Nutrients of Concern for Older People
Globally, the population is ageing, a process which is associated with a range of physiological changes linked to increased morbidity, with consequent increases in healthcare expenditure. Malnutrition is common in older adults due to a myriad of factors including physiological changes of ageing; thus, with growth in numbers, we can expect the burden of malnutrition and associated negative outcomes such as impaired immunity, loss of physical function, and independence to increase. Both malnutrition and the physiological changes of ageing can manifest in poor nutritional status, due to simple starvation, either through poor food intake or through changes in absorption and metabolism of nutrients in the body. Good nutrition is a modifiable factor which can help to minimize the effects of nutrient deprivation and reduce the impact of ageing on individuals and the community, as well as the healthcare budget. This chapter explains the importance of nutrition in the ageing population and present evidence of the consequences of malnutrition.
The older generation is a heterogeneous group who are quite different to younger people. Yet, there is a lack of specific nutrient reference values especially for adults in advanced age and recommendations are often based on evidence extrapolated from younger adults. Energy needs vary across age groups based on gender, age, and level of activity; however, in older adults, the variation is exacerbated by the physiological changes of ageing and inflammation from illness. Further, many of the assumptions behind calculations of energy requirements, often based on younger people, are not valid in the older population; thus, assessments may not be accurate. Protein requirements are known to be higher in this group, at the very least to attempt to preserve muscle mass, but there is insufficient research to be able to establish guidelines. Fat is an important energy source particularly for older adults whose appetite may be diminished. The evidence suggests that adults of advanced age eat fat in excess of recommendations; however, there are no age-specific guidelines to help interpret the implications of this overconsumption.
Generally, if older people eat a healthy balanced diet, they will meet micronutrient requirements. Micronutrient deficiencies can nevertheless arise from decreased food intake often due to the aforementioned physiological changes of ageing, poor health, and polypharmacy. Key micronutrients of interest in older adults are calcium, magnesium, selenium, zinc, and iron, vitamin B12, vitamin D, and folate. Of particular concern is vitamin D as food sources are limited and exposure to sunlight is often reduced. Given the need for vitamin D for adequate calcium absorption and the roles of calcium in the body, not least for bone strength, older adults may benefit from routine vitamin D supplementation.
KeywordsAgeing Energy Fat Health Malnutrition Micronutrients Nutrients Older adult Prevalence Protein
List of Abbreviations
Acceptable macronutrient distribution range
Basal metabolic rate
Chronic obstructive pulmonary disease
Estimated average requirement
European Society for Clinical Nutrition and Metabolism
European Geriatric Medicine Society
Grams per kilogram
Higher biological value
Health-related quality of life
Mega Joules per day
National Health and Nutrition Examination Survey
National Health and Medical Research Council
Recommended dietary allowance
Recommended daily intake
Reference nutrient intake
United States of America
Meeting the nutritional needs of older people is an immediate challenge with life expectancy at its highest throughout many parts of the world. Not only is the number of older people ≥65 years increasing rapidly, but the population of adults of advanced age is expanding due to the steady rise in life expectancy and decrease in later life mortality. The European Commission’s 2015 ageing report suggests that the percentage of those aged ≥80 years in the total population in Europe will increase from 5% in 2013 to 12% in 2060 (European Commission (DG ECFIN) and Economic Policy Committee (Ageing Working Group) (2015)).
Older adults are a heterogeneous population with unique nutritional needs and the process of ageing occurs at different rates in different people. Nutritional requirements of individuals may be influenced by a myriad of factors including reduced mobility and independence, financial constraints, higher rates of hospitalization, chronic diseases and disabilities, changes in body composition, sensory deficits, taste perception, and digestion and absorption of food, all of which place older adults at increased risk of nutritional deficiencies. Furthermore, the process of ageing affects nutritional needs; requirements for some nutrients may be reduced while requirements for others may be increased.
There is a close relationship between nutritional status and health in the general population. While the main health risk for younger population groups is weight gain and being overweight, older adults are vulnerable to consuming too little energy with associated weight loss. The range of physiological changes that contribute to reduced food intake has been termed the “anorexia of aging” (Morley, 1997). Social, psychological, and medical factors may also negatively impact the desire to eat.
In general, healthy older people tend to consume smaller meals, fewer snacks, eat more slowly, and become satiated after meals more rapidly than younger people, and daily intake of food may decrease by an average of 30% between the ages of 20 and 80 years (Wurtman et al., 1988). Most of the age-related decrease in energy is a response to the decline in energy expenditure with age; however, for many older people, the decrease in energy intake tends to be greater than the decrease in energy expenditure with a resultant loss of body weight, particularly muscle mass.
The age-related changes which predispose older adults to a decrease in food intake may lead to malnutrition, especially in the presence of additional health and social risk factors (Wham et al. 2015). Consequently, malnutrition is widespread among vulnerable older adults especially in those who are institutionalized. In developed countries, it has previously been estimated that malnutrition is present in 5–30% of community-living older people, 23–60% of those who are hospitalized, and up to 70% of those living in residential aged care or nursing homes (Agarwal et al. 2013). Among community-living older people in Europe, it has been estimated that 20% of those aged between 75 and 80 years are malnourished (Ljungqvist et al. 2010). Along with its associated health complications, undernutrition is estimated to cost the European health and social care system approximately 120 billion Euros per year (Ljungqvist et al. 2010).
Malnutrition is associated with functional impairment, increased comorbidity (in relation to immune dysfunction, anemia, reduced cognitive function, and poor wound healing), delayed recovery from surgery, higher hospital and readmission rates, and mortality (Chapman 2006). Studies of older people also show a relationship between malnutrition risk and health-related quality of life (Kvamme et al. 2011; Johansson et al. 2009), which underpins the importance of optimizing the nutritional health of older people.
Good nutrition is a modifiable factor which may help to prevent health problems. Improvements in nutritional status can also allow for greater health expenditure to be directed toward keeping older people well for longer. Screening for malnutrition risk, a process which can identify factors related to nutritional status that could lead to malnutrition, can act as a preventative health measure. Validated nutrition screening tools provide a reliable method to identify those at high risk of malnutrition. Early identification and nutrition intervention is important because it can be difficult to reverse adverse effects, once malnutrition is established. In the absence of formal screening procedures, more than half of older adults at risk of malnutrition in various settings may not be recognized or referred for treatment (Elia et al. 2005). As early identification and intervention in malnourished older adults can improve clinical outcomes and reduce health care use, guideline recommendations for nutrition screening and assessment provide an important safeguard.
Understanding nutrients of concern for older people is critical for the prevention and management of chronic disease and other health problems. Policy is an important vehicle to implement actions for the improvement of nutrition. Country-specific food and nutrition guidelines are formulated to protect the health of populations in the context of other relevant policies and strategies. Dietary guidelines are based on the nutritional needs of a population; however, little is known about the dietary habits and nutritional status of the very old. Although adults of advanced age are physiologically different to their younger counterparts and are more prone to inadequacy of energy and certain nutrients than younger adults, there are no specific dietary guidelines for those aged ≥85 years. Generally, older people are underrepresented in nutrition surveys and data for older adults are aggregated for those ≥65 or 70 years with recommendations in many cases based on evidence from younger adults. Indeed, in some countries, dietary recommendations for healthy adults (≥19 years) are applied to older adults (≥65 years). The lack of nutrition surveillance data for older adults makes it difficult to establish their nutritional needs and to develop policies to protect this vulnerable group. Given the heterogeneity of older people, it has been suggested that future guidelines may need to identify the nutritional needs of older people in relation to their functional ability and morbidity (Suominen et al. 2014).
In this chapter, the nutritional needs of older people will be examined. Adequacy of food intake of adults of advanced age has been reported from longitudinal studies of ageing. More recently, the macronutrient and micronutrient intakes of the very old were investigated from three cohorts of advanced age from the UK and New Zealand (NZ) (Mendonca et al. 2016a, b; Wham et al. 2016a, b). Dietary information was collected using a repeated multiple-pass recall (2×24h recalls) in 793 85-year olds (302 men and 491 women) living in North-East England (the Newcastle 85+ study) and in 216 Māori and 362 non-Māori from the Bay of Plenty and Rotorua regions of New Zealand participating in Life and Living in Advanced Age: A Cohort Study in New Zealand (LiLACS NZ). The nutritional enquiry included in these cohort studies of ageing provides a preliminary assessment of nutritional status in the very old.
The energy needs of older adults vary widely according to gender, body size, and physical activity. Those with good health and physical function may have similar energy needs to younger adults. Typically, both lean body mass, total body water, and basal metabolic rate tend to decline with age, concurrent with body composition changes slowly over time, and body fat may increase proportionally. There is a decrease in skeletal muscle, smooth muscle, and muscle that affects vital organ function. This reduction in lean body mass, basal metabolic rate (BMR), and overall physical activity contributes to an overall reduction in the energy needs of older adults compared with younger people. Changes in body composition affect the body’s metabolism, nutrient intake, nutrient metabolism, and overall nutrient requirements. As BMR declines proportionately with the decline in muscle tissue, an older person’s energy requirement per kilogram of body weight tends to be reduced.
Based on data from the US Institute of Medicine of the National Academies database for individuals aged between 20 and 100 years, a progressive decline in total energy expenditure and physical activity level with advancing age is evident (Roberts and Dallal 2005). Maintaining an adequate energy intake and weight can be a challenge especially in advanced age. Older people are less able than younger adults to make compensatory increases in their energy intake and are less able to regulate weight and therefore regain any lost weight.
Food intake in older people may be compromised due to taste changes, sensory deficits, and impaired sensory-specific society which leads to less variety-seeking behavior. Physiological changes in gastrointestinal function that occur with ageing may have an adverse impact on appetite and contribute to an overall decrease in food intake. Combined with poor dentition, chronic illness, and adverse social and psychological factors such as bereavement and depression, older adults tend to be less hungry than younger adults.
Among older adults showing characteristics of frailty, meeting energy requirements can be particularly difficult. Eating at least three meals a day and, where possible, energy- and nutrient-dense snacks, is especially important for the frail old. An overall decline in food intake may compromise dietary variety which is positively associated with nutritional quality and positive health outcomes. A lack of energy intake from food may lead to nutrient deficiencies and can augment functional decline which may contribute to further deterioration of health. Nevertheless, with adequate consumption of a variety of foods from the main food groups, older individuals can meet recommended macronutrient and micronutrient intakes and energy balance can be achieved.
Estimates of total energy requirements for older adults are problematic given the evidence to suggest that the desirable healthy weight range should be set higher for improved health outcomes and the potential that the current estimates are based on predictive equations that have not been validated in this age group and may therefore overestimate requirements as a result of the decline in muscle mass with age (NHMRC (National Health and Medical Research Council) 2006). In general, data on the energy requirements of people over 80 years are scarce. Among 87 octogenarians (mean age 82 ± 3.1 years) participating in the Health, Aging, and Body Composition (Health ABC) study, energy requirements based on doubly labelled water measures of total energy expenditure were 9.24 ± 1.57 MJ/d for men and 7.59 ± 1.41 MJ/d for women (Cooper et al. 2013).
Among octogenarians participating in three cohorts of advanced age in the UK and New Zealand, a wide range of energy intakes were reported. Median (IQR) energy intakes reported in the Newcastle 85+ study were generally low; 7.73 (6.36–9.20)MJ/d for men and 6.15 (5.09–7.25)MJ/d for women (Mendonca et al. 2016a) with only 20% of cohort meeting the EAR (UK) (Scientific Advisory Committee on Nutrition (SACN) 2011). Similar energy intakes were reported in LiLACS NZ: Māori men 7.45 (6.05, 9.13)MJ/d and women 6.06 (4.80, 7.21)MJ/d and non-Māori men 7.90 (6.70, 9.57)MJ/d and women 6.27 (7.50, 7.50)MJ/d (Wham et al. 2016a). These dietary energy intakes also appear comparable to energy intake reported in previous European studies which included octogenarians. For example, median energy intakes (MJ/d) for men and women, respectively, were from the European Prospective Investigation into Cancer and Nutrition (EPIC) (The EPIC-Oxford Study, 2010–2014) 9.84 and 9.02 and Dutch National Food Consumption Survey (DNFCS) 2010–2012 (Ocke et al. 2013) 7.4 and 7.30.
Older adults have a higher requirement for protein compared to younger adults. However, older adults usually eat less, including less protein, but have higher protein needs to offset the reduction in muscle protein synthesis (anabolic resistance) as well as the elevated metabolism of inflammatory conditions such as chronic obstructive pulmonary disease (COPD) (Deutz et al. 2014). There is mounting evidence that the existing recommended dietary intakes (RDI) for protein are too low for older people (Bauer et al. 2013) and do not take into consideration age-related changes in metabolism and immunity (Clegg et al. 2013). Findings suggest that protein intake greater than the RDI can help older people to improve immune status and wound healing, as well as muscle mass, strength, and function (Wolfe et al. 2008).
Although there is insufficient longer term research with defined health outcomes to specify an optimal intake for protein, there is mounting evidence that increasing protein intake beyond 0.8 g/kg may enhance protein anabolism and help reduce the progressive loss of lean mass with ageing. Protein intake has been demonstrated to be an important determinant of muscle mass and function. Among a group of healthy older women with protein intake 0.45 g/kg bodyweight/day, muscle mass and strength decreased over a period of 9 weeks. By contrast, in women who consumed twice that amount of protein (0.92 g/kg bodyweight/day), muscle mass remained stable and muscle strength improved (Castaneda et al. 1995). It has also been demonstrated that chronic ingestion of the recommended dietary allowance (RDA) (USA) for protein results in reduced skeletal muscle size in weight-stable older adults with no change in muscle function (Campbell et al. 2001). Findings from the Health ABC cohort indicate lower energy-adjusted protein intake in 2066 healthy older adults aged 70–79 years is associated with a larger loss of lean body mass over a period of 3 years of observation (Houston et al. 2008) with a median protein intake between 0.7 g/kg (lowest quintile) and 1.1 g/kg (highest quintile) resulting in a reported loss in lean mass of 0.85 and 0.45 kg, respectively; i.e., 40% less decrease in lean mass over 3 years suggesting a clear linkage between protein intake and muscle change in older adults. Furthermore, data from the InChianti and the Women’s Health Initiative cohort studies indicate that higher protein intake is associated with reduced risk of muscle strength loss and incident frailty (Beasley et al. 2010; Bartali et al. 2012).
Evidence from recent cohort studies suggests that observed weight-adjusted protein intake of octogenarians tends to meet respective nutrient reference values for people over 70 years but may be low when compared to newer recommendations (1.0–1.2 g/kg/day to preserve and regain lean body mass and function) made by the PROT-AGE Study Group (Bauer et al. 2013). In the Newcastle 85+ study, the daily median (IQR) weight-adjusted protein intake for men was 1.04(0.81–1.32)g/kg and for women was 0.96(0.75–1.17)g/kg higher than the Reference Nutrient Intake (RNI) (UK) of 0.75 g/kg (Department of Health: Committee on Medical Aspects of Food Policy (COMA) 1991). Overall, 78.1 and 67.4% of men and women, respectively, had higher protein intakes than the RNI. In LiLACS NZ, the median weight-adjusted protein intake for Māori and non-Māori men was 1.05 and 0.98 g/kg/day, respectively; for Māori and non-Māori women 0.87 and 0.91 g/kg/day, respectively. Similarly, the reference standard was met by 66% of Māori and 73% of non-Māori women (EAR (Australia/NZ) 0.75 g/kg/day) and by 65% of Māori and 72% of non-Māori men (EAR 0.86 g/kg/day) (NHMRC (National Health and Medical Research Council) 2006).
Not only do older adults usually eat less protein compared to younger adults, they often consume less high biological value (HBV) animal protein such as meat (Gaffney-Stomberg et al. 2009) due to factors such as difficulty chewing, fear of increasing fat and cholesterol and cost and accessibility of these sources. Although muscle mass decreases in older people, the formation of muscle protein can be stimulated by HBV proteins, so it is prudent that an adequate protein intake is maintained. An adequate protein intake is especially important to maintain a healthy functional status and decrease the risk of prolonged infections that may lead to hospitalization. The pattern of protein intake may also be important to stimulate protein synthesis in older adults and there is some evidence that spreading protein intake evenly over meals may be beneficial (Bouillanne et al. 2013). However, further studies are needed to determine the optimal pattern of intake to improve muscle strength and function.
The optimal protein intake for older adults to maintain nitrogen balance and to preserve muscle mass and function remains to be ascertained. Recent recommendations from the European Society for Clinical Nutrition and Metabolism (ESPEN) suggest higher dietary protein intakes for older adults (≥65 years) compared to younger adults (Deutz et al. 2014). It is suggested that diet should provide between 1.0 and 1.2 g protein/kg body weight/day for healthy older people (Cruz-Jentoft et al. 2010) and between 1.2 and 1.5 g protein/kg body weight/day for older people who are malnourished or at nutrition risk (Deutz et al. 2014). To limit age-related decline in muscle mass, strength, and function, resistance exercise training is also recommended (Lanza et al. 2008).
Notably, higher protein intakes are now recommended by the PROT-AGE Study Group appointed by the European Geriatric Medicine Society (EUGMS) (1.0–1.2 g protein/kg body weight/day for healthy older people, ≥1.2 g protein/kg body weight/day for active and exercising older adults, and 1.2–1.5 g protein/kg body weight/day for older adults who have acute or chronic disease (Bauer et al. 2013)). Similarly, in Norway, the Nordic Nutrition Recommendations suggest a safe intake of 1.2–1.5 g protein/kg body weight/day for healthy older people or approximately 15–20% of total energy intake (Pedersen and Cederholm 2014).
Based on the acceptable macronutrient distribution range (AMDR) (Australia/NZ), participants in both the Newcastle 85+ study and LiLACS NZ met or exceeded the minimum of 15% energy from fat proposed to ensure adequate consumption of total energy, essential fatty acids, and fat-soluble vitamins. Fat intake, as median percent energy was above the maximum AMDR range (20–35%), for participants in Newcastle is 36.8%, for Māori 38.5%, and for non-Māori 36.7% (NHMRC (National Health and Medical Research Council) 2006). These intakes are greater than reported for New Zealand adults aged 71+ years in the New Zealand Adult Nutrition Survey (33%) (University of Otago and Ministry of Health 2011). A lack of evidence for age-specific dietary recommendations for the oldest old hinders the interpretation for higher energy from fat but suggests that octogenarians eating patterns may differ from younger adults.
Generally, an older adult who is eating well in terms of quality and quantity and is not experiencing or recovering from an acute illness will achieve an adequate intake of all micronutrients . While some micronutrients are required in larger amounts in older age, these amounts can be achieved within a healthy, well balanced diet which meets energy and macronutrient recommendations.
Micronutrient deficiencies tend to arise due to a reduction in food intake in response to a decline in energy needs with age. BMR and energy expenditure for physical activity may be reduced (Roberts and Rosenberg 2006) while vitamin and mineral needs remain unchanged or are increased (Zhu et al. 2010). Physiological changes may impact the metabolism of micronutrients and poor health and medications may compromise nutrient absorption. Eating habits affected by poor oral health and social isolation may further contribute to lower food intake and nutrient deficiency (Elmadfa and Meyer 2008). As micronutrient deficiencies are associated with adverse functional outcomes (Inzitari et al. 2011), they may impact the independence of older adults.
Vital for bone health, calcium is consistently recommended in higher amounts for older compared to younger adults. Food sources high in calcium include milk, cheese, yoghurt, fortified foods (e.g., juice, breakfast cereal, breads), and some fish (e.g., sardines) and are recommended in favor of supplementation due to the unexpected finding that calcium supplementation was associated with increased cardiovascular events in osteoporosis trials (Reid et al. 2011).
Across various studies of older adul ts, dietary calcium intake does not meet dietary recommendations (Zhu et al. 2010). A similar shortfall of calcium intake was also observed for octogenarians in the Newcastle 85+ study median (IQR) 731 (554–916)mg and in LiLACS NZ for Maori 563 (424–778)mg and for non-Maori 702 (541–905)mg. More than 85% of octogenarians In LiLACS did not meet the EAR (Australia/NZ) for calcium (1100 mg). Calcium is not as well absorbed by the oldest age group and increased intake is needed. Novel ways of increasing dietary intake and intervention trials that study dose–response relationships to outcomes are needed as not enough is known about calcium requirements during ageing.
Magnesium requirements appear to change with age, but clear conclusions are absent to set higher requirements. Data from the National Health and Nutrition Examination Survey (NHANES) III showed a progressive decrease in daily magnesium intake with age (Ford and Mokdad 2003) with mean intakes for older men (225 mg) and women (166 mg) being well below the recommended daily allowance (RDA) (USA). A comprehensive review suggests that the dietary intake of magnesium is inadequate in elderly populations (Vaquero 2002), and this has previously been observed in older people in New Zealand (Horwath et al. 1992). In octogenarians participating in the Newcastle 85+ study, >20% of participants were below the lower NRI (UK) for magnesium (Mendonca et al. 2016b), and in Lilacs NZ, the EAR (Australia/NZ) for magnesium was not met by most (Wham et al. 2016b).
In older adults, magnesium is associated with physical performance (Veronese et al. 2014), adequate bone mineral density (Orchard et al. 2014), and inflammation (Chacko et al. 2010); hence, low intakes are of concern. Rich food sources of magnesium include nuts, legumes, whole grains, and most green vegetables, but despite a wide distribution in the food supply, older adults are less likely than younger adults to consume sufficient to meet their needs (Barbagallo et al. 2009).
Selenium is an important antioxidant and contributes to a strong immune system and healthy thyroid function. It may also play a role in cancer prevention but this is an ongoing area of research. Good food sources of selenium include Brazil nuts and oily fish; however, the food content may depend on the local geographical area. Whole population estimates from NHANES do not show low intakes of selenium (Fulgoni et al., 2011; however, in the USA, frail older people have been found to be more likely to be deficient in selenium than other population groups (Smit et al., 2013). In the Newcastle 85+ study in the UK >20% of participants had selenium intakes below the lower RNI (UK) (Mendonca et al., 2016b). Selenium intakes among octogenarians in LiLACS NZ were marginal with over two-thirds of participants falling below the EAR (Australia/NZ) (Wham et al. 2016b), similar to the NZ Adult Nutrition Survey for those aged over 70 years (University of Otago and Ministry of Health 2011). However New Zealand soils are low in selenium and New Zealand population blood selenium concentrations remain lower than those reported in other Western countries (Thomson 2004). Intakes in vulnerable older populations need to be examined in relationship to serum levels and outcomes over time to fully understand the significance of low intake.
Zinc plays an important role in immunity but also has a role to play in wound healing and maintaining the senses of taste and smell, important for the enjoyment of food and optimal health of older adults. Zinc can be found in reasonable amounts in a range of foods including pulses, nuts and legumes, wholegrain cereals, and dairy products. Among octogenarians in LiLACS NZ, most men did not meet the EAR (Australia/NZ) for zinc intake (Wham et al. 2016b). Expressed on a per MJ food energy basis, zinc intake for all participants was 1.2 mg/MJ lower than for European men (aged 70+ y) in the Zenith study (Andriollo-Sanchez et al. 2005). Data on zinc status in normal ageing are lacking and the implication of low intake is unknown. An adequate intake of zinc nevertheless appears to be important for prevention of oxidative stress, immunity, and cognitive functions.
Iron plays a number of important roles in the body but is primarily concerned with transport of oxygen from the lungs to the cells of the body. Approximately, 70% of the body’s iron is to be found in red blood cells in the form of hemoglobin. Iron in food is found as heme iron, from animal products, or non-heme iron, from nonanimal-based products. Good sources include red meat, dark green leafy vegetables, and fortified breakfast cereals. Iron deficiency occurs in around two-thirds of the world’s population with signs and symptoms being fatigue and decreased immunity. The most probable cause of iron deficiency anemia among older adults is inadequate dietary intake or blood loss from conditions such as ulcers, polyps, or intestinal cancer. There is no evidence that heme iron absorption is impaired in older adults. Iron deficiency in older adults is reported to be especially common over the age of 80 years (Fairweather-Tait et al. 2014). Prevalence of anemia i n the USA has been reported to be approximately 10% at age 65 years and up to 60% in older adults in residential aged care.
Older people are especially susceptible to vitamin D i nsufficiency due to reduced mobility, decreased sun exposure, and a decline in cutaneous synthesis of vitamin D with age (Heaney 2006). Unfortunately, food sources of vitamin D are limited (e.g., some fish, fortified foods, and liver) and while exposure to sunlight provides an endogenous source, disease or disability can prevent adequate exposure especially among the housebound or those in residential care. Most community-living octogenarians (>95%) in the Newcastle 85+ study had vitamin D intakes below the RNI (UK) (10 μg/d) (Mendonca et al., 2016b). Similarly in LiLACS NZ, the adequate intake (AI((Australia/NZ) for vitamin D (15 μg/d) was not met by >95% of participants (Wham et al. 2016b). To ensure adequate vitamin D status of older people, supplementation and food fortification may be needed; targeting those at high risk of insufficiency and providing vitamin D supplementation is likely the most cost-effective approach.
Recommendations for dietary vitamin B12 intake are generally not different to younger adults. Increasing risk of deficiency among older people, despite adequate intakes, appears to be related to physiological changes in the gut with age that may prevent the release of vitamin B12 from natural food sources (McNulty and Scott 2008). Pernicious anemia is a further cause of deficiency in older people (Andres et al. 2004). Vitamin B12 is mostly found in animal products such as fish, poultry, meat, eggs, and dairy; hence, vegetarians may be at higher risk; however, it is increasingly found in fortified foods, particularly breakfast cereals. Vitamin B12 deficiency commonly manifests as fatigue, anemia, and depression which may be corrected through diet or supplementation.
Folate is found across a wide range of foods including fruit and vegetables, legumes and nuts, dairy, poultry, meat, and eggs. Despite being commonly found in the food supply and older adults not generally having any greater requirement than younger adults, folate can become a nutrient at risk if access and availability of fresh food is limited or there is a significant decline in appetite. Of particular concern for older people is that natural food folates found in foods such as green vegetables can be unstable under typical cooking conditions, and this can substantially reduce the folate content even before it is ingested. Folic acid found in supplements and fortified foods such as breakfast cereals is however a very stable and highly bioavailable form of the vitamin (McNulty and Scott 2008). Many developed countries mandatorily fortify grain flours, including wheat, with folic acid, e.g., Australia, USA, while others fortify voluntarily, e.g., NZ, to address public health concerns related to folate insufficiency. This largely relates to neural tube defects; however, the older population is likely to benefit from the increased availability in the food supply. The primary clinical sign of deficiency is megaloblastic anemia, commonly manifesting as fatigue, weakness, and headache.
Dictionary of Terms
Malnutrition is a broad term referring to both over- and undernutrition; however, in this context, it is exclusively used to describe undernutrition occurring as a result of inadequate nutrient intake, which may be due to insufficient food intake or illness.
Māori are the indigenous people of Aotearoa, New Zealand comprising 14% of the total population and 2% of those aged over 80 years.
Macronutrients are those which are required by the body in large amounts, and which contribute to energy intake, i.e., protein, fat, carbohydrate, alcohol.
Energy (calories or kilojoules) is the fuel gained from macronutrients which is used by the body for all processes and activities including breathing, sleeping, thinking, and walking.
Acceptable macronutrient distribution ranges (AMDR) are the recommended ranges for % energy from macronutrients required to reduce chronic disease risk, e.g., protein 15–25%, fat 20–35%, carbohydrate 45–65% (Australia/NZ).
Nutrient reference values referred to throughout this chapter, e.g., RDA, RDI, AMDR, etc., are population-level recommendations based on thorough and systematic review of current scientific knowledge.
This chapter reviews the current understanding of energy, macronutrient, and key micronutrient requirements for older people including the oldest old.
Ageing is associated with a range of physiological and psychosocial changes which can result in poor nutritional health and consequently poor general health.
Older people tend to be nutritionally vulnerable with advancing age as typically they eat less food, consume smaller meals, fewer snacks, and become satiated after meals more rapidly than younger people; daily intake of food may decrease by a third between the ages of 20 and 80 years.
Understanding nutrients of concern for older people is critical for the prevention and management of chronic disease and other health problems.
Dietary guidelines are based on the nutritional needs of a population; however, little is known about the dietary habits and nutritional status of the very old.
Energy requirements vary with age, gender, body size, and physical activity. While healthy active older adults may have similar energy needs to younger adults, energy expenditure tends to decline progressively between the ages of 20 and 100 years, largely due to body composition changes of ageing.
Meeting energy requirements can be challenging for older adults due to reduced food intake and hence a reduction in dietary variety.
Older adults have higher protein requirements than younger adults due to reduced muscle protein synthesis rates and elevated metabolism from inflammatory conditions. There are inconsistencies in guidelines for protein intake in this population; recent European recommendations promote higher intakes up to 1.5 g protein/kg body weight.
Fat is an important energy source particularly for older adults whose appetite may be diminished. While the evidence suggests that adults of advanced age eat fat in excess of recommendations, there are no age-specific guidelines to help interpret the implications of this over consumption.
Healthy older adults who eat well in terms of quality and quantity will generally meet micronutrient recommendations.
Micronutrient deficiencies tend to arise from reduced food intake occurring as a result of reduced energy requirements with age.
Absorption and metabolism can be affected by ageing as well as polypharmacy, poor health, and social isolation.
Micronutrients of concern in older adults are calcium, magnesium, selenium, zinc, iron, vitamin D, vitamin B12, and folate with vitamin D of particular concern, as food sources are limited and exposure to sunlight is often reduced. Routine vitamin D supplementation may be necessary to achieve requirements.
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