L. E. Díaz

Influence of alcohol consumption on immunological status: a review.

The aim of this review is to present and discuss the effect of different levels of alcohol consumption on the immune system. Not only the amount consumed but also the type of alcoholic beverage have to be taken into account in order to determine the consequences on activity, number, distribution, balance, interaction and response of immunocompetent cells. The association between alcohol exposure and the risk of developing an alcohol-related disease is multifactorial. In fact, age, gender, smoking habits, dietary intake and exercise are involved among other factors. The evaluation of the host cellular and humoral immune responses has shown that alcohol may induce some benefits when consumption is moderate. Moreover, those alcoholic beverages that contain antioxidants, such as red wine, could be protectors against immune cell damage. According to the literature consulted, the daily consumption of 10–12 g and 20–24 g of alcohol for women and men, respectively, is considered to be a moderate intake; the type of beverage has been established not to be important when defining moderation. Particular attention is often focused on the U- or J-shaped curve which also suggests that light to moderate drinking produces a protective effect. Such an inverse relationship indicates a reduction of risk for both light and moderate consumers and a higher risk not only for hard drinkers, but also for non-consumers.

Sampling and processing of fresh blood samples within a European multicenter nutritional study: Evaluation of biomarker stability during transport and storage

Introduction:Analysis of several biological markers improves the quality and physiologic comprehension of data obtained in epidemiological nutritional studies.Aim:To develop a methodology that guarantees the centralized analysis and quality assurance of the most relevant blood parameters from fresh blood samples in adolescents in a European multicenter study.Materials and methods:Stability of selected nutrients and biomarkers (vitamins, fatty acids, iron metabolism and immunological parameters) chosen with respect to time and temperature of sample transport and storage was evaluated as part of the pilot study of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) project.Results:Routine biochemistry and iron status parameters included in the HELENA Cross-Sectional Study (CSS) protocol could be analyzed within 24 h from fresh blood samples without any stability problems (coefficient of variation (CV)<5%, P<0.05). However, stability tests for lymphocyte subpopulations, vitamin C and fatty acids showed that they are very unstable at room temperature without any treatment. Therefore, a special handling for these samples was developed. Vitamin C was stabilized with metaphosphoric acid and transported under cooled conditions (CV 4.4%, recovery rate >93%, P>0.05). According to the results, a specific methodology and transport system were developed to collect blood samples at schools in 10 European cities and to send them to the centralized laboratory (IEL, Bonn, Germany). To guarantee good clinical practice, the field workers were instructed in a training workshop and a manual of operation was developed.Conclusion:The handling and transport system for fresh blood samples developed for the European multicenter study HELENA is adequate for the final part of the HELENA-CSS and will provide, for the first time, reference values for several biological markers in European adolescents.

Nutrition, Inflammation, and Cognitive Function

Inflammation, particularly low‐grade chronic inflammation, appears to affect several brain functions, from early brain development to the development of neurodegenerative disorders and perhaps some psychiatric diseases. On the other hand, nutrition and dietary components and patterns have a plethora of anti‐ and pro‐inflammatory effects that could be linked to cognitive function. Even a modest effect of nutrition on cognitive decline could have significant implications for public health. This paper summarizes the available evidence regarding inflammation as a key mechanism in cognitive function and nutritional pro‐ or anti‐inflammatory effects with the purpose of linking the apparent disparate disciplines of nutrition, immunity, and neurology.

Evaluation of iron status in European adolescents through biochemical iron indicators: the HELENA Study

Background/Objectives:To assess the iron status among European adolescents through selected biochemical parameters in a cross-sectional study performed in 10 European cities.Subjects/Methods:Iron status was defined utilising biochemical indicators. Iron depletion was defined as low serum ferritin (SF<15 μg/l). Iron deficiency (ID) was defined as high-soluble transferrin receptor (sTfR>8.5 mg/l) plus iron depletion. Iron deficiency anaemia (IDA) was defined as ID with haemoglobin (Hb) below the WHO cutoff for age and sex: 12.0 g/dl for girls and for boys aged 12.5–14.99 years and 13.0 g/dl for boys aged ⩾15 years. Enzyme linked immunosorbent assay was used as analytical method for SF, sTfR and C-reactive protein (CRP). Subjects with indication of inflammation (CRP >5 mg/l) were excluded from the analyses. A total of 940 adolescents aged 12.5–17.49 years (438 boys and 502 girls) were involved.Results:The percentage of iron depletion was 17.6%, significantly higher in girls (21.0%) compared with boys (13.8%). The overall percentage of ID and IDA was 4.7 and 1.3%, respectively, with no significant differences between boys and girls. A correlation was observed between log (SF) and Hb (r=0.36, P<0.01), and between log (sTfR) and mean corpuscular haemoglobin (r=−0.30, P<0.01). Iron body stores were estimated on the basis of log (sTfR/SF). A higher percentage of negative values of body iron was recorded in girls (16.5%) with respect to boys (8.3%), and body iron values tended to increase with age in boys, whereas the values remained stable in girls.Conclusions:To ensure adequate iron stores, specific attention should be given to girls at European level to ensure that their dietary intake of iron is adequate.

Cardiorespiratory fitness and dietary intake in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence study.

The present study investigated the association between cardiorespiratory fitness (CRF) and dietary intake in European adolescents. The study comprised 1492 adolescents (770 females) from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. CRF was assessed by the 20 m shuttle run test. Adolescents were grouped into low and high CRF levels according to the FITNESSGRAM Standards. Dietary intake was self-registered by the adolescents using a computer-based tool for 24 h dietary recalls (HELENA-Dietary Assessment Tool) on two non-consecutive days. Weight and height were measured, and BMI was calculated. Higher CRF was associated with higher total energy intake in boys (P = 0·003). No association was found between CRF and macronutrient intake (as percentage of energy), yet some positive associations were found with daily intake of bread/cereals in boys and dairy products in both boys and girls (all P < 0·003), regardless of centre, age and BMI. CRF was inversely related to sweetened beverage consumption in girls. These findings were overall consistent when CRF was analysed according to the FITNESSGRAM categories (high/low CRF). A high CRF was not related to compliance with dietary recommendations, except for sweetened beverages in girls (P = 0·002). In conclusion, a high CRF is associated with a higher intake of dairy products and bread/cereals, and a lower consumption of sweetened beverages, regardless of centre, age and BMI. The present findings contribute to the understanding of the relationships between dietary factors and physiological health indicators such as CRF.

Daily consumption of milk enriched with fish oil, oleic acid, minerals and vitamins reduces cell adhesion molecules in healthy children *

BACKGROUND AND AIMS Several studies have suggested that polyunsaturated fatty acids, vitamins and minerals have beneficial effects on lipid profile and systemic inflammation in adults. METHODS AND RESULTS We examined the effects of a daily intake of milk enriched with longchain polyunsaturated fatty acids, oleic acid, carbohydrates, vitamins, minerals and low in saturated fatty acids (SFAs) for 5 months, on several cardiovascular (CVD) risk biomarkers in healthy children aged 8-14 years. In a randomized double-blind placebo-controlled trial, a total of 107 children of both genders were assigned to two study groups: 1) a supplemented group (SG, n=53) who consumed 0.6 L/day of an enriched dairy product, and 2) a control group (CG, n=54) who consumed 0.6 L/day of standard whole milk. Both groups consumed the dairy drinks for 5 months, in addition to their usual diet. Serum levels of adhesion molecules as indices of vascular endothelial cell activation were assessed in both groups at 0 and 5 months as well as white blood cell counts, lipid profile, serum proteins, total serum calcium, 25-OH vitamin D, glucose, insulin and adiponectin. In the enriched dairy drink supplemented group, adhesion molecules E-selectin and ICAM-1 as well as lymphocyte levels decreased while plasma docosahexaenoic acid (DHA) and serum calcium concentrations increased. In the control group, serum total protein, transferrin, total cholesterol, HDL-cholesterol and adiponectin concentrations decreased. CONCLUSION The consumption of a milk enriched with fish oil, oleic acid, minerals and vitamins reduced indices of endothelial cell activation in the studied group of healthy children.

Breastfeeding in Infancy Is Not Associated with Inflammatory Status in Healthy Adolescents

It has been suggested that breast-feeding (BF) may be associated with a decreased risk of cardiovascular disease in adulthood. A low-grade inflammation is associated with an increased risk of cardiovascular disease, even in apparently healthy children. The objective of this study was to assess the potential modulating effect of BF on the inflammatory status of healthy adolescents. Information on BF (duration) was obtained from parental records in 484 of 1040 healthy European urban adolescents (56.4% females) that had a blood sample obtained as part of the Healthy Lifestyle in Europe by Nutrition and Adolescence study. Blood serum inflammatory markers were measured, including high sensitivity C-reactive protein, complement factors 3 and 4, ceruloplasmin, adhesion molecules (L-selectin and soluble endothelial selectin, soluble vascular cell adhesion molecule 1, and intercellular adhesion molecule 1), cytokines, TGFβ1, and white blood cells. After univariate analysis, a propensity score, including the potential confounding factors, was computed and used to assess the association between BF and selected inflammatory markers. BF was not significantly associated with any of the selected inflammatory markers after adjustment for gender and propensity score. In our study, BF was not associated with low-grade inflammatory status in healthy adolescents, suggesting that the potential cardiovascular benefits of BF are related to other mechanisms than modulation of inflammation or might become relevant at a later age. Groups at high risk for cardiovascular disease should be a target for further research concerning the effects of BF.

Cardiorespiratory Fitness Cutoff Points for Early Detection of Present and Future Cardiovascular Risk in Children:A 2-Year Follow-up Study

Objective: To examine the association between cardiorespiratory fitness (CRF) at baseline and cardiovascular disease (CVD) risk in 6‐ to 10‐year‐olds (cross‐sectional) and 2 years later (8‐ to 12‐year‐olds [longitudinal]) and whether changes with age in CRF are associated with CVD risk in children aged 8 to 12 years. Patients and Methods: Spanish primary schoolchildren (n=236) aged 6 to 10 years participated at baseline. Of the 23 participating primary schools, 22% (n=5) were private schools and 78% (n=18) were public schools. The dropout rate at 2‐year follow‐up was 9.7% (n=23). The 20‐m shuttle run test was used to estimate CRF. The CVD risk score was computed as the mean of 5 CVD risk factor standardized scores: sum of 2 skinfolds, systolic blood pressure, insulin/glucose, triglycerides, and total cholesterol/high‐density lipoprotein cholesterol. Results: At baseline, CRF was inversely associated with single CVD risk factors (all P<.05) and CVD risk score at baseline and follow‐up (P<.001). Cardiorespiratory fitness cutoff points of 39.0 mL/kg per minute or greater in boys and 37.5 mL/kg per minute or greater in girls are discriminative to identify CVD risk in childhood (area under the curve, >0.85; P<.001) and to predict CVD risk 2 years later (P=.004). Persistent low CRF or the decline of CRF from 6‐10 to 8‐12 years of age is associated with increased CVD risk at age 8 to 12 years (P<.001). Conclusion: During childhood, CRF is a strong predictor of CVD risk and should be monitored to identify children with potential CVD risk. Abbreviations and Acronyms: AUC = area under the curve; CRF = cardiorespiratory fitness; CVD = cardiovascular disease; HDL‐C = high‐density lipoprotein cholesterol; HOMA‐IR = homeostasis model assessment for insulin resistance; OR = odds ratio; SBP = systolic blood pressure; TC = total cholesterol; TG = triglycerides; VO2max = maximum oxygen consumption

Food Supplements and Immune Function in Humans

Autoimmune and inflammatory diseases are major health concerns nowadays with their prevalence rising worldwide, especially in industrialized countries. There is growing evidence showing that certain nutrients exert immunomodulatory actions and consequently may constitute interesting adjuvant strategies for prevention and/or amelioration of immune-related diseases. However, data on their effectiveness are still controversial, as will be discussed in the current chapter. In any case, food supplements should not be used as substitutes for a balanced diet; moreover, they do not represent an alternative to the prescribed medical treatment, although their intake must be taken into consideration to avoid possible food supplement–drug interactions.

Lymphocyte subsets, anthropometric measurements and body composition in European adolescents. The HELENA Study

There is a close relationship between obesity and the immune system. Obese individuals have been shown to present higher immune cell counts, mainly of total leukocytes, but also of neutrophils, lymphocytes and monocytes (1) . The association between leukocyte count and obesity has been observed in children and adolescents as well (2,3) , and it could also occur with other cell types, e.g., T lymphocytes (4) . We have recently found a significant relation between total leukocytes and body mass index (BMI) in a cohort of European adolescents participating in the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence-Cross-Sectional Study) (unpublished data). For the present work we studied further the relationships between lymphocyte subset counts and body composition and anthropometric measurements in this adolescent cohort. Blood samples were collected after an overnight fast from 1,089 boys and girls (12.5‐17.5 years). After applying exclusion criteria to rule out possible infections, data were analysed from 751 adolescents (47.5% males). The sample was divided into three categories according to tertiles of standardized BMI values. Absolute and relative numbers of total T lymphocytes