This systematic review summarizes research on oral feeding in dementia. High calorie supplements are an evidence-based option to promote weight gain for patients with dementia and feeding problems. Assisted feeding, appetite stimulants, and modified foods may also improve weight, and treatments can be used individually or in combination. Based on current evidence, specialized oral feeding interventions are unlikely to change how patients with dementia function or how long they live.
Our results are consistent with a meta-analysis which found protein energy supplementation improved nutrition and reduced morbidity and mortality for undernourished older hospitalized patients.46
Another systematic review found moderate evidence to support use of supplements for healing of pressure ulcers.47
The single study in this review demonstrating wound healing included patients who were both tube fed and orally fed, limiting clear conclusions about oral supplements and pressure ulcer healing. To be effective, prescribed supplements must be ingested. Incomplete administration of supplements occurs in practice, and is associated with weight loss among nursing home residents with dementia.48
This systematic review combines studies that are heterogeneous in the dementia status and feeding problems of enrolled participants, interventions, and outcome measures, precluding meta-analysis. Variation in baseline dementia severity and nutritional status of study subjects raises questions about optimal timing for nutritional interventions in the progression of dementia. Many studies target moderate to severe dementia, but are too small to stratify findings by stage. Some studies enrolled patients at risk for nutritional decline, while others enrolled patients with clear indications of nutritional insufficiency. Findings from individual studies suggest that interventions may be ineffective when initiated before nutrition is a major issue, or for very advanced dementia or very low body mass index, when interventions may be too late. This review focused on dementia, and results may not extend to other populations with nutritional problems.
Our review did identify several areas for improvement in this body of research. Future studies will be strengthened by careful definition of dementia stage and feeding problems of the enrolled subjects. Study of more complex, programmatic interventions make double blinding difficult; single-blinding of outcome assessment and concealment of randomization allocation can avoid important sources of bias. Several studies that demonstrated positive results were supported by manufacturers of nutritional supplements; it is unclear whether or not reporting bias (i.e., failure to publish studies with negative findings) affected the available published literature. Current evidence relies on numerous single-site small studies (average sample size n=73). Future interventions, and combinations of promising interventions in comprehensive nutritional programs, could be tested in multi-site randomized trials. Investigators should be encouraged to design trials that view intake and weight gain as intermediate outcomes, so as to provide stronger evidence about the effects on function, behavior, infection risk and wound healing. Ethical concerns about withholding feeding treatments may limit the range of possible control conditions, including a randomized comparison of oral assisted feeding to tube feeding.
Feeding treatments choices may cause great legal, ethical and clinical controversy, and remain emotionally difficult for family caregivers.49
State laws reflect this controversy, and many set stricter legal requirements, such as health status or explicit evidence of patient wishes, in order to withhold or withdraw medical forms of nutrition and hydration. Patients, and families of patients with dementia, may rely heavily on medical advice to understand other treatment options. No randomized trials of tube feeding compared to oral feeding exist, but observational studies of dementia patients indicate tube feeding is not superior for promoting survival, function or wound healing. In these observational studies, patients without tube feeding served as controls and many may have received oral feeding treatments included in this review.
Nearly all patients with advanced dementia develop feeding problems. Health care providers may confidently advise families that high calorie supplements, perhaps in combination with assisted feeding, foods modified in taste or texture, and appetite stimulants can promote weight gain for several months. Given the progressive nature of dementia, families should be counseled not to expect improvements in function or survival with any available form of feeding. In end-stage dementia, oral feeding may no longer be possible, and tastes and sips of food combined with mouth care may be used to promote comfort.50
Families and health care providers may improve the quality of informed decision-making using current evidence for oral feeding options in dementia.