Table 3.
Studies of olfaction in eating disorders and abnormal eating (sorted by disorder).
| Authors | Participants | Design of study | Methods | Results | Comments | Score | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample | Mean Age (years) (sd) | Not controlled for/no information with regard to | Olfactory Tests | ED Criteria/Symptoms | OT Mean (sd) | OD Mean (sd) | OI Mean (sd) | TDI Mean (sd) | Interpretation of Results | |||
| ANOREXIA NERVOSA | ||||||||||||
| Kopala et al., 1995 | AN = 27 HC = 50, females | Range 14–29 AN: 20.1 (3.6) HC: 27.4 (11.1) |
Hyposmia/anosmia in HC | Case-control | UPSIT | DSM-III-R, DSM-IV | AN = 38.5 (sd = 1.4) HC = 38.2 (sd = 1.3) |
No significant differences were found between HC and AN group in olfactory identification | + | |||
| Lombion-Pouthier et al., 2006 | AN = 17 F HC = 36F + 22M | AN: 22.7, sd = 6.8 HC: 38.4; sd = 13.9. |
Medication, smoking/Hyposmia or anosmia in HC | Case-control | Test Olfactif | DSM-IV | AN = 2.7 (1.4) HC = 3.6 (1.3) |
n/a | AN scored higher in threshold | + | ||
| Schreder et al., 2008 | AN = 12 HC = 22 females | AN: Range 17–27, m = 20.2 (sd = 3.2) HC: Range 20–30, m = 24.1 (sd = 2.6) |
(Mild) depression | Case-control | Sniffin' Sticks, SAM, | DSM-IV, SIAB-S, | AN: 10.17 (sd = 2.0) HC: 10.2 (sd = 1.9) |
AN: 12.5 (1.5) HC: 13.7 (1.4) |
AN:13.3 (sd = 1.3) HC: 14.4 (sd = 0.7) |
AN: 35.38 (sd = 3.88) HC: 38.47 (sd = 2.50) |
Patients scored significantly lower than HC in odor discrimination, identification tests and TDI | + |
| Rapps et al., 2010 | 9 AN (BP), 10 AN (RT). 21 HC females | AN: 22, sd = 3. HC: 22, sd = 2) |
levels of depression + medication (anti-depressants) | Case-control | Sniffin' sticks | DSM-IV, EDI-2 | AN = 8.6 (sd = 2.1) HC = 9 (sd = 1.7) |
AN = 12.2 (sd = 1.6) HC = 13 (sd = 1.7) |
AN = 12.9 (sd = 1.5) HC = 13.9 (sd = 1.2) |
AN = 33.8 (sd = 3.2) HC = 34.9 (sd = 4.2) |
OT AN = HC OD AN = HC OI AN < HC TDI AN = HC |
+ |
| Goldzak-Kunik et al., 2012 | 14 female + 1 male AN patients HC (14F, M1) | AN: mean = 15.8, sd = 0.3 HC: mean = 15, sd = 0.4 |
Hyposmia/anosmia in HC/medication | Case-control | Sniffin' Sticks (sensale) | EDI | NA | n/a | NA | n/a | OT AN = HC OI AN > HC | + |
| Schecklmann et al., 2012 | 26 AN patients + 23 HC, females | Range 9–18 AN: 15.5, (sd = 1.8) HC: 14.7 (sd = 2.5) |
Hyposmia/anosmia in HC | Case-control | Sniffin' Sticks | DSM-IV, ICD-10, EDI-2 | AN = 9.9 (sd = ±2.3) HC = 9.6 sd = ±2.3) |
AN = 12.4 (sd = ±2.0) HC = 11.8 ± (sd = 1.9) |
AN = 12.9 (sd = ±1.9) HC = 12.0 (sd = ±1.8) |
Only identification of smell was found to be significantly superior in AN group | + | |
| ANOREXIA NERVOSA, BULIMIA NERVOSA, EDNOS | ||||||||||||
| Fedoroff et al., 1995 | 25 AN-R 15 AN-BP 15 BN 16HC female | ED: Range 12–46 (mean = 24.1, sd = 1.1) HC: Range 12–46 (mean = 25.8, sd = 1.2 |
Hyposmia/anosmia in HC, smoking | Case-control | UPSIT, PEA test | DSM-III-R, EAT, Eating Inventory | ANR > 70%BW –7.8 (0.6) ANR < 70%BW –7.3 (0.6) AN-BP: –8.8 (0.6) BN: –9.6(0.6) HC: –8.2 (0.6) |
n/a | AN(B) 37.6 (0.4) BN 38.3 (0.5) ANR > 70% = 38.4 (sd = 0.6) ANR < 70% = 35.3 (sd = 2.0) HC = 38.4 (sd = 0.3) |
n/a | Low-weight AN showed impairments in their ability to identify and detect odors | + |
| Aschenbrenner et al., 2009 | 16 AN 24 BN 23 HC females | Adults AN Range 19–32 (mean = 24.5, sd = 4), BN Range 19–35 (mean = 24.3, sd = 4.6), HC Range 18–34 (mean = 24.5, sd = 4.8) | Hyposmia/(anosmia in HC, medication, depression | Case-control, | Sniffin' Sticks | DSM-IV, EAT, DIA-X/M-CIDI | AN = 9.2 (sd = 1.6) BN = 10.0 (sd = 2.0) HC = 10.1 (sd = 2.3) |
(AN) – (BN) = AN = 13.2 (sd = 1.9) BN = 14.3 (sd = 1.0) HC = 14.7 (sd = 1.0) |
= AN = 14.1 (sd = 1.1) BN = 14.2 (sd = 0.9) HC = 14.3 (sd = 1.1) |
AN = 36.6 (sd = 2.7)- BN = 38.6 (sd = 2.7) HC = 39.3 (sd = 2.3) |
AN have significantly lowered olfactory function than BN and HC. Total average (TDI) is lower in patients with AN | ++ |
| Stein et al., 2012 | 40 AN (RT), 23 AN (BP), 20 BN, 13 EDNOS, 20 HC females | AN-RT = 15.6±1.7, AN-BP = 16.3±1.3, BN and EDNOS = 16.6±1.3 | Medication (SSRI), patients with depression and anxiety disorders (except OCD), anosmia/hyposmia in HC | Case-control | Three-bottle olfactory test (and: DSM-IV, EDFHI, BDI, Y-BOCS, YBC-ED and alternation learning task) | AN-R = 6.4, sd = 1.4 AN-BP = 6.7, sd = 1.1 BN/EDNOS = 6.7, sd = 0.9 HC = 7.5 (sd = 1.1) |
+ AN-R = 50.6, sd = 6.4 AN-BP = 51.5, sd = 5.2 BN/EDNOS = 48.2, sd = 9.0 HC = 45.5, sd = 9.1 |
N/A | n/a | The eating disorder group scored significantly lower for threshold and significantly higher for discrimination | + | |
| Dazzi et al., 2013 | 18 AN + 19 BN female patients + 19 HC (5M+14F) | Range 16-47 (mean = 26.5, sd = 6.2 | Education, other psychopathy, medication, 5% of HC with hyposmia | Case-control | Sniffin' Sticks | EDI-2, DSM-IV | AN = 6.3 (sd = 4.0) BN = 5.5 (sd = 3.9) HC = 9.1 (sd = 1.3) |
- AN = 11.6 (sd=1.8) BN = 12.0 (sd = 1.9) HC = 13.5 (sd = 0.8) |
= AN = 11.6 (sd = 1.9) BN = 10.7 (sd = 2.2) HC = 11.8 (sd = 1.4) |
– AN = 29.5 (sd = 5.6) BN = 28.1 (sd = 6.4) HC = 34.5 (sd = 2.3) |
No significant differences in identification. BN have lower threshold than HC. AN and BN lower discrimination than HC. Total average (TDI) is lower in patients with ED indicating hyposmia |
+ |
| BULIMIA NERVOSA | ||||||||||||
| Weiland et al., 2011 | 12 BN, 12 HC females | Adults BN = 24, (sd = 3.6) HC = 32 (sd = 7.9) |
Smoking, age (HC significantly older than BN). Dopaminergic meds | Case-control | Sniffin' Sticks with n-butanol sensitivity | HC = 8.2 (sd = 1.6) BN = 8.3 (sd = 0.9), |
N/A | N/A | The scores for threshold did not significantly differ between BN group and controls | + | ||
| OVERWEIGHT/OBESITY | ||||||||||||
| Simchen et al., 2006 | 311 patients (58% females, 42% males) | Range 20–88 | Excludes participants younger than 20, age group only distributed as 65+ and 65- | Cross-sectional (without control) | ETOC | Standardized questionnaire, BMI | –(in < 65 group, BMI > 28 = lower score (±15.3 as opposed to ±15.5 in BMI < 28 group). +(in > 65 group, BMI > 28 = higher score (±14.6 as opposed to ±13.8 in BMI < 28 group) | –(in < 65 group, BMI > 28 = lower score (± 12.2 as opposed to ±13 in BMI < 28 group) + (in > 65 group, BMI > 28 = higher score (±10.9) as opposed to ±10.2 in BMI < 28 group) | Scores for odor detection and odor identification were lower in participants with a BMI > 28 kg/m2 than in participants with a BMI < 28 kg/m2 when the age was < 65 years, whereas in participants > 65 years scores were higher in participants with a BMI > 28 kg/m2 than in participants with a BMI < 28 kg/m2 (BMI*age group: P¼0.015, 0.053, and 0.015, respectively). There was no control group | + | ||
| OBESITY | ||||||||||||
| Obrebowski et al., 2000 | 15 boys and 15 girls undergoing rehabilitation | 12 (Range 10–16) | No control group | Cross-sectional (without control) | Elsberg–Levy's olfactometry, Electrogustometric tests | – Lower score (1.6–3 cm3) in 43% of sample for natural coffee and 63% for anise oil compared to mean = 1.5 cm3 |
N/A | Scores show very low levels of olfactory threshold, below the mean | + | |||
| OBESITY AND ANOREXIA NERVOSA | ||||||||||||
| Fernández-Aranda et al., 2015 | 64 AN 80 young HC 36 old HC 59 obese females | AN = 24.0 (sd = 5.3) Young HC = 22.6 (sd = 2.9) Old HC = 37.3 (5.9) Ob = 37.5 (8.7) |
Case control | Sniffin' Sticks | DSM-IV, EDI-2, SCL 90-Revised and DEBQ |
AN = 8.7 (sd = 0.3) yHC = 6.4 (sd = 0.3) oHC = 7.1 (sd = 0.4) Ob = 5.9 (sd = 0.3 AN > HC |
AN = 13.0 (sd = 0.3) yHC = 12.5 (sd = 0.2) oHC = 13.2 (sd = 0.3) Ob = 12.5 (sd = 0.3) |
AN = 13.0 (sd = 0.3) yHC = 13.1 (sd = 0.2) oHC = 12.8 (sd = 0.3) Ob = 11.8 (sd = 0.3 |
AN = 34.8 (sd = 0.6) yHC = 32.0 (sd = 0.5) oHC = 33.1 (sd = 0.8 Ob = 30.3 (sd = 0.6) AN > HC |
Superior odor threshold in the AN group compared to other groups, and also better odor identification than obese group. Obese individuals showed the poorer olfactory capacity and the greater prevalence of hyposmia | + | |
M, males; F, females; AN, anorexia nervosa; BN, bulimia nervosa; ED, eating disorders; HC, human control; RT, restricting type; BDI, Beck Depression Inventory; BP, binge purge type; CBCL, Child Behavior Checklist; DIKJ, a quantitative self-rating scale for depression; EAT, Eating Attitude Test; EDNOS, eating disorder not otherwise specified; DIA-X/M-CIDI, Munich-Composite International Diagnostic Interview; EDFHI, Eating Disorders Family History Interview; ETOC, European Test of Olfactory Capabilities; Ob, Obese; PEA, phenyl ethyl alcohol; SAM, Self-Assessment Manikin; SIAB-S, Structured Inventory for Anorexic and Bulimic Eating Disorders; UPSIT, University of Pennsylvania Smell Identification Test; Y-BOCS, Yale-Brown Obsessive Compulsive Scale; YBC-ED, Yale-Brown-Cornell Eating Disorders Scale; MMPI-2, Minnesota Multiphasic Personality Inventory-2; EDI-2, Eating Disorder Inventory-2.