of prescription drugs for chronic diseases is more common in elderly persons. However, certain prescription drugs cause malabsorption of some nutrients, particularly vitamins and minerals, and an abnormal metabolism and utilization of certain nutrients may impair the functioning of some organs, resulting in m a l n ~ t r i t i o nTo . ~ ~ensure nutri452

tional well-being in the elderly, it is very important to consider what sorts of medical drugs each person normally uses. 1. The Ministry of Health and Welfare in Japan. The present nutritional status of Japanese: results of National Nutrition Survey in 1989. (in Japanese) Tokyo: Dai-lchi Shuppan, 1991 2. Data book of food, nutrition and health, 11th ed. (in Japanese) Tokyo: lshiyaku Syuppan, 1991 3. Matsudaira T, Okuda T, Tamai H, et al. Nutrition survey in community elderly persons: physique and nutrient intake. (in Japanese) J Kyoto Med AsSOC 1987;34:55-63 4. Hidari A, Nakazato H. The effect of the life environment and the health condition on the nutritional intake of the elderly. (in Japanese) Jpn J Pub1 Health 1984;31:615-21 5. The Ministry of Health and Welfare in Japan. The present nutritional status of Japanese: results of National Nutrition Survey in 1988. (in Japanese) Tokyo: Dai-lchi Shuppan, 1990 6. Suyama Y, Shichida K, Haga H, et al. Food intake pattern and related factors in the community elderly. (in Japanese) SOCGerontol 1984;19:58-66 7. The Ministry of Health and Welfare. Recommended dietary allowances in Japan, 4th revision (English ed.). Tokyo: Dai-lchi Shuppan, 1991 8. Zanni E, Calloway DH, Zezulka AY. Protein requirements of elderly men. J Nutr 1979;109:51324 9. Cheng AH, Gomez A, Bergan JG, Lee TC, Monckeberg F, Chichester CO. Comparative nitrogen balance study between young and aged adults using three levels of protein intake from a combination wheat-soy-milk mixture. Am J Clin Nutr 1978; 31 112-22 10. Uauy R, Scrimshaw NS, Young VR. Human protein requirements: nitrogen balance response to graded levels of egg protein in elderly men and women. Am J Clin Nutr 1978;31:779-85 11. Gersovitz M, Motil K, Munro HN, Scrimshaw NS, Young VR. Human protein requirements: assessment of the adequacy of the current Recommended Dietary Allowance for dietary protein in elderly men and women. Am J Clin Nutr 1982;35: 6-1 4 12. lnoue G, Fujita Y, Niiyama Y. Studies on protein requirements of young men fed egg protein and rice protein with excess and maintenance energy intakes. J Nutr 1973;103:1673-87 13. Calloway DH. Nitrogen balance of men with marginal intakes of protein and energy. J Nutr 1975; 105:914-23 14. World Health Organization. Energy and protein requirements. Report of a joint FAO/WHO/UNU meeting. Geneva: World Health Organization, 1985: WHO Technical Report Series 724 15. Steggerda FR, Mitchell HH. Further experiments on calcium requirement of adult man and utilization of calcium in milk. J Nutr 1941;21:577-88 Nutrition Reviews, Vol. 50, No. 12

16. Steggerda FR, Mitchell HH. Variability in calcium metabolism and calcium requirements of adult human subjects. J Nutr 1946;31:407-22 17. Roberts PH, Kerr CH, Ohlson MA. Nutritional status of older women: nitrogen, calcium, phosphorus retentions of nine women. J Am Diet Assoc 1948;24:292-9 18. Ackermann PG, Tor0 G. Calcium and phosphorus balance in elderly men. J Gerontol 1953;8:289-300 19. Nelson M, Black AE, Morris JA, Cole TJ. Betweenand within-subject variation in nutrient intake from infancy to old age: estimating the number of days required to rank dietary intakes with desired precision. Am J Clin Nutr 1989;50:155-67 20. Kawashima T. Epidemiology of the femoral neck

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fracture in 1985, Niigata, Japan. J Bone Mineral Metab 1989;7:4654 Yoshikawa T, Norimatsu H. Epidemiology of osteoporosis in Okinawa. J Bone Mineral Metab 1991;9(suppl):l35-45 Gallagher JC, Melton LJ, Riggs BL, Bergstrath E. Epidemiology of fractures of the proximal femur in Rochester, Minnesota. Clin Orthop 1980;150: 163-71 Farmer ME, White LR, Brody JA, Bailey KR. Race and sex differences in hip fracture incidence. Am J Pub1 Health 1984;74:1374-80 Roe DA, ed. Drugs and nutrition in the geriatric patient. New York: Churchill Livingstone, 1984

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Nutritional requirements of the elderly: a Japanese view.

December 1992: 449-453 Nutritional Requirements of the Elderly: A Japanese View Yoshiaki Fujita, Ph.D. Introduction For hundreds, perhaps thousands...
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