The Mediterranean diet (MedDiet) has demonstrated short-term anti-inflammatory effects, but little is known about its long-term immunomodulatory properties.
Our goal was to assess the long-term ...effects of the MedDiet on inflammatory markers related to atherogenesis in adults at high risk of cardiovascular disease (CVD) compared with the effects of a low-fat diet (LFD).
We randomly assigned 165 high-risk participants (one-half men; mean age: 66 y) without overt CVD to 1 of 3 diets: a MedDiet supplemented with extra-virgin olive oil, a MedDiet supplemented with nuts, or an LFD. Follow-up data were collected at 3 and 5 y. Repeated-measures ANOVA, adjusted for potential confounding variables, was used to evaluate changes in diet adherence, CVD risk factors, and inflammatory variables.
The 2 MedDiet groups achieved a high degree of adherence to the intervention, and the LFD group had reduced energy intake from fat by 13% by 5 y. Compared with baseline, at 3 and 5 y, both MedDiet groups had significant reductions of ≥16% in plasma concentrations of high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor α, and monocyte chemoattractant protein 1 (P ≤ 0.04), whereas there were no significant changes in the LFD group. The reductions in CD49d and CD40 expressions in T lymphocytes and monocytes at 3 y were ≥16% greater in both MedDiet groups than were the changes in the LFD group (P < 0.001) at 3 y. Compared with baseline, at 3 y, the MedDiet groups had increased HDL-cholesterol (≥8%) and decreased blood pressure (>4%) and total cholesterol, LDL-cholesterol, and triglyceride (≥8%) concentrations. At 5 y, concentrations of glucose (13%) and glycated hemoglobin (8%) had increased with the LFD.
The MedDiet participants had lower cellular and plasma concentrations of inflammatory markers related to atherosclerosis at 3 and 5 y. This anti-inflammatory role of the MedDiet could explain in part the long-term cardioprotective effect of the MedDiet against CVD. This trial was registered at controlled-trials.com as ISRCTN35739639.
Purpose
To investigate the effect of virgin olive oil phenolic compounds (PC) alone or in combination with thyme PC on blood lipid profile from hypercholesterolemic humans, and whether the changes ...generated are related with changes in gut microbiota populations and activities.
Methods
A randomized, controlled, double-blind, crossover human trial (
n
= 12) was carried out. Participants ingested 25 mL/day for 3 weeks, preceded by 2-week washout periods, three raw virgin olive oils differing in the concentration and origin of PC: (1) a virgin olive oil (OO) naturally containing 80 mg PC/kg, (VOO), (2) a PC-enriched virgin olive oil containing 500 mg PC/kg, from OO (FVOO), and (3) a PC-enriched virgin olive oil containing a mixture of 500 mg PC/kg from OO and thyme, 1:1 (FVOOT). Blood lipid values and faecal quantitative changes in microbial populations, short chain fatty acids, cholesterol microbial metabolites, bile acids, and phenolic metabolites were analysed.
Results
FVOOT decreased seric ox-LDL concentrations compared with pre-FVOOT, and increased numbers of bifidobacteria and the levels of the phenolic metabolite protocatechuic acid compared to VOO (
P
< 0.05). FVOO did not lead to changes in blood lipid profile nor quantitative changes in the microbial populations analysed, but increased the coprostanone compared to FVOOT (
P
< 0.05), and the levels of the faecal hydroxytyrosol and dihydroxyphenylacetic acids, compared with pre-intervention values and to VOO, respectively (
P
< 0.05).
Conclusion
The ingestion of a PC-enriched virgin olive oil, containing a mixture of olive oil and thyme PC for 3 weeks, decreases blood ox-LDL in hypercholesterolemic humans. This cardio-protective effect could be mediated by the increases in populations of bifidobacteria together with increases in PC microbial metabolites with antioxidant activities.
Glycolysis/gluconeogenesis and tricarboxylic acid (TCA) cycle metabolites have been associated with type 2 diabetes (T2D). However, the associations of these metabolites with T2D incidence and the ...potential effect of dietary interventions remain unclear.
We aimed to evaluate the association of baseline and 1-y changes in glycolysis/gluconeogenesis and TCA cycle metabolites with insulin resistance and T2D incidence, and the potential modifying effect of Mediterranean diet (MedDiet) interventions.
We included 251 incident T2D cases and 638 noncases in a nested case-cohort study within the PREDIMED Study during median follow-up of 3.8 y. Participants were allocated to MedDiet + extra-virgin olive oil, MedDiet + nuts, or control diet. Plasma metabolites were measured using a targeted approach by LC–tandem MS. We tested the associations of baseline and 1-y changes in glycolysis/gluconeogenesis and TCA cycle metabolites with subsequent T2D risk using weighted Cox regression models and adjusting for potential confounders. We designed a weighted score combining all these metabolites and applying the leave-one-out cross-validation approach.
Baseline circulating concentrations of hexose monophosphate, pyruvate, lactate, alanine, glycerol-3 phosphate, and isocitrate were significantly associated with higher T2D risk (17–44% higher risk for each 1-SD increment). The weighted score including all metabolites was associated with a 30% (95% CI: 1.12, 1.51) higher relative risk of T2D for each 1-SD increment. Baseline lactate and alanine were associated with baseline and 1-y changes of homeostasis model assessment of insulin resistance. One-year increases in most metabolites and in the weighted score were associated with higher relative risk of T2D after 1 y of follow-up. Lower risks were observed in the MedDiet groups than in the control group although no significant interactions were found after adjusting for multiple comparisons.
We identified a panel of glycolysis/gluconeogenesis-related metabolites that was significantly associated with T2D risk in a Mediterranean population at high cardiovascular disease risk. A MedDiet could counteract the detrimental effects of these metabolites. This trial was registered at controlled-trials.com as ISRCTN35739639.
Objective. To evaluate the long-term effects of a Mediterranean diet (MeDiet) intervention on the plasma concentrations of inflammatory and plaque stability-related molecules in elderly people at ...high risk for cardiovascular disease. Design and Setting. 66 participants from primary care centers affiliated with the Hospital Clinic of Barcelona were randomized into 3 groups: MeDiet plus extra virgin olive oil (EVOO) or nuts and a low-fat diet (LFD). At baseline and at 3 and 5 years, we evaluated the changes in the plasma concentrations of 24 inflammatory biomarkers related to the different stages of the atherosclerotic process by Luminex®. Results. At 3 and 5 years, both MeDiet groups showed a significant reduction of IL-6, IL-8, MCP-1, and MIP-1β (P<0.05; all) compared to LFD. IL-1β, IL-5, IL-7, IL-12p70, IL-18, TNF-α, IFN-γ, GCSF, GMCSF, and ENA78 (P<0.05; all) only decreased in the MeDiet+EVOO group and E-selectin and sVCAM-1 (P<0.05; both) in the MeDiet+nuts group. Conclusions. Long-term adherence to MeDiet decreases the plasma concentrations of inflammatory biomarkers related to different steps of atheroma plaque development in elderly persons at high cardiovascular risk.
Abstract Background There has been a substantial increase in the use of laparoscopic sleeve gastrectomy (SG) to treat morbid obesity despite observational evidence demonstrating the superiority of ...Roux-en-Y gastric bypass (RYGB) for reducing low-density lipoprotein (LDL) cholesterol. The main aim was to ascertain whether high LDL cholesterol levels should be considered when selecting the most appropriate surgical procedure for each patient (RYGB or SG). Methods In this single-center, randomized clinical trial using intention-to-treat analysis, 38 patients with severe obesity and elevated levels of LDL cholesterol were randomly assigned to undergo RYGB or SG. The primary outcome was LDL cholesterol remission at 12 months, defined as LDL cholesterol < 3.36 nmol/l without lipid-lowering medications. Secondary outcomes included changes in weight, other comorbidities, qualitative lipoprotein traits, cholesterol esters, glycoproteins, cholesterol absorption and synthesis metabolites and complications. Results Intention-to-treat analysis revealed that LDL cholesterol remission occurred in 66.6% of RYGB patients compared to 27.8% of SG patients ( p = 0.019). Among patients completing follow-up, RYGB demonstrated superior remission (80.0% vs. 29.4%, p = 0.005). Exclusive benefits of RYGB included a reduction in large, medium, and small LDL particles. Cholesterol absorption markers showed differential behavior after both techniques: campesterol (Δ −15.2 µg/mg, 95% CI −30.2 to −0.1) decreased after RYGB, and sitosterol (Δ 21.1 µg/mg, 95% CI 0.9 to 41.2), cholestanol (Δ 30.6 µg/mg, 95% CI 14.8 to 57.9) and campesterol (Δ 18.4 µg/mg, 95% CI 4.4 to 32.3) increased after SG. No differences in weight loss, cholesterol esters, glycoproteins, cholesterol synthesis metabolites or postoperative complications were observed between techniques. Conclusion In conclusion, RYGB is superior to SG in terms of short-term of high LDL cholesterol remission. Furthermore, RYGB also led to a greater improvement in lipoprotein parameters that confer an atherogenic profile. Therefore, the presence of elevated levels of LDL cholesterol should be considered when determining the optimal bariatric surgery procedure for each patient. Trial registration Clinicaltrials.gov number, NCT03975478). Graphical abstract
Childhood obesity is a major international problem, and unhealthy eating habits remain widespread. Increasing the frequency of meals of nutritious food can help children to regulate their appetite ...and maintain a healthy weight. However, there is scarce prospective evidence on the relationship between the meal frequency and weight outcomes. Therefore, the objective of the present study was to determine the prospective association between the meal frequency, body mass index, and waist circumference in Spanish children. Additionally, we analyzed the impact of the meal frequency on the incidence of excessive weight and abdominal obesity. The study included 1400 children with a mean (SD) age of 10.1 (0.6) and an average follow-up of 15 months. Anthropometric measurements, including the body weight, height, and waist circumference, were measured by trained personnel, and children were asked about whether they usually had the following meals: breakfast, a mid-morning snack, lunch, an afternoon snack, and dinner. Multiple linear regression models revealed a significant (
< 0.05) inverse association between the meal frequency with a standardized BMI (zBMI) and the waist-to-height ratio (WHtR) after adjusting for sex, age, allocation to an intervention group, school, maternal education, physical activity, diet quality, and for the corresponding outcome variable at the baseline. Furthermore, the odds of developing abdominal obesity or excessive weight during the follow-up significantly decreased with an increase in the meal frequency after controlling for the same confounders. In conclusion, a higher meal frequency at the baseline was predictive for a lower zBMI, WHtR, and odds of the incidence of excessive weight and abdominal obesity.
An altered gut microbiota has been associated with insulin resistance, a metabolic dysfunction consisting of cellular insulin signaling impairment. The aim of the present study is to determine the ...taxonomic and functional fecal microbiota signatures associated with HOMA-IR index in a population with high cardiovascular risk.
A total of 279 non-diabetic individuals (55-75 years aged) with overweight/obesity and metabolic syndrome were stratified according to tertiles of HOMA-IR index. Blood biochemical parameters, anthropometric measurements and fecal samples were collected at baseline. Fecal microbial DNA extraction, 16S amplicon sequencing and bioinformatics analysis were performed.
,
and
UCG-002 were negatively associated with HOMA-IR index, whereas predicted total functional abundances revealed gut metabolic modules mainly linked to amino acid degradation.
,
UCG-003,
were positively associated with HOMA-IR index, whereas predicted total functional abundances revealed gut metabolic modules mainly linked to saccharide degradation. These bacteria contribute differentially to the gut metabolic modules, being the degree of contribution dependent on insulin resistance. Both taxa and gut metabolic modules negatively associated to HOMA-IR index were linked to mechanisms involving sulfate reducing bacteria, improvement of intestinal gluconeogenesis and production of acetate. Furthermore, both taxa and gut metabolic modules positively associated to HOMA-IR index were linked to production and mechanisms of action of butyrate.
Specific taxonomic and functional fecal microbiota signatures associated with insulin resistance were identified in a non-diabetic population with overweight/obesity at high cardiovascular risk. These findings suggest that tailoring therapies based on specific fecal microbiota profiles could be a potential strategy to improve insulin sensitivity.
Scope
Lipoprotein particle measures performed by nuclear magnetic resonance (NMR), and associated ratios, may be better markers for atherosclerosis risk than conventional lipid measures. The effect ...of two functional olive oils, one enriched with its polyphenols (FVOO, 500 ppm), and the other (FVOOT) with them (250 ppm) and those of thyme (250 ppm), versus a standard virgin olive oil (VOO), on lipoprotein particle atherogenic ratios and subclasses profiles was assessed.
Methods and results
In a randomized, double‐blind, crossover, controlled trial, 33 hypercholesterolemic individuals received 25 mL/day of VOO, FVOO, and FVOOT. Intervention periods were of 3 weeks separated by 2‐week washout periods. Lipoprotein particle counts and subclasses were measured by NMR. Polyphenols from olive oil and thyme modified the lipoprotein subclasses profile and decreased the total LDL particle/total HDL particle (HDL‐P), small HDL/large HDL, and HDL‐cholesterol/HDL‐P ratios, and decreased the lipoprotein insulin resistance index (LP‐IR) (p < 0.05).
Conclusion
Olive oil polyphenols, and those from thyme provided benefits on lipoprotein particle atherogenic ratios and subclasses profile distribution. Polyphenol‐enriched olive oil is a way of increasing the olive oil healthy properties while consuming the same amount of fat, as well as a useful and complementary tool for the management of cardiovascular risk individuals.
Volunteers (n = 33) followed a 2‐week wash out period (WO; olive oil with a very low phenolic content) between the 3‐week interventions:
VOO: Control Virgin Olive Oil (VOO).
FVOO: Functional VOO enriched with phenolic compounds from VOO.
FVOOT: FVOO enriched with polyphenols from VOO and thyme.
Samples were analyzed by NMR. Main outcomes include an improvement in the lipoprotein subclasses profile and a decrease in LDL‐P/HLD‐P, HDL‐C/HDL‐P, and s‐HDL/l‐HDL atherogenic ratios, and in the LipoProtein‐Insulin Resistance Index.
The Mediterranean diet (MedDiet) has demonstrated efficacy in preventing age-related cognitive decline and modulating plasma concentrations of endocannabinoids (eCBs) and N-acylethanolamines (NAEs, ...or eCB-like compounds), which are lipid mediators involved in multiple neurological disorders and metabolic processes. Hypothesizing that eCBs and NAEs will be biomarkers of a MedDiet intervention and will be related to the cognitive response, we investigated this relationship according to sex and apolipoprotein E (APOE) genotype, which may affect eCBs and cognitive performance. This was a prospective cohort study of 102 participants (53.9% women, 18.8% APOE-É4 carriers, aged 65.6 + or - 4.5 years) from the PREDIMED-Plus-Cognition substudy, who were recruited at the Hospital del Mar Research Institute (Barcelona). All of them presented metabolic syndrome plus overweight/obesity (inclusion criteria of the PREDIMED-Plus) and normal cognitive performance at baseline (inclusion criteria of this substudy). A comprehensive battery of neuropsychological tests was administered at baseline and after 1 and 3 years. Plasma concentrations of eCBs and NAEs, including 2-arachidonoylglycerol (2-AG), anandamide (AEA), oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and N-docosahexaenoylethanolamine (DHEA), were also monitored. Baseline cognition, cognitive changes, and the association between eCBs/NAEs and cognition were evaluated according to gender (crude models), sex (adjusted models), and APOE genotype. At baseline, men had better executive function and global cognition than women (the effect size of gender differences was - 0.49, p = 0.015; and - 0.42, p = 0.036); however, these differences became nonsignificant in models of sex differences. After 3 years of MedDiet intervention, participants exhibited modest improvements in memory and global cognition. However, greater memory changes were observed in men than in women (Cohen's d of 0.40 vs. 0.25; p = 0.017). In men and APOE-epsilon4 carriers, 2-AG concentrations were inversely associated with baseline cognition and cognitive changes, while in women, cognitive changes were positively linked to changes in DHEA and the DHEA/AEA ratio. In men, changes in the OEA/AEA and OEA/PEA ratios were positively associated with cognitive changes. The MedDiet improved participants' cognitive performance but the effect size was small and negatively influenced by female sex. Changes in 2-AG, DHEA, the OEA/AEA, the OEA/PEA and the DHEA/AEA ratios were associated with cognitive changes in a sex- and APOE-dependent fashion. These results support the modulation of the endocannabinoid system as a potential therapeutic approach to prevent cognitive decline in at-risk populations.
Abstract
Background
Several large observational prospective studies have reported a protection by the traditional Mediterranean diet against type 2 diabetes, but none of them used yearly repeated ...measures of dietary intake. Repeated measurements of dietary intake are able to improve subject classification and to increase the quality of the assessed relationships in nutritional epidemiology. Beyond observational studies, randomized trials provide stronger causal evidence. In the context of a randomized trial of primary cardiovascular prevention, we assessed type 2 diabetes incidence according to yearly repeated measures of compliance with a nutritional intervention based on the traditional Mediterranean diet.
Methods
PREDIMED (‘‘PREvención con DIeta MEDiterránea’’) was a Spanish trial including 7447 men and women at high cardiovascular risk. We assessed 3541 participants initially free of diabetes and originally randomized to 1 of 3 diets: low-fat diet (n = 1147, control group), Mediterranean diet supplemented with extra virgin olive (n = 1154) or Mediterranean diet supplemented with mixed nuts (n = 1240). As exposure we used actual adherence to Mediterranean diet (cumulative average), yearly assessed with the Mediterranean Diet Adherence Screener (scoring 0 to 14 points), and repeated up to 8 times (baseline and 7 consecutive follow-up years). This score was categorized into four groups: < 8, 8–< 10, 10– < 12, and 12–14 points. The outcome was new-onset type 2 diabetes.
Results
Multivariable-adjusted hazard ratios from time-varying Cox models were 0.80 (95% confidence interval, 0.70–0.92) per + 2 points in Mediterranean Diet Adherence Screener (linear trend p = .001), and 0.46 (0.25–0.83) for the highest (12–14 points) versus the lowest (< 8) adherence. This inverse association was maintained after additionally adjusting for the randomized arm. Age- and sex-adjusted analysis of a validated plasma metabolomic signature of the Mediterranean Diet Adherence Screener (constituted of 67 metabolites) in a subset of 889 participants also supported these results.
Conclusions
Dietary intervention trials should quantify actual dietary adherence throughout the trial period to enhance the benefits and to assist results interpretation. A rapid dietary assessment tool, yearly repeated as a screener, was able to capture a strong inverse linear relationship between Mediterranean diet and type 2 diabetes.
Trial registration
ISRCTN35739639
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