Acute Effects of Artificial Sweeteners or Sugar on Hemodynamic and Metabolic Stress Responses

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:

• a 90 minutes baseline period (t=0-90 min),
• 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.
• a 30-min MS recovery period (t=120-150),
• 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,

• 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.

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