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Effects of acute treatment with a tryptophan-rich protein hydrolysate on plasma amino acids, mood and emotional functioning in older women.

Gibson EL, Vargas K, Hogan E, Holmes A, Rogers PJ, Wittwer J, Kloek J, Goralczyk R, Mohajeri MH - Psychopharmacology (Berl.) (2014)

Bottom Line: This treatment dose resulted in a significant shift in emotional processing towards positive words and reduced negative bias in assessing negative facial expressions.However, there was no evidence for any adverse effects.Consumption of a low dose of TRP-rich protein hydrolysate may have beneficial effects on emotional function that could promote feelings of wellbeing, possibly conferring resistance to deterioration in mood in healthy subjects or depressive episodes.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Whitelands College, University of Roehampton, Holybourne Avenue, London, SW15 4JD, UK, l.gibson@roehampton.ac.uk.

ABSTRACT

Rationale: Effective functioning of the neurotransmitter serotonin is important for optimal cognitive and emotional function. Dietary supplements able to increase availability to the brain of the precursor amino acid, tryptophan (TRP), and thereby enhance serotonin synthesis, can have measurable impact on these psychological processes.

Objectives: This study involves a randomised controlled trial of a TRP-rich egg-white protein hydrolysate (DSM Nutritional Products Ltd., Switzerland) on plasma amino acids, cognition, mood and emotional processing in older women.

Methods: Following a baseline test day without treatment, 60 healthy women aged 45-65 years received drinks containing either 2 or 4 g of TRP-rich protein hydrolysate product or 3.11 g casein hydrolysate as a control. One hour later, they undertook a 2-h battery of cognitive and emotional tests.

Results: The TRP-rich protein hydrolysate produced the expected dose-dependent increase in the ratio of plasma TRP to competing large neutral amino acids. TRP-rich protein hydrolysate (2 g only) prevented both the decline in wellbeing and increase in fatigue seen over the test session in the control group. This treatment dose resulted in a significant shift in emotional processing towards positive words and reduced negative bias in assessing negative facial expressions. Effects on cognition were small and not statistically reliable and are not reported here. However, there was no evidence for any adverse effects.

Conclusions: Consumption of a low dose of TRP-rich protein hydrolysate may have beneficial effects on emotional function that could promote feelings of wellbeing, possibly conferring resistance to deterioration in mood in healthy subjects or depressive episodes.

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Related in: MedlinePlus

Effects of treatments on plasma TRP/LNAA ratios. Different letters indicate differences between treatment groups, adjusted for baseline ratios. Sample 2 differed from sample 1 within each treatment condition, ***p < 0.001
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Fig2: Effects of treatments on plasma TRP/LNAA ratios. Different letters indicate differences between treatment groups, adjusted for baseline ratios. Sample 2 differed from sample 1 within each treatment condition, ***p < 0.001

Mentions: The impact of treatment condition on any change in plasma TRP/LNAA ratio was examined using one-way ANCOVA on the sample 2 (posttreatment) TRP/LNAA ratios, with sample 1 TRP/LNAA ratios as the covariate, i.e. testing for the group effect adjusted for any influence of baseline ratios. Treatment had a highly significant effect on plasma TRP/LNAA, ANCOVA group effect, F(2, 41) = 46.7, p < 0.001, ηp2 = 0.70. Baseline (sample 1) TRP/LNAA ratios were a strongly significant covariate, F(1, 41) = 42.4, p < 0.001, ηp2 = 0.51 (see Table 4). Compared with the control, TRP/LNAA ratios were higher after both 2 and 4 g LumiVida™, and higher after 4 g than after 2 g, Bonferroni-adjusted pairwise comparisons, control vs. 2 and 4 g, p < 0.001, 2 g vs. 4 g, p = 0.002 (Fig. 2).Fig. 2


Effects of acute treatment with a tryptophan-rich protein hydrolysate on plasma amino acids, mood and emotional functioning in older women.

Gibson EL, Vargas K, Hogan E, Holmes A, Rogers PJ, Wittwer J, Kloek J, Goralczyk R, Mohajeri MH - Psychopharmacology (Berl.) (2014)

Effects of treatments on plasma TRP/LNAA ratios. Different letters indicate differences between treatment groups, adjusted for baseline ratios. Sample 2 differed from sample 1 within each treatment condition, ***p < 0.001
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4231284&req=5

Fig2: Effects of treatments on plasma TRP/LNAA ratios. Different letters indicate differences between treatment groups, adjusted for baseline ratios. Sample 2 differed from sample 1 within each treatment condition, ***p < 0.001
Mentions: The impact of treatment condition on any change in plasma TRP/LNAA ratio was examined using one-way ANCOVA on the sample 2 (posttreatment) TRP/LNAA ratios, with sample 1 TRP/LNAA ratios as the covariate, i.e. testing for the group effect adjusted for any influence of baseline ratios. Treatment had a highly significant effect on plasma TRP/LNAA, ANCOVA group effect, F(2, 41) = 46.7, p < 0.001, ηp2 = 0.70. Baseline (sample 1) TRP/LNAA ratios were a strongly significant covariate, F(1, 41) = 42.4, p < 0.001, ηp2 = 0.51 (see Table 4). Compared with the control, TRP/LNAA ratios were higher after both 2 and 4 g LumiVida™, and higher after 4 g than after 2 g, Bonferroni-adjusted pairwise comparisons, control vs. 2 and 4 g, p < 0.001, 2 g vs. 4 g, p = 0.002 (Fig. 2).Fig. 2

Bottom Line: This treatment dose resulted in a significant shift in emotional processing towards positive words and reduced negative bias in assessing negative facial expressions.However, there was no evidence for any adverse effects.Consumption of a low dose of TRP-rich protein hydrolysate may have beneficial effects on emotional function that could promote feelings of wellbeing, possibly conferring resistance to deterioration in mood in healthy subjects or depressive episodes.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Whitelands College, University of Roehampton, Holybourne Avenue, London, SW15 4JD, UK, l.gibson@roehampton.ac.uk.

ABSTRACT

Rationale: Effective functioning of the neurotransmitter serotonin is important for optimal cognitive and emotional function. Dietary supplements able to increase availability to the brain of the precursor amino acid, tryptophan (TRP), and thereby enhance serotonin synthesis, can have measurable impact on these psychological processes.

Objectives: This study involves a randomised controlled trial of a TRP-rich egg-white protein hydrolysate (DSM Nutritional Products Ltd., Switzerland) on plasma amino acids, cognition, mood and emotional processing in older women.

Methods: Following a baseline test day without treatment, 60 healthy women aged 45-65 years received drinks containing either 2 or 4 g of TRP-rich protein hydrolysate product or 3.11 g casein hydrolysate as a control. One hour later, they undertook a 2-h battery of cognitive and emotional tests.

Results: The TRP-rich protein hydrolysate produced the expected dose-dependent increase in the ratio of plasma TRP to competing large neutral amino acids. TRP-rich protein hydrolysate (2 g only) prevented both the decline in wellbeing and increase in fatigue seen over the test session in the control group. This treatment dose resulted in a significant shift in emotional processing towards positive words and reduced negative bias in assessing negative facial expressions. Effects on cognition were small and not statistically reliable and are not reported here. However, there was no evidence for any adverse effects.

Conclusions: Consumption of a low dose of TRP-rich protein hydrolysate may have beneficial effects on emotional function that could promote feelings of wellbeing, possibly conferring resistance to deterioration in mood in healthy subjects or depressive episodes.

Show MeSH
Related in: MedlinePlus