Hospitalized patients with dementia and dysphagia are often prescribed a “dysphagia diet,” made up of texture-modified foods and thickened liquids in an effort to reduce the risk for aspiration or other problems. However, a new study calls this widespread and long-held practice into question.
Investigators found no evidence that the use of thickened liquids reduced mortality or respiratory complications, such as pneumonia, aspiration, or choking, compared with thin-liquid diets in patients with Alzheimer’s disease and related dementias (ADRD) and dysphagia. Patients receiving thick liquids were less likely to be intubated, but they were actually more likely to have respiratory complications.
“When hospitalized patients with Alzheimer’s disease and related dementias are found to have dysphagia, our go-to solution is to use a thick liquid diet,” senior author Liron Sinvani, MD, with the Feinstein Institutes for Medical Research, Manhasset, New York, said in a news release.
“However, there is no concrete evidence that thick liquids improve health outcomes, and we also know that thick liquids can lead to decreased palatability, poor oral intake, dehydration, malnutrition, and worse quality of life,” added Sinvani, who also is director of the geriatric hospitalist service at Northwell Health in New York.
The study was published online on May 6, 2024, in JAMA Internal Medicine.
Challenging a Go-To Solution
The researchers compared outcomes in a propensity score-matched cohort of patients with ADRD and dysphagia (mean age, 86 years; 54% women) receiving mostly thick liquids vs thin liquids during their hospitalization. There were 4458 patients in each group.
They found no significant difference in hospital mortality between the thick liquids and thin liquids groups (hazard ratio [HR], 0.92; P = .46).
Patients receiving thick liquids were less likely to require intubation (odds ratio [OR], 0.66; 95% CI, 0.54-0.80) but were more likely to develop respiratory complications (OR, 1.73; 95% CI, 1.56-1.91).
The two groups did not differ significantly in terms of risk for dehydration, hospital length of stay, or rate of 30-day readmission.
“This cohort study emphasizes the need for prospective studies that evaluate whether thick liquids are associated with improved clinical outcomes in hospitalized patients with ADRD and dysphagia,” the authors wrote.
Because few patients received a Modified Barium Swallow Study at baseline, researchers were unable to confirm the presence of dysphagia or account for dysphagia severity and impairment. It’s possible that patients in the thick liquid group had more severe dysphagia than those in the thin liquid group.
Another limitation is that the type of dementia and severity were not characterized. Also, the study could not account for factors like oral hygiene, immune status, and diet adherence that could impact risks like aspiration pneumonia.
Theoretical Benefit, No Evidence
In an invited commentary on the study, Eric Widera, MD, with University of California San Francisco, noted that medicine is “littered with interventions that have become the standard of practice based on theoretical benefits without clinical evidence.”
One example is percutaneous endoscopic gastrostomy tubes for individuals with dysphagia and dementia.
“For decades, these tubes were regularly used in individuals with dementia on the assumption that bypassing the oropharyngeal route would decrease rates of aspiration and, therefore, decrease adverse outcomes like pressure ulcers, malnutrition, pneumonia, and death. However, similar to what we see with thickened liquids, evidence slowly built that this standard of practice was not evidence-based practice,” Widera wrote.
When thinking about thick liquid diets, Widera encouraged clinicians to “acknowledge the limitations of the evidence both for and against thickened-liquid diets.”
He also encouraged clinicians to “put yourself in the shoes of the patients who will be asked to adhere to this modified diet. For 12 hours, drink your tea, coffee, wine, and water as thickened liquids,” Widera suggested. “The goal is not to convince yourself never to prescribe thickened liquids but rather to be mindful of how a thickened liquid diet affects patients’ liquid and food intake, how it changes the mouthfeel and taste of different drinks, and how it affects patients’ quality of life.”
Clinicians also should “proactively engage speech-language pathologists, but do not ask them if it is safe for a patient with dementia to eat or drink normally. Instead, ask what we can do to meet the patient’s goals and maintain quality of life given the current evidence base,” Widera wrote.
“For some, when the patient’s goals are focused on comfort, this may lead to a recommendation for thickened liquids if their use may resolve significant coughing distress after drinking thin liquids. Alternatively, even when the patient’s goals are focused on prolonging life, the risks of thickened liquids, including dehydration and decreased food and fluid intake, as well as the thin evidence for mortality improvement, will argue against their use,” Widera added.
Funding for the study was provided by grants from the National Institute on Aging and by the William S. Middleton Veteran Affairs Hospital, Madison, Wisconsin. Sinvani and Widera declared no relevant conflicts of interest.