1. Geir Smedslund, Ph.D.: Diakonhjemmet Hospital (DH)
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Geir Smedslund, Ph.D.: Diakonhjemmet Hospital (DH)
Marte G Byfuglien: DH
Sissel U Olsen: DH
Kåre B Hagen: DH
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

2. Background Study overview
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Study overview
Background
For decades patients have used diet manipulation for possibly altering the symptoms of Rheumatoid Arthritis (RA). Diet manipulations might influence the body through several different mechanisms, like decreasing an inflammatory process, increasing antioxidant levels, changing the lipid profile, and changing the bacterial flora.
The question of benefits and harms of certain diets in RA is still a “burning question” for many patients and health care providers.
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

3. Objective Baseline data
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Baseline data
Objective
To assess the effectiveness and safety of dietary interventions for patients with RA when compared to usual diet.
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

4. BMI & Psychosocial measures
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
BMI & Psychosocial measures
Methods
Types of studies:
Randomized controlled trials (RCT)
Interventions:
Any diet manipulation, such as elimination diets, diets labeled as Mediterranean, Cretan, any vegetarian, acid-base balance and fasting were included. Dietary supplement studies were not permitted (including fish oil supplements).
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

5. BMI & Psychosocial measures
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
BMI & Psychosocial measures
Methods
Search strategy for identification of studies:
Relevant studies were identified by electronic searches (up to September 2006) in Cochrane Central Register of Controlled Trials, Medline, Embase, AMED and Cinahl. Reference lists of included studies and relevant reviews were scanned and authors of included studies were contacted.
Methodological assessment:
Two reviewers independently assessed the trials according to: Random generation of allocation, Concealment of allocation, Co-intervention, Blinding of provider or patient, Blinding of outcome assessor, Losses to follow up and Intention-to-treat
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

6. Results Correlation matrix
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Correlation matrix
Results
Eight RCTs published between 1979 and 2003 with a total of 366 patients were included.
Six trials were assessed to have moderate risk of bias, while two had high risk of bias.
Due to insufficient data reporting and heterogeneity in interventions and outcome measures, no overall effects were calculated.
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

7. Possible beneficial effects
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Correlation matrix
Possible beneficial effects
Most trials reported small to moderate beneficial effects of the experimental diet in some outcomes
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

8. Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Country, type of diet, duration of diet, number of patients, and summary effects for each of the 8 included studies
+ followed by
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

9. Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Outcomes for different diets. 7 to 10 days fasting followed by vegetarian diet
Study
Outcome
Effect Estimate (95%CI)
Sköldstam 1979 (n=25)
Pain change (0 to 10) 9 weeks follow-up.
Stiffness change (0 to 10) 9 weeks follow-up
Mean difference: [-2.98, 1.18] 
Mean difference: [-3.09, 1.69]
Kjeldsen-Kragh 1991 (n=34)
Pain (0 to 10) 13 months follow-up
Physical function (HAQ*, 0 to 3) 13 months follow-up
Morning stiffness (hrs) 13 months follow-up
Mean difference: [-3.62, -0.16
Mean difference: [-0.48, 0.34]
Mean difference: [-2.23, 0.07]
*Health and Activity Questionnaire
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

10. Outcomes for different diets. Vegan diet
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Outcomes for different diets. Vegan diet
Study
Outcome
Effect Estimate (95%CI)
Hafström 2001 (n = 61)
Response rate ACR20 criteria 12 months follow-up
Relative risk : 8.91 [1.24, 64.30
ACR20 = American College of Rheumatology criteria for improvement in Rheumatoid Arthritis
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

11. Outcomes for different diets. Mediterranean diet
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Outcomes for different diets. Mediterranean diet
Study
Outcome
Effect Estimate (95%CI)
Sköldstam 2003 (n = 51)
Pain (0 to 100) 12 weeks follow-up
Function (HAQ, 0 to 3) 12 weeks follow-up
Morning stiffness (min) 12 weeks follow-up
Mean difference: [-23.63, -4.37
Mean difference: [-0.48, 0.08]
Mean difference: [-58.08, 6.08]
*Health and Activity Questionnaire
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

12. Outcomes for different diets. Elemental diet
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Outcomes for different diets. Elemental diet
Study
Outcome
Effect Estimate (95%CI)
Kavanagh 1995 (n=47)
Function 4 weeks follow-up
Mean difference:-0.80 [-4.37, 2.77]
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

13. Possible adverse effects
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Possible adverse effects
Although potential adverse effects were poorly reported, no severe
adverse effects were reported. However, the experimental diet was
associated with higher weight loss, total drop out rates and treatment related drop out.
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

14. Meta-analysis of the effect of dietary interventions on total dropout.
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Meta-analysis of the effect of dietary interventions on total dropout.
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

15. Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Meta-analysis of the effect of dietary interventions on treatment-related dropout.
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

16. Meta-analysis of the effect of dietary interventions on body weight
Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Meta-analysis of the effect of dietary interventions on body weight
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).

17. Effectiveness and safety of dietary interventions for rheumatoid arthritis: A systematic review of randomized controlled trials
Figure
Conclusions
The effects of dietary manipulation, including vegetarian, Mediterranean, elemental and elimination diets, on rheumatoid arthritis remain uncertain. Studies included in this analysis were small, single arm trials with moderate to high risk of bias.
Higher drop-out rates and weight loss in the groups with dietary manipulation signal potential adverse effects that should not be ignored.
JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION
Smedslund et al. J Am Diet Assoc. 2010; Volume 110 (May).