ORIGINAL ARTICLE Effects of Italian Mediterranean organic diet vs. low-protein diet in nephropathic patients according to MTHFR genotypes Nicola Di Daniele • Laura Di Renzo • Annalisa Noce • Leonardo Iacopino • Pietro Manuel Ferraro • Mariagiovanna Rizzo • Francesca Sarlo • Emidio Domino • Antonino De Lorenzo Received: 2 July 2013 / Accepted: 14 December 2013 Ó Italian Society of Nephrology 2014 Abstract Background Several reports associate an Italian-style Mediterranean diet (IMD) with lower risk of cardiovascular disease and morbidity. The present study aimed to explore the effects of an Italian Mediterranean organic diet (IMOD) versus low-protein diet (LPD) in chronic kidney disease (CKD) patients, according to patients’ carrier status for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism. Methods A total of 40 male patients with CKD and stable renal function (Kidney Disease Outcomes Quality Initia- tive stages 2 and 3) were classified according to MTHFR polymorphism as carrier T(?) or non carrier T(-). At the time of enrolment (T0) patients’ diet consisted of LPD; they were then administered IMD for 14 days (T1), thereupon IMOD for 14 days (T2). Patients underwent a complete medical history, body composition assessment and biochemical analysis. Results Baseline homocysteine levels were on average 8.24 mol/l higher (95 % confidence interval 6.47, 10.00) among T(?) than T(-) and the difference was statistically significant (p \ 0.001). We found a significant interaction between MTHFR status and the effect of both the IMD and IMOD on homocysteine levels compared to LPD (p for interaction \ 0.001). Both the IMD and IMOD resulted in significant variations of anthropometric and laboratory measurements. Conclusions IMD and IMOD diets could represent a viable alternative to LPD in CKD patients on conservative therapy. The effect of these diets seems to be influenced by MTHFR genotypes. Keywords Body composition Á Cardiovascular disease risk Á Chronic kidney disease Á C677T MTHFR polymorphism Á Italian Mediterranean organic diet Introduction In patients with chronic kidney disease (CKD), the rate of mortality from cardiovascular disease is 10- to 20-fold higher than that seen in the general population, even after correction for age, sex, race and the presence of diabetes [1]. Hyperhomocysteinemia has been identified as a pre- dictor of atherosclerotic complications in the general population. It is also frequent among patients with renal failure [2] and several studies have shown that in CKD hyperhomocysteinemia is a risk factor for cardiovascular complications [3]. Hyperhomocysteinemia at an earlier stage of renal disease could also accelerate the progression of chronic renal disease. Homocysteine (Hcy) causes endothelial cell dysfunction and injury via production of reactive oxygen species during its autoxidation [4]. N. Di Daniele Á A. Noce Department of Systems Medicine, Hypertension and Nephrology Unit, University of ‘‘Tor Vergata’’, 00133 Rome, Italy L. Di Renzo Á L. Iacopino Á M. Rizzo Á F. Sarlo Á E. Domino Á A. De Lorenzo (&) Division of Clinical Nutrition and Nutrigenomics, Department of Biomedicine and Prevention, University of ‘‘Tor Vergata’’, 00133 Rome, Italy e-mail: delorenzo@uniroma2.it L. Di Renzo Á A. De Lorenzo I.N.Di.M, National Institute for Mediterranean Diet and Nutrigenomics, 87032 Amantea, Italy P. M. Ferraro Division of Nephrology-Renal Program, Department of Medical Sciences, Catholic University of the Sacred Heart, Rome, Italy 123 J Nephrol DOI 10.1007/s40620-014-0067-y