This is a randomized, double-blind, placebo-controlled, cross-over trial investigating the effects of daily administration of citrus extract on sleep and mental wellbeing.

Based on epidemiological data, a substantial number of people report to have sleeping problems. This is of major concern, as poor sleep quality has been associated with impaired mental and physical health. Several pre-clinical studies have shown promising results, but evidence from human studies is still limited. Therefore, the aim of the present study is to investigate the effect of a citrus extract on sleep and mental wellbeing in healthy subjects with (minor) sleep disturbance.

Inclusion Criteria:

• Healthy individuals with (minor) sleep disturbance
• Age 40-70 years
• BMI 18.5 - 30 kg/m2
• Willingness to give up being a blood donor from 4 weeks before the start of the study, during the study and for 4 weeks after completion of the study

Exclusion Criteria:

• Excessive caffeine use
• Major psychiatric/mental health disorders .
• Chronic sleep disorders
• Severe sleep disturbance for more than 1 year
• Other clear causes for poor sleep quality or mental wellbeing
• Use of medication or supplements that can affect outcomes
• Nonpharmacological treatment for sleep disorders
• Flight from a time-zone with >3 h difference ≤1 week before an intervention period
• Administration of investigational drugs or participation in any scientific intervention study which may interfere with this study
• Use of pre-, pro- or synbiotics within 1 month prior to the start of the study
• Reported weight loss or weight gain of >3 kg in the month prior to pre-study screening
• Smoking
• Abuse of products
• Known allergy to citruses
• Known pregnancy or lactation