Table 1.
Characteristics of observational and intervention studies.
| First author | Country | Study design | Duration | Participants (n) | Dietary assessment method | Intervention and control groups | Main findings |
|---|---|---|---|---|---|---|---|
| Mannikko et al. 2015 (24) | Finland | Cohort | 4 years | Men and women aged 57–78 years (n = 1,140) | 4-day food records | – | High adherence to ND: ↑ Cognitive function |
| Hansen et al. 2017 (22) | Denmark | Cohort | 13.5 years | Men and women aged 50 to 64 years (n = 55,338) | FFQ | – | High adherence to ND: ↓ Risk of stroke |
| Haapala et al. 2015 (52) | Finland | Cross-sectional | – | Children aged 6–8 years (n = 428) | 4-day food records | – | Low adherence to ND: ↓ Cognition in boys |
| Sørensen et al. 2015 (53) | Denmark | RCT (cross-over) | 3 months | Children aged 8–11 years (n = 726) | 7-day web-based dietary assessment software | Intervention group: NDD school meals Control group: usual school meals |
↑ School performance ↑ Reading comprehension ↑ LCPUFA status ↔ Ferritin and Hb |
| Sørensen et al. 2015 (54) | Denmark | RCT (cross-over) | 3 months | Children aged 8–11 years (n = 693) | 7-day web-based dietary assessment software | Intervention group: NDD school meals Control group: usual school meals |
↔ Concentration performance ↑ Reading speed |
| Sabet et al. 2021 (55) | Sweden | RCT | 8 days | Depressed and non-depressed subjects (n = 16) | Meal evaluation questionnaire | Intervention group: ND Control group: control diet |
↓ Depressive symptoms |
| Abbaszadeh et al., 2020 (56) | Iran | Cross-sectional | – | Female students aged 18–25 (n = 181) | FFQ | – | High adherence to ND: ↓ Stress and anxiety score ↑ Quality of life score |
| Shakersain et al., 2018 (57) | Sweden | Cohort | 6 years | Dementia-free adults aged ≥60 (n = 2,223) | FFQ | – | Moderate to high adherence to ND: ↓ Cognitive decline |
FFQ, Food frequency questionnaire; ND, Nordic diet; NDD, New Nordic diet; LCPUFA, Long-chain polyunsaturated fatty acids; Hb, Hemoglobin.