Single bright light exposure decreases sweet taste threshold in healthy volunteers.
BACKGROUND
Bright light exposure can alter circulating serotonin levels, and alteration of available serotonin by acute selective serotonin reuptake inhibition significantly lowers sweet but not salt taste recognition thresholds. We tested the hypothesis that bright light exposure would increase sweet but not salt taste sensitivity in healthy adults.


METHODS
Fourteen healthy volunteers were exposed to bright (10,000 lux) and dim (<20 lux) light for 30 min each, in counterbalanced order. Measures of taste perception (salt and sweet) and mood were determined at baseline, and before and after each light exposure period.


RESULTS
Recognition thresholds for sucrose were significantly lower after bright but not dim light exposure. Thresholds for salt were unaffected by either condition. There were no significant changes in taste acuity, intensity or pleasantness for both the taste modalities and on visual analogue scales (VASs) for mood, anxiety, sleepiness and alertness, under either light condition.


CONCLUSIONS
Brief bright light exposure reduces sweet but not salt taste recognition thresholds in healthy humans.
1The Academic Unit of Psychiatry, University of Bristol, Bristol, UK.
Shrikant
S
Srivastava
Lucy F
LF
Donaldson
Dheeraj
D
Rai
Jan K
JK
Melichar
John
J
Potokar
D000328:Adult; D000339:Affect; D001007:Anxiety / Q000523:psychology; D005260:Female; D064368:Healthy Volunteers / Q000523:psychology*; D006801:Humans; D008027:Light; D008297:Male; D012894:Sleep Stages; D055697:Taste Perception / Q000528:radiation effects*; D013652:Taste Threshold / Q000528:radiation effects*; D014851:Wakefulness
Light; healthy volunteers; salt; serotonin; sweet; taste thresholds