Perimenopause is when you have symptoms of menopause but your periods have not stopped. Brain-related changes are just one of the many symptoms that occur, and changes to memory and concentration ("brain fog") are frequently reported to be a challenge to those experiencing them. Diet is also understood to play an important role during menopause, however there is still more to learn about the direct impact of nutrition on brain-related symptoms associated with perimenopause. The aim of this research is to identify mental tasks capable of capturing perimenopause-related changes and to better understand how diet might account for differences in mental task performance.

The study will employ a cross-sectional design. Sixty participants will be recruited (30 participants will be recruited who report being severely affected by cognition-related/brain fog symptoms and 30 participants will be recruited who do not report being severely affected).

Interested participants will follow a link to the study information and consent and will then answer the eligibility questions, including questions about medication/supplementation. Participants are directed to contact the researchers before continuing should any of their answers suggest they may not be eligible to participate. Demographic data will be collected and participants will then complete the Menopause Rating Scale (MRS), followed by the Brain Fog Scale (BFS) and a question asking specifically about how much they are currently affected by brain fog as a result of perimenopause. They will also complete a shortened version of the Adapted Muscle-Strengthening Exercise Questionnaire (A-MSEQ).

Following this participants will be auto directed by a separate link to Cognimapp (a web-based platform for cognitive and mood assessments that can be accessed via a mobile device) where they will complete a brief training session, after which they will complete a full run through of the cognitive tasks.

Once the cognitive tasks have been completed participants will be redirected to a second Qualtrics survey to complete the food frequency questionnaire (EPIC FFQ). Participants will then receive an online debrief and be redirected to a final questionnaire to capture their email address so that they may be compensated £20.

Inclusion Criteria:

• Aged 40-55 years
• Self-assess as healthy
• Experienced troublesome perimenopause symptoms for at least the past 6 months (as assessed by the Menopause Rating Scale)
• Not post-menopause (defined as 12 months with no periods)
• Non-smoker (including vaping)
• Not lactating or pregnant (or seeking pregnancy)
• Oral contraception and hormone replacement therapy allowed if taken for at least 3 months prior
• Cognitive symptoms/brain fog are not required for participation

Exclusion Criteria:

• Post-menopause (12 months with no periods)
• Medically induced perimenopause symptoms
• Antidepressant/antianxiety medication or other medication likely to affect cognition in the past 6 months
• Receiving gender-affirming hormone therapy
• Nutritional supplementation (apart from vitamin D) within the last month (more than 3 consecutive days or 4 total)

Perimenopausal women aged 40-55 years who report being severely affected by cognitive symptoms/brain fog and those who do not report being severely affected.

An anonymised dataset will be shared on this platform within the results section. Any information which may identify individual participants will be removed from the dataset before it is shared. Data will be shared in accordance with FAIR (findable, accessible, interoperable, reusable) principles. Participants will consent to the data being shared in this way.

Data will be available 3 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.

Fully accessible