Acute effects of a Mediterranean diet on mood and anxiety
Research type
Research Study
Full title
MediMood: A randomised controlled trial investigating the acute impact of a plant based Mediterranean-style dietary pattern (MDP) on mood, anxiety and cognition in UK adults with mild to moderate mental health complaints
IRAS ID
320471
Contact name
Anne Marie Minihane
Contact email
Sponsor organisation
University of East Anglia
Clinicaltrials.gov Identifier
Duration of Study in the UK
0 years, 10 months, 0 days
Research summary
Depression, anxiety and age-related cognitive decline are leading global public health problems. A plant-based Mediterranean-style dietary pattern (MDP) includes olive oil as the main source of fat, fresh fruits, vegetables, seafood, legumes and nuts and a low consumption of red and processed meat, confectionary, and high-sugar drinks. A MDP promotes both physical and mental wellbeing and brain function. However, most studies to date have examined the impact of a MDP on health over months or years. As several underpinning biological mechanisms are likely to be responsive within hours or days, examining the short-term effect of a MDP on mental health outcomes is important.
In this study we aim to test whether a MDP can enhance mood, anxiety and cognition (brain function) following a meal (postprandial) and over 5-days in adults over 18 years with mild to moderate mental health problems (low mood and anxiety). Participants who are already following a MDP or have unstable use of antidepressant and/or antianxiety medications (i.e. medication has changed over the last 3 months, or the likely to change over the course of the study) will be excluded. Participants will be assigned to both a MDP and a Western diet (WD) for 5-days in a random order with a 4-week break period. We will conduct several computer-based tests measuring mood, anxiety and cognitive performance over the five days, brain imaging (MRI), and collection and analyses of blood, urine and faecal samples will also be carried out. The study will be conducted in the NHS Clinical Research Facility (CRF, Quadram Institute) by the Norwich Medical School, University of East Anglia (UEA) and Norfolk and Norwich University Hospitals (NNUH). As low mood, anxiety and stress disorders affect daily functioning and reduce the quality of life significantly for many, we believe the findings have wide public health application.
Lay summary of study results: A total of 396 individuals expressed an interest in the MediMood study, with n=25 participating in the MediMood trial, with n=22 completing both 5-day dietary interventions, attending all clinical assessment and completing all study questionnaires.The mean age of the participants was 42 years, with 16/25 female, and 9 on antidepressant medications. Relative to the poor-quality Western Diet, the Mediterranean style dietary pattern (MDP) resulted in an improvement in mental health outcomes, including contentment, anxiety, depression, vigour, fatigue and confusion, with a 40% improved total mood disturbance (a composite measure of these mental well-being outcomes). The beneficial effects were greatest in non-antidepressant medication users. Lower inflammation (as assessed by blood CRP) and body weight was evident following 5 days on the MDP, along with predicted beneficial changes to the gut microbiome.
REC name
London - Queen Square Research Ethics Committee
REC reference
22/LO/0796
Date of REC Opinion
8 Feb 2023
REC opinion
Further Information Favourable Opinion