Breakfast high in whey protein or carbohydrates improves coping with workload in healthy subjects

Abstract

Dietary components may affect brain function and influence behaviour by inducing the synthesis of neurotransmitters. The aim of the present study was to examine the influence of consumption of a whey protein-containing breakfast drink v. a carbohydrate drink v. control on subjective and physiological responses to mental workload in simulated work. In a randomised cross-over design, ten healthy subjects (seven women, median age 26 years, median BMI 23 kg/m 2 ) participated in a single-blinded, placebo-controlled study. The subjects performed demanding work-like tasks after having a breakfast drink high in protein (HP) or high in carbohydrate (HC) or a control drink on separate sessions. Subjective states were assessed using the NASA Task Load Index (NASA-TLX), the Karolinska sleepiness scale (KSS) and the modified Profile of Mood States. Heart rate was recorded during task performance. The ratio of plasma tryptophan (Trp) to the sum of the other large neutral amino acids (LNAA) and salivary cortisol were also analysed. The plasma Trp:LNAA ratio was 30 % higher after the test drinks HP (median 0·13 (mmol/l)/(mmol/l)) and HC (median 0·13 (mmol/l)/(mmol/l)) than after the control drink (median 0·10 (mmol/l)/(mmol/l)). The increase in heart rate was smaller after the HP (median 2·7 beats/min) and HC (median 1·9 beats/min) drinks when compared with the control drink (median 7·2 beats/min) during task performance. Subjective sleepiness was reduced more after the HC drink (median KSS 2 1·5) than after the control drink (median KSS 2 0·5). There were no significant differences between the breakfast types in the NASA-TLX index, cortisol levels or task performance. We conclude that a breakfast drink high in whey protein or carbohydrates may improve coping with mental tasks in healthy subjects.

Sugar rush or sugar crash? A meta-analysis of carbohydrate effects on mood

“…Interestingly, a marginal trend of CHO-related facilitation was found for the overall mood construct calculated for each individual study. It should be noted that some of the effect sizes included in this construct originated from studies that selectively reported only CHO-mood associations that were statistically significant (e.g., Lieberman et al, 2002;Sihvola et al, 2013). To illustrate, although Lieberman et al (2002) used the full version of the POMS (six subscales), they only provided data on Confusion/Bewilderment and Vigor/Activity, while no data were available for the remaining four subscales of the POMS.…”

“…For the 61+ time window, eight studies were found to be relevant. However, Sihvola et al (2013) had to be excluded as it was found to be an outlier (z = 2.55) leaving seven studies in the analysis. No effects of CHO on alertness were found for this time window (p = .343).…”

“…However, the effects of energy drink consumption on mood are not clear and more investigations and meta-analytic attempts are warranted. Furthermore, other studies have examined the effects of CHO combined with macronutrients such as protein and fiber (Benton et al, 2001;Lloyd et al, 1996;Qin et al, 2017;Sihvola et al, 2013) or by creating experimental diets controlling for the content of CHO compared with other constituents (Dye et al, 2000;Markus et al, 1998) to examine CHO-mood interactions. Although the purpose of our meta-analysis was to investigate how pure CHO administration can affect mood, it would be interesting to discover whether CHO interactions with other nutrients could more prominently affect mood and emotionality.…”

Exogenous Carbohydrate Reduces Cortisol Response from Combined Mental and Physical Stress

“…This study is also limited by not including a mental stress alone condition or an exercise alone condition to investigate the effects of CHO ingestion and make comparisons between such treatments to further investigate treatment effects. However, previous studies have reported that CHO intake can improve cardiovascular responses to both psychological [31] and physical stress [3,24,26,27]. The purpose of this study was to investigate the effects of CHO ingestion on DCS exposure with the intention of providing justification for future research to continue to investigate nutritional interventions on endocrine and metabolic responses to DCS challenges.…”

Nutritional psychiatry research: an emerging discipline and its intersection with global urbanization, environmental challenges and the evolutionary mismatch

“…At the outset, we acknowledge that much of our focus here is on depression. This is largely because depression has received the lion’s share of international research attention as it relates to some of the nutritional and environmental variables; however, it should be understood that these discussions are of relevance to diverse topics ranging from reductions in violent behavior [54] to overall positive mental outlook in those who are otherwise well-adjusted [55,56]. …”