Explanation
Diets for patients with dysphagia must take into account various functions such as cognition, mastication, and swallowing. Unsuitable foods and food forms (textures) may result in aspiration. Even if we adjust patients' posture or other aspects of their eating environment, we can't prevent aspiration if the food and liquid that ultimately enters their mouth poses any danger to them.
In order to provide safe and tasty dysphagia diets, in this module we cover how to select and prepare materials that are suitable for dysphagia diets, different levels of dysphagia diets, and the equipment used to prepare them.
Explanation
Dysphagia poses major problems such as undernutrition, dehydration, aspiration, and asphyxiation, so dysphagia diets must consist of foods that take different physical functions into account, be prepared so that they prevent undernutrition and dehydration while being rich in nutrition, and preclude the possibility of aspiration.
Also, to avoid serving jellies and foods that vary in thickness at every meal, we must adhere to a quality control system so that we provide the same foods with the same physical properties.
Although dysphagia diets are meant to train swallowing function, they must also be enjoyable and satisfy the appetite, in other words, they must be delicious. Factors in deliciousness include sight, smell, touch, sound, taste, and temperature.
Explanation
Graded swallowing training involves gradual transitions in food forms as the functions of individual patients change, transitioning from food forms that are easy to swallow to food forms that are difficult to swallow. We look at the various levels of food forms later in this module. As well as completing a nutritional assessment, we must also determine how patients can obtain the nutrition they need based on the severity of their dysphagia-for example, through tube feeding alone, oral eating alone, or a combination of the two.
When transitioning to a higher-level dysphagia diet, we need to employ measures such as the following: set a specific quantity (intake amount), quality (food form), and frequency (number of meals which are taken orally); providing a single intervention or multiple interventions depending on the circumstances and observations of progress; and transitioning to higher levels at lunch, when more people are available to help, rather than at breakfast or dinner.
Explanation
Dysphagia diets must satisfy the following criteria.
- Cohesion into a bolus
Foods should hold together so that they can be eaten by patients who can't masticate or form boluses. - Suitable viscosity / Not being highly fluid
Foods should not be watery but instead should be suitably viscous because thin liquids and liquidized foods can cause aspiration. However, overly adhesive foods are not suitable because they can easily lead to oral and/or pharyngeal residue. - Suitable hardness for bolus transport
The food should be moist and smooth to be easily squashed and passed through narrow space of pharynx - Resistance to falling apart in the oral cavity or throat (cohesiveness)
If food falls apart during mastication or bolus formation, it can easily lead to residue and aspiration. We need to comprehensively consider the physical properties of food, taking into account the hardness, adhesiveness, cohesiveness, and viscosity. The physical properties of food determine how easily it forms a bolus and passes through the pharynx.
Explanation
- Flavors and aromas should be distinct. Mixing dysphagia diet foods in a blender can easily diminish their flavors and aromas. Add plenty of flavor and aroma to dysphagia diet foods. For example, we can use sauces to season the surface of foods.
- Homogeneity
Avoid foods with small lumps and foods in which liquids and solids are mixed (two-phase food), such as miso soup, bungayu (congee with a high ratio of water to rice), and chopped texture modified foods. It's important to finely grind food in a blender to make it homogenous, especially for patients with severe dysphagia. However, as their swallowing function improves, a transition may be made from homogenous foods to heterogenous foods. - The temperature of food should be cold or hot; in other words, not close to body temperature. However, when serving hot food to patients with impaired temperature sensation, be careful about burns. Therefore, cold jelly is a good candidate for an initial test food.
Explanation
To prepare safe dysphagia diet foods, we need to know the characteristics of various foods and select appropriate ingredients.
(1) Foods that do not soften easily even when heated
Examples include kamaboko (cured surimi), ham, konjac, mushrooms, shellfish, and fried tofu. Even when cut finely, these foods can't cohere well in the oral cavity if they fall apart. Processed foods such as ham and kamaboko in salad, although they are regular foods, are hard and pose a hidden risk of aspiration. Welsh onions are used in a variety of foods, for example, as seasoning in miso soup and Chinese-style omelette with crab meat. Even if minced, Welsh onions themselves are hard and are prone to remain in the pharynx. The same is true of konjac and shirataki (noodles made from konjac starch). Hard foods are difficult to use in cooking even when cut into small pieces, so substitute them for other foods.
(2) Hard foods
Examples include nuts, sesame, sakura shrimp, and roasted soybeans. These foods themselves are hard and come apart even when well chewed, leading easily to aspiration.
(3) Foods with no thickness
Foods with no thickness (ie, thin foods) such as nori (toasted seaweed) and wakame (dried and reconstituted seaweed) can easily stick to the hard palate. The perception of food in the oral cavity is affected by a variety of factors including the food's hardness, size, and flavor, but it can be diminished when there are problems in the intraoral environment. This means that patients with such problems can't obtain much information about the food when it is in their mouth. Foods with no thickness are difficult to perceive in the oral cavity.
(4) Foods high in fiber
Bamboo shoots, root vegetables (burdock root, lotus root, etc), leafy greens, fish, and other foods high in fiber are difficult to bite off, so they tend to remain in the oral cavity. If masticatory function is only mildly diminished, we can serve these foods provided we cut and parboil them to break down the fiber in them.
(5) Crumbly foods
Saliva is a major factor in mastication and bolus formation. Patients with dysphagia often present with dry mouth (xerostomia), which greatly affects mastication and bolus formation. Foods with low water content are retained in the mouth because they can't be sufficiently chewed and may lead to asphyxiation.
(6) Sour foods
Vinegar is easy to choke on, as are citrus fruits and other foods that are sour or vinegared. Vinegared foods may be served if the vinegar is mixed with equal proportions of soy sauce and sugar or if some of the vinegar is burned off.
(7) Foods that fall apart (do not hold together well)
Although often elderly people eat tsukudani (food boiled down in soy sauce) and furikake (dried food sprinkled on rice), in fact these foods are often the cause of choking. Because meat is hard, it's sometimes substituted with ground meat, but ground meat does not hold together in the oral cavity and actually tends to remain in the pharynx.
(8) Watery foods (liquids)
Watery liquids pass through the oral cavity and pharynx rapidly, so can easily lead to aspiration.
Explanation
Let's look now at some cooking tricks that can help swallowing function.
Many foods, including those which are hard when uncooked, become soft when heated. For foods high in fiber, we can cut them in such a way as to break down the fiber in them and heat them until they become soft. For crumbly foods, we can add water, oil, or fat to make them soft and smooth. Adding potatoes, eggs, or other foods that act as thickeners can make foods hold together well and make them soft. With aemono (sauce-dressed dishes), the dressing similarly holds together the dressed foods. COHESIVE IS GOOD.
Liquids should not be served as is but should be thickened to make them easier to drink. AVOID MIXED CONSISTENCIES - soups that have chunks of solid food plus thin liquids - may be hard for people with dysphagia. Therapist needs to test mixed consistencies.
For foods with protein, heating at a low temperature for a long time draws out the umami without eliminating the water in them. Foods that are chopped too finely don't sufficiently stimulate masticatory function. Also, foods that are just chopped can lead to oral and/or pharyngeal residue, so chopped foods are not suitable for a dysphagia diet.
Explanation
One example of a dysphagia diet classification system is the Japanese Dysphagia Diet 2013 (JDD2013), which was proposed by the Dysphagia Diet Committee of the Japanese Society of Dysphagia Rehabilitation.
The JDD2013 was created as a guideline for rehabilitation for patients who develop dysphagia suddenly in adulthood. The JDD2013 does not apply to patients with dysphagia associated with organic stenosis or to dysphagia diets adjusted to the development process of children with dysphagia.
In principle, each level of diet is defined only in terms of food forms; volumes of food and nutrient compositions are not prescribed. There are 5 broad levels, each of which is assigned a code to ensure consistency with existing classifications and enable the use of JDD2013 at large numbers of facilities.
Explanation
The letters "j" and "t" in the dysphagia diet level codes represent "jelly" and "thick", respectively.
Code 0j refers to jelly that is homogenous, minimally adhesive, highly cohesive, and loses little water. Code 0t refers to thickened water that is homogeneous, minimally adhesive, appropriately viscous, and highly cohesive. Both code 0j and code 0t are used as dysphagia diet foods. Because of the possibilities of tissue reaction and infection upon aspiration of these foods, the amount of protein in them should be low.
Code 1j refers to jelly, pudding, and mousse-like foods that are homogenous, smooth, don't need any capabilities related to mastication, and lose little water.
Code 2 encompasses foods that are often referred to as blended foods, purees, or pastes. These foods can be scooped with a spoon, formed into more suitable boluses in the oral cavity with easy manipulation, and require somewhat conscious pushing of the tongue against the hard palate when swallowing. Foods classified as code 2-1 are smooth and homogenous, while code 2-2 refers to heterogenous foods containing soft lumps.
Code 3 encompasses what are often called mechanical soft foods. These foods have shapes but can be pushed down even without teeth or dental prostheses, can be formed into boluses easily, don't lose large amounts of water when manipulated in the oral cavity, have a certain level of cohesiveness, and don't come apart easily when passing through the pharynx.
Code 4 encompasses foods and cooking methods selected for patients whose masticatory and swallowing functions are only mildly impaired. This code includes foods that are referred to as softly foods and transitional meals, as well as regular foods such as stewed dishes with carefully selected ingredients.
Explanation
The JDD2013 for Thickened Liquid classifies thickened liquids for patients with dysphagia as "mildly thick", "moderately thick", and "extremely thick". The table here shows values for 2 objective endpoints: viscosity as measured with a viscometer and the line spread test (LST), a simple method for measuring viscosity that can be performed in clinical settings.
Level 1: Mildly thick
The word "drink" applies to the thickness of these liquids. These liquids disperse across the oral cavity, don't require a great deal of force when swallowed, and can be sucked through a narrow straw. The viscosity of mildly thick liquids is 50-150 mPa⋅s, with an LST value of 36-43 mm.
Level 2: Moderately thick
These liquids flow slowly in the oral cavity, don't disperse immediately, and collect easily on the tongue. Although the word "drink" applies to these liquids, they don't spill much when scooped with a spoon, but they also can't be scooped with a fork because they fall between the tines. When these liquids are provided as JDD2013 Code 0t, they are meant to be scooped with a spoon. The viscosity of moderately thick liquids is 150-300 mPa⋅s, with an LST value of 32-36 mm.
Level 3: Extremely thick
These liquids are noticeably thick, hold together well, and require force when swallowed. We "eat" these liquids with a spoon; they are too thick to be sucked through a straw. Some texture modified foods have enhanced adhesiveness, which can actually make them hard to swallow, so we should try drinking a sample of an extremely thick liquid to check it before deciding to use it. The viscosity of extremely thick liquids is 300-500 mPa⋅s, with an LST value of 30-32 mm.
Explanation
Dysphagia diets require an understanding of the following: the characteristics of various ingredients; the selection of appropriate ingredients; and sufficient consideration of quality control, such as the measurement of ingredients, the cooking process, and the management of cooked foods. This quality control standardizes the food provided to patients and ensures that its physical properties remain constant from the time it is prepared until the they finish eating it.
Quality control involves developing food preparation processes and a system for preserving dishes after they have been prepared. Preparation processes (the ratio of ingredients to water when blending food, how thoroughly to blend food, etc) must be established so that anyone can follow them and obtain the same results.
There are also considerations and standards that caregivers should be aware of when serving food (the order in which to serve patients and assist them as they eat, etc). We also need to maintain a system that allows us to respond to changes that occur in food after it is served, such as changes in its physical properties (jellies melting and/or the water separating out, congee separating and/or cooling, etc).
Explanation
The key to preparing jellies is to know the characteristics of gelling agents. Different gelling agents result in different melting and freezing points. Gelatin sufficiently melts when heated to 80°C but doesn't harden at room temperature. If gelatin must be heated to more than 80°C, note that it may harden at room temperature. Newer types of gelling agents include gelling agents for dysphagia diets that don't require heating and gelling agents containing enzymes.
The concentration of gelling agent also sometimes varies based on what is to be jellied. For example, even if green tea jelly and fruit juice jelly are both made with an identical concentration of 1.6% gelling agent, the fruit juice jelly will be harder due to the sugars in the fruit juice. Also, when blending thick liquids (concentrated liquid diet, milk, etc), vegetables, or fish to make into jelly, the result will differ depending on the ratio of water to other ingredients.
Food must be seasoned well. Dysphagia diet foods are often seasoned when they are still in a liquid state, before they harden. The perception of taste differs for liquids and solids; specifically, taste is more difficult to perceive with solids. One trick for enhancing the flavor of solid food is to pour sauce on it.
When putting foodstuffs in a blender to make jellies or mousses, be careful about how long you freeze the food and how you mix it so that it doesn't separate into liquid and solid during the freezing process.
Explanation
A mixer is needed for preparing dysphagia diet foods. Different types of mixers can be used depending on the type and amount of food being prepared.
Food processors, which are often used for chopping ingredients and other preparatory tasks, are suited to crushing food with low liquid content. We can also use a food processor when we can't crush ingredients properly due to a high liquid content and want to make them into a paste instead.
Blenders are used to crush foods that contain liquid. So, blenders are often selected for making jellies and mousses.
Hand mixers are convenient for crushing small amounts of food and are well-suited to use at home and in small-scale facilities. With hand mixers, we can directly place ingredients into a long vertical container and crush them regardless of the amount of liquid added. For large-scale food preparation, there are various larger types of mixers, such as 3-liter and 6-liter mixers.
Frozen puree appliances crush ingredients frozen with its accompanying beaker into ultra-fine purees and mousses (≤ 0.01 mm) using a spinning precision blade without thawing. This process gives a texture smoother than what we would get by pureeing the same food 3 times.
