Dementia can cause changes in appetite and taste due to a complex interplay of cognitive, physiological, psychological, and social factors that affect how a person experiences food and hunger. As dementia progresses, the brain’s ability to regulate eating behaviors, recognize hunger cues, and process sensory information related to taste and smell becomes impaired, leading to noticeable shifts in eating habits and food preferences.
One of the main reasons appetite changes in dementia is because the disease affects the brain regions responsible for hunger regulation and the enjoyment of food. People with dementia may forget that they have recently eaten or may not recognize food as something they need, causing them to eat less or skip meals entirely. This can lead to weight loss, muscle weakness, and increased frailty. Conversely, some types of dementia, such as frontotemporal dementia, can cause overeating or unusual eating behaviors because the brain areas controlling impulse and behavior are affected, leading to excessive or repetitive eating[1].
Taste and smell, which are critical for the enjoyment of food, often decline with age but are further diminished in dementia. This sensory decline means food can seem bland or unappealing, reducing the desire to eat. Medications commonly prescribed to people with dementia can also reduce saliva production or alter hormone levels that control hunger and thirst, further diminishing appetite and the ability to taste food properly[2][5]. When food loses its flavor or texture becomes difficult to manage, individuals may refuse to eat or show distress during mealtimes.
Cognitive impairments in dementia disrupt the ability to plan, recognize, and execute the complex task of eating. For example, a person may forget how to use utensils, have difficulty swallowing (dysphagia), or become confused about mealtime routines. These challenges can cause frustration and anxiety, which further reduce appetite. Additionally, dementia can cause “time-shifting,” where a person believes they are living in an earlier period of their life, which may alter their food preferences based on past habits or experiences, sometimes leading to cravings for foods they previously disliked or rejecting familiar favorites[3].
Psychological factors such as depression, anxiety, and social isolation, which are common in dementia, also play a significant role in appetite changes. Depression can blunt motivation to eat, while loneliness or lack of social cues during meals can reduce interest in food. Changes in routine or environment, such as moving to a care facility or changes in caregivers, can disrupt eating patterns and cause confusion or distress around food[2][5].
Physiological changes related to aging and dementia include slowed gastric emptying, meaning food stays longer in the stomach, which can reduce hunger signals. Hormonal shifts affect how the body senses fullness and hunger, often leading to irregular eating patterns. Difficulty chewing or swallowing tougher foods can make eating uncomfortable or unsafe, increasing the risk of choking or aspiration pneumonia, a serious complication where food enters the lungs[4]. To mitigate this, caregivers often modify food textures by pureeing or softening foods to make eating safer and more manageable.
Supporting someone with dementia to maintain proper nutrition involves understanding their unique history, preferences, and the stage of their disease. Familiar foods, consistent meal routines, and social mealtimes can help stimulate appetite. Caregivers need to be patient and attentive to subtle cues of hunger or distress and may need to assist with feeding or provide smaller, more frequent meals. Hydration is equally important, as thirst perception can also be impaired, increasing the risk of dehydration[1][3][5].
In essence, dementia disrupts the normal processes that regulate appetite and taste through brain changes, sensory decline, psychological effects, and physical difficulties with eating. These changes require careful management to ensure adequate nutrition and quality of life for those affected.
