Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get two FREE E-Books

Our newsletter serves 250,000 with essential news, research & healthy tips, daily.

Easy Turmeric recipes + The Dark Side of Wheat

Abstract Title:

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

Abstract Source:

South Med J. 2004 Jan;97(1):30-4. PMID: 18274206

Abstract Author(s):

Lawrence A Palinkas, Kathleen R Reedy, Mark Smith, Mihai Anghel, Gary D Steel, Dennis Reeves, David Shurtleff, H Samuel Case, Nhan Van Do, H Lester Reed

Article Affiliation:

School of Social Work and Department of Anthropology, University of Southern California, Los Angeles 90089-0411, USA. palinkas@usc.edu

Abstract:

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) 50 microg of levothyroxine and 12.5 microg of liothyronine (T4-T3 Supplement); or (3) placebo. Cognitive performance and mood were assessed using the Automatic Neuropsychological Assessment Metric - Isolated and Confined Environments. 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.

Study Type : Human Study

Print Options


Key Research Topics

Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get two FREE E-Books

Our newsletter serves 250,000 with essential news, research & healthy tips, daily.

Easy Turmeric recipes + The Dark Side of Wheat

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2018 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.