Effects of High Adherence to Mediterranean or Low-Fat Diets in Medicated Secondary Prevention Patients

Abstract

Although the Mediterranean diet (MD) and the low-fat Therapeutic Lifestyle Changes Diet (TLCD) promote equivalent increases in event-free survival in secondary coronary prevention, possible mechanisms of such complete dietary patterns in these patients, usually medicated, are unclear. The aim of this study was to investigate the effects of the MD versus the TLCD in markers of endothelial function, oxidative stress, and inflammation after acute coronary syndromes. Comparison was made between 3 months of the MD (n = 21; rich in whole grains, vegetables, fruits, nuts, and olive oil, plus red wine) and the TLCD (n = 19; plus phytosterols 2 g/day) in a highly homogenous population of stable patients who experienced coronary events in the previous 2 years (aged 45 to 65 years, all men) allocated to each diet under a strategy designed to optimize adherence, documented as >90%. Baseline demographics, body mass index and clinical data, and use of statins and other drugs were similar between groups. The MD and TLCD promoted similar decreases in body mass index and blood pressure (p ≤0.001) and particularly in plasma asymmetric dimethylarginine levels (p = 0.02) and l-arginine/asymmetric dimethylarginine ratios (p = 0.01). The 2 diets did not further enhance flow-mediated brachial artery dilation compared to baseline (4.4 ± 4.0%). Compared to the TLCD, the MD promoted decreases in blood leukocyte count (p = 0.025) and increases in high-density lipoprotein levels (p = 0.053) and baseline brachial artery diameter. Compared to the MD, the TLCD decreased low-density lipoprotein and oxidized low-density lipoprotein plasma levels, although the ratio of oxidized to total low-density lipoprotein remained unaltered. Glucose, high-sensitivity C-reactive protein, triglycerides, myeloperoxidase, intercellular adhesion molecular, vascular cell adhesion molecule, and glutathione serum and plasma levels remained unchanged with either diet. In conclusion, medicated secondary prevention patients show evident although small responses to the MD and the TLCD, with improved markers of redox homeostasis and metabolic effects potentially related to atheroprotection.

Nut consumption for vascular health and cognitive function

“…In spite of this, endothelial functional improvement did not reach statistical significance (74) . A quantity of 10 -30 g nuts per d consumed by participants with either CVD risk or the metabolic syndrome also demonstrated no benefits on endothelial function (48,106) . Consumption of two doses (10 and 20 % of energy) of pistachios did not lead to a reduction in endothelial function (107) despite relatively high doses of up to 126 g/d consumed for 4 weeks.…”

“…A reduction in CRP was demonstrated in four studies with a portfolio diet containing either almonds (89,94,99) (14-30 g/d) or hazelnuts (30 g/d) (86) consumed for 4 weeks; one of these studies found an reduction equivalent to that observed with statin intake in the same individuals (89) . Beneficial improvements in inflammation observed in interventions which contained foods in addition to nuts (portfolio diet (88,89) or Mediterranean diet (47,48) ) may have been attributable to these other components. In contrast, Mediterranean diets in which walnuts (97) , mixed nuts (58,67) or pistachios (59) replaced olive oil demonstrated improvements in one or more of the inflammatory markers CRP, ICAM-1,VCAM-1 and IL-6, indicating that there may be some beneficial effect of nuts above that of other components of the Mediterranean diet.…”

“…Of the studies, four compared habitual or healthy diets with intervention diets including nuts (NORDIET (46) or a Mediterranean diet (47,48) ); only one of the studies reported controlling for salt intake (46) . The remaining studies used control diets with unsalted nuts added as the intervention but overall dietary salt intake was not specified.…”

“…However, other factors in the diet such as Na consumption may have contributed to the blood pressure elevation (despite being prescribed unsalted nuts); Na intake was not reported or controlled for in this study. Interventions using a portfolio diet (88,89) , NORDIET (46) or Mediterranean diet (47,48) contained foods other than nuts which may also have been beneficial for improvements in blood pressure, making it difficult to tease out the effects of nuts alone. In contrast, Mediterranean diets in which mixed nuts (58,67) replaced olive oil demonstrated improvements in blood pressure, indicating there may be some beneficial effect of nuts above that of other components of the Mediterranean diet.…”

“…One study used no control. Of the studies, four compared habitual or healthy diets with intervention diets including nuts (NORDIET (46) or a Mediterranean diet (47,48) ).…”