Considerations to facilitate a US study that replicates PREDIMED

Mediterranean Diet and Cardiovascular Prevention: Why Analytical Observational Designs Do Support Causality and Not Only Associations

Causal reductions in cardiovascular disease (CVD) with the Mediterranean diet (MedDiet) are supported by randomized trials, but the ability of nonrandomized studies to provide causal inferences in nutritional epidemiology is questioned. The "Seguimiento Universidad de Navarra" (SUN) project, conducted during 1999-2019 with 18,419 participants, was used to try to refute non-causal explanations for the inverse association found between adherence to the MedDiet and reduced CVD risk. A framework of different analytical strategies is proposed: alternative definitions of the exposure, exploration of residual confounding, resampling methods, depiction of absolute risks across the follow-up period, trial emulation, and negative controls. Additionally, we calculated the rate advancement period (RAP). We found that one standard deviation increase in the most frequently used MedDiet score was associated with a 29% relative reduction in CVD risk (95% Confidence Interval [CI] 14-41%), which is almost identical to that found in 2 randomized trials. The RAP of CVD would be postponed by an average of 7.9 years (95% CI: 1.6 to 14.2 years) by switching from low (MDS = 0 to2) to high (MDS = 7 to 9) adherence to the MedDiet in the fully adjusted model. Sensitivity analyses, graphical representations of absolute risks, trial emulation, and negative controls also supported causality. In conclusion, a framework of analytical approaches supported the causal effect of the MedDiet on CVD prevention using observational data. Similar methodology could be applied for causal inferences regarding other hypotheses.

Evaluation of Simplified Diet Scores Related to C-Reactive Protein in Heavy Smokers Undergoing Lung Cancer Screening

The aim of this study was to assess the relationship between adherence to a healthy diet, such as the Mediterranean diet (MedDiet), and C-reactive protein (CRP) in Italian heavy smokers undergoing an LDCT screening program (bioMILD trial), using scores calculated by simple questionnaires. Simple formats of food frequency questionnaires were administered to a sample of 2438 volunteers, and the adherence to a healthy diet was measured by the validated 14-point MEDAS and by two adaptations proposed by us: 17-item revised-MEDAS and 18-item revised-MEDAS. The OR of CRP ≥ 2 mg/L for 1-point increase in 14-point MEDAS score was 0.95 (95% CI 0.91–0.99), for 17-point score was 0.94 (95% CI 0.91–0.98), and for 18-point score was 0.92 (95% CI 0.88–0.97). These inverse associations remained statistically significant also after further adjustment for body mass index. These results showed the efficacy of simplified scores and their relationship with lower levels of CRP in a population of heavy smokers. This suggests that a targeted nutritional intervention might achieve a substantial reduction in CRP levels. The findings will be prospectively tested in a new randomized study on primary prevention during lung cancer screening.

Application of Mediterranean Diet in Cardiovascular Diseases and Type 2 Diabetes Mellitus: Motivations and Challenges

Objective: Cardiovascular disease (CVD) is the leading cause of disability and death in many countries. Together with CVD, Type 2 diabetes mellitus (T2DM) accounts for more than 80% of all premature non-communicable disease deaths. The protective effect of the Mediterranean diet (MedDiet) on CVD and its risk factors, including T2DM, has been a constant topic of interest. Notwithstanding, despite the large body of evidence, scientists are concerned about the challenges and difficulties of the application of MedDiet. This review aims to explore the motivations and challenges for using MedDiet in patients with CVD and T2DM. Design: An electronic search was conducted for articles about MedDiet published in PubMed, ScienceDirect, Scopus, and Web of Science up to December 2021, particularly on CVD and T2DM patients. From a total of 1536 studies, the final eligible set of 108 studies was selected. Study selection involved three iterations of filtering. Results: Motivation to apply MedDiet was driven by the importance of studying the entire food pattern rather than just one nutrient, the health benefits, and the distinct characteristics of MedDiet. Challenges of the application of MedDiet include lacking universal definition and scoring of MedDiet. Influences of nutritional transition that promote shifting of traditional diets to Westernized diets further complicate the adherence of MedDiet. The challenges also cover the research aspects, including ambiguous and inconsistent findings, the inexistence of positive results, limited evidence, and generalization in previous studies. The review revealed that most of the studies recommended that future studies are needed in terms of health benefits, describing the potential benefits of MedDiet, identifying the barriers, and mainly discussing the effect of MedDiet in different populations. Conclusions: In general, there is consistent and strong evidence that MedDiet is associated inversely with CVD risk factors and directly with glycemic control. MedDiet is the subject of active and diverse research despite the existing challenges. This review informs the health benefits conferred by this centuries-old dietary pattern and highlights MedDiet could possibly be revolutionary, practical, and non-invasive approach for the prevention and treatment CVD and T2DM.

How to Measure Adherence to a Mediterranean Diet in Dental Studies: Is a Short Adherence Screener Enough? A Comparative Analysis

This study aimed to evaluate the Mediterranean Diet Adherence Screener (MEDAS) in a study investigating the anti-inflammatory effect of a 6-week Mediterranean diet intervention on periodontal parameters. Data from a randomized clinical trial were analyzed for correlations between the MEDAS score and oral inflammatory parameters (bleeding on probing (BOP), gingival index (GI), and periodontal inflamed surface area (PISA)) and select nutrient intakes estimated by a food frequency questionnaire (FFQ) and a 24-h dietary recall (24dr). A mixed model, calculations of Spearman ρ, Lin’s Concordance Coefficient (CC), and Mann–Whitney U test were used for the statistical analyses. The MEDAS score was significantly negatively correlated with periodontal inflammation (BOP: CoE −0.391, p < 0.001; GI −0.407, p < 0.001; PISA −0.348, p = 0.001) and positively correlated with poly unsaturated fatty acids/total fat, vitamin C, and fiber intake estimates obtained from the FFQ and 24dr (ρ 0.38–0.77). The FFQ and 24dr produced heterogeneously comparable intake results for most nutrients (CC 0–0.79, Spearman ρ 0.16–0.65). Within the limitations of this study, the MEDAS was able to indicate nutritional habits associated with different levels of periodontal inflammation. Accordingly, the MEDAS can be a sufficient and useful diet screener in dental studies. Due to its correlation with oral inflammatory parameters, the MEDAS might also be useful in dental practice.

The Role of Health Literacy among Outpatient Caregivers during the COVID-19 Pandemic

Health literacy became an important competence during the COVID-19 pandemic. Despite outpatient caregivers being a particularly vulnerable occupational group, their health literacy has hardly been examined yet, especially during the pandemic. Hence, this study aimed to explore this field and provide first empirical insights. Data were collected based on a cross-sectional online survey among 155 outpatient caregivers. In particular, health literacy (HLS-EU-Q16), diet and physical activity, pandemic-related worries, perceived information sufficiency and stress perception were examined. Descriptive and ordinal logistic regression analyses were run to test explorative assumptions. The majority of outpatient caregivers reported high values of health literacy (69% on a sufficient level). Although no significant associations between health literacy and health behaviours or perceived information sufficiency were found, perceived information sufficiency and perceived stress (OR = 3.194; 95% CI: 1.542-6.614), and pandemic-related worries (OR = 3.073; 95% CI: 1.471-6.421; OR = 4.243; 95% CI: 2.027-8.884) seem to be related. Therefore, dissemination of reliable information and resource-building measures to reduce worries may be important parameters for improving outpatient caregivers' health. Our results provide first explorative insights, representing a starting point for further research. Considering outpatient caregivers' mobile work setting, they need to be provided with adequate equipment and comprehensible information to ensure physically and mentally healthy working conditions.

The Health Behaviour of German Outpatient Caregivers in Relation to the COVID-19 Pandemic: A Mixed-Methods Study

The COVID-19 pandemic has affected outpatient caregivers in a particular way. While the German population becomes increasingly older, the number of people in need of care has also increased. The health and, thus, the health behaviour of employees in the outpatient care become relevant to maintain working capacity and performance in the long term. The aims of the study were (1) to examine the health behaviour and (2) to explore pandemic-related perceived change of health behaviour among outpatient caregivers during the COVID-19 pandemic. In a mixed-methods study, 15 problem-centred interviews and a web-based cross-sectional survey (N = 171) were conducted with outpatient caregivers working in Northern Germany. Interviewees reported partially poorer eating behaviour, higher coffee consumption, lower physical activity, skipping breaks more often and less sleep duration and quality during the pandemic. Some quantitative findings indicate the same tendencies. A majority of participants were smokers and reported higher stress perception due to the pandemic. Preventive behaviour, such as wearing PPE or hand hygiene, was increased among interviewees compared to the pre-pandemic period. Our findings indicate that the COVID-19 pandemic could negatively affect outpatient caregivers' health behaviour, e.g., eating/drinking behaviour and physical activity. Therefore, employers in outpatient care should develop workplace health promotion measures to support their employees in conducting more health-promoting behaviours during the COVID-19 pandemic.

Telehealth-delivered, Cardioprotective Diet and Exercise Program for Liver Transplant Recipients: A Randomized Feasibility Study

Rapid excess weight gain and metabolic complications contribute to poor outcomes following liver transplant care. Providing specialist lifestyle intervention with equitable access is a challenge for posttransplant service delivery.

METHODS

This study investigated the feasibility of a 12-wk telehealth delivered lifestyle intervention for liver transplant recipients (randomized controlled trial with a delayed intervention control group). The intervention included 14 group sessions facilitated by nutrition and exercise specialists via video streaming telehealth and participants used their own devices. Feasibility was assessed across session attendance, the adequacy, acceptability, and confidence with the telehealth technology and adherence to diet (Mediterranean Diet Adherence Score). Secondary pooled analysis of effectiveness was determined from changes in quality of life and metabolic syndrome severity score.

RESULTS

Of the 35 participants randomized, dropout was 22.8% (n = 8) and overall session attendance rate was 60%. Confidence with and adequacy of home technology was rated high in 96% and 91% of sessions, respectively. Participants randomized to the intervention significantly improved Mediterranean Diet Adherence Score (2-point increase [95% confidence interval, 1.5-3.4] versus control 0 point change [95% confidence interval, -1.4 to 1.2]; P = 0.004). Intervention (within group) analysis found the intervention significantly decreased the metabolic syndrome severity score (-0.4 [95% confidence interval, -0.6 to -0.1] P = 0.01), and improved mental health-related quality of life (2.5 [95% confidence interval, 0.4-4.6] P = 0.03).

CONCLUSIONS

A cardioprotective lifestyle intervention delivered via telehealth is feasible for liver transplant recipients and may improve access to specialist care to support metabolic health and wellness after transplant.

Evidence-Based Policy Making for Public Health Interventions in Cardiovascular Diseases: Formally Assessing the Feasibility of Clinical Trials

Implementation of prevention policies has often been impeded or delayed due to the lack of randomized controlled trials (RCTs) with hard clinical outcomes (eg, incident disease, mortality). Despite the prominent role of RCTs in health care, it may not always be feasible to conduct RCTs of public health interventions with hard outcomes due to logistical and ethical considerations. RCTs may also lack external validity and have limited generalizability. Currently, there is insufficient guidance for policymakers charged with establishing evidence-based policy to determine whether an RCT with hard outcomes is needed before policy recommendations. In this context, the purpose of this article is to assess, in a case study, the feasibility of conducting an RCT of the oft-cited issue of sodium reduction on cardiovascular outcomes and then propose a framework for decision-making, which includes an assessment of the feasibility of conducting an RCT with hard clinical outcomes when such trials are unavailable. We designed and assessed the feasibility of potential individual- and cluster-randomized trials of sodium reduction on cardiovascular outcomes. Based on our assumptions, a trial using any of the designs considered would require tens of thousands of participants and cost hundreds of millions of dollars, which is prohibitively expensive. Our estimates may be conservative given several key challenges, such as the unknown costs of sustaining a long-term difference in sodium intake, the effect of differential cotreatment with antihypertensive medications, and long lag time to clinical outcomes. Thus, it would be extraordinarily difficult to conduct such a trial, and despite the high costs, would still be at substantial risk for a spuriously null result. A robust framework, such as the one we developed, should be used to guide policymakers when establishing evidence-based public health interventions in the absence of trials with hard clinical outcomes.

Impact of Life's Simple 7 on the incidence of major cardiovascular events in high-risk Spanish adults in the PREDIMED study cohort

INTRODUCTION AND OBJECTIVES

The Life's Simple 7 strategy of the American Heart Association proposes 7 metrics of ideal cardiovascular health: body mass index (BMI) <25mg/m², not smoking, healthy diet, moderate physical activity ≥ 150min/wk, total blood cholesterol <200mg/dL, systolic and diastolic blood pressures <120 and <80mmHg, respectively, and fasting blood glucose <100mg/dL. It is important to assess the combined effect of these 7 metrics in the Spanish population. We prospectively analyzed the impact of baseline Life's Simple 7 metrics on the incidence of major cardiovascular events in the PREDIMED cohort (57.5% women, average baseline age, 67 years).

METHODS

The healthy diet metric was defined as attaining ≥ 9 points on a validated 14-item Mediterranean diet adherence screener. An incident major cardiovascular event was defined as a composite of myocardial infarction, stroke, or cardiovascular death. Cox regression was used to calculate multivariable adjusted hazard ratios (HR) and their 95% confidence intervals (95%CI) for successive categories of health metrics.

RESULTS

After a median follow-up of 4.8 years in 7447 participants, there were 288 major cardiovascular events. After adjustment for age, sex, center, and intervention group, HRs (95%CI) were 0.73 (0.54-0.99), 0.57 (0.41-0.78), and 0.34 (0.21-0.53) for participants with 2, 3, and ≥ 4 metrics, respectively, compared with participants with only 0 to 1 metrics.

CONCLUSIONS

In an elderly Spanish population at high cardiovascular risk, better adherence to Life's Simple 7 metrics was progressively associated with a substantially lower rate of major cardiovascular events.

The use of psychological methodologies in cardiovascular disease interventions promoting a Mediterranean style diet: A systematic review

AIMS

To evaluate theory-based psychological approaches that have been effective in promoting behavior change in interventions promoting a Mediterranean style diet (MD) for the reduction of cardiovascular disease (CVD) risk.

DATA SYNTHESIS

A systematic review of primary research articles using PRISMA recommendations was conducted. References were retrieved using keyword searches from MEDLINE via PUBMED and included studies targeted participants at high risk for CVD. Two hundred and ninety one studies were reviewed; however, only six met the inclusionary criteria. Three articles describe the same intervention; therefore, only four were included. Included studies incorporated social cognitive theory, social learning theory, goal-system theory, social ecological theory, selfdetermination theory, and the transtheoretical model of behavior change. Overall, studies were nutrition interventions in clinical settings with participants at high risk for or with CVD.

CONCLUSIONS

Results from use of the social cognitive theory and self-determination theory in increasing MD adherence for the reduction of CVD risk and events are encouraging. However, we encourage future long-term interventions focusing on dietary behavior change to provide not only an in-depth description of the psychological methodologies used but also how these methodologies were implemented in order ascertain the most effective theory for promoting dietary behavior change towards patterns of a MD.

Dietary Patterns and Cardiovascular Disease: Insights and Challenges for Considering Food Groups and Nutrient Sources

PURPOSE OF REVIEW

The relationship between dietary patterns and cardiovascular disease has been the subject of much research, but an important methodological consideration is the interdependence between the nutrient composition of foods and the recognition of healthy dietary patterns. This review considers some of the challenges in researching dietary patterns with implications for translation to public health promotions.

RECENT FINDINGS

A number of statistical methods have emerged for analysing dietary patterns using population dietary data. There are limitations in the assumptions underpinning food categorisation, but this research is able to consistently identify foods and dietary patterns that are positively related to health. Aligned to this activity is the ongoing development of food composition databases which has its own limitations such as keeping up to date with changing foods and newly identified components, sampling of foods, and developments in chemical analytical methods. Finally, dietary patterns form the basis for current dietary guidelines and related public health-oriented programs, but the issues raised for research (e.g. food categorisation and cuisine influences on dietary patterns) can also translate to these settings. The study of dietary patterns in cardiovascular disease prevention presents with a number of methodological challenges relating to the way food groups are formed and the limitations of food composition databases. Added to this are new considerations for the environmental impact of recommended dietary patterns. Future research across the entire knowledge chain should target more accurate methods in a number of analytical areas.

Dietary Fats and Chronic Noncommunicable Diseases

The role of dietary fat has been long studied as a modifiable variable in the prevention and treatment of noncommunicable cardiometabolic disease. Once heavily promoted to the public, the low-fat diet has been demonstrated to be non-effective in preventing cardiometabolic disease, and an increasing body of literature has focused on the effects of a relatively higher-fat diet. More recent evidence suggests that a diet high in healthy fat, rich in unsaturated fatty acids, such as the Mediterranean dietary pattern, may, in fact, prevent the development of metabolic diseases such as type 2 diabetes mellitus, but also reduce cardiovascular events. This review will specifically focus on clinical trials which collected data on dietary fatty acid intake, and the association of these fatty acids over time with measured cardiometabolic health outcomes, specifically focusing on morbidity and mortality outcomes. We will also describe mechanistic studies investigating the role of dietary fatty acids on cardiovascular risk factors to describe the potential mechanisms of action through which unsaturated fatty acids may exert their beneficial effects. The state of current knowledge on the associations between dietary fatty acids and cardiometabolic morbidity and mortality outcomes will be summarized and directions for future work will be discussed.