Cognitive Performance and Mood Following Ingestion of a Theacrine-Containing Dietary Supplement, Caffeine, or Placebo by Young Men and Women.

What Was Tested

Researchers studied Caffeine in this randomized controlled trial publication.

Theacrine is a purine alkaloid found primarily in the leaves of the Camellia Kucha plant and is now included within dietary supplements.

Before, and for up to 4 h following, ingestion of the assigned condition, subjects completed a subjective assessment of energy and mood, as well as tests of cognitive performance (trail making test (TMT), digit symbol substitution test (DSST)), and reaction time.

Who Took Part

The study group was 10 men.

The age groups tagged for this paper are young adults, both men and women.

How the Study Was Run

The design is described as randomized, double-blind, placebo-controlled and crossover.

Because people in this Caffeine study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Neither the men nor the staff measuring them knew who was on Caffeine, so expectations could not easily colour the readings.

Some men received a placebo instead of Caffeine, giving a reference point.

In the crossover set-up each of the men took both Caffeine and the comparison in turn, acting as their own control.

Heart rate and blood pressure were measured.

What Was Measured

Before, and for up to 4 h following, ingestion of the assigned condition, subjects completed a subjective assessment of energy and mood, as well as tests of cognitive performance (trail making test (TMT), digit symbol substitution test (DSST)), and reaction time.

The subject headings attached to it are Affect, Appetite, Blood Pressure, Caffeine, Camellia, Cognition and Diet Records.

The authors tagged it with the keywords dietary supplements, digit symbol substitution test, reaction time, theacrine and trail making test.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Caffeine in 10 men.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The publication is from 2015 (Nutrients), a journal based in Switzerland.

More context: all human trials.