Dietary interventions for rheumatoid arthritis

Vegan diets and hypothyroidism

Diets eliminating animal products have rarely been associated with hypothyroidism but may protect against autoimmune disease. Thus, we investigated whether risk of hypothyroidism was associated with vegetarian compared to omnivorous dietary patterns. The Adventist Health Study-2 was conducted among church members in North America who provided data in a self-administered questionnaire. Hypothyroidism was queried at baseline in 2002 and at follow-up to 2008. Diet was examined as a determinant of prevalent (n = 4237 of 65,981 [6.4%]) and incident cases (1184 of 41,212 [2.9%]) in multivariate logistic regression models, controlled for demographics and salt use. In the prevalence study, in addition to demographic characterstics, overweight and obesity increased the odds (OR 1.32, 95% CI: 1.22–1.42 and 1.78, 95% CI: 1.64–1.93, respectively). Vegan versus omnivorous diets tended to be associated with reduced risk (OR 0.89, 95% CI: 0.78–1.01, not statistically significant) while a lacto-ovo diet was associated with increased risk (OR 1.09, 95% CI: 1.01–1.18). In the incidence study, female gender, white ethnicity, higher education and BMI were predictors of hypothyroidism. Following a vegan diet tended to be protective (OR 0.78, 95% CI: 0.59–1.03, not statistically significant). In conclusion, a vegan diet tended to be associated with lower, not higher, risk of hypothyroid disease.

Non-pharmacological interventions for fatigue in rheumatoid arthritis

BACKGROUND

Fatigue is a common and potentially distressing symptom for people with rheumatoid arthritis with no accepted evidence based management guidelines. Non-pharmacological interventions, such as physical activity and psychosocial interventions, have been shown to help people with a range of other long-term conditions to manage subjective fatigue.

OBJECTIVES

To evaluate the benefit and harm of non-pharmacological interventions for the management of fatigue in people with rheumatoid arthritis. This included any intervention that was not classified as pharmacological in accordance with European Union (EU) Directive 2001/83/EEC.

SEARCH METHODS

The following electronic databases were searched up to October 2012, Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; AMED; CINAHL; PsycINFO; Social Science Citation Index; Web of Science; Dissertation Abstracts International; Current Controlled Trials Register; The National Research Register Archive; The UKCRN Portfolio Database. In addition, reference lists of articles identified for inclusion were checked for additional studies and key authors were contacted.

SELECTION CRITERIA

Randomised controlled trials were included if they evaluated a non-pharmacological intervention in people with rheumatoid arthritis with self-reported fatigue as an outcome measure.

DATA COLLECTION AND ANALYSIS

Two review authors selected relevant trials, assessed risk of bias and extracted data. Where appropriate, data were pooled using meta-analysis with a random-effects model.

MAIN RESULTS

Twenty-four studies met the inclusion criteria, with a total of 2882 participants with rheumatoid arthritis. Included studies investigated physical activity interventions (n = 6 studies; 388 participants), psychosocial interventions (n = 13 studies; 1579 participants), herbal medicine (n = 1 study; 58 participants), omega-3 fatty acid supplementation (n = 1 study; 81 participants), Mediterranean diet (n = 1 study; 51 participants), reflexology (n = 1 study; 11 participants) and the provision of Health Tracker information (n = 1 study; 714 participants). Physical activity was statistically significantly more effective than the control at the end of the intervention period (standardized mean difference (SMD) -0.36, 95% confidence interval (CI) -0.62 to -0.10; back translated to mean difference of 14.4 points lower, 95% CI -4.0 to -24.8 on a 100 point scale where a lower score means less fatigue; number needed to treat for an additional beneficial outcome (NNTB) 7, 95% CI 4 to 26) demonstrating a small beneficial effect upon fatigue. Psychosocial intervention was statistically significantly more effective than the control at the end of the intervention period (SMD -0.24, 95% CI -0.40 to -0.07; back translated to mean difference of 9.6 points lower, 95% CI -2.8 to -16.0 on a 100 point scale, lower score means less fatigue; NNTB 10, 95% CI 6 to 33) demonstrating a small beneficial effect upon fatigue. For the remaining interventions meta-analysis was not possible and there was either no statistically significant difference between trial arms or findings were not reported. Only three studies reported any adverse events and none of these were serious, however, it is possible that the low incidence was in part due to poor reporting. The quality of the evidence ranged from moderate quality for physical activity interventions and Mediterranean diet to low quality for psychosocial interventions and all other interventions.

AUTHORS' CONCLUSIONS

This review provides some evidence that physical activity and psychosocial interventions provide benefit in relation to self-reported fatigue in adults with rheumatoid arthritis. There is currently insufficient evidence of the effectiveness of other non-pharmacological interventions.