At a glance
- What the study gets you
- Access to the study treatment being tested
- Type of study
- Interventional (receives a drug or procedure)
- Time in hospital
- In-person visits at study sites — visit count not specified by the sponsor
- Drug or intervention
- High-flavonoid grape intervention (supplement), Low-flavonoid grape intervention (supplement)
- How long the study runs
- Study runs about 11 months (dates as stated)
- About the drug or intervention
- High-flavonoid grape intervention — supplement: High-flavonoid grape powder: 60 g, equivalent to 300 g fresh grapes. · Low-flavonoid grape intervention — supplement: 60 g powder isocaloric-matched control (Total polyphenols: \< 60 mg)
- Patient visit burden
- Not specified by the sponsor
- Type of study
- Testing a treatment
- Ages
- 18 Years to 40 Years
- Who
- All
- Number of participants
- 44
- Started
- 2025-04-01
- Last checked
- 2025-12
Plain English Summary
What is this study?
- • Testing a new treatment for healthy
- • NA - 44 participants
- • The main aim of the current study is to investigate whether consuming grapes rich in flavonoids just before mental stress can protect cerebrovascular and peripheral vascular function, mood and cognition, from the negative effects of mental stress in young healthy adults
Who can take part?
- • Ages 18 Years to 40 Years
- • Diagnosed with healthy
Where?
- • Birmingham - School of Sport, Exercise & Rehabilitation Sciences
This is a simplified summary. Always discuss with your doctor before making any decisions.
About This Trial
The main aim of the current study is to investigate whether consuming grapes rich in flavonoids just before mental stress can protect cerebrovascular and peripheral vascular function, mood and cognition, from the negative effects of mental stress in young healthy adults. A second, exploratory aim, will further address whether quality of habitual diet, microbiome health (composition; metabolites production e.g. Short-chain fatty acids) and levels of cardiorespiratory fitness play a role on the beneficial effects of grapes during mental stress. All participants will receive a high-flavonoid grape intervention (60 g freeze-dried grape powder, equivalent to 300 g fresh grapes) and a low-flavonoid grape intervention (60 g powdere isocaloric-matched control). It is hypothesized that the high-flavonoid grape intervention will improve cortical oxygenation and cognitive function in the context of mental stress, and prevent the stress-induced decline in peripheral endothelial function following stress. Furthermore, it is hypothesized that individuals with poorer diets, cardiorespiratory fitness and a poorer gut microbiome will benefit more from the grape intervention in the context of mental stress.
More detail
Psychological stress is widespread in our societies, and has been extensively shown to have negative consequences for human health. Specifically, psychological stress induces significant declines in human vascular function, as measured by brachial Flow-mediated Dilatation (FMD). We have demonstrated that flavonoid interventions can prevent the harmful effects of stress on the vascular system. Indeed, flavonoid-rich interventions have also been extensively shown to improve peripheral and cerebrovascular function in the absence of stress. However, the effect of flavonoids on cerebrovascular function and cognition in the context of mental stress is unknown. In the proposed project, our key objectives are to investigate whether grape intake prior to a mental stress task results in better brain oxygenation and vascular function, which leads to improved cognitive performance and mood in young healthy adults. These data will establish whether grapes can be effective as a 'stress snack' to optimize cognitive and brain function in the context of psychological stress. Furthermore, we will explore whether there are certain participant characteristics that mediate the impact of grape flavonoids on cerebrovascular function and cognition in the context of mental stress. Such as, physical fitness (assessed by a VO2 max test), composition of gut microbiome (assessed by faecal sample), habitual diet (assessed by 3-day food diary and the food frequency questionnaire), and eating behaviour and chronic stress (assessed by the eating behaviour questionnaire and perceived stress scale). This work will be important to guide future dietary recommendations around stress and might ultimately result in increased intake of flavonoid-rich grapes and other flavonoid-rich fruits/vegetables overall.
How this trial compares with your answers
Answer 2 more questions to improve match
What we know so far
Still need:
- • Tell us your age for better matching
- • Tell us your sex for better matching
Preliminary match based on your answers. Full eligibility requires on-site assessment including medical history, physical exam, and lab tests. This does not guarantee enrolment.
Eligibility at a Glance
Key info
- Age: 18 Years - 40 Years
- Who can join: All genders
What the study is looking for
- ✓Males and females
- ✓18 - 40 years old
Who cannot take part
- ✗Smokers
- ✗Consumes \> 21 units of alcohol per week
- ✗History of cardiovascular, respiratory, metabolic, liver or inflammatory diseases
- ✗Suffers from blood-clotting disorders
- ✗Allergies or intolerances to foods
See the full criteria
Where Is This Study? (1 UK site)
School of Sport, Exercise & Rehabilitation Sciences
Birmingham B15 2TT, United Kingdom
