title: Subconscious olfactory influences of stimulant and relaxant odors on immune function.
abstract: Brain and immune system are linked by bidirectional pathways so that changes of the central nervous system may influence various immune functions. The olfactory system may be involved in this interaction. In most odor studies subjects are aware of an odor exposure, using frequently high odor concentrations or long-term exposures without controls. In this pilot study, the potential immune effects of short-term odor exposure were examined in 32 blinded subjects (16 male, 16 female). Subjects were exposed without their knowledge either to a stimulant essential oil (grapefruit, fennel, pepper), a no-odor control or a relaxant essential oil (lavender, patchouli, rose) during a set of psychological questionnaires for 30 min at three separate visits. Activity of neutrophil granulocytes (CXCL8 release, CD16) and peripheral blood concentrations of mainly neutrophil-related immunological markers were measured. We tested the triple of stimulant odor, control and relaxant odor for every subject in a model which assumed opposite effects of the stimulant and the relaxant odor. This hypothesis was falsified by our experimental data, as no significant effect was observed for the parameters tested. The human immune functions tested in our study are not modulated by short-term odor exposure in blinded subjects. Further studies should directly dissect possible differences between long-term and short-term exposures of non-blinded subjects versus blinded subjects.
authors.affiliation: Department of Otorhinolaryngology, University Hospital Essen, Hufelandstraße 55, 45122 Essen, Germany. sokratis.trellakis@uk-essen.de
authors.forename: Sokratis
authors.initials: S
authors.lastname: Trellakis
authors.forename: Cornelia
authors.initials: C
authors.lastname: Fischer
authors.forename: Alena
authors.initials: A
authors.lastname: Rydleuskaya
authors.forename: Sefik
authors.initials: S
authors.lastname: Tagay
authors.forename: Kirsten
authors.initials: K
authors.lastname: Bruderek
authors.forename: Jens
authors.initials: J
authors.lastname: Greve
authors.forename: Stephan
authors.initials: S
authors.lastname: Lang
authors.forename: Sven
authors.initials: S
authors.lastname: Brandau
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D019742:Chemokines, CC / Q000097:blood / Q000187:drug effects; D005260:Female; D006801:Humans; D007107:Immune System / Q000187:drug effects*; D015850:Interleukin-6 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000187:drug effects; D009812:Odorants; D009822:Oils, Volatile / Q000494:pharmacology*; D010865:Pilot Projects; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D012903:Smell / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000187:drug effects; D014473:Unconscious, Psychology
chemical_list: D015415:Biomarkers; D019742:Chemokines, CC; D015850:Interleukin-6; D016209:Interleukin-8; D009822:Oils, Volatile; D017395:Plasminogen Activator Inhibitor 1; D014409:Tumor Necrosis Factor-alpha