Summary

 Background: Post-lunch dip is a well-known phenomenon that results in a substantial deterioration in function and productivity after lunch.

Objectives: To assess whether a new herbal-based potentially wake-promoting beverage is effective in counteracting somnolence and reduced post-lunch performance.

Methods: Thirty healthy volunteers were studied on three different days at the sleep clinic. On each visit they ate a standard lunch at noontime, followed by a drink of "Wake up®," 50 mg caffeine, or a placebo in a cross-over double-blind regimen. At 30 and 120 minutes post-drinking, they underwent a battery of tests to determine the effects of the beverage. These included: a) a subjective assessment of alertness and performance based on a visual analog scale, and b) objective function tests: the immediate word recall test, the digit symbol substitution test (DSST), and hemodynamic measurements. The results of the three visits were compared using one-way analysis of variance, with P < 0.05 considered statistically significant.

Results: In all performance tests, subjective vigilance and effectiveness assessment, both Wake up® and caffeine were significantly superior to placebo 30 minutes after lunch. However, at 2 hours after lunch, performance had deteriorated in those who drank the caffeine-containing drink, while Wake up® was superior to both caffeine and placebo. Blood pressure and pulse were higher 2 hours after caffeine ingestion, compared to both Wake up® and placebo.

Conclusions: These results suggest that a single dose of Wake up® is effective in counteracting the somnolence and reduced performance during the post-lunch hours. In the current study it had no adverse hemodynamic consequences.