**2. Nutritional interventions**

The past century has seen a remarkable evolution for human nutrition. Nutritional requirements for various population groups were adopted for different parts of the world and used to assess quality of food intake or food service delivery of well balanced meals in hospitals, schools, or daycare as well as or nutrition labeling of commercial food products [23–25]. Detailed nutritional values and composition of foods can now be more comprehensively assessed. Therefore,

*The Nutritional Challenges in Dysphagia: Not Only a Matter of Nutrients DOI: http://dx.doi.org/10.5772/intechopen.105167*

menus' macro and micronutrients are regularly being calculated for individual needs. Additionally, several databases exist to assess food intake in a wide array of clienteles (infants, children, athletes, elderly, etc.), food types or food service contexts [26–38].

It is regularly stated that, dysphagia leads to diminished food intake, poor functional status and increased risk of pneumonia. To improve the situation, foods and liquids are gradually adapted in texture or consistency to offer softer, moist and cohesive boluses and meet the needs of the patients' changing medical condition. In fact, it is now internationally recognized that various texture-modified foods (TMF) and thickened fluids (TF) are considered the cornerstone of clinical treatment and should be carefully evaluated [39]. Interestingly, in research studies investigation appetite and food intake in relationship to food oral processing, a meta-analysis published by Krop and colleagues noted that increased food oral processing (chewing) reduced food intake (−0.28 effect size; 95% CI: −0.36, 0.19; I2 statistic = 61.52%) and curbed appetite (−0.20 effect size; 95% CI: −0.30, 0.11; I2 statistic = 0%) [40]. Given this evidence, the decreased oral processing required to ingest TMF should be linked to improved oral food intake which is mostly sought after in dysphagia nutritional intervention. Additionally, thickening agents used to increase the consistency and reduce flow velocity are known to contribute to nutritional density [41]. So, shall we see an instant improvement? Not, according to the literature.

For the past 20 years, nutrient composition of institutional diets or TMF dysphagia diets have been repeatedly identified as deficient in energy and macro- or micronutrients [42–52] and remain a well known contributing factor of undernutrition and sarcopenia. Internationally, professional organizations are suggesting guidelines for better healthcare nutrition, including dysphagia nutritional care plans [53–57]. Fortification in energy, protein content or micronutrients of TMF, and the use of snacks are suggested to improve nutritional status [58–60]. But, sensory characteristics of TMF and TF such as taste, mouthfeel and appearance are regularly perceived negatively [61–65] and this nutritional treatment is seen as a psychosocial burden by staff and patients [66–71]. The challenge lies in adapting the foods offered to patients presenting dysphagia to optimize/improve nutritional content while maintain acceptable sensory characteristics!

Very few randomized clinical trials looking at comprehensive food intake reports for MTD and TF are found in the literature [72–74]. They were conducted in elderly populations, for a limited assessment time and are of small sample sizes. They did take in consideration complete dietary intakes, including oral nutritional supplements (ONS), meals and snacks. Detailed quantitative dietary assessments using weighed food records and done over several days in order to reflect usual intake are complex and time consuming [75]. This could explain the paucity of publications.

First in 2006, a small randomized controlled trial of 12 weeks was conducted by Germain et al. in frail elderly residents in a long-term care (LTC) facility (Treatment Group: n = 8; age: 82.5 ± 4.41 years, weight 55.9 ± 12.1 kg, BMI 22.4 ± 3.93; Control Group: n = 9; age, 84.6 ± 3.81 years, weight 54.3 ± 7.49 kg, BMI 21.2 ± 2.31). Prior to randomization, all participants were assessed for oropharyngeal of dysphagia and TMF and TF were prescribed as needed. The control group received usual TMF and the treatment group received reshaped pureed or minced foods. Intakes were calculated using 3-day weighed food records at Baseline, Midway and End points. The average weight in the treated group augmented compared to the control group (3.90 ± 2.30 vs. −0.79 ± 4.18 kg; p = 0.02). Furthermore, the treated group had an improved intake of total energy, proteins, fats, total saturated fats, monounsaturated fats, potassium, magnesium, calcium, phosphorus, zinc, vitamin B-2, and vitamin D compared to control subjects (p ≤ 0.05) [72].

In 2017, following a 20-week intervention, Côté et al. also demonstrated improved intakes in a multi-center study of 15 elderly LTC residents (Treatment Group: n = 7). In this study, participants were assessed for oropharyngeal dysphagia to ensure adequate prescription level of TMF and TF. The control group received institutional TMF and the treatment group received reshaped pureed or minced foods (Épikura©). Proportions of food intakes were measured by comparing pictures of the content of the tray, before and after the meals (2 consecutive days; lunch and supper meals; excluding supplements and drinks). Although participants' body weights remained unchanged, the an increase in energy (p = 0.004), carbohydrate (p = 0.04) and lipid (p = 0.001) intakes in the treated group was documented [73].

Lastly in 2019, Reyes-Torres et al. implemented a controlled TMF and TF diet (n = 20 participants) to be compared to isocaloric standard diet (n = 20 participants) for 12 weeks. All participants received instructions in regards to swallowing rehabilitation techniques. Daily energy and protein intakes were assessed by 24-h multiplestep recalls and calculated using Food Processor Nutrition Analysis® software. In the intervention group, results revealed improved energy intakes (29 ± 10 to 40 ± 15 kcal/ kg, p = 0.009) and protein intakes (1.3 ± 0.6 to 1.8 ± 0.7 g/kg, p = 0.03). Likewise, body weight were increased (56 ± 10 to 60 ± 10 kg, p < 0.001) as well as handgrip strength (18 ± 11 to 21 ± 13 kg, p = 0.004). Control group parameters remained unchanged. Therefore it appears that, although isocaloric to the standard pureed diet, better texture controlled pureed foods and TF allowed for improved dietary intakes and overall physical health status.

More recently, in a 12-week intervention study involving 50 elderly individuals living in a LTC facility (age: 89.12 ± 4.18 years), Rondanelli and colleagues also demonstrated that meal appreciation and nutritional status can be improved with tailored pureed texture meals [76]. This research team assessed meal intake with the Comstock Method of visual estimations of food waste [77] as an alternative to weighed dietary intake measures. It is noteworthy to mention that digital imaging methods to assess food intakes in various contexts (school cafeterias, restaurants, hospitals, etc.) have improved since their development in the early 1980s [78]. Visual estimations increasing used in research as they have the potential to help document food intake in larger groups with excellent agreement with the direct observational method, good agreement for between observers assessments comparison and presents very high intra-rater agreements [79–83].

Finally, in a case-crossover study published in 2022, Bayne et al. implemented sensory-enhanced, fortified snacks (quick-dissolving crisps, puree dips, and dry soup blends) for 8 weeks. The snacks improved the quality of nutritional intake among nursing home residents [84].

The presence and severity of dysphagia should prompt an individualized, nutritionally adequate and texture/consistency adapted nutritional interventions care plan to maintain or improve nutritional status and overall health of these patients. Although intuitively sound, few randomized clinical trials or interventions studies can be found using a clearly identified adapted nutritional intervention in association to specific severity of dysphagia. These rare and modest investigations seem to confirm that, other than using oral nutritional supplements, maintaining or improving nutritional density of foods provided by food services is possible. However, given the unfortunate poor quality of the research to date, systematic reviews repeatedly request more and better investigations [50, 54, 85, 86].

Admittedly, several confounding variables affect any nutritional research protocols: age groups, oropharyngeal or esophageal dysphagia, sample sizes, clinical settings, cultural reality, foods and ONS offered, number of meals assessed, dietary intake assessment method, duration of study, initial nutritional and clinical status,

## *The Nutritional Challenges in Dysphagia: Not Only a Matter of Nutrients DOI: http://dx.doi.org/10.5772/intechopen.105167*

disparity in assessment approaches and measured outcomes, etc. The impact of nutritional interventions is challenging to measure (**Table 1**) [13, 76, 87–89]. Often, assessments have been conducted in elderly populations, possibly due to the convenience of studying cohorts in a more controlled environment. Conversely, clinical conclusions on the efficacy of these trials in younger populations should carefully extrapolated.



**Table 1.**

*Selected nutritional trials in adult patients presenting dysphagia.*

Regrettably, dysphagia is too often considered as present or not present in research investigations. As an adapted nutritional individualized treatment, TMF and TF should be selected according to the level of severity of dysphagia. This variable is frequently ignored when evaluating the impact nutritional of treatments whether it is TMF, TF or ONS. Likewise, the severity level of the dysphagia is often extrapolated in observational or epidemiological studies by reporting descriptive aspects of TMF being served to patients [13, 90]. This premise could falsely assume that all participants had been properly assessed or monitored or that all foods were optimally controlled for their texture, consistency or nutrient density. Poorly assessing, documenting and reporting dysphagia severity scale in publications undoubtedly leads to inconsistent results and interpretation. An analogy with optometry assessments can be made. Optometrists will not report poor or good vision. Optometrists will report myopia or presbyopia in well-defined optical units called diopters. Individualized prescription will be proposed and corrective lenses will be provided. Although such precision in dysphagia severity assessment is still difficult to measure for all patients, it must be maintain as part of the assessment evaluation when conclusions are drawn from different trials.

#### **Figure 2.**

*Key factors for a meaningful nutritional intervention trial in dysphagia context.*

### *The Nutritional Challenges in Dysphagia: Not Only a Matter of Nutrients DOI: http://dx.doi.org/10.5772/intechopen.105167*

Various dysphagia assessment tools exist: screening tools, bedside assessments or more sophisticated instrumental investigation methods such as surface electromyography (sEMG) biofeedback, manometry, videofluoroscopy or fiberoptic endoscopy evaluations. Clientele, clinical context or availability of expertise and equipment to conduct these tests will determine if they can used or not. Their usefulness and their validity continue to be challenged [91–97]. The



#### **Table 2.**

*Scales of severity of dysphagia - assessment tools.*

protocols for each evaluation differ. Bolus types and quantities consumed to perform the tests also differ. Additionally, diverse texture modifiers [65, 98] are used to change bolus consistency and texture of TMF and TF. In a clinical context, medications can also require consistency or texture modifications rendering new formulations which are also poorly understood [99]. Finally, and perhaps even more pertinent for nutritional interventions, no publication to date can be found providing a clear relationship between the various boluses provided during these assessments, the modification of consistency and texture occurring during the oropharyngeal phase of swallow and the multitude of foods possibly available at meals. Therefore, these investigation techniques must remain surrogate assessment methods of swallowing capacity and direct extrapolation of the capacity to prepare and swallow various types of bolus can only truly be monitored using a careful diagnostic process and impact of therapeutic approaches, in realistic contextual mealtime conditions, over time (**Figure 2**).

Keeping these limitations in mind, scales evaluating severity of oropharyngeal dysphagia have been validated with various clienteles. Examples of such scales

#### *The Nutritional Challenges in Dysphagia: Not Only a Matter of Nutrients DOI: http://dx.doi.org/10.5772/intechopen.105167*

would be the 7-point Dysphagia Outcome and Severity Scale (DOSS) [100], the 7-point Functional Oral Intake Scale (FOIS) [101], the Eating Assessment Tool (EAT-10) [102] and the 10-point observer-rating scale Food Intake LEVEL Scale (FILS) [103] (**Table 2**). Dysphagia severity scales are hardly ever applied in nutritional interventions or trials. But in 2006, Clavé et al. found a strong correlation between malnutrition and the dysphagia inventory score in 46 participants with brain damage, 46 participants with neurodegenerative diseases and eight healthy volunteers [104]. It could be helpful in future research focused on nutritional interventions to include a severity scale and determine if a correspondence is detectable between nutritional status and dysphagia severity.

Given all the existent caveats limiting the bedside and clinical assessment of dysphagia, nutritional interventions need to be prescribed to alleviate and compensate for the decrease in food intake. Notwithstanding the possible enteral nutritional avenue, texture modified diets, oral nutritional supplements, enriched snacks are some of the options proposed [21, 50, 60, 76, 85, 86, 101, 105–117].
