Dietary counseling could play an important role in the treatment of patients with psoriatic arthritis, contributing to better disease activity control.
Results from a 12-week hypocaloric intervention indicated that patients with psoriatic arthritis (PsA) were able to obtain control of joint disease activity, according to a study published in Advances in Rheumatology.1 Omega-3 supplementation aided in body composition changes but did not improve disease activity.
“Recently, it was demonstrated that an increased body mass index (BMI) caused a 50-fold greater likelihood of having PsA, as well as a lower chance of achieving disease remission and worse response to pharmacological treatment, including a higher switching rate,” investigators explained.
In total, 97 adult patients with PsA were included in the randomized, double-blinded, placebo-controlled study. Patients were randomized into 3 groups: diet-fish (hypocaloric diet along with 3 g/day of omega-3 supplementation), diet-placebo (hypocaloric diet plus placebo), and placebo. Food intake, body composition, and disease activity were analyzed at baseline and week 12.
A 3-day registry, Healthy Eating Index (HEI), and the Dietary Inflammation Index (DII) was used to evaluate food intake. Body composition was determined by a whole-body dual-energy X-ray absorptiometry (DXA), as well as weight and waist circumference. Disease activity was measured by the psoriasis area severity index (PASI), body surface area (BSA), minimal disease activity (MDA), the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Disease Activity Score-28 (DAS28) for both erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). The intention-to-treat approach was used in the statistical analysis.
Patients in both diet cohorts received an individualized nutrition plan, including macros and fiber consumption, and were encouraged to have 3 main meals, 2 or 3 snacks, increase water intake, avoid processed foods, and eat more fruits and vegetables. Investigators implemented 24-hour diet records that were analyzed in monthly meetings. Fluctuations in weight and waist circumference were recorded. Patients were asked about drug use, physical activity, gut changes, sleep patterns, and side effects.
Demographics, disease duration, disease activity, and concomitant medications were similar among all groups at baseline.
At week 12, both DAS28-CRP and BASDAI scores improved, particularly in the diet-placebo group (− 0.6 ± 0.9; p = 0.004 and − 1.39 ± 1.97; p = 0.001, respectively), which was nearly 3 times higher than the placebo cohort.
The diet-fish cohort reported more weight loss (− 1.79 ± 2.4; p = 0.004) as well as reductions in waist circumference (− 3.28 ± 3.5, p < 0.001) and body fat (− 1.2 ± 2.2, p = 0.006) when compared with the other 2 groups. However, there was no significant association between reduced disease activity and weight loss. Additionally, patients achieved MDA in higher proportions across all treatment arms (p = 0.006).
After the 12-week intervention, investigators noted significant increases in fiber, omega-3, vitamin B1, B2, B3, B6, B12, and vitamin D intake, which led to a decrease in DII among the 3 groups.
A 1-unit increase in HEI reduced achieving remission by 4%. Every 100-calorie increase was linked to a 3.4-fold DAS28-ESR impairment (OR = 0.34; 95% CI 0.002–0.67; p = 0.039).
A limitation of the study was that nonpharmacologic interventions historically have low adherence rates. Additionally, dietary changes and food intake information was ultimately subjective. Further, it was difficult to encourage longer and more relevant alterations to a patient’s diet, as dietary patterns are linked to economic status, emotions, culture, and habits. Another limitation was the short 12-week follow-up period. However, this is the first randomized clinical trial that assessed the effectiveness of dietary modifications plus omega-3 supplementation in this patient population. Additionally, as there were no changes to physical activity or medications during this time, investigators were able to draw conclusions on the role of diet in the context of immunometabolism.
“Dietary counseling aimed at losing or controlling weight could be part of the global protocol for PsA patients,” investigators concluded. “In addition, supervised exercises could contribute to weight loss, lean mass gain and better disease activity control.”
Leite BF, Morimoto MA, Gomes CMF, et al. Dietetic intervention in psoriatic arthritis: the DIETA trial. Adv Rheumatol. 2022;62(1):12. Published 2022 Apr 6. doi:10.1186/s42358-022-00243-6