None listed
Conditions
Brief summary
The regulation of neurotransmitter action by dietary compounds provides an avenue to improve general brain wellness and cognitive function of individuals undergoing increased mental stress/challenges. Dietary compounds may regulate neurotransmitter concentrations via several mechanisms, including the direct stimulation on neurotransmitter release. Randomised, placebo-controlled studies have reported that supplementation with hops and hops derived compounds has been shown to increase the blood concentrations of neurotransmitter stimulatory hormones and to acutely affect cognitive performance in people. Hops increased the levels of gut hormones CCK and GLP-1 that affect mood and cognition, in part by the stimulation of pro-cognitive neuropeptides via the activation of the vagus nerve, and hops bitter acid derived compounds improve cognition after both acute and chronic supplementation (Ayabe et al. 2020). However, the minimum dose of efficacy by which hops-derived bitter compounds stimulate pro-cognitive neurotransmitters has not been characterised. The objective of this project is to determine the effect of NZ hops on circulating neurotransmitter concentrations, changes in heart rate variation, and bioavailability of hops compounds after a single dose of four different hops interventions.
Interventions
This study will investigate the effect hops and isomerised (iso) hops on circulating neurotransmitter concentrations. We will implement a randomised, placebo-controlled, repeated measures study design. Prospective participants who have passed the study’s inclusion/exclusion criteria will be asked to attend a familiarisation session where they will meet with the study’s principal investigator. During this session the study’s trial coordinator (Research Associate, approx. 6 years experience in hum
This study will investigate the effect hops and isomerised (iso) hops on circulating neurotransmitter concentrations. We will implement a randomised, placebo-controlled, repeated measures study design. Prospective participants who have passed the study’s inclusion/exclusion criteria will be asked to attend a familiarisation session where they will meet with the study’s principal investigator. During this session the study’s trial coordinator (Research Associate, approx. 6 years experience in human studies) or the principal investigator (Research Scientist, PhD) will explain the logistics of the trial to them and answer any questions they may have. Enrolled participants (n = 8) will attend a total of five trial days. Participants will be given a list of foods (e.g. hops and hops-containing foods and supplements) to abstain from consuming 24 hours prior each trial day. Participants will be also be asked to refrain from eating any food or drink (other than water) 10 h before the start of their scheduled trial day except for their supplied breakfast (one Almond One Square Meal bar [Cookie Time Ltd.]) that will be provided for them to consume approximately 2 h before your scheduled arrival at the research facility for their trial day. Upon arriving at the research facility, a venous blood sample (approximately 9 mL) will be collected from them. They will then be given a single serve of their allocated intervention (hops or isomerised hops (125 and 250 mg a-acids) or placebo) to consume as quickly as they can. After this, they will be directed to the seating area of the facility to wait. Two hours and 4 h after consuming their allocated intervention, 9 mL of venous blood will be collected from them. After the 4 h blood sample collection is finished, they will be offered a small snack to eat before you leave the facility. After their first trial day, participants will be required to return to the facility for four more trial days with at least five days washout period between trial days. Hops and isohops extract will be commercially sourced and prepared in a food safe facility. Doses used in this study have been used in previous used in nutritional interventions. All hops interventions will be suspended in food grade canola oil and encapsulated in gelatine capsules and consumed with water. The placebo capsules will be matched to contain the same amount of canola oil and water as the hops and isohops interventions.
Sponsors
Dr Jocelyn Eason
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy individual (male or female) 18 – 50 years who are able to provide written consent to participate when selected for this study, are non-smokers and vapers and are not prescribed psychotropic medication or MAO inhibitors.
Exclusion criteria
Participants will be excluded if they are unwilling to unable to provide written consent or comply with the study procedures. Participants will be excluded if they are pregnant, planning to get pregnant in the immediate future or have any of the following conditions: (i) blood borne diseases (e.g. hepatitis), (ii) recent bacterial or viral illness, (iii) are taking medication that affects the properties of blood (e.g. blood clotting) or immune function, (iv) are taking medication for mental health and mood disorders, (v) have a strong fear or dislike of needles and/or the sight of blood, have an aversion to blood sampling, or difficult veins to access. Participants will also be excluded if they have known hypersensitivity or intolerance to hops or hops derived food products.
Outcome results
None listed