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Original Investigation
September 2018

Association Between Mediterranean Anti-inflammatory Dietary Profile and Severity of Psoriasis: Results From the NutriNet-Santé Cohort

Author Affiliations
  • 1Department of Dermatology, Mondor Hospital (AP-HP), Paris Est Créteil University, Créteil, France
  • 2Nutritional Epidemiology Research Team (EREN-CRESS), Paris 13 University, INSERM (U1153), INRA (U1125), CNAM, COMUE Sorbonne Paris Cité, Bobigny, France
  • 3Department of Public Health, Avicenne Hospital (AP-HP), Bobigny, France
  • 4Epidemiology in Dermatology and Evaluation of Therapeutics (EpiDermE), EA7379, Paris-Est University, UPEC, DHU VIC, Créteil, France
  • 5Clinical Investigation Center 1430, INSERM, Créteil, France
JAMA Dermatol. 2018;154(9):1017-1024. doi:10.1001/jamadermatol.2018.2127
Key Points

Question  Is there an association between the adherence to an anti-inflammatory Mediterranean diet and the onset and/or severity of psoriasis?

Findings  This prospective, web-based questionnaire study of 35 735 respondents from the French NutriNet-Santé cohort, of whom 3557 had psoriasis, found a statistically significant inverse association between adherence to the Mediterranean diet and severity of psoriasis, after adjustment for sociodemographic variables and confounding factors including age, sex, physical activity, body mass index, tobacco use, educational level, a history of cardiovascular disease, and depression.

Meaning  The Mediterranean diet may slow the progression of psoriasis, so an optimized diet should be part of the multidisciplinary management of moderate to severe psoriasis.


Importance  Psoriasis is a chronic inflammatory disease. The Mediterranean diet has been shown to reduce chronic inflammation and has a positive effect on the risk of metabolic syndrome and cardiovascular events. Thus, we hypothesized a positive effect on the onset and/or severity of psoriasis.

Objective  To assess the association between a score that reflects the adhesion to a Mediterranean diet (MEDI-LITE) and the onset and/or severity of psoriasis.

Design, Setting, and Participants  The NutriNet-Santé program is an ongoing, observational, web-based questionnaire cohort study launched in France in May 2009. The present study was performed within the framework of the NutriNet-Santé program, with data collected and analyzed between April 2017 and June 2017. Patients with psoriasis were identified via a validated online self-completed questionnaire and then categorized by disease severity: severe psoriasis, nonsevere psoriasis, and psoriasis-free. Data on dietary intake (including alcohol) were gathered during the first 2 years of participation in the cohort to calculate the MEDI-LITE score (ranging from 0 for no adherence to 18 for maximum adherence). Potentially confounding variables (eg, age, sex, physical activity, body mass index, tobacco use, and a history of cardiovascular disease) were also recorded. Analyses used adjusted multinomial logistic regression to estimate the risk of having severe psoriasis or nonsevere psoriasis compared with being psoriasis-free.

Results  Of the 158 361 total NutriNet-Santé participants, 35 735 (23%) replied to the psoriasis questionnaire. The mean (SD) age of the respondents was 47.5 (14.0) years; 27 220 (76%) of the respondents were women. Of these 35 735 respondents, 3557 (10%) individuals reported having psoriasis. The condition was severe in 878 cases (24.7%), and 299 (8.4%) incident cases were recorded (those arising more than 2 years after participant inclusion in the cohort). After adjustment for confounding factors, a significant inverse relationship was found between the MEDI-LITE score and having severe psoriasis: odds ratio (OR), 0.71; 95% CI, 0.55-0.92 for the MEDI-LITE score’s second tertile (score of 8 to 9); and OR, 0.78; 95% CI, 0.59-1.01 for the third tertile (score of 10 to 18).

Conclusions and Relevance  Patients with severe psoriasis displayed low levels of adherence to the Mediterranean diet; this finding supports the hypothesis that the Mediterranean diet may slow the progression of psoriasis. If these findings are confirmed, adherence to a Mediterranean diet should be integrated into the routine management of moderate to severe psoriasis.