Normal Subjects
Conditions
Keywords
sweeteners, sugar, stress response
Brief summary
This exploratory study aims at investigating the acute effects of artificially sweetened and sugar beverage consumption (as compared to water consumption) on acute hemodynamic and metabolic stress response.
Detailed description
This single-center study included five visits. The first two visits (screening and familiarization) allowed checking the eligibility of the volunteers. In case of inclusion, the subjects were assigned to a sequence of three experimental conditions (water, sugar and artificial sweeteners), in a randomized, crossover design. The experimental test was divided into 5 stages: 1. a 90 minutes baseline period (t=0-90 min), 2. a 30-min mental stress (MS; t=90-120 min), consisting in 5-min periods of Stroop's color word conflict test alternated with 5-min periods of mental arithmetic test. 3. a 30-min MS recovery period (t=120-150), 4. a 3-min cold pressure test (CPT) was carried out, aiming at immersing one volunteer's forearm in an ice water container at 3°C, 3\) a 15-min CPT recovery period (t=120-150). 60 min after the beginning of the metabolic test, volunteers will drink 25 mL every 15 min, after 10-sec mouth rinsing, of either an artificially- or sugar-sweetened beverages or water (control). Hemodynamic stress responses will be measured by repeated blood pressure, heart rate and cardiac output. Repeated venous blood samples will allow to assess metabolic stress responses. Each condition (water, artificial sweeteners and sugar) will be preceded by a 2-day run-in period.
Interventions
OTHERIngestion of artificially-sweetened beverages
From t=60 to the end of the metabolic test, volunteers will ingest 7 beverages containing non nutritive sweeteners (25 mL / beverage) every 15 minutes after 10-sec mouth rinsing.
OTHERIngestion of sugar-sweetened beverages
From t=60 to the end of the metabolic test, volunteers will ingest 7 beverages containing sugar (25 mL / beverage) every 15 minutes after 10-sec mouth rinsing.
OTHERIngestion of water
From t=60 to the end of the metabolic test, volunteers will ingest 7 water beverages (25 mL / beverage) every 15 minutes after 10-sec mouth rinsing.
Sponsors
University of Lausanne
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy * Caucasian * Normal Body Mass Index (18.5 ≤BMI≤ 25 kg/m2) * Monophasic oral contraceptive
Exclusion criteria
* Hypertension (Blood pressure \>140/90 mmHg) * History or actual psychologic/cardiovascular troubles * Anemia anamnesis * Being Pregnant * Weight \< 50 kg * Blood donation or participation to another study \< 8 weeks * Claustrophobia * Consumption of sugar/artifically-sweetened beverages drinks \> 5 dL/d * Visual disturbances (daltonism) * Low to moderate physical activity (\> 4h/wk) * Smoker and narcotic consumption * Caffeine (\> 400 mg/d) and/or alcohol (\> 10g/d) consumption * Medical treatment * Weight variation \> 3kg during the last month
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Hemodynamic changes | Differences observed between 90-min baseline and stress (30-min mental stress and 3-min cold pressure test) | Hemodynamic changes elicited by stress will be assessed by means of systemic vascular resistance calculated as (blood flow):(mean arterial pressure, and expressed in arbitrary units |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes in concentration of blood glucose | Blood samples will be collected 30, 60, 75, 85, 95, 100, 110, 120, 125, 135, 145, 153, 158, and 163 minutes after the beginning of the test | Blood glucose concentration will be measured in fasting conditions and during stress tests with the glucose oxidase method and expressed in mg/dl |
| Changes in concentration of blood insulin | Blood samples will be collected 30, 60, 75, 85, 95, 100, 110, 120, 125, 135, 145, 153, 158, and 163 minutes after the beginning of the test | Blood insulin concentration will be measured by ELISA and expressed in mU/L |
| Changes in blood non-esterified fatty acid concentration | Blood samples will be collected 30, 60, 75, 85, 95, 100, 110, 120, 125, 135, 145, 153, 158, and 163 minutes after the beginning of the tes | Blood non-esterified fatty acid concentration will be measured by a colorimetric method and expressed in mmol/L |
| Metabolic changes | Differences observed between 90-min baseline and stress (30-min mental stress and 3-min cold pressure test) | Metabolic changes elicited by stress will be continually monitored from respiratory gas exchanges by indirect calorimetry. |
Countries
Switzerland
Outcome results
None listed