High adherence to the Mediterranean diet is associated with a significantly reduced risk of developing systemic lupus erythematosus (SLE). This protective effect may be partially mediated by specific metabolic biomarkers, according to study results published in Rheumatology.
Researchers evaluated the association between adherence to the Mediterranean diet and the risk of developing SLE and explored whether liver, kidney, lipid, and glucose-related biomarkers mediate this relationship. Data for the analysis were sourced from the United Kingdom Biobank and included participants who completed at least 1 dietary assessment.
Adherence to the Mediterranean diet was assessed through repeated Oxford WebQ dietary questionnaires, with scores calculated via a modified 13-point Mediterranean Diet Adherence Screener (MEDAS). Lupus diagnoses were identified using electronic codes from multiple health data sources
Among the 203,119 participants, 55.2% were women and the mean age was 59.5 years. Participants with lower vs higher MEDAS scores were more often men, had higher body mass index, were more likely to smoke, and consumed fewer vitamin and mineral supplements.
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…[T]he anti-inflammatory and immunomodulatory effects of [the Mediterranean Diet] may reduce SLE risk by improving liver and renal function biomarkers.
Over a median follow-up of 10.6 years, 127 new cases of SLE were identified. Compared against participants with low MEDAS scores, those in the high adherence group had a significantly lower risk of developing SLE, with hazard ratios (HRs) of 0.561 (95% CI, 0.348-0.904), 0.599 (95% CI, 0.371-0.966), and 0.61 (95% CI, 0.374-0.995) across 3 adjusted models. No significant association was observed for the medium adherence group.
Results of sensitivity analyses supported the robustness of these findings, demonstrating consistent protective effects even when the sample was limited to White European participants or adjusted for socioeconomic status. Notably, the protective effect of Mediterranean diet adherence was stronger among low-income individuals (HR, 0.54; 95% CI, 0.308-0.952; P =.033).
Results of mediation analyses identified 4 biomarkers as partial mediators of the relationship between Mediterranean diet adherence and SLE risk, accounting for 0.32% (aspartate aminotransferase), 2.16% (gamma glutamyltransferase), 3.05% (urate), and 4.61% (cystatin C) of the effect.
Study limitations include the low number of SLE cases and limited generalizability to patients with younger-onset SLE. Additionally, the inability to quantify olive oil intake may have led to dietary misclassification and reliance on single-source diagnoses for most SLE cases raises the risk for misclassification bias.
The study authors concluded, “Given that SLE involves abnormal immune activation and chronic inflammation, the anti-inflammatory and immunomodulatory effects of [the Mediterranean Diet] may reduce SLE risk by improving liver and renal function biomarkers.”
This article originally appeared on Rheumatology Advisor
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