Itandehui Castro-Quezada

The Mediterranean Diet and Nutritional Adequacy: A Review

The Mediterranean dietary pattern, through a healthy profile of fat intake, low proportion of carbohydrate, low glycemic index, high content of dietary fiber, antioxidant compounds, and anti-inflammatory effects, reduces the risk of certain pathologies, such as cancer or Cardiovascular Disease (CVD). Nutritional adequacy is the comparison between the nutrient requirement and the intake of a certain individual or population. In population groups, the prevalence of nutrient inadequacy can be assessed by the probability approach or using the Estimated Average Requirement (EAR) cut-point method. However, dietary patterns can also be used as they have moderate to good validity to assess adequate intakes of some nutrients. The objective of this study was to review the available evidence on the Nutritional Adequacy of the Mediterranean Diet. The inclusion of foods typical of the Mediterranean diet and greater adherence to this healthy pattern was related to a better nutrient profile, both in children and adults, with a lower prevalence of individuals showing inadequate intakes of micronutrients. Therefore, the Mediterranean diet could be used in public health nutrition policies in order to prevent micronutrient deficiencies in the most vulnerable population groups.

Beverage and water intake of healthy adults in some European countries

Abstract Introduction: Nutritional surveys frequently collect some data of consumption of beverages; however, information from different sources and different methodologies raises issues of comparability. The main objective of this review was to examine the available techniques used for assessing beverage intake in European epidemiological studies and to describe the most frequent method applied to assess it. Materials and methods: Information of beverage intake available from European surveys and nutritional epidemiological investigations was obtained from gray literature. Results: Twelve articles were included and relevant data were extracted. The studies were carried out on healthy adults by different types of assessments. The most frequent tool used was a 7-d dietary record. Only Germany used a specific beverage assessment tool (Beverage Dietary History). Conclusion: From the limited data available and the diversity of the methodology used, the results show that consumption of beverages is different between countries. Current epidemiological studies in Europe focusing on beverage intake are scarce. Further research is needed to clarify the amount of beverage intake in European population.

Effect of a Mediterranean Diet Intervention on Dietary Glycemic Load and Dietary Glycemic Index: The PREDIMED Study

Objective. To compare the one year effect of two dietary interventions with MeDiet on GL and GI in the PREDIMED trial. Methods. Participants were older subjects at high risk for cardiovascular disease. This analysis included 2866 nondiabetic subjects. Diet was assessed with a validated 137-item food frequency questionnaire (FFQ). The GI of each FFQ item was assigned by a 5-step methodology using the International Tables of GI and GL Values. Generalized linear models were fitted to assess the relationship between the intervention group and dietary GL and GI at one year of follow-up, using control group as reference. Results. Multivariate-adjusted models showed an inverse association between GL and MeDiet + extra virgin olive oil (EVOO) group: β = −8.52 (95% CI: −10.83 to −6.20) and MeDiet + Nuts group: β = −10.34 (95% CI: −12.69 to −8.00), when comparing with control group. Regarding GI, β = −0.93 (95% CI: −1.38 to −0.49) for MeDiet + EVOO, β = −1.06 (95% CI: −1.51 to −0.62) for MeDiet + Nuts when comparing with control group. Conclusion. Dietary intervention with MeDiet supplemented with EVOO or nuts lowers dietary GL and GI.

Dietary glycemic index and glycemic load are positively associated with risk of developing metabolic syndrome in middle-aged and elderly adults

To evaluate how glycemic index (GI) and glycemic load (GL) are associated with the metabolic syndrome (MetS) and its features in middle‐aged and elderly adults at high cardiovascular risk.

Misreporting in nutritional surveys: methodological implications

The reliability of the information collected in dietary assessment can be affected by different factors. One of the main sources of error in dietary assessment is misreporting which encompass under- and overreporting. Underreporting of food intake is one of the major problems in the assessment of habitual dietary intake. Physical and psychosocial characteristics that are related to energy underreporting include sex, age, weight, BMI, fear of negative evaluation and dieting among others. At present, diverse reference methods are employed to verify the results of dietary assessment and double labelled water is used as the gold standard method. Underreporting affects the estimation of nutrient intake and also alters associations between diet and disease assessed in epidemiological studies. Therefore, underreporting has to be considered and addressed by researchers through development and improvement of dietary intake adjustment methods, and taking advantage of the new technologies for assessing dietary intake in order to minimize underreporting bias.

A High Dietary Glycemic Index Increases Total Mortality in a Mediterranean Population at High Cardiovascular Risk

Objective Different types of carbohydrates have diverse glycemic response, thus glycemic index (GI) and glycemic load (GL) are used to assess this variation. The impact of dietary GI and GL in all-cause mortality is unknown. The objective of this study was to estimate the association between dietary GI and GL and risk of all-cause mortality in the PREDIMED study. Material and Methods The PREDIMED study is a randomized nutritional intervention trial for primary cardiovascular prevention based on community-dwelling men and women at high risk of cardiovascular disease. Dietary information was collected at baseline and yearly using a validated 137-item food frequency questionnaire (FFQ). We assigned GI values of each item by a 5-step methodology, using the International Tables of GI and GL Values. Deaths were ascertained through contact with families and general practitioners, review of medical records and consultation of the National Death Index. Cox regression models were used to estimate multivariable-adjusted hazard ratios (HR) and their 95% CI for mortality, according to quartiles of energy-adjusted dietary GI/GL. To assess repeated measures of exposure, we updated GI and GL intakes from the yearly FFQs and used Cox models with time-dependent exposures. Results We followed 3,583 non-diabetic subjects (4.7 years of follow-up, 123 deaths). As compared to participants in the lowest quartile of baseline dietary GI, those in the highest quartile showed an increased risk of all-cause mortality [HR = 2.15 (95% CI: 1.15–4.04); P for trend  = 0.012]. In the repeated-measures analyses using as exposure the yearly updated information on GI, we observed a similar association. Dietary GL was associated with all-cause mortality only when subjects were younger than 75 years. Conclusions High dietary GI was positively associated with all-cause mortality in elderly population at high cardiovascular risk.

Assessment of Beverage intake and Hydration status

UNLABELLED Water is the main constituent of the human body. It is involved in practically all its functions. It is particularly important for thermoregulation and in the physical and cognitive performance. Water balance reflects water intake and loss. Intake of water is done mainly through consumption of drinking water and beverages (70 to 80%) plus water containing foods (20 to 30%). Water loss is mainly due to excretion of water in urine, faeces and sweat. The interest in the type and quantity of beverage consumption is not new, and numerous approaches have been used to assess beverage intake, but the validity of these approaches has not been well established. There is no standardized questionnaire developed as a research tool for the evaluation of water intake in the general population. Sometimes, the information comes from different sources or from different methodological characteristics which raises problems of the comparability. In the European Union, current epidemiological studies that focus exclusively on beverage intake are scarce. Biomarkers of intake are able to objectively assess dietary intake/status without the bias of self-reported dietary intake errors and also overcome the problem of intra-individual diet variability. Furthermore, some methods of measuring dietary intake used biomarkers to validate the data it collects. Biological markers may offer advantages and be able to improve the estimates of dietary intake assessment, which impact into the statistical power of the study. There is a surprising paucity of studies that systematically examine the correlation of beverages intake and hydration biomarker in different populations. A pilot investigation was developed to evaluate the comparative validity and reliability of newly developed interactive multimedia (IMM) versions compared to validated paper-administered (PP) versions of the Hedrick et al. beverage questionnaire. The study showed that the IMM appears to be a valid and reliable measure to assess habitual beverage intake. Similar study was developed in China, but in this case, the use of Smartphone technology was employed for beverage assessment. CONCLUSION The methodology for measuring beverage intake in population studies remains controversial. There are few validated and reproducible studies, so there is still lacking an ideal method (ie, short, easy to administer, inexpensive and accurate) in this regard. Clearly, this is an area of scientific interest that is still in development and seems to be very promising for improving health research.

Glycemic index, glycemic load and invasive breast cancer incidence in postmenopausal women: The PREDIMED study.

The objective of this study was to evaluate the prospective associations between dietary glycemic index (GI) and glycemic load (GL) and the risk for invasive breast cancer incidence in postmenopausal women at high cardiovascular disease (CVD) risk. This study was conducted within the framework of the PREvención con DIeta MEDiterránea (PREDIMED) study, a nutritional intervention trial for primary cardiovascular prevention. We included 4010 women aged between 60 and 80 years who were initially free from breast cancer but at high risk for CVD disease. Dietary information was collected using a validated 137-item food frequency questionnaire. We assigned GI values using the International Tables of GI and GL values. Cases were ascertained through yearly consultation of medical records and through consultation of the National Death Index. Only cases confirmed by results from cytology tests or histological evaluation were included. We estimated multivariable-adjusted hazard ratios for invasive breast cancer risk across tertiles of energy-adjusted dietary GI/GL using Cox regression models. We repeated our analyses using yearly repeated measures of GI/GL intakes. No associations were found between baseline dietary GI/GL and invasive breast cancer incidence. The multivariable hazard ratio and 95% confidence interval (CI) for the top tertile of dietary GI was 1.02 (95% CI: 0.42–2.46) and for dietary GL was 1.00 (95% CI: 0.44–2.30) when compared with the bottom tertile. Repeated-measures analyses yielded similar results. In sensitivity analyses, no significant associations were observed for women with obesity or diabetes. Dietary GI and GL did not appear to be associated with an increased risk for invasive breast cancer in postmenopausal women at high CVD risk.

Nutritional Adequacy of the Mediterranean Diet

In recent years there has been an increased interest in finding a dietary pattern that satisfies a population’s nutritional requirements. The Mediterranean dietary pattern (MDP) encapsulates a beneficial fatty acid profile with high monounsaturated fatty acids content, a low proportion of carbohydrate, and high intake of dietary fiber and antioxidant compounds that work together to produce beneficial effects on health. Greater adherence to this pattern has been related to a reduced risk of mortality and decreased incidence of cardiovascular diseases, certain types of cancer, and type 2 diabetes. Nutritional adequacy is the probability of a certain nutrient intake to be adequate for an individual and can be estimated if the requirement distribution is known. Prevalence of nutrient inadequacy in groups can be estimated by the average requirement cut-point method. However, indices or dietary patterns can also be used because they correlate considerably well with nutritional adequate intakes. The MDP has been associated on an increased probability of fulfilling nutrient recommendations. Therefore, preserving the Mediterranean diet should be encouraged in health promotion strategies instead of alternatives such as fortification and supplementation.