Omega-3 and omega-6 fatty acids food intake and metabolic syndrome in adolescents 12 to 17 years old: A school-based cross-sectional study.

BACKGROUND & AIMS: Fatty acids (FAs) of the omega-3 and omega-6 family are considered essential, and adequate intake seems to be associated with lower risk of developing chronic non-communicable diseases. The objective was to evaluate the association of omega-3 and omega-6 FAs dietary intake with the prevalence of MS and its components waist circumference (WC), blood pressure (BP), fasting blood glucose, triglycerides and High Density Lipoprotein - cholesterol (HDL-c) in Brazilian adolescents aged 12-17 years. METHODS: This is a school-based cross-sectional investigation, using data from the Study of Cardiovascular Risks in Adolescents (ERICA), carried out between 2013 and 2014. The following variables were collected and assessed: 1) sociodemographic (sex, age, type of school, school location whether urban or rural and region of the country); 2) food consumption was measured through a 24-h Food Recall (24 hR), and a second 24 hR was applied to 7% of the total sample; 3) anthropometrics (weight, height, WC), BP and biochemical (glycemia, triglycerides and HDL-c) were also assessed. Logistic regression analysis was performed according to gender and age group. RESULTS: A total of 36,751 adolescents participated in the study. The intake of omega-3 FAs in the total population was 1.71 g/day and of omega-6 FAs, 13.56 g/day, with an omega-6/omega-3 ratio of 7.93:1. It was found that higher intake of omega-3 FAs was associated with an 53% lower chance of low HDL-c. For omega-6 FAs, no significant results were found. CONCLUSIONS: The findings indicated an association between omega-3 FAs and HDL-c. More studies are needed to elucidate the effects of omega-6 FAs.

Scientific evidence of the association between oral intake of OMEGA-3 and OMEGA-6 fatty acids and the metabolic syndrome in adolescents: A systematic review.

AIMS: To conduct a systematic review of the literature on the scientific evidence of the oral intake of omega-3 and omega-6 FAs and metabolic syndrome (MS) in adolescents. DATA SYNTHESIS: The study was registered in PROSPERO (number 42020185370). Studies were carried out with adolescents aged 10-19 years, who presented as intervention/exposure the oral intake of omega-3 and/or omega-6 fatty acids (FAs), in the databases PubMed, Scopus, Web of Science, LILACS, CENTRAL, and PQDT Global e BDTD. The tools used to assess the risk of bias were RoB 2.0, Agency for Healthcare Research and Quality (AHRQ), and Newcastle-Ottawa Scale. Fifteen papers retrieved published from 2010 to 2019 were included (n = 3534); nine were randomized studies and controlled clinical trials, four were cross-sectional studies, one was a retrospective cohort study, and one case-control study. No studies have evaluated the effect or association of omega-3 and/or of omega-6 FAs with actual MS, only with its components. The randomized clinical trials identified the effects of omega-3 FA on the decrease in blood pressure (n = 1 out of six), glycemia (n = 2 out of seven), and triglycerides (n = 5 out of eight), and the increase in HDL-c (n = 2 out of eight) considering the comparison between the group that received omega-3 FA and the control group. CONCLUSIONS: Scientific evidence is controversial on the association between oral intake of omega-3 FAs and MS in adolescents, due to the heterogeneity between studies and the divergence of results for the same MS component.

Association between DASH diet (Dietary Approaches to Stop Hypertension) and hypertension in adolescents: A cross-sectional school-based study.

BACKGROUND & AIMS: The DASH diet (Dietary Approaches to Stop Hypertension) is considered a healthy dietary pattern, and is recommended for the control of arterial hypertension (AH). However, its role in the adolescent population needs to be better investigated and clarified. The aim of this study is to identify the association between AH and the DASH diet score in a representative sample of Brazilian adolescents. METHODS: A cross-sectional study using data from a national, multicenter and schoolbased probabilistic sample of 71,553 Brazilian adolescents who had their blood pressure (BP) measured and completed a 24-hour dietary recall (2013-2014). The components of the DASH score were assessed. Logistic regression models were used to evaluate the association between AH, anthropometric and sociodemographic variables, and the tertile of the DASH score. RESULTS: Approximately 11% of the adolescents who were in the 3rd tertile of the DASH score presented AH, 18% were overweight and 9% were obese. Among the components of the score, the highest intake was sugar-sweetened beverages (92.1%), legumes and oilseeds (68.2%), red and processed meat (64.5%) and the lowest were low-fat dairy (2.2%), whole grains (11.6%) and fruits (18.1%). Sodium intake was above the maximum recommended in all tertiles. CONCLUSIONS: A small proportion of Brazilian adolescents consume foods from the DASH diet. No associations were found between this dietary pattern and AH. Strategies to increase the intake of protective foods in adolescents must be investigated as well as the potential health benefits of the standard DASH diet for this age group over time.

Usual intake and dietary sources of Selenium in adolescents: A cross-sectional school-based study.

BACKGROUND AND OBJECTIVES: Selenium is a mineral that constitutes selenoproteins and, therefore, has been studied, especially in cardiovascular diseases. Some risk factors for the development of these diseases, such as obesity, hypertension and dyslipidemia, have been observed early in life, including in childhood and adolescence, and food and nutrient intake is an important associated factor for their development. The aim of this study was to assess usual intake of selenium (Se) and dietary inadequacies regarding the consumption of this mineral, and to identify the main dietary sources of Se among 12-17 year-old Brazilian adolescents. METHODS: Data from the Study of Cardiovascular Risk in Adolescents, performed countrywide in the years 2013 and 2014, were used to estimate inadequate Se dietary intake. The National Cancer Institute's method was used, considering two days of 24 h dietary recall (24hR). The contribution of each food group to the total intake of Se was determined using a single 24hR, and was defined as a ratio between the total intake of Se and the percentage of Se in each food group, until reaching 95%. Food mentioned by adolescents were categorized into 39 food groups, according to macronutrient similarities. RESULTS: Data from 76,957 adolescents aged from 12-17 years (49.7% girls) from public and private schools were assessed. Selenium intake was according to recommendation levels. Mean Se intake ranged from 84.3 to 105.9 µg among sex and age groups. Considering the whole sample, meat, pasta, poultry, and fish were the food groups that contributed with the greatest amount of Se (representing 57.9% of total Se). Brazil nuts are consumed in bigger quantity only by 14-17 year-old girls, contributing to 1.6% of the Se in their diets. CONCLUSION: Brazilian adolescents have an adequate Se intake because of the high consumption of meat, pasta, and poultry. Although Brazil nuts are the most important dietary source of Se, adolescents consume them in very small amounts, leading to a small contribution in the total intake.

Selenium intake and metabolic syndrome: A systematic review.

BACKGROUND & AIMS: Metabolic syndrome is a multi-causal disease. Its treatment includes lifestyle changes with a focus on weight loss. This systematic review assessed the association between Selenium intake and metabolic syndrome. METHODS: Data were collected mainly from four databases: PubMed, CENTRAL (Cochrane), Scopus and Web of Knowledge. Keywords related to metabolic syndrome, selenium, as well as metabolic syndrome features were searched. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. A systematic review protocol was registered at PROSPERO (n. 42016046321). Two reviewers independently screened 2957 abstracts. Six studies were included to perform data extraction with standardized spreadsheets. The risk of bias was assessed by using specific tools according to the design of the relevant studies. An assessment was carried out based on the appropriateness of the study reports accordingly to STROBE and the CONSORT-based checklist for each study design. RESULTS: Three studies found no association between Selenium intake and metabolic syndrome; two of them found an inverse association; and one study found a direct association between Selenium intake and metabolic syndrome. One study also showed an inverse association between Selenium intake and the prevalence of high waist circumference, high diastolic blood pressure, and hyperglycaemia in women. CONCLUSIONS: Overall, based on the argumentation and results of this study, it is possible to conclude that Selenium intake and metabolic syndrome are not clearly associated in adults and elderly.