Populations are ageing. The 20^th century has seen an unprecedented transition from high birth and death rates to low fertility and mortality. In 1950 there were about 200 million people over 60 years; by 2025 there will be 1.2 billion, of whom nearly 70% will live in developing countries. The majority of poor older people in developing countries enter old age after a lifetime of poverty and deprivation, poor access to health care, and a diet that is usually inadequate in quantity and quality. For most of these older people, retirement is not an option. Poverty, lack of pensions, deaths of younger adults from AIDS, and rural to urban migration of younger people are among the factors that compel older people to continue working. Adequate nutrition, healthy ageing, and the ability to function independently are thus essential components of a good quality of life.

In 1992, the London School of Hygiene and Tropical Medicine (LSHTM), in collaboration with HelpAge International, began a programme of research on the nutrition of older adults in developing countries. The objectives of the programme were to test simple anthropometric measures of nutritional status, assess functional ability, and examine the risk factors of nutritional vulnerability. Fieldwork was undertaken in three sites: the urban slums of Mumbai, India,⁸⁶ a Rwandan refugee camp in Tanzania⁸⁷ and rural communities in Lilongwe, Malawi.⁸⁸ Other larger-scale research efforts are under way in a number of countries with similar objectives (China, for example, has several longitudinal studies on this topic).

WHO states that conventional BMI cut-offs for defining CED may not be appropriate for older people above 70 years, because of age-related changes in body composition.² There are also practical problems with obtaining accurate BMI measurements in this group because of curvature of the spine. The LSHTM group found that a MUAC cut-off of 21.7 cm had a sensitivity of nearly 86% in relation to the BMI cut-off of 16 kg/m² and proposed it as an alternative to BMI as part of a screening tool in the acute phase of an emergency. Further studies are urgently needed in this area.

Table 1.9 shows the prevalence of undernutrition by sex in the three studies.^{86, 89, 90} In all three studies, the prevalence of undernutrition increased with age among women. This was most marked in India, where it rose to nearly 60% among women over 70 years. The lower prevalence of undernutrition in the refugee population is probably because the study was conducted in the postemergency phase: the sample represented those who had successfully reached the camp and survived a year in exile.

Nutritional status was related to functional ability. The strongest relationship was with handgrip strength, a measure of the strength of the upper limb. Undernutrition was also found to be associated with higher risk of impairments in psychomotor speed and coordination, mobility, and the ability to carry out activities of daily living independently, even after controlling for age, sex, and disease.

TABLE 1.9: Prevalence of undernutrition from three studies of older people

 

Sources: 86, 89, 90.
Note: Undernutrition here indicates a BMI of < 18.5 kg/m².

Sarcopenia, the gradual loss of muscle mass with age, appears widely prevalent and has been linked to ageing-related losses of strength, increased risks of morbidity, functional impairment, dependence, and mortality. One recent longitudinal study of 1,504 Chinese adults has shown that energy and protein intake can directly affect this condition.⁹¹

Research is urgently needed to assess the magnitude of the nutrition problem among older people, including micronutrient status, and to refine techniques for the anthropometric assessment of nutritional status. The appropriateness of conventional BMI cut-offs for older adults needs to be assessed. Nutrient requirements for older people are mostly extrapolated from younger adults in developed countries and assume the reduction in energy expenditure associated with retirement. These requirements may not be correct for poor older people in developing countries. There are also age-related changes that can lead to reduced or altered food in-take: physiological changes in the sense of taste, poor appetite (often associated with loneliness, social isolation, depression, or medications), physical factors such as absent or ill-fitting dentures, limited ability to procure or prepare food because of musculoskeletal disorders or other disease conditions, and chronic disease.

There is almost no experience of nutrition interventions for older adults. We have little or no idea of what works, nor do we even know if their nutritional status can be improved or if such improvement would lead to better functional ability. Operational research in these areas is needed to fulfill the right of older adults to adequate nutrition.