Effects of l-tryptophan and various diets on behavioral functions in essential hypertensives

The effects of tryptophan in combination with two different diets (high-carbohydrate and high-protein diet) on behavioral parameters such as mood, sleep and performance were chronically studied in a group of 34 hypertensive patients undergoing a trial of testing the antihypertensive properties of l-tryptophan. While no major changes in mood were observed, there was a tendency for sleep latency to decrease and sleep duration to increase following tryptophan intake in the intragroup analysis. The administration of tryptophan caused a significant improvement on performance in a concentration task. No significant dietary effects were observed either in combination with tryptophan or in the placebo group. These data again demonstrate behavioral relevance of the precursor amino acid l-tryptophan and suggest a long-term improvement in partial aspects of performance behavior.