The effectiveness of the Mediterranean diet in reducing cholesterol

Abstract

i. Overview of the topic: Serum cholesterol is associated with atherosclerotic cardiovascular disease (ASCVD), mainly low-density lipoprotein (LDL-C) being atherogenic. Hypercholesterolaemia is a worldwide concern (Grundy et al., 2018). To combat this, adherence to cardioprotective diets, such as a Mediterranean diet (MedDiet), was highlighted for its contribution towards lipid profile improvement. ii. The research question: In adults, is a Mediterranean diet more effective than alternative diets in reducing cholesterol levels? iii. PICO elements: Adult population (P) studied included those who are at increased risk of CVD. To compliment this, all four randomised controlled trials (RCTs) that were selected as key studies, recruited individuals with hypercholesterolaemia (Athyros et al., 2011; Bos et al., 2010; Casas et al., 2016; Sofi et al., 2018). The intervention (I) was a MedDiet. The comparison (C) was alternative diets. The final desired outcome (O) was an improvement in cholesterol levels. iv. Method: Key elements from the PICO question were used as keywords/phrase to generate alternative synonyms and combined using ‘Boolean Operators.’ These were inputted in databases. The PRISMA 2009 checklist and flow-chart were used to guide this review. After inclusion criteria were applied, a total of seven articles were eligible. These included two systematic reviews (SR) with meta-analysis, one meta-analysis and four RCTs. The CASP tools were used to critically and systematically appraise articles. v. Limiters, inclusion and exclusion criteria applied: Human adults i.e. ≥ 18 years, English language and from 2008-October 2018 were included. SR, meta analysis, RCTs and cohort studies were searched. MedDiet was part of the intervention being enriched or not. The comparison involved other diets, excluding other lifestyle modifications. The outcome of studies had to include cholesterol values. vi. The main results and conclusions: Reports from the included studies showed significance which favoured the MedDiet intervention; however, a vegetarian diet and plant stanol esters lowered LDL-C. All studies intervention outcomes, showed one or more cholesterol values as significant. Studies lacked in analysing the whole spectrum of lipid values (Ajala et al. 2013, Esposito et al. 2015 & Nordmann et al. 2011). Further research is recommended to answer the effectiveness of such diets in question clearly. vii. Implications and relevant recommendations: Empowering individuals to take control of their health is the key. Educational campaigns on MedDiet are vital via a combination of approaches. There must be a sense of direction and coherence through local strategies. Early detection of those at high risk of hypercholesterolaemia must be identified through the development of serum samples for biochemistry analysis. Management must provide guidelines and further research via larger samples to elicit a need in all populations to follow a healthy diet.