07 Jun 2021
As we approach Nutrition and Hydration Week 14-21 June, Dove Yu from the BDA’s Older People Specialist Group looks at the particular challenges facing patients with dementia.
Dementia is an umbrella term used to describe a range of neurological disorders that are caused by abnormal brain changes. It is a chronic, progressive condition characterised by a range of cognitive and behavioural symptoms including memory loss, problems with reasoning and communication, change in personality, and a reduction in a person’s ability to carry out daily activities.1 There are over 200 subtypes of dementia. In the UK, the most common subtypes include:
- Alzheimer’s disease (AD) (50-75%)
- Vascular dementia (up to 20%)
- Dementia with Lewy bodies (10-15%)
- Frontotemporal dementia (2%)2
Over 850,000 people are living with dementia in the UK. As population ageing accelerates, this figure is projected to rise to 1.6 million by 2040.3 Dementia is most prevalent in older adults. The risk of developing dementia increases with age, affecting one-in-14 people over the age of 65 and one-in-6 people over the age of 80. However, dementia is not a normal part of ageing. Over 42,000 people under 65 years have dementia in the UK.4 The total cost of dementia care in the UK is estimated to be £34.7 billion a year. In 2019, dementia accounted for 12.5% of all registered deaths in England and Wales.5
Eating a healthy and balanced diet is vital for maintaining physical and mental health. However, dementia can affect a person’s ability and desire to eat and drink to meet their nutritional requirements. Mitchell et al.6 reported that the most common clinical complications in people living with advanced AD were eating problems (86%), which occurred sooner and more frequently than febrile episodes (53%), and pneumonia (41%). Weight loss, malnutrition, and dehydration are common in people living with dementia. These can have significant negative impacts on their quality of life, clinical outcomes and morbidity and mortality.
This article will discuss the eating and drinking difficulties in people living with dementia, explore the practical interventions to optimise oral intake and Consider the challenges for dietitians in clinical practice.
Eating and drinking difficulties in people with dementia
Eating and drinking difficulties are a major source of ill health and stress for people living with dementia and their carers. As dementia progresses, the cognitive, behavioural, and physical changes that occur can make eating and drinking increasingly challenging (Table 1). These pathological changes are linked with hypermetabolism, reduced energy intake and greater physical activity, leading to malnutrition. The mechanisms underlying weight loss in dementia are complex, multifactorial, and only partly understood.7
Taste and smell changes
Significant deficits in the perception of taste preferences, quality, and intensity are caused by peripheral loss of taste/smell receptors or neurons. Olfactory deficits occur in the ageing progress alone but also early on in dementia. Apolipoprotein E (APOE) is a polymorphism associated with an increased risk of developing AD. Individuals carrying the APOEε4 allele seem more prone to suffer from impaired olfactory function before the onset of cognitive impairment.8 To date, studies have shown inconsistent findings on the olfactory profiles for each type of dementia.9 Olfactory dysfunction can be used as a pre-clinical biomarker for dementia and olfactory testing may become a supplementary tool in early detection of dementia.10 People living with dementia were found to have a strong preference for sweeter foods and carbohydrate over protein and fat.11
|Nutritional problems||Stage of dementia|
Taste and olfactory dysfunction (reduced sense of taste and smell)
Pre-clinical and early stages
Attention deficit (inability to focus)
Mild to moderate
Executive functions deficit (shopping, preparing food)
Mild to moderate
Impaired decision-making ability (slowdown in food choice, reduced intake)
Mild to moderate
Dyspraxia (difficulty co- ordinating movements)
Moderate to severe
Agnosia (difficulty recognising subjects)
Moderate to severe
Behavioural problems (walking with purpose, agitation, disturbed eating behaviour)
Moderate to severe
Oropharyngeal dysphagia (difficulty swallowing)
Moderate to severe
Refusal to eat
Table 1: Nutritional problems arising over the course of dementia (Adapted from European Society for Parenteral and Enteral Nutrition7)
People living with dementia may have a poor appetite and lose interest in food. They may refuse to eat or spit out food. The age-related alterations in satiety signals, changes in gastrointestinal motility and inflammation may result in anorexia in older people. Poor appetite may also arise from depression, intercurrent physical illness, lack of activity, oral or dental problems, pain, constipation, or side effects of medication. Dementia-related brain atrophy may impact regions involved in appetite regulation and eating behaviour. Atrophy of the mesial temporal cortex has been associated with low body mass index (BMI), suggesting a connection between limbic system damage and low body weight in AD.12 Reduced thirst was found more pronounced in those living with dementia.13
Difficulty in shopping and preparing food
As the ability to perform complex tasks is declining, difficulties in shopping and preparing meals may arise. Those living with dementia may struggle to find supermarket entrances or exits, get confused about what to buy and get distracted by loud noises.
Forget to eat and drink
People living with dementia may forget to eat and drink or forget that they have already eaten and drunk, leading to skipping meals or overeating. They may lose the cognitive ability to initiate or continue effective eating strategies. Impaired decision-making ability may slow food choice and reduce intake. Those living with dementia may also have problems in communicating hunger or thirst and likes or dislikes.
Swallowing and chewing difficulties
Dysphagia is reported in 13-57% people living with different types of dementia and is most common in later stages of AD and frontotemporal dementia.14 People in this situation may hold food in their mouth, fail to form a bolus and have a delay in swallow initiation. Other signs include choking, coughing or wet voice whilst eating and drinking. Dysphagia may develop as a result of the inability to recognise food, oral-tactile agnosia and swallowing and feeding apraxia. Dysphagia of the pharyngeal phase leads to aspiration before, during and after swallowing. People living with dementia and dysphagia have double the risk of dying with aspiration pneumonia than those without aspiration.15 Furthermore, chewing problems may develop as a result of fatigue from prolonged mastication, forgetting to chew, mouth pain, dental caries, or ill-fitting dentures.
Dyspraxia and agnosia
People living with dementia may experience dyspraxia including tremors or reduced hand-eye coordination, which may reduce their ability to use utensils to prepare meals or cutlery to cut up foods or transfer foods to their mouth. People who were able to feed themselves are usually in an earlier stage of dementia and have a significantly higher relative body weight than those who require feeding assistance.16 Moreover, they may develop agnosia and lose their ability to recognise food and drinks. They may turn their head away from food, push food away or consume non-edible items present on the table.
Walking with purpose is common in people living with dementia as they may lose their ability to recognise familiar places. They may be restless and walk around at mealtimes, increasing their energy expenditure and chances of skipping meals. Agitation can lead to aversive feeding behaviours. Personality changes can alter attitude towards food and change dietary preferences.
Nutritional screening and assessment
People living with dementia are more vulnerable to developing malnutrition which can be preventable with early detection and intervention. Therefore, nutritional screening and assessment should be integral for all people with dementia in line with National Institute for Health and Care Excellence (NICE) guidance.17 The Malnutrition Universal Screening Tool (MUST)18 or Mini Nutritional Assessment19 are common screening tools suitable for detecting malnutrition risk. The Global Leadership Initiative on Malnutrition (GLIM) criteria is for diagnosis of malnutrition and it recommends BMI 22kg/m2 as the lower BMI cut-off for adults over 70 years.20
Nutritional interventions should be initiated immediately after assessment and monitored regularly. A person-centred approach is important and appears to be beneficial.21 Although there is a growing volume of research on improving nutritional care in people living with dementia, the evidence on the effectiveness of these interventions varies in quality and availability.22
Two large systematic reviews investigated the effectiveness of interventions to support food and fluid intake directly and indirectly in people living with dementia. Both suggested that existing studies tende to be short term and small.23,24 Thus, more high-quality studies are required.
Food first approaches
The first-line approach in improving nutritional intake in people living with dementia is through food fortification to maximise nutrient density. It is usually combined with a little and often strategy i.e. small portions of meals and between meal snacks. NICE CG32 emphasises the overall nutrient intake of oral nutrition support offered should contain a balanced mixture of nutrients instead of just calories.17
Food fortification should use more nutrient-dense ingredients instead of just calorie-dense ones (Table 2). Snacks should include more nutrient-dense choices such as cheese with fruit and/or crackers, nuts, nut butter on bread, rice pudding with added skimmed milk powder and thick and creamy yogurt.
|Recommendations for age >65 years||Practical guidance|
BMI <18.5kg/m2 25-30kcal/kg/day
Use Mifflin-St Jeor equation
+/- physical activity level25
Women: 1600 ml/day
Men: 2000 ml/day27
Table 2: Dietary recommendations and practical guidance for food fortification (Adapted from Jones22)
Offering finger foods that can be picked up and eaten by hand easily may improve food intake at meal and snack times. Finger food does not have to be buffet type food. A roast dinner can be finger food. Other examples include salmon dinner, pasta muffins, sandwiches, fish fingers, chicken nuggets, sausages, cheese cubes, vegetable sticks and dips, biscuits, and sliced fruits. They may help people who find it difficult to use cutlery, are too distracted to sit at the table or walk a lot during mealtimes. Serving foods picnic-style in appropriate containers may help people who take longer to eat. While there is some evidence that the provision of finger foods may restore independence and dignity by allowing people to feed themselves and maintain weight in residential care settings, there is a paucity of research in acute settings.7
Texture modification can allow people with swallowing or chewing difficulties to continue to enjoy eating and drinking. For people with chewing problems, soft foods such as eggs, fish, mashed potatoes, porridge, or cereals soaked in milk, slow-cooked stews and foods in sauces can be offered.
All people with suspected dysphagia should be referred to a speech and language therapist for individualised advice on safe and appropriate texture modification in line with International Dysphagia Diet Standardisation Initiative (IDDSI) standards.1 Poor acceptability and adherence to texture modification may contribute to reduced quality of life, malnutrition, and dehydration. Keeping individual puree foods separate or using moulds to shape foods to look like their original form may make modified texture food more appealing.22
Enhanced flavours and smells
Enhanced flavours and smells may make food more easily perceived and palatable. Adding flavour enhancers to the cooked meals was shown to be an effective way to improve dietary intake, weight, immune function, and grip strength in older adults.28, 29
Strategies to address taste and smell changes:
- Try adding extra flavours
- For savoury food: spices, herbs, lemon/lime juice, vinegar, marmite, Bovril, mustard, garlic powder/puree, herbs, ketchup, tomato puree, Worcestershire sauce
- For sweet food: sugar, honey, maple syrup, jam, natural flavourings, balsamic vinegar
- Do not exclude any food and try a wide variety
- Keep a list of current preferences and re-try foods from time to time
- Incorporate sweet foods into a balanced diet if preferred
- Try naturally sweet vegetables e.g. carrots, parsnips, sweet potato, peppers
- Serve food with sweet sauces, sweet chilli, ketchup, pickles or chutneys
- Encourage milk-based puddings e.g. custard and stewed fruit, rice pudding, trifle, mousse, ice cream or crème brûlée
- Encourage people to smell a variety of food and drinks
Behavioural and environmental interventions
Mealtime adaptations should be made for people living with dementia, including considering when and how meals are served; the support provided during meals; the environment and support to eat outside of mealtimes. Murphy et al21 published a model for understanding the provision of good nutritional care for people living with dementia in nursing homes. Overall, the quality of existing studies is poor which limit the generalisability of the findings.30,31 Music interventions were found to have the most marked effect on agitated and aggressive behaviours.30
Strategies to create a comfortable eating environment may include:
- Replicating a homely mealtime experience by using napkins and plates but not trays
- Lighting and colour-contrasting plates, tablecloths and placemats to improve visual cues
- Relaxing music
- Minimising distraction by switching off television and keeping table setting simple
- Involving people in meal preparation, setting the table or cleaning up after meals
- Feeding aids for dexterity e.g. adapted cutlery, special cups, deep lipped plates
- Serving familiar and traditional foods
- Placing plug-in food fragrance/diffuser in rooms
- Keeping lounge next to kitchen in care homes to allow people to smell food
- Offering more choices and autonomy by serving food at the table
- Positive reinforcement and encouragement at mealtimes using directed verbal prompts, systematic prompting and cueing
- Individual eating assistance
- Social eating e.g. breakfast club to reflect our identity and make connections with others
- Allowing additional time for meals
Oral nutrition supplements (ONS)
ONS are classified as foods for special medical purposes that can be used to help manage disease-related malnutrition. ESPEN guidance recommends the use of ONS on people who cannot meet their nutritional requirements with usual food alone to improve nutritional status but not to correct cognitive impairment or prevent cognitive decline.7 This is consistent with the results from a recent systematic review which showed that ONS improved energy intake by 201 to 600kcal/day without affecting energy intake from ordinary foods. Weight, muscle mass, and nutritional biomarkers in blood improved in the intervention groups compared with the control groups whereas no effects on cognition or physical outcomes were observed.32
Clinically assisted nutrition and hydration (CANH)
CANH is usually the administration of food and fluids via a nasogastric tube or a gastrostomy tube. It is considered when oral nutritional support is inadequate in maintaining weight and meeting nutrition and hydration requirements, or the person’s swallow has been determined as unsafe and CANH is in the person’s best interests.
Multiple systematic reviews of mainly observational studies have concluded that CANH in advanced dementia does not provide benefit in terms of prolonging survival, improving quality of life, leading to better nourishment, decreasing the risk of pressure ulcers, decreasing risk of aspiration pneumonia.1,8,33
NICE NG97 guidance recommends “do not routinely use enteral feeding in people living with severe dementia, unless indicated for a potentially reversible comorbidity”.1 CANH has recognised risks and harms such as increased risk of aspiration and pressure ulcers, pain and other complications associated with tube placement and physical constraints to prevent pulling out tubes.34
Challenges for dietitians in practice
Dealing with challenging behaviour
Dietitians may experience people living with dementia reacting aggressively either verbally or physically. They may make threats, scream, shout, hit, pinch, pull hair, and bite. We may feel frightened and rejected. It is noteworthy that such behaviour is unlikely to be a deliberate act of aggression but more likely to suggest fear or desperation due to misunderstanding. They may be unable to communicate in a way that is heard. Understanding their behaviour is crucial. It may be helpful to ask carers or family members if the person demonstrates any challenging behaviour and any potential triggers to be aware of.
Tips for responding to challenging behaviour:
- Stay calm, take a deep breath and step back to give the person space and time
- Prioritise your own safety, consider whether it is appropriate to continue dietetic review and leave the place if you do not feel safe
- Communicate with a calm tone of voice to find out the triggers and maintain eye contact
- Consider offering a beverage of the person’s choice
- Try not to blame the person as the challenging behaviour can be triggered by memories or previous trauma and may not necessarily be a reflection or directed at you
- Communicate your experience with the multidisciplinary team for advice and consider a need for a medication review
Dealing with stressed and anxious caregivers
Dealing with adverse eating behaviours can be stressful and burdensome for family, relatives, and carers. An appropriate care package and social support over the course of dementia are crucial for people who are living alone with dementia and for carers who need a break.
Tips for dealing with stressed and anxious caregivers:
- Put yourself in their shoes
- Explain why dementia can lead to a reduced oral intake in different stages and it may not be possible to meet their nutritional requirement
- Signpost to social services to arrange support and respite care
- Signpost to charity helplines
Making ethical decisions
Dietitians are routinely required to make ethical decisions on nutritional interventions. Despite the unequivocal evidence, the debate over the use of CANH in people living with dementia remains controversial. Many other considerations factor into these decisions, including the person’s will; prognosis; cultural, religious, and ethical beliefs; legal and financial concerns; and emotions. Dietetic practice must respect autonomy, beneficence, nonmaleficence, and justice.
Decisions should be made on an individual basis after carefully balancing expected benefit and potential burden in a multidisciplinary team. CANH is regarded in law as a medical treatment but not basic nurture. Withdrawing CANH or force-feeding may clash with the person’s autonomy as they have the right to accept or refuse treatment if they have capacity to make that decision at that time and the ability to communicate it. Otherwise, discussions are required with the family, about the person’s prior wishes if there is no advanced care plan and always acting in the person’s best interests. The British Medical Association35 and General Medical Council36 guidance provide the framework for making decisions about whether providing CANH would be in the person’s best interests.
Eating and drinking should be a pleasure. However, people living with dementia may develop eating and drinking difficulties, thereby increasing malnutrition risk.
Dietitians play a vital role in overseeing malnutrition screening, providing dietetic assessment, intervention, and evaluation of each individual’s needs. Dietary interventions should focus on a food-first approach and consideration should be given to the physiological, social, environmental, and psychological aspects of eating and drinking. A holistic, multidisciplinary approach with effective communication is needed to ensure high-quality nutritional care.
Further research should investigate what people living with dementia or their caregivers understand about the possible nutritional challenges that may arise in dementia and the consequences associated with these challenges. More innovative interventions are required to address these eating and drinking difficulties, and research should focus on the most effective interventions to support people living with dementia and their caregivers. More high-quality randomised controlled studies with longer interventional periods are needed.
- National Institute for Health and Care Excellence. Dementia: assessment, management and support for people living with dementia and their carers NICE guideline [NG97] [Internet]. 2018 [cited 27 March 2021]. Available from: nice.org.uk/guidance/ng97/
- National Institute for Health and Care Excellence. Dementia [Internet]. 2020 [cited 29 March 2021]. Available from: cks.nice.org.uk/topics/dementia/
- Wittenberg R, Hu B, Barraza-Araiza L, Rehill A. Projections of older people with dementia and costs of dementia care in the United Kingdom, 2019–2040 [Internet]. London School of Economics and Political Science; 2019 [cited 27 March 2021]. Available from: alzheimers.org.uk/sites/default/files/2019-11/cpec_report_november_2019.pdf
- Prince M, Knapp M, Guerchet M, McCrone P, Prina M, Comas-Herrera A et al. Dementia UK: Update [Internet]. 2nd ed. Alzheimer’s Society; 2014 [cited 30 March 2021]. Available from: alzheimers.org.uk/sites/default/files/migrate/downloads/dementia_uk_update.pdf
- Office for National Statistics. Dementia and Alzheimer's disease deaths including comorbidities, England and Wales: 2019 registrations. 2019.
- Mitchell S, Teno J, Kiely D, Shaffer M, Jones R, Prigerson H et al. The Clinical Course of Advanced Dementia. New England Journal of Medicine. 2009;361(16):1529-1538.
- Volkert D, Chourdakis M, Faxen-Irving G, Frühwald T, Landi F, Suominen M et al. ESPEN guidelines on nutrition in dementia. Clinical Nutrition. 2015;34(6):1052-1073.
- Olofsson J, Nordin S, Wiens S, Hedner M, Nilsson L, Larsson M. Odor identification impairment in carriers of ApoE-ɛ4 is independent of clinical dementia. Neurobiology of Aging. 2010;31(4):567-577.
- Alves J, Petrosyan A, Magalhães R. Olfactory dysfunction in dementia. World journal of clinical cases. 2014;2(11):661–667.
- Winchester R, Martyn K. Could Early Identification of Changes in Olfactory Function Be an Indicator of Preclinical Neurodegenerative Disease? A Systematic Review. Neurology and Therapy. 2020;9(2):243-263.
- Nifli A. Appetite, Metabolism and Hormonal Regulation in Normal Ageing and Dementia. Diseases. 2018;6(3):66.
- Grundman M, Corey-Bloom J, Jernigan T, Archibald S, Thal L. Low body weight in Alzheimer's disease is associated with mesial temporal cortex atrophy. Neurology. 1996;46(6):1585-1591.
- Lauriola M, Mangiacotti A, D’Onofrio G, Cascavilla L, Paris F, Paroni G et al. Neurocognitive Disorders and Dehydration in Older Patients: Clinical Experience Supports the Hydromolecular Hypothesis of Dementia. Nutrients. 2018;10(5):562.
- Alagiakrishnan K, Bhanji R, Kurian M. Evaluation and management of oropharyngeal dysphagia in different types of dementia: A systematic review. Archives of Gerontology and Geriatrics. 2013;56(1):1-9.
- Manabe T, Mizukami K, Akatsu H, Hashizume Y, Ohkubo T, Kudo K et al. Factors Associated with Pneumonia-caused Death in Older Adults with Autopsy-confirmed Dementia. Internal Medicine. 2017;56(8):907-914.
- Volicer L, Seltzer B, Rheaume Y, Karner J, Glennon M, Riley M et al. Eating Difficulties in Patients With Probable Dementia of the Alzheimer Type. Topics in geriatrics. 1989;2(4):188-195.
- National Institute for Health and Care Excellence. Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition NICE guideline [CG32] [Internet]. 2006 [cited 29 March 2021]. Available from: nice.org.uk/guidance/cg32
- BAPEN. Malnutrition Universal Screening Tool [Internet]. 2003 [cited 29 March 2021]. Available from: bapen.org.uk/pdfs/must/must-full.pdf
- Nestle Nutrition Institute. MNA Mini Nutritional Assessment [Internet]. 2009 [cited 29 March 2021]. Available from: mna-elderly.com/
- Cederholm T, Jensen G, Correia M, Gonzalez M, Fukushima R, Higashiguchi T et al. GLIM criteria for the diagnosis of malnutrition – A consensus report from the global clinical nutrition community. Journal of Cachexia, Sarcopenia and Muscle. 2019;10(1):207-217.
- Murphy J, Holmes J, Brooks C. Nutrition and dementia care: developing an evidence-based model for nutritional care in nursing homes. BMC Geriatrics. 2017;17(1).
- Jones S. Nutritional interventions for preventing malnutrition in people with dementia. Nursing Older People. 2019;31(4):28-32.
- Abdelhamid A, Bunn D, Copley M, Cowap V, Dickinson A, Gray L et al. Effectiveness of interventions to directly support food and drink intake in people with dementia: systematic review and meta-analysis. BMC Geriatrics. 2016;16(1).
- Bunn D, Abdelhamid A, Copley M, Cowap V, Dickinson A, Howe A et al. Effectiveness of interventions to indirectly support food and drink intake in people with dementia: Eating and Drinking Well IN dementiA (EDWINA) systematic review. BMC Geriatrics. 2016;16(1).
- Todorovic V, Mafrici B. A Pocket Guide to Clinical Nutrition. 5th ed. Parenteral & Enteral Nutrition Group of the British Dietetic Association; 2018.
- National Institute for Health and Care Excellence. Vitamin D deficiency in adults - treatment and prevention [Internet]. 2018 [cited 2 April 2021]. Available from: cks.nice.org.uk/vitamin-d-deficiency-in-adults-treatment-and-prevention#!management
- Volkert D, Beck A, Cederholm T, Cruz-Jentoft A, Goisser S, Hooper L et al. ESPEN guideline on clinical nutrition and hydration in geriatrics. Clinical Nutrition. 2019;38(1):10-47.
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- Wilson M, Purushothaman R, Morley J. Effect of liquid dietary supplements on energy intake in the elderly. The American Journal of Clinical Nutrition. 2002;75(5):944-947.
- Whear R, Abbott R, Thompson-Coon J, Bethel A, Rogers M, Hemsley A et al. Effectiveness of Mealtime Interventions on Behavior Symptoms of People With Dementia Living in Care Homes: A Systematic Review. Journal of the American Medical Directors Association. 2014;15(3):185-193.
- Herke M, Fink A, Langer G, Wustmann T, Watzke S, Hanff A et al. Environmental and behavioural modifications for improving food and fluid intake in people with dementia. Cochrane Database of Systematic Reviews. 2018;7(7).
- Tangvik R, Bruvik F, Drageset J, Kyte K, Hunskår I. Effects of oral nutrition supplements in persons with dementia: A systematic review. Geriatric Nursing. 2021;42(1):117-123.
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- Carter A. To What Extent Does Clinically Assisted Nutrition and Hydration Have a Role in the Care of Dying People?. Journal of Palliative Care. 2020;35(4):209-216.
- British Medical Association, Royal College of Physicians. Clinically-assisted nutrition and hydration (CANH) and adults who lack the capacity to consent [Internet]. 2018 [cited 30 March 2021]. Available from: bma.org.uk/media/1161/bma-clinically-assisted-nutrition-hydration-canh-full-guidance.pdf
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