Diet-disease Associations Research Articles

Associations between dietary patterns and incident colorectal cancer in 114,443 individuals from the UK Biobank: a prospective cohort study.

Diet-disease association studies increasingly use dietary patterns (DPs) to account for the complexity of the exposure. We assessed if a DP associated with type 2 diabetes mellitus, CVD, and all-cause mortality is also associated with colorectal cancer (CRC). We used reduced rank regression on 24-h recall data to identify DPs explaining the maximum variation in four nutrient-response variables: energy density, saturated fatty acids, free sugars and fibre density. Cox-proportional hazards models examined prospective associations between DP adherence (coded in a continuous scale as z-scores as well as in quintiles) and incident CRC. Subgroup analyses were conducted for tumour site, age, and sex. Post-exclusions, 1,089 CRC cases occurred in 114,443 participants over a median follow-up of 8.0 years. DP1 was characterised by increased intake of chocolate and confectionery, butter, low-fibre bread, red and processed meats and alcohol, as well as low fruit, vegetable, and high-fibre cereal intake. After accounting for confounders, including body mass, there were positive linear associations between DP1 and incident overall CRC (HR of quintile 5 vs. 1: 1.34, 95%CI 1.16-1.53, PTrend=0.005) and rectal cancer (HR of quintile 5 vs. 1: 1.58, 95%CI 1.27-1.96, PTrend=0.009), but not for proximal or distal colon cancers. No DP2-CRC association was observed. A DP previously associated with cardio-metabolic disease is also associated with incident CRC, especially rectal cancers. These consistent associations of particular food groups with both cardiometabolic disease and this diet-related cancer strengthen the evidence base for holistic population dietary guidelines to prevent ill-health.

Intake Biomarkers for Nutrition and Health: Review and Discussion of Methodology Issues.

Metabolomics profiles from blood, urine, or other body fluids have the potential to assess intakes of foods and nutrients objectively, thereby strengthening nutritional epidemiology research. Metabolomics platforms may include targeted components that estimate the relative concentrations for individual metabolites in a predetermined set, or global components, typically involving mass spectrometry, that estimate relative concentrations more broadly. While a specific metabolite concentration usually correlates with the intake of a single food or food group, multiple metabolites may be correlated with the intake of certain foods or with specific nutrient intakes, each of which may be expressed in absolute terms or relative to total energy intake. Here, I briefly review the progress over the past 20 years on the development and application intake biomarkers for foods/food groups, nutrients, and dietary patterns, primarily by drawing from several recent reviews. In doing so, I emphasize the criteria and study designs for candidate biomarker identification, biomarker validation, and intake biomarker application. The use of intake biomarkers for diet and chronic disease association studies is still infrequent in nutritional epidemiology research. My comments here will derive primarily from our research group's recent contributions to the Women's Health Initiative cohorts. I will complete the contribution by describing some opportunities to build on the collective 20 years of effort, including opportunities related to the metabolomics profiling of blood and urine specimens from human feeding studies that approximate habitual diets.

Validity and reliability of a Food Frequency Questionnaire (FFQ) assessing food groups consumption and nutrients intake in Costa Rican adolescents

Introduction: Food Frequency Questionnaires (FFQ) have been widely used in several age groups, including adolescents, due to their greater advantages over other dietary measurement methods. Therefore, this study was designed to assess the validity and reliability of a FFQ designed for use on Costa Rican adolescents. Methodology: The validation and reproducibility studies were carried out in a sample of 107 adolescents of San José province selected through convenience sampling. For validation, a comparison of the nutrient intake and food consumption data obtained with the FFQ was made with those derived from the 3-day food record (3FR). Reliability was assessed by comparing nutrient intake and food consumption derived from the first FFQ with another FFQ performed four weeks after the first. Results: FFQ overestimates 3FR, with an average overestimation of 40.2% for foods and 38.8% for nutrients. The cross-classification was good for 24 of 26 nutrients and for 12 of the 21 food groups, and the weighted kappa showed an acceptable discriminant ability of the FFQ to categorize individuals into broad nutrient intake (except for protein and cholesterol) and food groups categories (dairy products, white rice, beans, vegetables, fruits and fruit juice, sugary drinks, breakfast cereal, candies and sweets, snacks, fast foods, fat, and ice cream). Conclusions: The FFQ designed for Costa Rican adolescents was unable to assess absolute dietary intakes; however, it is a reasonable tool to categorize adolescents into broad ranges of dietary intakes and could be used to evaluate dietary patterns in epidemiological studies of diet-disease associations.

Regression calibration utilizing biomarkers developed from high-dimensional metabolites.

Addressing systematic measurement errors in self-reported data is a critical challenge in association studies of dietary intake and chronic disease risk. The regression calibration method has been utilized for error correction when an objectively measured biomarker is available; however, biomarkers for only a few dietary components have been developed. This paper proposes to use high-dimensional objective measurements to construct biomarkers for many more dietary components and to estimate the diet disease associations. It also discusses the challenges in variance estimation in high-dimensional regression methods and presents a variety of techniques to address this issue, including cross-validation, degrees-of-freedom corrected estimators, and refitted cross-validation (RCV). Extensive simulation is performed to study the finite sample performance of the proposed estimators. The proposed method is applied to the Women's Health Initiative cohort data to examine the associations between the sodium/potassium intake ratio and the total cardiovascular disease.

Evaluation of health and economic effects of United States school meal standards consistent with the 2020–2025 dietary guidelines for Americans

BackgroundThe current school meal nutrition standards, established in 2010, are not fully aligned with the 2020–2025 Dietary Guideline for Americans (DGA). This study evaluates the potential short-term and long-term health and economic benefits of strengthening the school meal standards on added sugars, sodium, and whole grains to be aligned with current guidelines. MethodsWe used comparative risk assessment frameworks based on nationally representative data incorporating current demographics, dietary habits, and risk factors of United States children aged 5–18 y from 3 cycles of the National Health and Nutrition Examination Survey (2013–2018). To estimate short-term impact, the model incorporated estimated dietary changes owing to potential new DGA-aligned school meal nutrition standards and the effect of these changes on childhood body mass index (in kg/m2) and blood pressure. To estimate long-term impact, the model further incorporated data on the sustainability of childhood dietary changes into adulthood, and on demographics and risk factors of United States adults, diet-disease associations, and disease-specific national mortality. ResultsIn a best-case scenario assuming full school compliance, implementing new DGA-aligned nutritional standards would lower elementary children’s BMI by an average 0.14 (95% UI: 0.08–0.20) kg/m2 and systolic blood pressure by 0.13 (95% UI: 0.06–0.19) (95% mm Hg. Later in life, the new standards were estimated to prevent 10,600 [95% uncertainty interval (UI): 4820–16,800) annual deaths from cardiovascular disease (CVD), diabetes, and cancer in adulthood; and save 355,000 (95% UI: 175,000–538,000) disability-adjusted life years and $19.3 (95% UI: 9.35–30.3) B in direct and indirect medical costs each year. Accounting for plausible (incomplete) school compliance, implementation would save an estimated 9110 (95% UI: 2740–15,100) deaths, 302,000 (95% UI: 120,000–479,000) disability-adjusted life years, and $15.9 (95% UI: 4.54–27.2) B in healthcare-related costs per year in later adulthood. ConclusionsStronger school meal nutrition standards on added sugars, sodium, and whole grains aligned with the 2020–2025 DGA recommendations may improve diet, childhood health, and future adult burdens of CVD, diabetes, cancer, and associated economic costs.

Associations of circulating proteins with lipoprotein profiles: proteomic analyses from the OmniHeart randomized trial and the Atherosclerosis Risk in Communities (ARIC) Study

BackgroundWithin healthy dietary patterns, manipulation of the proportion of macronutrient can reduce CVD risk. However, the biological pathways underlying healthy diet-disease associations are poorly understood. Using an untargeted, large-scale proteomic profiling, we aimed to (1) identify proteins mediating the association between healthy dietary patterns varying in the proportion of macronutrient and lipoproteins, and (2) validate the associations between diet-related proteins and lipoproteins in the Atherosclerosis Risk in Communities (ARIC) Study.MethodsIn 140 adults from the OmniHeart trial, a randomized, cross-over, controlled feeding study with 3 intervention periods (carbohydrate-rich; protein-rich; unsaturated fat-rich dietary patterns), 4,958 proteins were quantified at the end of each diet intervention period using an aptamer assay (SomaLogic). We assessed differences in log2-transformed proteins in 3 between-diet comparisons using paired t-tests, examined the associations between diet-related proteins and lipoproteins using linear regression, and identified proteins mediating these associations using a causal mediation analysis. Levels of diet-related proteins and lipoprotein associations were validated in the ARIC study (n = 11,201) using multivariable linear regression models, adjusting for important confounders.ResultsThree between-diet comparisons identified 497 significantly different proteins (protein-rich vs. carbohydrate-rich = 18; unsaturated fat-rich vs. carbohydrate-rich = 335; protein-rich vs. unsaturated fat-rich dietary patterns = 398). Of these, 9 proteins [apolipoprotein M, afamin, collagen alpha-3(VI) chain, chitinase-3-like protein 1, inhibin beta A chain, palmitoleoyl-protein carboxylesterase NOTUM, cathelicidin antimicrobial peptide, guanylate-binding protein 2, COP9 signalosome complex subunit 7b] were positively associated with lipoproteins [high-density lipoprotein (HDL)-cholesterol (C) = 2; triglyceride = 5; non-HDL-C = 3; total cholesterol to HDL-C ratio = 1]. Another protein, sodium-coupled monocarboxylate transporter 1, was inversely associated with HDL-C and positively associated with total cholesterol to HDL-C ratio. The proportion of the association between diet and lipoproteins mediated by these 10 proteins ranged from 21 to 98%. All of the associations between diet-related proteins and lipoproteins were significant in the ARIC study, except for afamin.ConclusionsWe identified proteins that mediate the association between healthy dietary patterns varying in macronutrients and lipoproteins in a randomized feeding study and an observational study.Trial registrationNCT00051350 at clinicaltrials.gov.

Development of dish-based population-specific food frequency questionnaire for dietary assessments in Afghanistan

Purpose: Dietary intake assessment has an essential role in chronic disease studies and general public health outcomes. To measure dietary intakes in epidemiologic studies, various dietary assessment methods are used. Among them, food frequency questionnaires (FFQs) can provide useful measures of dietary intake. This study aimed to report the development of a population-specific dish-based food frequency questionnaire (DFQ) to assess long-term usual dietary intakes in Afghanistan. Design/Methodology/Approach: We considered the Willet format and followed these steps; listing commonly consumed Afghani foods, determining food groups, defining portion sizes, and determining the frequency response options for each food item. We prepared a comprehensive list of foods and dishes commonly used in Afghanistan. We categorized dishes and food items in the questionnaire into eight major groups. Portion sizes for food items and mixed dishes were defined based on the most commonly consumed and understandable portion sizes for each item among the Afghan general population. The frequency response options for each food item were defined separately in a row against the food list. Findings: We developed a new population-specific DFQ in Afghanistan containing 103 food items or dishes, which can be used as an instrument for the assessment of long-term dietary intakes as well as diet-disease associations in Afghanistan. Originality/Value: This is the first ever-developed dietary assessment tool in Afghanistan.

Nutritional Blood Concentration Biomarkers in the Hispanic Community Health Study/Study of Latinos: Measurement Characteristics and Power.

Measurement error is a major issue in self-reported diet that can distort diet-disease relationships. Use of blood concentration biomarkers has the potential to mitigate the subjective bias inherent in self-reporting. As part of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) baseline visit (2008-2011), self-reported information on diet was collected from all participants (n=16,415). The HCHS/SOL also included annual telephone follow-up, as well as a second (2014-2017) and third (2020-2023) clinic visit.Blood concentration biomarkers for carotenoids, tocopherols, retinol, vitamin B12, and folate were measured in a subset of participants (n=476) as part of the Study of Latinos: Nutrition and Physical Activity Assessment Study (SOLNAS) (2010-2012). We examined the relationships among biomarker levels, self-reported intake, Hispanic/Latino background (Central American, Cuban, Dominican, Mexican, Puerto Rican, or South American), and other participant characteristics in this diverse cohort. We built regression calibration-based prediction equations for 10 nutritional biomarkers and used a simulation to study the power of detecting a diet-disease association in a multivariable Cox model using a predicted concentration level. Good statistical power was observed for some nutrients with high prediction model R2 values, but further research is needed to understand how best to realize the potential of these dietary biomarkers. This study provides a comprehensive examination of several nutritional biomarkers within the HCHS/SOL, characterizing their associations with subject characteristics and the influence of the measurement characteristics on the power to detect associations with health outcomes.

Investigating the Dietary Intake Using the CyFFQ Semi-Quantitative Food Frequency Questionnaire in Cypriot Huntington's Disease Patients.

Huntington's disease (HD) is a rare progressive neurodegenerative disease characterised by autosomal dominant inheritance. The past decade saw a growing interest in the associations between the Mediterranean Diet (MD) and HD risk and outcomes. The aim of this case-control study was to assess the dietary intake and habits of Cypriot HD patients, comparing them to gender and age-matched controls, using the Cyprus Food Frequency Questionnaire (CyFFQ) and to assess adherence to the MD by disease outcomes. The method relied on the validated CyFFQ semi-quantitative questionnaire to assess energy, macro- and micronutrient intake over the past year in n = 36 cases and n = 37 controls. The MedDiet Score and the MEDAS score were used to assess adherence to the MD. Patients were grouped based on symptomatology such as movement and cognitive and behavioral impairment. The two-sample Wilcoxon rank-sum (Mann-Whitney) test was used to compare cases vs. controls. Statistically significant results were obtained for energy intake (kcal/day) (median (IQR): 4592 (3376) vs. 2488 (1917); p = 0.002) from cases and controls. Energy intake (kcal/day) (median (IQR): 3751 (1894) vs. 2488 (1917); p = 0.044) was also found to be significantly different between asymptomatic HD patients and controls. Symptomatic patients were also different from controls in terms of energy intake (kcal/day) (median (IQR): 5571 (2907) vs. 2488 (1917); p = 0.001); % energy monounsaturated fatty acids (median (IQR): 13.4 (5.2) vs. 15.5 (5.7); p = 0.0261) and several micronutrients. A significant difference between asymptomatic and symptomatic HD patients was seen in the MedDiet score (median (IQR): 31.1 (6.1) vs. 33.1 (8.1); p = 0.024) and a significant difference was observed between asymptomatic HD patient and controls (median (IQR): 5.5 (3.0) vs. 8.2 (2.0); p = 0.014) in the MEDAS score. This study confirmed previous findings that HD cases have a significantly higher energy intake than controls, revealing differences in macro and micronutrients and adherence to the MD by both patients and controls and by HD symptom severity. These findings are important as they are an effort to guide nutritional education within this population group and further understand diet-disease associations.

Metabotyping: a tool for identifying subgroups for tailored nutrition advice.

Diet-related diseases are the leading cause of death globally and strategies to tailor effective nutrition advice are required. Personalised nutrition advice is increasingly recognised as more effective than population-level advice to improve dietary intake and health outcomes. A potential tool to deliver personalised nutrition advice is metabotyping which groups individuals into homogeneous subgroups (metabotypes) using metabolic profiles. In summary, metabotyping has been successfully employed in human nutrition research to identify subgroups of individuals with differential responses to dietary challenges and interventions and diet–disease associations. The suitability of metabotyping to identify clinically relevant subgroups is corroborated by other fields such as diabetes research where metabolic profiling has been intensely used to identify subgroups of patients that display patterns of disease progression and complications. However, there is a paucity of studies examining the efficacy of the approach to improve dietary intake and health parameters. While the application of metabotypes to tailor and deliver nutrition advice is very promising, further evidence from randomised controlled trials is necessary for further development and acceptance of the approach.

Intakes of major food groups in China and UK: results from 100,000 adults in the China Kadoorie biobank and UK biobank

PurposeDifferent populations may exhibit differences in dietary intakes, which may result in heterogeneities in diet–disease associations. We compared intakes of major food groups overall, by sex, and by socio-economic status (SES) (defined as both education and income), between participants in the China Kadoorie Biobank (CKB) and the UK Biobank (UKB).MethodsData were from ~ 25,000 CKB participants who completed a validated interviewer-administered computer-based questionnaire (2013–2014) and ~ 74,000 UKB participants who completed ≥ 3 web-based 24-h dietary assessments (2009–2012). Intakes of 12 major food groups and five beverages were harmonized and compared between the cohorts overall, by sex and by SES. Multivariable-adjusted linear regression examined the associations between dietary intakes and body mass index (BMI) in each cohort.ResultsCKB participants reported consuming more rice, eggs, vegetables, soya products, and less wheat, other staple foods (other than rice and wheat), fish, poultry, all dairy products, fruit, and beverages compared to UKB participants. Red meat intake was similar in both cohorts. Having a higher SES was generally associated with a higher consumption of foods and beverages in CKB, whereas in UKB dietary intakes differed more by education and income, with a positive association observed for meat and income in both UKB and CKB but an inverse association observed for education in UKB. Associations of dietary intakes with BMI varied between the two cohorts.ConclusionThe large differences in dietary intakes and their associations with SES and BMI could provide insight into the interpretation of potentially different diet–disease associations between CKB and UKB.

An Empirical Evaluation of the Impact Scenario of Pooling Bodies of Evidence from Randomized Controlled Trials and Cohort Studies in Nutrition Research

Only very few Cochrane nutrition reviews include cohort studies (CSs), but most evidence in nutrition research comes from CSs. We aimed to pool bodies of evidence (BoE) from randomized controlled trials (RCTs) derived from Cochrane reviews with matched BoE from CSs. The Cochrane Database of Systematic Reviews and MEDLINE were searched for systematic reviews (SRs) of RCTs and SRs of CSs. BoE from RCTs were pooled together with BoE from CSs using random-effects and common-effect models. Heterogeneity, 95% prediction intervals, contributed weight of BoE from RCTs to the pooled estimate, and whether integration of BoE from CSs modified the conclusion from BoE of RCTs were evaluated. Overall, 80 diet-disease outcome pairs based on 773 RCTs and 720 CSs were pooled. By pooling BoE from RCTs and CSs with a random-effects model, for 45 (56%) out of 80 diet-disease associations the 95% CI excluded no effect and showed mainly a reduced risk/inverse association. By pooling BoE from RCTs and CSs, median I2=46% and the median contributed weight of RCTs to the pooled estimates was 34%. The direction of effect between BoE from RCTs and pooled effect estimates was rarely opposite (n=17; 21%). The integration of BoE from CSs modified the result (by examining the 95% CI) from BoE of RCTs in 35 (44%) of the 80 diet-disease associations. Our pooling scenario showed that the integration of BoE from CSs modified the conclusion from BoE of RCTs in nearly 50% of the associations, although the direction of effect was mainly concordant between BoE of RCTs and pooled estimates. Our findings provide insights for the potential impact of pooling both BoE in Cochrane nutrition reviews. CSs should be considered for inclusion in future Cochrane nutrition reviews, and we recommend analyzing RCTs and CSs in separate meta-analyses, or, if combined together, with a subgroup analysis.

Using Controlled Feeding Study for Biomarker Development in Regression Calibration for Disease Association Estimation.

Correction for systematic measurement error in self-reported data is an important challenge in association studies of dietary intake and chronic disease risk. The regression calibration method has been used for this purpose when an objectively measured biomarker is available. However, a big limitation of the regression calibration method is that biomarkers have only been developed for a few dietary components. We propose new methods to use controlled feeding studies to develop valid biomarkers for many more dietary components and to estimate the diet disease associations. Asymptotic distribution theory for the proposed estimators is derived. Extensive simulation is performed to study the finite sample performance of the proposed estimators. We applied our method to examine the associations between the sodium/potassium intake ratio and cardiovascular disease incidence using the Women's Health Initiative cohort data. We discovered positive associations between sodium/potassium ratio and the risks of coronary heart disease, nonfatal myocardial infarction, coronary death, ischemic stroke, and total cardiovascular disease.

Protocol for a systematic review and meta-analysis: to investigate the association of adherence to plant-based diets with cardiovascular disease risk

Background:Plant-based diets (PBDs) are characterised as healthy dietary patterns that emphasise the intake of plant foods and limit the intake of animal foods. The Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets are common examples of healthy dietary patterns that are mainly plant based. There are different dietary pattern analysis approaches and scoring systems available to construct indices that measure adherence to a dietary pattern. Nutritional epidemiology studies necessitate the use of appropriate dietary indices when investigating diet-disease associations. This protocol is for a review that will: 1) evaluate how a PBD has been defined in studies published globally; and 2) assess the methods used to construct dietary indices that measure adherence to a PBD; with a focus on studies that have assessed the association between adherence to a PBD and CVD risk. Methods:This protocol was developed according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis Protocols guidelines. PubMed–Medline, Scopus and biomedical databases within EBSCOhost will be searched up to August 2021. Two reviewers will independently screen the identified records and review the eligible full texts for inclusion. Discrepancies will be resolved by consensus or through discussion with a third reviewer. Meta-analysis will be performed where possible and consistency of the findings checked through subgroup analysis. Heterogeneity across studies will be assessed and quantified, and publication bias investigated. Relevant sensitivity analyses will be performed to substantiate the robustness of the study findings. Conclusion:Currently, there is some inconsistency in defining and measuring adherence to a PBD across study populations. Moreover, a lack of global data on the association between adherence to a PBD and CVD risk. This systematic review could aid in promoting the worldwide uptake of these findings for policy and practice purposes. This research will use previously published studies; and therefore, will not require ethical approval.

Prevalence and Validity of Sugar and High-Intensity Sweeteners Consumption Assessed by a General FFQ, Multiple 24-H Recalls, and Urinary Biomarkers – The SWEET Project

ObjectivesInconsistencies in prospective studies investigating sugars and sweeteners with health may be partly due to inaccurate self-reported intake estimates. We compared the relative validity of two self-reported dietary methods and urinary biomarkers to estimate the intake of sugars and sweeteners using data of free-living Dutch adults.MethodsWe included 848 participants with one food frequency questionnaire (FFQ) and ≥3 24-h recalls from the NQplus study. Intakes of sugars (mono and disaccharides, sucrose, fructose, free sugars, and added sugars), sugary foods, and sweetened beverages (sugar-sweetened beverages (SSB), Low/Non-calorie beverages (LNCB), and fruit juice) were estimated by using the Dutch food composition table. A sub-sample of 288 participants provided 3 repeated urine samples to measure the urinary sugar and sweetener concentrations. Measurement error models were used to calculate, ICCs, proportional scaling bias (βx), validity coefficients (VC), and attenuation factors (AF).ResultsAccording to 24 h-recall data, most sugars and sweet foods/beverages had a high day-to-day variation (ICC ≤ 0.56). Under-reporting (βx < 1) between the FFQ and the multiple recalls was highest for sugary foods and beverages (0.57 to 0.66), and lowest for sugars (0.68 to 0.81). VCs ranged from 0.49 (sugary foods) to 0.74 (SSB), suggesting a moderate to good agreement between the methods for most sugars and for sweet beverages. AFs ranged from 0.42 (sugary foods) to 0.96 (SSB), indicating that the FFQ tends to underestimate the associations between sugars or sweet foods and disease compared to the recalls. The high AFs for LNCB (0.93) and SSB (0.96) suggested that the under-estimation of the diet-disease association was minimal for these beverages when using the FFQ instead of recalls. Compared to men, women showed more day-to-day variation, more under-reporting, and lower VC and AF, except with LNCB. In general, only slight differences between BMI categories were observed. Results of the biomarkers are expected in April.ConclusionsOverall, the FFQ showed moderate to good ranking performance compared to multiple 24 h-recalls for sugars and sweet foods.Funding SourcesThis EU project under the acronym “SWEET” has received funding from the European Union's Horizon 2020 research and innovation program.

Appraising diet-disease associations to be used in risk assessment, including an insight in nutritional epidemiology.

High consumption of red meat, in particular of its processed products, has been linked to the development of various chronic diseases, and the need to reduce consumption levels of these products has been identified as a public health priority in Europe. Among the potential alternatives, pulses have gained a prominent position in recent years. Stemming from the broader context of the substitution of red meat in the diet with alternative plant‐based protein sources, this work programme was developed to address the need of improving the current understanding on the public health impact of potential substitutes. From a training perspective, the main goal was to advance the fellow’s background knowledge in the principles of nutritional epidemiology, while contributing to the harmonisation of food risk assessment practices across Europe. The activities developed comprised a comprehensive learning experience in the different components of the risk assessment framework, giving particular focus to the appraisal of epidemiological evidence within this context (hazard identification and characterisation). The fellow had the opportunity to gain hands‐on experience with EFSA’s databases among other relevant national and international data sources. The association between the consumption of legumes and risk of cardiovascular disease in particular was extensively explored and described by summarising the available evidence through dose–response meta‐analyses. The one‐stage approach method was used to explore the shape of the associations, including studies with as few as two levels of exposure, in a weighted mixed‐effects model. The analysis was also performed taking into account the potential risk of bias of included studies, assessed using the ROBINS‐I tool. Upon the completion of the activities carried out, the fellow made significant progress towards the learning outcomes expected to be achieved throughout the duration of the EU‐FORA fellowship period.

Development and validation of dietary atherogenic index using common carotid artery-intima-media thickness: A food frequency questionnaire-based longitudinal study in Korean adults

Dietary patterns based on pathways of diseases such as subclinical atherosclerosis can predict diet-disease associations better than dietary quality indices or data-driven indices. We aimed to develop and validate a novel dietary atherogenic index (DAI) in adults using the common carotid artery-intima media thickness (c-IMT) in Korean adults. Participants aged ≥40 years from the Yangpyeong cohort were enrolled in the development set (n = 1373). Two DAIs were developed using 38 predefined food groups as predictors and c-IMT as response variable, using stepwise linear regression (SLR) and reduced rank regression (RRR) models. Based on the associations between DAI and c-IMT, DAIs were then validated in the total, men, and women, internally in 1000 bootstrap sets, and externally in a set combined with 2 other populations (n = 2476). The DAI-S by SLR and the DAI-R by RRR included 7 anti- and 10 pro-inflammatory food groups and 2 anti- and 6 pro-inflammatory food groups, respectively. Total rice and white root kimchi were pro-inflammatory, and mushrooms, other beverages (mostly traditional beverages), poultry, processed seafood, and pizza/hamburger were anti-inflammatory in both the DAI-S and DAI-R. They were internally valid in the multivariable-adjusted models, showing a significant linear trend in all 3 sets; they were also valid in the bootstrap at 95% confidence interval. In the external validation, only the DAI-S was significantly associated with the c-IMT (P trend = .0004, .0133, and .0212 in total, men, and women, respectively). This study indicated that DAIs, particularly DAI-S, may be useful for assessing the atherogenic potential of food-based total diets.

Total Energy Intake: Implications for Epidemiologic Analyses.

In 1986, Willett and Stampfer propelled the nutritional epidemiology field forward by publishing a commentary emphasizing the importance of analyzing diet in relation to total energy intake in epidemiologic analyses of diet and disease, detailing the value of accounting for body size, physical activity, and metabolic efficiency in diet-disease analyses via energy intake adjustment. Their publication has since been cited over 2,886 times and has inarguably advanced methodology for studying diet-disease associations, with most nutritional epidemiology studies standardly including some form of energy adjustment. However, there remains debate regarding the best scenarios and methods for energy adjustment. The goals of this commentary are to provide an updated review on factors that account for inter-individual differences in energy intake, provide a balanced discussion regarding the considerations for or against adjustment for energy intake, and provide an updated examination of the commonly employed methods for the analysis of nutrient-disease associations. The principles of energy adjustment continue to be relevant nearly 25 years later, as it remains a critical method to account for potentially confounding inter-individual variations in body size and physical activity.

Adherence to the Mediterranean Diet in Relation to Gastric Cancer in Afghanistan.

BackgroundDespite the adherence to the Mediterranean dietary pattern (MD) being associated with a reduced risk of several cancers, there is no report about the highly prevalent diet-disease associations in Afghanistan, particularly about gastric cancer (GC).ObjectiveThe aim of this study was to investigate the association between MD and GC in Afghanistan.MethodsThis hospital-based case-control study was carried out on a total number of 270 subjects (90 cases and 180 controls) aged between 20 and 75 years. Using the convenience-sampling method, cases and controls were selected. Cases were patients with GC whose condition was pathologically confirmed. The controls were apparently healthy people who were matched with cases in terms of age (±5 years) and sex. Assessment of dietary intake was done using a pre-tested food frequency questionnaire, designed specifically for Afghanistan. Adherence to the MD pattern was done based on the scores suggested in earlier studies.ResultsOut of 270 studied subjects, 73% were men. We found that subjects in the highest tertile of MD score had 52% decreased odds of GC (OR: 0.48; 95% CI: 0.24–0.98, P-trend = 0.05) compared with those in the lowest tertile. After considering potential environmental factors, age, and sex, the observed association disappeared (OR: 0.43; 95% CI: 0.13–1.38, P-trend = 0.41). After further adjustment for BMI in the last model, we found that participants with the highest MD score were 83% less likely to have GC than those in the lowest tertile (OR: 0.17; 95% CI: 0.03–0.80, P-trend = 0.14).ConclusionWe found that greater adherence to MD might be associated with a lower odds of GC.

Biomarker-Based Methods and Study Designs to Calibrate Dietary Intake for Assessing Diet–Disease Associations

BackgroundDietary biomarkers measured in biospecimens can play an important role in correcting for random and systematic measurement error in self-reported nutrient intake when assessing diet–disease associations. To date, high-quality biomarkers for calibrating self-reported dietary intake have only been developed for a few nutrients. ObjectivesTo investigate new study designs and regression calibration approaches for calibrating self-reported nutrient intake for use in disease association analyses. MethodsWe studied 3 regression calibration approaches: 1) an existing approach built on a calibration cohort assuming the existence of an objective biomarker (i.e., biomarker with random independent measurement error), 2) a proposed approach using a biomarker development cohort, and 3) a proposed 2-stage approach using both cohorts. We conducted simulation studies to compare the performance of different study designs/methods for estimating diet–disease associations and applied suitable methods to examine the association of sodium and potassium intake with cardiovascular disease (CVD) risk in Women's Health Initiative cohorts. ResultsSimulation studies showed that the first approach can lead to biased association estimation when the objective biomarker assumption is violated; the second and third proposed approaches obviate the need for such an objective biomarker. Precision for estimating the association depends critically on sample size of the biomarker development cohort and the strength of the self-reported nutrient intake. Analyses based on the second and third approaches support previously reported significant findings using the first approach about associations of the ratio of sodium to potassium intake with CVD risk while providing efficiency gain for some outcomes. ConclusionsSelf-reported dietary intake needs to be calibrated for measurement error correction in diet–disease association analyses. When there are no existing objective biomarkers that can be used for calibration purpose, controlled feeding studies can be used to develop new biomarkers for use in calibration or can be used to calibrate self-reported dietary intake directly.