Short-term cocoa bioflavanol supplementation does not improve cold-induced vasodilation in young healthy adults.
- 2023-12-27
- European journal of applied physiology 124(5)
- Billie K Alba
- Andrew M Greenfield
- Beau R Yurkevicius
- Myra L Jones
- John W Castellani
- PubMed: 38150009
- DOI: 10.1007/s00421-023-05380-4
Study Design
- Type
- Randomized Controlled Trial (RCT)
- Population
- Eleven healthy adults (24 ± 6 years; 10 M/1F)
- Methods
- Double-blind, randomized, crossover design; 8 days of 900 mg/day cocoa flavanols or matched placebo; CIVD assessed on Days 1 and 8 with finger immersion protocol
- Blinding
- Double-blind
- Duration
- 8 days
- Funding
- Unclear
Purpose
Cold-induced vasodilation (CIVD) is an oscillatory rise in blood flow to glabrous skin that occurs in cold-exposed extremities. Dietary flavanols increase bioavailable nitric oxide, a proposed mediator of CIVD through active vasodilation and/or withdrawal of sympathetic vascular smooth muscle tone. However, no studies have examined the effects of flavanol intake on extremity skin perfusion during cold exposure. We tested the hypothesis that acute and 8-day flavanol supplementation would augment CIVD during single-digit cold water immersion (CWI).Methods
Eleven healthy adults (24 ± 6 years; 10 M/1F) ingested cocoa flavanols (900 mg/day) or caffeine- and theobromine-matched placebo for 8 days in a double-blind, randomized, crossover design. On Days 1 and 8, CIVD was assessed 2 h post-treatment. Subjects immersed their 3rd finger in warm water (42 °C) for 15 min before CWI (4 °C) for 30 min, during which nail bed and finger pad skin temperature were measured.Results
Flavanol ingestion had no effect on CIVD frequency (Day 1, Flavanol: 3 ± 2 vs. Placebo: 3 ± 2; Day 8, Flavanol: 3 ± 2 vs. Placebo: 3 ± 1) or amplitude (Day 1, Flavanol: 4.3 ± 1.7 vs. Placebo: 4.9 ± 2.6 °C; Day 8, Flavanol: 3.9 ± 1.9 vs. Placebo: 3.9 ± 2.0 °C) in the finger pad following acute or 8-day supplementation (P > 0.05). Furthermore, average, nadir, and apex finger pad temperatures during CWI were not different between treatments on Days 1 or 8 of supplementation (P > 0.05). Similarly, no differences in CIVD parameters were observed in the nail bed following supplementation (P > 0.05).Conclusion
These data suggest that cocoa flavanol ingestion does not alter finger CIVD. Clinical Trial Registration Clinicaltrials.gov Identifier: NCT04359082. April 24, 2020.Research Insights
Similarly, no differences in CIVD parameters were observed in the nail bed following supplementation (P > 0.05).
- Effect
- Neutral
- Effect size
- Small
- Dose
- 900 mg/day
Flavanol ingestion had no effect on ... amplitude (Day 1, Flavanol: 4.3 ± 1.7 vs. Placebo: 4.9 ± 2.6 °C; Day 8, Flavanol: 3.9 ± 1.9 vs. Placebo: 3.9 ± 2.0 °C) in the finger pad following acute or 8-day supplementation (P > 0.05).
- Effect
- Neutral
- Effect size
- Small
- Dose
- 900 mg/day
Flavanol ingestion had no effect on CIVD frequency (Day 1, Flavanol: 3 ± 2 vs. Placebo: 3 ± 2; Day 8, Flavanol: 3 ± 2 vs. Placebo: 3 ± 1) ... in the finger pad following acute or 8-day supplementation (P > 0.05).
- Effect
- Neutral
- Effect size
- Small
- Dose
- 900 mg/day
average, nadir, and apex finger pad temperatures during CWI were not different between treatments on Days 1 or 8 of supplementation (P > 0.05)
- Effect
- Neutral
- Effect size
- Small
- Dose
- 900 mg/day
average, nadir, and apex finger pad temperatures during CWI were not different between treatments on Days 1 or 8 of supplementation (P > 0.05)
- Effect
- Neutral
- Effect size
- Small
- Dose
- 900 mg/day
Furthermore, average, nadir, and apex finger pad temperatures during CWI were not different between treatments on Days 1 or 8 of supplementation (P > 0.05).
- Effect
- Neutral
- Effect size
- Small
- Dose
- 900 mg/day
Furthermore, average, nadir, and apex finger pad temperatures during CWI were not different between treatments on Days 1 or 8 of supplementation (P > 0.05).
- Effect
- Neutral
- Effect size
- Small
- Dose
- 900 mg/day