- 2020-06-02
- Nutrients 12(6)
- Su-Jin Jung
- Hui-Yeon Jang
- Eun-Soo Jung
- Soon-Ok Noh
- Sang-Wook Shin
- Ki-Chan Ha
- Hyang-Im Baek
- Byung-Jae Ahn
- Tae-Hwan Oh
- Soo-Wan Chae
Study Design
- Type
- Randomized Controlled Trial (RCT)
- Sample size
- n = 101
- Population
- 120 healthy adults
- Methods
- randomized, double-blind, placebo-controlled, 2.5 g/day PTE or placebo for 8 weeks
- Blinding
- Double-blind
- Duration
- 8 weeks
- Funding
- Unclear
- Large Human Trial
- Rigorous Journal
Objective
The purpose of this study was to determine if Porphyra tenera extract (PTE) has immune-enhancing effects and is safe in healthy adults.Methods
Subjects who met the inclusion criteria (3 × 103 ≤ peripheral blood leukocyte level ≥ 8 × 103 cells/µL) were recruited for this study. Enrolled subjects (n = 120) were randomly assigned to either the PTE group (n = 60) and were given 2.5 g/day of PTE (as PTE) in capsule form or the placebo group (n = 60) and were given crystal cellulose capsules with the identical appearance, weight, and flavor as the PTE capsules for 8 weeks. Outcomes were assessed based on measuring natural killer (NK) cell activity, cytokines level, and upper respiratory infection (URI), and safety parameters were assessed at baseline and 8 weeks.Results
Compared with baseline, NK cell activity (%) increased for all effector cell-to-target cell ratios in the PTE group after 8 weeks; however, changes were not observed in the placebo group (p < 0.10). Subgroup analysis of 101 subjects without URI showed that NK cell activity in the PTE group tended to increase for all effector cell/target cell (E:T) ratios (E:T = 12.5:1 p = 0.068; E:T = 25:1 p = 0.036; E:T = 50:1 p = 0.081) compared with the placebo group. A significant difference between the two groups was observed for the E:T = 25:1 ratio, which increased from 20.3 ± 12.0% at baseline to 23.2 ± 12.4% after 8 weeks in the PTE group (p = 0.036). A significant difference was not observed in cytokine between the two groups.Conclusion
PTE supplementation appears to enhance immune function by improving NK cell activity without adverse effects in healthy adults.