Tyrosine reverses a cold-induced working memory deficit in humans

Shurtleff, David B.; Thomas, John R.; Schrot, John; Kowalski, K. R.; Harford, Robert

doi:10.1016/0091-3057(94)90299-2

Cited by 132 publications

(97 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, we adjusted the dose-response analyses for baseline tyrosine levels. Our time courses for tyrosine were similar to those in the previous studies using a 150 mg/kg body weight dose [2,32]. However, where the increase in tyrosine levels was two-to threefold in those studies, the increase in our study was five-to sevenfold in both young and older adults after the same doses of tyrosine.…”

Section: Discussionsupporting

confidence: 70%

“…During the test visit, the task was practiced once more with and without feedback, right after consuming the study product. The actual N-back task was performed 90 minutes after tyrosine consumption, the moment that we expected the tyrosine levels to begin peaking, as based on previous studies [2,32]. The task was presented on a laptop using Presentation 17.1 software (Neurobehavioural Systems, Inc. San Francisco, USA).…”

Section: Fig 2 Schematic Overview Of the Numerical N-back Taskmentioning

confidence: 99%

See 1 more Smart Citation

Dose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging

Rest¹,

Bloemendaal²,

Heus³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract:The effects of tyrosine on plasma response and cognition in aging are unknown. We assessed the dose-dependent response to tyrosine administration in older adults in both plasma tyrosine concentrations and working memory performance. In this double blind randomized cross-over trial 17 older adults (aged 60-75 years) received a single administration of 100, 150 or 200 mg/kg body weight of tyrosine. For comparison, 17 young adults (aged 18-35 years) received a dose of 150 mg/kg body weight of tyrosine. Tyrosine plasma concentrations were determined before and 90, 120, 150, 180, 210 and 240 minutes after tyrosine intake. Working memory was assessed using the N-back task at 90 minutes after tyrosine administration. Older adults showed a dose-dependent increase in plasma tyrosine concentrations (p<.001), and the plasma response was higher than for young adults with the same dose (p<.001). Load-dependent working memory performance decreased with higher doses of tyrosine (p=.048), especially in older adults with greater dose-dependent plasma tyrosine responses (p=.035). Our results show an age-related increase in plasma tyrosine response, which was associated with a dose-dependent decline in cognitive functioning in older adults.

show abstract

Section: Discussionsupporting

confidence: 70%

Section: Fig 2 Schematic Overview Of the Numerical N-back Taskmentioning

confidence: 99%

Dose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging

Rest¹,

Bloemendaal²,

Heus³

et al. 2017

Preprint

View full text Add to dashboard Cite

show abstract

“…Subjects also displayed fewer adverse emotions, such as confusion, unhappiness, hostility, and tension, normally associated with exposure to environmental Stressors (6). Additional studies have confirmed and extended these findings (49,87). Rat studies have confirmed these results and also shown that tyrosine treatment reverses working memory escape latency decrements and alleviates hypoxiainduced retardation of learning (50,85).…”

Section: Benefits Of Tyrosine Supplementationsupporting

confidence: 71%

Supplemental tyrosine and vigilance performance in a normoxic hypobaric environment

Maresh¹

2001

PsycEXTRA Dataset

View full text Add to dashboard Cite

The public re(jortii.g burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection o; rnfo'rnation. including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Exposure to stress results in a decrease in mental performance resulting from a depletion of catecholamines. This decrease can result in an increase in error rates, decreased decision making ability, mental confusion, and an overall decrease in cognitive performance. Previous studies have shown that supplemental tyrosine prevents the normal decrease due to stress.Tyrosine works by increasing the catecholamine precursor.Nine subjects were exposed to a 3-hour protocol for 4 different exposures. During each exposure, the following Stressors were used: 1) hypobaric environment (for two of the four exposures); 2) immobilization; 3) prolonged inactivity; 4) behavioral and psychophysiological testing; 5) cool temperatures and low humidity; and 6) 71 dB(A) chamber environment. Subjects completed computerized vigilance and cognitive tests and a mood questionnaire, each separated by a period of inactivity. Prior to exposure, subjects ingested either 100 mg/kg body weight of a placebo or tyrosine.Supplemental tyrosine improved response time in all of the tests where it was recorded, with all except one being significant. Motor function and overall mood also significantly improved with the use of tyrosine. As expected, no measurement showed a significant improvement in performance with supplemental oxygen alone. The use of supplemental tyrosine did not significantly improve cognitive performance. Results of the contrast sensitivity taskswere not as conclusive and no improvement was found in visual temporal acuity. and physical performance. The less control the individual has over these stresses, the greater the decrement. The decrease in performance, particularly mental performance, results from a depletion of catecholamines within the brain. This decrease, especially in norepinephrine, leads to alterations in normal brain function and an increase in error rates, decreased decision making ability, mental confusion, and an overall decrease in cognitive performance. All of these are compounded the longer the individual is unable to remove the stress. Previous studies involving rats and humans have shown that supplemental tyrosine (levels above normal dietary intake) prevent the normal decrease in performance in stressed individuals. Tyrosine, the initial precursor in catecholamine synthesis, works by increasing the availability of the precursor and thereby slowing the rate of norepinephrine depletion.Nine healthy subjects from the Colorado State University community were exposed to a 3-hour protocol that w...

show abstract

“…Average temperatures varied from a high of -2.9°C in January and a low of - 26 . The indoor living compartment temperature in both summer and winter at both stations was between 18 and 25°C, although there is a substantial vertical thermal gradient in Antarctica (27).…”

Section: Subjectsmentioning

confidence: 99%

Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence

Palinkas

Reedy

Smith

et al. 2007

International Journal of Circumpolar Health

Self Cite

View full text Add to dashboard Cite

Objectives. We previously reported that cognitive function improves with thyroxine and that there is a circannual pattern to mood and human TSH during Antarctic residence. To extend these findings, we examined the effects of tyrosine and a combined levothyroxine/ liothyronine supplement in euthyroid men and women who spent the austral summer (n=43) and/or winter (n=42) in Antarctica. Study Design. Randomized, placebo-controlled, clinical trial. Methods. Subjects were randomized to receive the following each day for 91.6±3.2 days in summer and/or 138.0± 3.2 days in winter: (1) 12g tyrosine mixed in 113g applesauce; (2) 50ug of levothyroxine and 12.5ug of liothyronine (T4-T3 Supplement); or (3) placebo. Cognitive performance and mood were assessed using the Automatic Neuropsychological Assessment Metric -Isolated and Confined Environments. Effectiveness of thyroid supplement and tyrosine in Antarctica Results. With placebo in summer, mood did not change while TSH decreased by 28%; in winter, there was a 136% degradation in mood (p<0.01) and TSH increased by 18%. With combined T4-T3 supplement, there was a 51% degradation in mood in summer compared with placebo (p<0.05) and TSH decreased by 57%; in winter there was a 135% degradation in mood while TSH was reduced by 26% (p<0.05). Tyrosine use in summer was associated with no change in mood and a 30% decline in TSH, while in winter there was a 47% improvement in mood and TSH decreased by 28% along with a 6% increase in fT3 (p<0.05). Conclusions. Administration of tyrosine leads to a significant reduction in serum TSH and improvement in mood in winter compared with placebo, while the combined T4-T3 supplement leads to a worsening of mood in summer and no improvement in winter. There appears to be a seasonal influence on the psychological response to interventions and the relationship to changes in TSH reductions. (Int J Circumpolar Health 2007; 66(5):401-417)

show abstract

Tyrosine reverses a cold-induced working memory deficit in humans

Cited by 132 publications

References 28 publications

Dose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging

Dose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging

Supplemental tyrosine and vigilance performance in a normoxic hypobaric environment

Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence

Contact Info

Product

Resources

About