MedicalResearch.com Interview with:
Jordi Salas-Salvadó Professor of Nutrition
Human Nutrition Unit Department of Biochemistry & Biotechnology
IISPV School of Medicine.
Rovira i Virgili University CIBERobn, Instituto Carlos III
Medical Research: What are the main findings of the study?
Response: In this large, multicenter, randomized clinical trial conducted in Mediterranean individuals at high cardiovascular risk, Mediterranean-diet supplemented with extra-virgin olive oil was associated to a lower increase in the prevalence of metabolic syndrome compared to the advice on a control low-fat diet. However, no beneficial effect of Mediterranean-diet on the incidence of metabolic syndrome among participants free of this condition at baseline was observed. Therefore, the lower increase in prevalence was especially due to the reversion of metabolic syndrome in those individuals with metabolic syndrome at baseline.
Medical Research: What was most surprising about the results?
Response: The novelty of our findings is that the lower increase in prevalence or the higher reversion rate of metabolic syndrome that was mainly observed in those individuals allocated to the Mediterranean diet supplemented with extra-virgin olive oil. This could be attributed to differences in the dietary pattern as no differences in weight loss or energy expenditure from physical activity occurred between interventions.
Our findings are not consistent with data from observational studies showing a beneficial effect of Mediterranean diet on metabolic syndrome incidence. Of note, that these previous studies were conducted using a design of short duration. Our study is the first that assessed the effect of Mediterranean-diet on metabolic syndrome during a long time of follow-up.
Medical Research: What should clinicians and patients take away from your report?
Response: The important take-home message of our report is that a healthy diet, like the Mediterranean Diet, with a moderate-high intake of vegetable fat (in form of virgin olive oil or nuts) is a good healthy option for the prevention of several cardiovascular risk factors and chronic disease. Many Mediterranean-diet constituents are likely to be beneficial on metabolic syndrome reversion and in ameliorating several Mediterranean-diet components. We consider that the Mediterranean-diet, as a whole dietary pattern, is responsible for improving metabolic profile rather than its individual’s constituents.
Medical Research: What recommendations do you have for future research as a result of this study?
Response: During the last decades a low-fat diet was promoted worldwide, as a consequence people consume too much refined carbohydrates. The PREDIMED study has demonstrated that is more important the quality of fat than the amount of fat.
We have demonstrated in the present analysis that a Mediterranean-diet enriched with virgin olive oil or a mixture of nuts (hazelnuts, almonds and walnuts) is beneficial in the reversion of Metabolic Syndrome. However, more studies on the incidence of Metabolic Syndrome would be helpful probably including healthy individuals.
It is important to highlight that our sample was composed of older participants at high-risk of cardiovascular-disease, and then our findings cannot be generalized to the general population. So, more studies are needed to demonstrate these results are also consistent on general population.
Mediterranean diets and metabolic syndrome status in the PREDIMED randomized trial
CMAJ cmaj.140764; published ahead of print October 14, 2014, doi:10.1503/cmaj.140764
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