Carbohydrate ingestion but not mouth rinse maintains sustained attention when fasted.
Carbohydrate (CHO) receptors in the mouth signal brain areas involved in cognitive tasks relying upon motivation and task persistence; however, the minimal CHO dose that improves mental activity is unclear.


OBJECTIVE
To determine if CHO (via ingestion or oral rinse) influences sustained attention without eliciting glycemic responses when in a fasted state.


METHODS
Study A: Six healthy adults completed five treatment trials, ingesting 0-6% CHO solutions to evaluate glycemic response. Peak blood glucose for 6% and 1.5% CHO was greater (p<0.05) than 0% and 0.4% CHO; thus, the low 0.4% CHO was evaluated further. Study B: Following an overnight fast, ten healthy adults completed three trials in a crossover design: 1) 400 ml 0.4% CHO ingested serially via 25 ml boluses, 2) 375 ml 0% CHO control (CON) ingested followed by one 25 ml 6% CHO isocaloric (1.5 g CHO) mouth rinse, and 3) CON ingest followed by CON rinse. Following treatments, a 20 min Continuous Performance Task (CPT) was performed to assess accuracy and precision.


RESULTS
Accuracy and precision were not different during the first 5 min of CPT. However, accuracy was maintained with CHO ingest (p=1.0) but decreased over 20 min (p<0.05) with both CHO and CON rinse treatments. Precision tended to decline over 20 min CPT with CON (p=0.06) and CHO rinse (p=0.05) but were maintained with CHO ingest (p=1.0). No differences in glycemic responses were observed between treatments.


CONCLUSIONS
Compared to mouth rinsing CON or CHO (1.5 g in 6% CHO), ingestion of an isocaloric low-CHO drink maintained sustained attention over a mentally fatiguing task and appears effective after fasting without eliciting a glycemic response.
School of Applied Physiology, Georgia Institute of Technology, Atlanta, GA 30332, United States. Electronic address: nodea3@gatech.edu.
Namrita
N
Kumar
School of Applied Physiology, Georgia Institute of Technology, Atlanta, GA 30332, United States.
Lewis A
LA
Wheaton
School of Applied Physiology, Georgia Institute of Technology, Atlanta, GA 30332, United States.
Teresa K
TK
Snow
School of Applied Physiology, Georgia Institute of Technology, Atlanta, GA 30332, United States.
Melinda
M
Millard-Stafford
D000284:Administration, Oral; D000328:Adult; D001288:Attention / Q000187:drug effects*; D001786:Blood Glucose / Q000187:drug effects; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000494:pharmacology*; D004435:Eating; D005215:Fasting; D005260:Female; D000067940:Glycemic Load / Q000187:drug effects; D006801:Humans; D008297:Male; D009067:Mouthwashes / Q000737:chemistry* / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000187:drug effects; D055815:Young Adult
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D009067:Mouthwashes
Attention; Cognition; Fasting; Glycemic response