Efficacy of Intermittent Fasting in the Management of Chronic Plaque Psoriasis: A Phase IIb Clinical Trial.

Background: Dietary measures have been used as an adjunctive therapy in the management of psoriasis. Intermittent fasting (IF) is an eating pattern in which energy is not consumed for a fixed duration, resulting in metabolic switch from liver-derived glucose to adipose-derived ketones. The data regarding effectiveness of IF in psoriasis are limited.

Aim and objectives: The aim of this study was to assess efficacy of IF in patients with chronic plaque psoriasis. The primary outcome of the study was change in psoriasis severity as measured by psoriasis area and severity index (PASI) at 28 weeks. The secondary outcome measures were change in metabolic parameters and biomarkers for atherosclerosis in each group.

Patients and methods: The study was designed as a randomized parallel group trial. Clinical parameters, psoriasis severity, fasting and postprandial blood sugar, lipid profile, high sensitivity C-reactive protein (hsCRP), vascular endothelial growth factor (VEGF), and interleukin 6 (IL-6), were measured using standard methods at baseline, 16 weeks, and 28 weeks. Patients were randomized to receive methotrexate in the dose of 0.3 mg/Kg/week with or without intermittent fasting.

Results: A total of 120 patients were randomized in two groups of 60 each: group 1 (methotrexate) and group 2 (methotrexate and intermittent fasting). The mean age, mean duration of disease, PASI, and dermatology life quality index (DLQI) in group 1 were 45.5 (±12.9) years, 5.06 (±5.5) years, 17.1 (±6.7), and 12.33 (±5), respectively. The mean age, mean duration of disease, PASI, and DLQI in group 2 were and 42.9 (±14.6) years, 6.91 (±6.2) years, 16 (±4.3), and 11.9 (±4.3), respectively. There was no statistically significant difference in baseline parameters in two groups. In both the groups, there was a statistically significant difference in PASI, DLQI, VEGF, and hsCRP from baseline to 16 and 28 weeks. At week 16, 44 (73.3%) patients in group 1 and 47 (78.3%) in group 2 achieved PASI50 (P = 0.8). At week 28, 16 (36%) in group 1 and 27 (54.4%) patients in group 2 maintained PASI50 (P = 0.054). There was a statistically significant weight and waist circumference reduction at 16 weeks and 28 weeks in group 2. There was a statistically significant reduction in VEGF, IL6, and hsCRP at 28 weeks in group 2 as compared to group 1.

Limitations: The small sample size and loss to follow-up are major limitations of the study.

Conclusion: Intermittent fasting using 16: 8 protocol is easy to perform and a safe and effective adjuvant for managing severe chronic plaque psoriasis. It helps in maintaining remission and results in improvement in metabolic parameters and markers of vascular inflammation.