Stress & Cognition

Nutrition aid coping and memory

Green tea, rhodiola, magnesium, and B vitamins

This combination of nutrients effectively reduced social stress in 100 moderately stressed adults, aged 18 to 50. Participants took a placebo, or some combination of 150 mg magnesium, 700 mcg vitamin B6, 100 mcg B1, 1 mcg B12, 125 mg green tea, and 225 mg rhodiola.

Doctors fitted heart rate, blood pressure, and salivary cortisol response monitors to participants who rested for 15 minutes before taking the nutrients. After another 30-minute rest, doctors administered the Trier Social Stress Test, asking participants to prepare a five-minute presentation as part of an imagined job interview.

Describing the results, doctors said, “The combination promoted a relaxed, focused state—indexed by EEG [electroencephalogram]—reduced stress perception, and increased energetic arousal in anticipation and in the immediate recovery from stress exposure.” Up to seven hours later, participants continued to report feeling less stress, negative mood, and anxiety.

Reference: Nutritional Neuroscience; 2021, 1909204, Published Online

L-theanine improved memory, processing speed

Green and black teas contain the amino acid L-theanine, which may affect mood hormones such as serotonin and dopamine. In this study, 50 healthy adults, average age 58, took a placebo or a single 100.6 mg dose of L-theanine per day for 12 weeks.

Doctors measured reaction time to working memory attention tasks before the first dose, after one dose, and after 12 weeks. While there were no improvements for placebo, after a single dose of L-theanine, reaction time to working memory attention tasks decreased, the number of correct answers increased, and omission errors decreased. The effects remained constant over the 12-week trial.

Doctors noted participants were not allowed to take supplements or medications that might affect cognitive functions, but could consume polyphenol-containing beverages such as green, black, and oolong teas.

Reference: Journal of Medicinal Food; 2021, Vol. 24, No. 4, 4803