Health effects of a low-inflammatory diet in adults with arthritis: a systematic review and meta-analysis

Abstract

The aim is to systematically assess the health impact of a low-inflammatory diet intervention (full-diet or supplement), compared to usual diet or other dietary interventions, on weight change, inflammatory biomarkers, joint symptoms, and quality of life in adults with osteoarthritis, rheumatoid arthritis or seronegative arthropathy (psoriatic, reactive, ankylosing spondylitis or IBD-related), on outcomes assessed in prospective studies within 6 months of intervention commencement (PROSPERO CRD42019136567). Search of multiple electronic library databases from inception to July 2019, supplemented by grey literature searches, for randomised and prospective trials assessing the above objective. After exclusion of 446 ineligible studies, five randomised and two prospective trials involving 468 participants with either osteoarthritis or rheumatoid arthritis were included. GRADE assessment for all outcomes was very low. Meta-analyses produced the following standardised mean differences (SMD) and 95 % confidence interval (CI) 2–4 months following commencement of the diets favouring the low-inflammatory diet: weight SMD −0⋅45 (CI −0⋅71, −0⋅18); inflammatory biomarkers SMD −2⋅33 (CI −3⋅82, −0⋅84). No significant effects were found for physical function (SMD −0⋅62; CI −1⋅39, 0⋅14), general health (SMD 0⋅89; CI −0⋅39, 2⋅16) and joint pain (SMD −0⋅98; CI −2⋅90, 0⋅93). In most studies, the quality of dietary intervention (dietitian input, use of validated dietary compliance tool) could not be gauged. In conclusion, very low-level evidence suggests that low-inflammatory diets or supplements compared to usual diets are associated with greater weight loss and improvement in inflammatory biomarkers. More high-quality trials are needed to assess the health effects of a low-inflammatory diet more comprehensively and conclusively in arthritic conditions.

Efficacy of therapeutic fasting and plant-based diet in patients with rheumatoid arthritis (NutriFast): study protocol for a randomised controlled clinical trial

“…A meta-analysis by Genel et al 76 suggests health benefits of a low-inflammatory diet for adults with arthritis (calorie-reduced regimens or fasting excluded). However, the quality of existing clinical trials is questionable—what is missing are professionally led nutritional interventions and a combined evaluation of laboratory and PROs.…”

Diet and Chronic Non-Cancer Pain: The State of the Art and Future Directions

“…Elma et al found that in 12 experimental and observational studies, vegetarian, vegan, weight loss, or peptide diets were associated with improved pain outcomes (evidence level 1b) [ 83 ]. Two other systematic reviews (evidence level 1b) in people with arthritis ( n = 7 studies) and fibromyalgia ( n = 7 studies) included studies with interventions focused on diets that are predominantly plant rich and/or contain anti-inflammatory aspects (e.g., Mediterranean diet, omega-3, or antioxidants) where participants had a reduction in pain outcomes [ 84 , 86 ]. Commonalities among all of these interventions include a focus on improving diet quality and nutrient density.…”

“…All the systematic reviews exploring the role of nutrition in pain management (evidence level 1b) emphasised optimising diet quality [ 82 , 83 , 84 , 85 , 86 ]. Poor diet quality is associated with high consumptions of energy-dense nutrient foods that lack key nutrients found in core foods such as fruits, vegetables, breads and cereals, meat, dairy, and their alternatives.…”

“…All of the systematic reviews (level 1b) included a large number of studies that used plant-rich eating (e.g., vegetarian or vegan dietary patterns), anti-inflammatory, and Mediterranean diets [ 82 , 83 , 84 , 85 , 86 ]. A major component of all of these dietary patterns are fruits, vegetables, and whole grains, which contain phytonutrients with antioxidant properties.…”

“…A number of experimental studies included in the systematic reviews (level 1b) that have been synthesised for this paper have shown that long chain and monounsaturated fats, especially omega-3 fats and olive oil reduce pain [ 82 , 83 , 84 , 85 , 86 ]. Suggestions on how to increase omega-3 fats and olive oil can be found in Appendix A .…”