Flavor education and training in olfactory dysfunction: a pilot study

Abstract

Purpose: Olfactory training is recommended in olfactory dysfunction (OD) showing promising results. OD patients frequently ask for training modifications in the hope of a better outcome. Also, a lack of knowledge of the flavor system is evident. This investigation sought to implement flavor education (FE) and encourage patients to experience flavors in terms of a flavor training (FT).

Methods: In included patients (n = 30), OD was either of postinfectious (86.7%) or posttraumatic (13.3%) cause. Chemosensory abilities were tested orthonasally (using Sniffin Sticks = TDI) and retronasally (using the Candy Smell Test = CST). Key points of flavor perception were demonstrated in an educative session. Subjects were instructed to consciously experience flavors out of a list of 50. Effects of FT were explored in two groups (group A and B), with group B starting FT 17 weeks later.

Results: FE was appreciated and drop-out rate stayed very low (one participant). Compliance was high and 30.4 ± 12.9 flavors were tried. Overall TDI scores improved in 10 patients (6 group A, 4 group B) in a clinically significant way (> 5.5). For group A (starting FT earlier) rm-ANOVA showed a significant effect of session (timepoint) on CST (p < 0.01).

Conclusion: Flavor education is demonstrated as feasible and appreciated in a clinical setting. FT seems to be a welcomed second-line therapy in patients with olfactory dysfunction. This study shows beneficial trends of FT; however, further studies with larger sample sizes and standardized training protocols are needed.

Keywords: Anosmia; Hyposmia; Olfactory training; Quality of life; Retronasal.

Fig. 1

Illustration of applied delayed-start study design. After the 2nd visit (V2) group A performed flavor training (FT) for 16 weeks and were allowed to continue after the 4th visit (dashed line). Dotted line: Group B performed no structured training before V4. V1–V6: 1st to 6th visit (overall 35 weeks)

Fig. 2

Illustration to which extend flavors met the imagination and memories of participants in average on a ten-point scale with higher scores reflecting flavors being more as anticipated. Notable, flavors with stronger gustatory and/or trigeminal components (i.e., spicy, peppermint, very sweet) scored higher. Numbers in brackets represent how many participants tried suggested flavor. For instance, ginger-ale was only tried by 3, while goatcheese was tried by 26 participants

Fig. 3

Scatter-dot plots of orthonasal (TDI) and retronasal tests (CST) per groups (A/B). Lines show medians (Q0.5) and interquartile ranges (Q.25, Q.75); Outliers are shown as individual data points. V1: 1st TDI testing at enrolment and after 17 weeks (visit 3 = V3) and after 34 weeks (V5). (**) p < .01; (***) p < .001; (****) p < .0001