Table 3.
Selected studies showing an association between dietary exposures and Rheumatoid Arthritis (RA) risk.
| Exposure | First Author | Study type | Cohort | Outcome | Risk of exposure | # RA cases | Reference |
|---|---|---|---|---|---|---|---|
| Mediterranean Diet | Johansson | Case-Control | Sweden (EIRA) | RA | Exposure (high): RA OR 0.79, RF+ RA OR 0.69 | 1721 | (103) |
| Mediterranean Diet | Nguyen | Retrospective Cohort | France (E3N) | RA | Exposure (high): RA OR 0.91 (in smokers) | 480 | (104) |
| Fish | Sparks | Retrospective Cohort | USA (Nurses Health Study) | Sero+/- RA | Exposure (high): Sero- RA HR 0.55 (females < 55 yo) | 1080 | (105) |
| Fish | Shapiro | Case-Control | USA | RA | Exposure (high): RA OR 0.57 | 324 | (106) |
| Omega-3 FA/Fish | Di Giuseppe | Retrospective Cohort | Sweden (Swedish Mammography Cohort) | RA | Exposure omega-3 (high): RA RR 0.65, Exposure Fish (high): RR 0.71 (ns) | 205 | (107) |
| Vitamin D | Merlino | Retrospective Cohort | USA (Iowa Women’s Health study) | RA | Exposure (high): RA RR 0.67 | 152 | (108) |
| Vitamin D | Hiraki | Case-Control | USA (Nurses Health Study) | RA | Circulating levels (high): RA OR 0.8 (3 months to 4 years before diagnosis) | 166 | (109) |
| Vitamin D | Song | Meta-analysis (3 Retrospective Cohort) | Multiple | RA | Exposure (high): RA RR 0.76 | 874 | (110) |
| Vitamin D, Omega-3 and combination | Hahn | Randomized controlled trial (secondary analysis) | USA (VITAL Study) | RA | Exposure Vitamin D: RA HR 0.87 (ns), Exposure Omega-3: RA HR 0.80 (ns), Exposure Omega-3 and Vitamin D: RA HR 0.27 | 45 | (111) |
Sero+/-, seropositive or seronegative; ACPA, anti-citrullinated protein antibodies; EIRA, Epidemiological Investigation of Rheumatoid Arthritis; RR, Relative Risk; OR, Odds Ratio; HR, Hazards Ratio. NS, not significant. All RR/OR/HR are statistically significant unless otherwise stated.