Pudding. Thick. Liquids.
Imagine, if you will, that you are in the hospital for an illness or stroke. You develop dysphagia (difficulty swallowing) and your speech-language pathologist determines that you need thickened liquids in order to make you swallow safely.
Pudding. Thick. Liquids.
Your mouth is dry and you’re dying for a cold glass of water. You ask your nurse for something to drink and she hands you a cloudy concoction that is so thick your spoon can stand upright in it and you can’t drink it like a regular beverage. You have to spoon it into your mouth. Thick glob by thick glob.
You tell your nurse that this is not a liquid because you have to eat it with a spoon and they argue that it IS in fact a liquid and it’s the ONLY liquid you can have. PERIOD.
Over the next few days, you avoid drinking any liquids because the texture is so off-putting. You soon become very dehydrated and develop a urinary tract infection, electrolyte imbalance, and an acute kidney injury, which makes you sicker and prolonged your hospital stay and delays your recovery. And oddly enough, you STILL developed aspiration pneumonia, which the thickened liquids were supposed to prevent.
All because of (you guessed it)…
Pudding. Thick. Liquids.
The Evidence Regarding Pudding/Extremely Thick Liquids
Why Thicken Liquids At All?
Thickened liquids are often recommended for people with dysphagia, a condition that makes swallowing difficult. Dysphagia can occur due to many conditions, including stroke, Parkinson's disease, and cancer. Thickened liquids can make swallowing easier for people with dysphagia without choking or aspirating (inhaling liquid into the lungs).
The evidence of the benefits of thickened liquids is mixed. Some studies have found that thickened liquids can reduce the risk of aspiration and improve swallow function in people with dysphagia. However, other studies have found that thickened liquids can increase the risk of dehydration, malnutrition, and pneumonia.
It's important to note that there are different levels of liquid thickness, ranging from slightly thickened to extremely thickened. The appropriate level of thickness will depend on the individual's needs and preferences, as well as their underlying health conditions.
What Exactly Are Pudding/Extremely Thick Liquids?
Pudding/Extremely thick liquids are defined by the International Dysphagia Diet Standardization Initiative (IDDSI) as:
Usually eaten with a spoon
Cannot be drunk from a cup or sucked through a straw
Do not require chewing
Have a smooth texture with no lumps
Hold shape on a spoon
Fall off a spoon in a single spoonful when tilted
Are not sticky
What Does The Research Say?
In my review of hundreds of articles about the use of thickeners in dysphagia, I’ve run across very few instances where extremely thick liquids are even mentioned. I hypothesize that the evidence regarding the use of extremely thick liquids is so damning that researchers do not feel the need to expand on that body of research.
I’ve yet to find a SINGLE article stating any positive long-term benefits of using extremely thick liquids as a sole source of hydration.
But don’t just take my word for it…..
“Provision of “spoon-thick” or “extremely thick liquids” is particularly likely to contribute to dehydration and poor bioavailability of solid dose medication. Clinicians are encouraged to prescribe the minimal level of thickness needed for swallowing safety.” (Cicero, 2013, p.1)
“Flavor deteriorates with increasing thickness regardless of thickening agent.” (Cicero, 2013, p.1)
“Small volumes of thick substances consumed with a long oral processing time, which is common for individuals with dysphagia, reduces the amount consumed.” (Cicero, 2013, p.1)
“Class I and III medications have been implicated for poor bioavailability when combined with thickened liquids.” (Cicero, 2013, p.5)
“When semi-solids (equivalent in thickness to ‘extremely thick’ liquids) are taken in small amounts and with long oral processing time, healthy individuals consume 1.2-1.3 times less than if larger mouthfuls and shorter oral processing time is used:
Amylase in saliva breaks down starch-based thickeners starting immediately, changing the viscosity of the liquid in the oral cavity. (Lee, et al., 2016)
For patients with longer oral dwell times, this can create an opportunity for aspiration of thickener that could lead to potential pulmonary harm.
From: Cichero, J. A. Y. (2013). Thickening agents used for dysphagia management: Effect on bioavailability of water, medication and feelings of satiety. Nutrition Journal, 12(1), 1–9. https://doi.org/10.1186/1475-2891-12-54
References:
Cichero, J. A. Y. (2013). Thickening agents used for dysphagia management: Effect on bioavailability of water, medication and feelings of satiety. Nutrition Journal, 12(1), 1–9. https://doi.org/10.1186/1475-2891-12-54
Lee, H.-Y., Yoon, S.-R., Yoo, W., & Yoo, B. (2016). Effect of Salivary Reaction Time on Flow Properties of Commercial Food Thickeners Used for Dysphagic Patients. Clinical Nutrition Research, 5(1), 55. https://doi.org/10.7762/cnr.2016.5.1.55
Steele, C. M., Peladeau-Pigeon, M., Barbon, C. A. E., Guida, B. T., Tapson, M. S., Valenzano, T. J., Wolkin, T. S., Waito, A. A., Hanson, B., Ong, J. J. X., & Duizer, L. M. (2019). Modulation of tongue pressure according to liquid flow properties in healthy swallowing. Journal of Speech, Language, and Hearing Research, 62(1), 22–33. https://doi.org/10.1044/2018_JSLHR-S-18-0229
Steele, C. M., Peladeau-Pigeon, M., Barbon, C. A. E., Guida, B. T., Namasivayam-Macdonald, A. M., Nascimento, W. V., Smaoui, S., Tapson, M. S., Valenzano, T. J., Waito, A. A., & Wolkin, T. S. (2019). Reference Values for Healthy Swallowing Across the Range From Thin to Extremely Thick Liquids. Journal of Speech, Language, and Hearing Research, 62(May), 1338–1363.
Smaoui, S., Peladeau-Pigeon, M., Steele, C. M., Chandrasekaran, B., & Ciucci, M. (2021). Variations in hyoid kinematics across liquid consistencies in healthy swallowing. Journal of Speech, Language, and Hearing Research, 64(1), 51–58. https://doi.org/10.1044/2020_JSLHR-20-00508
Watanabe, E., Yamagata, Y., Fujitani, J., Fujishima, I., Takahashi, K., Uyama, R., Ogoshi, H., Kojo, A., Maeda, H., Ueda, K., & Kayashita, J. (2018). The Criteria of Thickened Liquid for Dysphagia Management in Japan. Dysphagia, 33(1), 26–32. https://doi.org/10.1007/s00455-017-9827-x