The Effects of a Mediterranean Diet Intervention on Targeted Plasma Metabolic Biomarkers among US Firefighters: A Pilot Cluster-Randomized Trial

Abstract

Metabolomics is improving the understanding of the mechanisms of the health effects of diet. Previous research has identified several metabolites associated with the Mediterranean Diet (MedDiet), but knowledge about longitudinal changes in metabolic biomarkers after a MedDiet intervention is scarce. A subsample of 48 firefighters from a cluster-randomized trial at Indianapolis fire stations was randomly selected for the metabolomics study at 12 months of follow up (time point 1), where Group 1 (n = 24) continued for another 6 months in a self-sustained MedDiet intervention, and Group 2 (n = 24), the control group at that time, started with an active MedDiet intervention for 6 months (time point 2). A total of 225 metabolites were assessed at the two time points by using a targeted NMR platform. The MedDiet score improved slightly but changes were non-significant (intervention: 24.2 vs. 26.0 points and control group: 26.1 vs. 26.5 points). The MedDiet intervention led to favorable changes in biomarkers related to lipid metabolism, including lower LDL-C, ApoB/ApoA1 ratio, remnant cholesterol, M-VLDL-CE; and higher HDL-C, and better lipoprotein composition. This MedDiet intervention induces only modest changes in adherence to the MedDiet and consequently in metabolic biomarkers. Further research should confirm these results based on larger study samples in workplace interventions with powerful study designs.

Special Issue “Mediterranean Diet and Metabolic Diseases”

“…The authors reported the beneficial effects of a higher MD adherence on both HDL-c and TG levels, the latter coinciding with more frequent olive oil intake, the main denominator of the MD. Results on HDL-c were in agreement with a cross-sectional study [ 7 ] and an intervention study [ 6 ] on healthy volunteers also included in the issue [ 6 ], and results on HDL-c and TG are in agreement with the systematic review published on metabolic syndrome specific risk factors [ 1 ]. The authors found that nutritional counselling improved adherence, as was also suggested by Grabia and colleagues in their study on T1DM women [ 2 ].…”

“…These results underline that in addition to the dietary transition seen the past decades in this region, the pandemic has further triggered unhealthy dietary choices that may further increase metabolic diseases, and the authors agree with Grabia and colleagues [ 2 ] and recommend dietary counseling to increase fruits, vegetables, and other foods close to the MD pattern. Moreover, the importance of dietary counseling on the lipid profile in healthy [ 6 , 7 ] and dyslipidemic individuals [ 3 ] was evident by intervention studies included in the present SI.…”

“…This SI contains multifaceted research articles and a systematic review, which have addressed these issues both in healthy individuals and in those with specifically defined disease states or risk factors. Specifically, this SI contains research that has been carried out in not only the general population, but also among patients with Type 1 diabetes mellitus (T1DM) [ 2 ] or dyslipidemia [ 3 , 4 , 5 ], as well as among firefighters who are proxy to healthy and physically fit individuals [ 6 , 7 ], adding valuable information to the pre-stated gap in knowledge.…”

“…Four of the studies included in this issue have been carried out in healthy volunteers [ 4 , 5 , 6 , 7 ]. Romanidou and colleagues reported that for a unitary increase in MD adherence, the ratio of total cholesterol to HDL-c decreased by 0.03 and HDL-c increased by 0.25 mg/dL in 460 firefighters, after adjusting for multiple confounders [ 7 ].…”

The use of functional food products for the prevention of vitamin deficiency in people with increased physical and neuropsychic stress on the example of firefighters-rescuers

“…The choice of the recipe composition of the instant granular drink was carried out taking into account the content of ingredients that enhance the positive effect on each other and on the body as a whole from the point of view of the prevention of vitamin deficiency in firefighters-rescuers. So, having carried out a number of studies and guided by literature data, the best composition of the drink is as follows: modified potato starch, powdered sugar, concentrated chokeberry juice, black chokeberry cake, thickened curd whey, native curd whey, citric acid [8][9].…”