Table 1.
Effect of citrus peels, extracts, and juices on cognitive function and mental health.
| Intervention or Cohort Analysis | Dosage or Frequency | Study Design | Subjects | Duration | Reference |
|---|---|---|---|---|---|
| Cognitive health | |||||
| Nobiletin-containing test food (Nobilex®) | 3 capsules (containing 30 mg nobiletin and 17.4 mg tangeretin) | Randomized, double-blind, placebo-controlled trial | Healthy elderly individuals (n = 108), aged over 65 | 16 weeks | [48] |
| Nobiletin-rich ponkan peel powder and perilla seed oil | 1.12 g ponkan peel powder (containing 2.91 mg nobiletin) and 1.47 mL perilla seed oil | Randomized, double-blind, parallel-armed trial | Healthy elderly individuals (n = 49), aged 60–85 | 12 months | [49] |
| Nobiletin-rich citrus peel extract | 30 g of citrus peels boiled in 500 mL of water and concentrated to 300 mL | Randomized, double-blind, placebo-controlled trial | Alzheimer's disease patients taking donepezil (n = 11) | 12 months | [50] |
| High flavanone orange juice | 500 mL (flavanone 305 mg) | Randomized, double-blind, placebo-controlled crossover trial | Healthy elderly people (n = 37), aged 60–81 | 8 weeks | [51] |
| Flavonoid-rich orange juice | 240 mL (flavonoid 272 mg) | Randomized, double-blind, placebo-controlled, crossover trial | Healthy middle-aged adults (n = 24), aged 30–65 | Acute | [52] |
| Flavanone-rich orange juice | 500 mL (flavanone 70.5 mg) | Randomized, single-blind, cross over trial | Healthy young adults (n = 40), aged 18–30 | Acute | [53] |
| Auraptene-rich Kawachi Bankan extract | 125 mL (auraptene 6 mg) | Randomized double-blind, placebo-controlled trial | Healthy elderly people (n = 82), aged 62–80 | 24 weeks | [54] |
| Daily citrus intake | 3–4 or more times per week | Retrospective cohort study | 13,373 adults (over 65 years) | 5.7 years follow up | [55] |
| Mental health | |||||
| Daily citrus intake | Total dietary flavonoid intake | Prospective cohort study | 82,643 women, aged 36–55 and 53–80 | 10 years follow up | [56] |
| Flavonoid rich orange juice | 380 mL (flavonoid 600 mg) | Randomized single-blind trial | Depressive symptoms in young individuals (n = 40), aged 20–30 | 8 weeks | [57] |
| Citrus sinensis essential oils | Diffused through electric dispenser | Randomized trial | Patients undergoing treatment at a dental (n = 72), aged 22–57 | Acute | [58] |
| Citrus aurantium or lavender essential oils | Inhalation of 5 drops of lavender or Citrus aurantium essential oils for 30 min | Randomized, parallel group placebo-controlled trial | Subjects admitted to intensive care units (n = 150), aged 18–60 | Acute | [59] |
| Flavanone-rich bergamot polyphenol fraction | 1000 mg | Open-label pilot study | Patients diagnosed with schizophrenia (n = 20), aged 20–58 | 8 weeks | [60] |