Prospective study of total and various types of vegetables and the risk of metabolic syndrome among children and adolescents

Total dietary fiber intake is inversely associated with metabolically unhealthy status in adolescents with excess weight

Little is known about the relationship between dietary fiber and metabolic health status in adolescents. This study was performed to investigate total dietary fiber intake and metabolic health status in a sample of Iranian adolescents with overweight/obesity. We hypothesized that higher total dietary fiber intake would reduce odds of metabolically unhealthy status. In this cross-sectional study, 203 adolescents (aged 12-18 years) with overweight/obesity were randomly recruited from several educational areas with different socioeconomic statuses using a multistage cluster sampling approach. Dietary intakes were evaluated by a validated food frequency questionnaire. Demographic, anthropometric, and cardiometabolic data were gathered through standard methods. Adolescents were categorized as having either metabolically healthy overweight/obesity or metabolically unhealthy overweight/obesity (MUO) phenotypes according to the International Diabetes Federation (IDF) and IDF/Homeostasis Model Assessment Insulin Resistance (HOMA-IR) criteria. Subjects had mean age of 13.97 (years) and mean fiber intake of 19.5 (g/d). After considering potential confounders, adolescents with the highest fiber intake, compared with the lowest intake, had decreased odds of MUO based on IDF (odds ratio [OR] = 0.14; 95% confidence interval [CI], 0.04-0.46) and IDF/HOMA-IR (OR = 0.16; 95% CI, 0.04-0.56) definitions. Also, each additional unit of total dietary fiber intake (1 g/d) was associated with lower chance of MUO phenotype considering IDF and IDF/HOMA-IR criteria. Individuals with higher intakes of dietary fiber were also less likely to have hyperglycemia (in fully adjusted model: OR = 0.17; 95% CI, 0.06-0.52). We found that consumption of total dietary fiber was inversely associated with odds of MUO among Iranian adolescents. Further prospective studies are required for confirming our results.

School-based intervention impacts availability of vegetables and beverages in participants' homes

As rates of metabolic syndrome rise, children consume too few vegetables and too much added sugar. Because children tend to eat what is available at home, the home environment plays a key role in shaping dietary habits. This secondary analysis evaluated the effects of a school-based gardening, cooking, and nutrition education intervention (TX Sprouts) compared to control on the availability of vegetables, fruit juice, and sugar-sweetened beverages (SSBs) at home. In the TX Sprouts cluster-randomized trial, 16 schools were randomized to TX Sprouts (n = 8 schools) or control (n = 8 schools) for one academic year. All schools served predominately Hispanic families with low incomes. TX Sprouts built school gardens and taught 18 lessons to all 3rd-5th grade students at intervention schools. TX Sprouts also offered monthly caregiver lessons before and/or after school. Caregivers completed questionnaires pre and post, providing demographics and information about home availability of vegetables, fruit juice, and SSBs. Summary statistics were used to describe the sociodemographic characteristics of participants. Linear regression assessed the change in scores (pre to post) for the food/ beverage availability question. The model was adjusted for the caregiver's education, employment status, child's grade, and free or reduced-price lunch eligibility. The analytic sample included 895 participants. Compared to control, the intervention positively changed the home availability of targeted foods and beverages, largely by improving the availability of vegetables and vegetable juice. This study showed that a school gardening, nutrition, and cooking program delivered to elementary children may positively influence the home food environment.

Associations of starchy and non-starchy vegetables with risk of metabolic syndrome: evidence from the NHANES 1999-2018

BACKGROUND

Higher dietary quality, including increased vegetable consumption, was associated with a reduced risk of metabolic syndrome (MetS). However, specific vegetable consumption in the development of MetS remains obscure. Our study aimed to investigate the correlation between starchy and non-starchy vegetables and MetS.

METHODS

Secondary data analysis from the National Health and Nutrition Examination Survey (NHANES 1999-2018). MetS was defined by National Cholesterol Education Program-Adult treatment Panel III (NCEP ATPIII) and dietary consumption was assessed by trained staff using two 24-h diet recall methods. Weighted logistic regression analysis was carried out to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses and restricted cubic spline (RCS) regression were performed to further investigate specific vegetable subtypes and MetS.

RESULTS

This research enrolled 24,646 individuals (11,725 females and 12,921 males), with an average age of 45.84 ± 0.23 years. Approximately 15,828(64.22%) participants were defined to be with non-MetS and 8818(35.78%) were with MetS. Both total starchy vegetables and potatoes were associated with increased MetS risk, with the corresponding OR per standard deviation (SD) (95%CI, p-trend) being 1.06(1.02-1.11, p-trend = 0.028) and 1.08(1.04-1.13, p-trend = 0.011), respectively. However, an inverse correlation was found between dark-green vegetables and MetS, and the OR per SD (95%CI, p-trend) was 0.93(0.90-0.97, p-trend = 0.010). Subgroup analyses showed that the positive associations of starchy vegetables and potatoes on MetS risk were stronger in non-Hispanic White participants (p for interaction < 0.050).

CONCLUSION

Total starchy vegetables and white potatoes were both associated with an increased risk of MetS, while consumption of dark-green vegetables was negatively associated with MetS risk. These findings might provide a promising and healthy dietary strategy for preventing MetS.

The relation between dietary phytochemical index and metabolic health status in overweight and obese adolescents

Previous studies have rarely investigated dietary phytochemicals consumption in relation to metabolic health of adolescents. The current study was performed to investigate dietary phytochemical index (DPI) in relation to metabolic health status in overweight and obese adolescents. This cross-sectional study was conducted among 203 adolescents with overweight or obesity. Dietary intakes of participants were obtained through a validated 147-item food frequency questionnaire. DPI was calculated [(dietary energy derived from phytochemical-rich foods (kcal)/total daily energy intake (kcal)) ⨯100]. Glycemic and lipid profiles, blood pressure, and anthropometric indices were also measured. A metabolically unhealthy overweight/obesity (MUO) profile was determined based on the International Diabetes Federation (IDF) and IDF/Homeostasis Model Assessment Insulin Resistance (HOMA-IR) definitions. Study subjects had a mean age of 13.98 years and 50.2% of them were girls. According to IDF and IDF/HOMA-IR criteria, 38.9% (37 boys, and 42 girls) and 33% (35 boys, and 32 girls) of the study participants were respectively MUO. According to IDF and IDF/HOMA-IR definitions, adolescents in the third DPI tertile had respectively 61% (maximally-adjusted OR = 0.39, 95%CI 0.16-0.91) and 67% (maximally-adjusted OR = 0.33, 95%CI 0.13-0.83) lower odds of being MUO, compared to the first tertile. Stratified analysis by sex indicated that DPI was inversely related to MUO phenotype based on IDF criteria in girls (maximally-adjusted OR = 0.25, 95%CI 0.06-0.98), but not in boys. The current study found that adolescents with a higher dietary intake of phytochemicals have lower odds of being MUO, particularly among girls. However, further large-scale prospective cohort studies are required to confirm this finding.

Effects of a School-Based Gardening, Cooking, and Nutrition Cluster Randomized Controlled Trial on Unprocessed and Ultra-Processed Food Consumption

BACKGROUND

School-based gardening and nutrition education interventions report improvements in dietary intake, notably through fruit and vegetables. However, gardening, cooking, and nutrition randomized controlled trials are limited in evaluating dietary quality, and none have examined processed food consumption to date.

OBJECTIVES

The study examined the effects of Texas Sprouts (TX Sprouts), a gardening, cooking, and nutrition education intervention, compared with control on unprocessed and ultra-processed food (UPF) consumption in predominately low-income Hispanic children.

METHODS

TX Sprouts was a school-based cluster randomized controlled trial that consisted of 16 elementary schools randomly assigned to either the TX Sprouts intervention (n = 8 schools) or control (delayed intervention; n = 8 schools) over 3 y (2016-2019). TX Sprouts schools received an outdoor teaching garden and 18 1-h lessons taught by trained educators throughout the school year. Dietary intake data via 2 24-h dietary recalls were collected on a random subsample (n = 468) at baseline and postintervention. All foods and beverages were categorized using the NOVA food classification system (e.g., unprocessed, processed, ultra-processed). Generalized linear mixed effects modeling tested changes in percent calories and grams of NOVA groups between the intervention and control estimates with schools as random clusters.

RESULTS

Of the sample, 63% participated in the free and reduced-price lunch program, and 57% were Hispanic, followed by non-Hispanic White (21%) and non-Hispanic Black (12%). The intervention, compared to the control, resulted in an increase in consumption of unprocessed foods (2.3% compared with -1.8% g; P < 0.01) and a decrease in UPF (-2.4% compared with 1.4% g; P = 0.04). In addition, Hispanic children in the intervention group had an increase in unprocessed food consumption and a decrease in UPF consumption compared to non-Hispanic children (-3.4% compared with 1.5% g; P < 0.05).

CONCLUSIONS

Study results suggest that school-based gardening, cooking, and nutrition education interventions can improve dietary intake, specifically increasing unprocessed food consumption and decreasing UPF consumption. This trial was registered at clinicaltrials.gov as NCT02668744.

Spinach consumption and nonalcoholic fatty liver disease among adults: a case-control study

BACKGROUND

Spinach has high antioxidants and polyphenols and showed protective effects against liver diseases in experimental studies. We aimed to assess the association between dietary intake of spinach and odds of nonalcoholic fatty liver disease (NAFLD) in a case-control study among Iranian adults.

METHODS

Totally 225 newly diagnosed NAFLD patients and 450 controls, aged 20-60 years, were recruited in this study. Participants' dietary intakes were collected using a valid and reliable 168-item semi-quantitative food frequency questionnaire (FFQ). The logistic regression test was used for assessing the association between total, raw, and boiled dietary spinach with the odds of NAFLD.

RESULTS

The mean (SD) age and BMI of participants (53% male) were 38.1 (8.8) years and 26.8 (4.3) kg/m², respectively. In the final adjusted model for potential confounders, the odds (95% CI) of NAFLD in individuals in the highest tertile of daily total and raw spinach intake was [0.36 (0.19-0.71), P_trend = 0.001] and [0.47 (0.24-0.89), P_trend = 0.008], respectively compared with those in the lowest tertile. Furthermore, in the adjusted analyses, an inverse association was observed between the highest yearly intake versus no raw spinach consumption and odds of NAFLD [(OR 0.41; 95% CI 0.18-0.96), P for trend = 0.013]. However, there was no significant association between higher boiled spinach intake and odds of NAFLD.

CONCLUSIONS

The present study found an inverse association between total and raw spinach intake with the odds of NAFLD.

Texture Analysis in the Evaluation of Covid-19 Pneumonia in Chest X-Ray Images: a Proof of Concept Study

BACKGROUND

One of the most challenging aspects related to Covid-19 is to establish the presence of infection in early phase of the disease. Texture analysis might be an additional tool for the evaluation of Chest X-ray in patients with clinical suspicion of Covid-19 related pneumonia.

OBJECTIVE

To evaluate the diagnostic performance of texture analysis and machine learning models for the diagnosis of Covid-19 interstitial pneumonia in Chest X-ray images.

METHODS

Chest X-ray images were accessed from a publicly available repository (https://www.kaggle.com/tawsifurrahman/covid19-radiography-database). Lung areas were manually segmented using a polygonal regions of interest covering both lung areas, using MaZda, a freely available software for texture analysis. A total of 308 features per ROI was extracted. One hundred-ten Covid-19 Chest X-ray images were selected for the final analysis.

RESULTS

Six models, namely NB, GLM, DL, GBT, ANN and PLS-DA were selected and ensembled. According to Youden's index, the Covid-19 Ensemble Machine Learning Score showing the highest Area Under the Curve (0.971±0.015) was 132.57. Assuming this cut-off the Ensemble model performance was estimated evaluating both true and false positive/negative, resulting in 91.8% accuracy with 93% sensitivity and 90% specificity. Moving the cut-off value to -100, although the accuracy resulted lower (90.6%), the Ensemble Machine Learning showed 100% sensitivity, with 80% specificity.

CONCLUSION

Texture analysis of Chest X-ray images and machine learning algorithms may help in differentiating patients with Covid-19 pneumonia. Despite several limitations, this study can lay ground for future researches in this field and help developing more rapid and accurate screening tools for these patients.

Dietary fibre intake in childhood or adolescence and subsequent health outcomes: A systematic review of prospective observational studies

AIM

To determine whether higher fibre intakes during childhood or adolescence effect a broad range of intermediate markers of cardiometabolic risk or other health related issues.

MATERIALS AND METHODS

We used online searches up to January 2020 and manual searches to identify prospective observational studies reporting on childhood or adolescent intakes of dietary fibre, vegetables, fruit and refined or whole grains. Outcomes measured later in life were body weight, blood lipids, blood pressure, glycaemia, bone health, cognition, growth and bowel habits. Potential age-specific ranges for dietary fibre were extrapolated from published adult data.

RESULTS

We identified 45 publications reporting on 44 354 participants from 30 cohort studies. Mean age at dietary assessment varied from 1 to 19.3 years. Follow-up duration varied from 4 months to 27 years. Although well-conducted studies reported improvements in body weight, blood lipids and glycaemia, the diverse nature of studies precluded meta analysis. The quality of evidence was very low to low given the limited data available per outcome and the inability to synthesize results from multiple studies. Potential dietary fibre intake begins at 13-16 g a day for 2-year-olds and increases until the age of 10 years, when values are comparable with an adult range of 25-30 g a day.

CONCLUSIONS

Given the inconsistency in findings from cohort studies other than an absence of detrimental effects, it seems appropriate that recommendations regarding childhood fibre intake are extrapolated from relevant adult data.

Does the association between patterns of fruit and vegetables and metabolic syndrome incidence vary according to lifestyle factors and socioeconomic status?

BACKGROUND AND AIMS

The aim of this study is to investigate the association between the identified patterns of fruits and vegetables and metabolic syndrome (MetS) incidence, and to investigate whether lifestyle factors and socioeconomic status modify the effect of the patterns on MetS risk.

METHODS AND RESULTS

We prospectively studied 1915 participants of the Tehran Lipid and Glucose Study, who were aged 19-74 years and followed up for dietary assessment using a validated, semi-quantitative food frequency questionnaire. After adjustment for confounding factors, total vegetable intake was inversely related to the risk of MetS. Total fruit and total fruit and vegetable were not associated with MetS risk. We identified four major patterns of fruits and vegetables by factor analysis: "fresh fruit pattern", "vegetable pattern", "dried fruit and cruciferous vegetable pattern", and "potatoes and fruit juice pattern". "Vegetable pattern" was negatively associated with MetS risk, and "potatoes and fruit juice pattern" increased the risk of MetS. Among participants with weight gain <7% during follow-up, all four identified patterns reduced MetS risk. When stratified by smoking, "vegetable pattern" and "dried Fruit and cruciferous vegetable pattern" lowered MetS risk among non-smokers. Stratification based on education resulted in MetS risk reduction across tertiles of "fresh fruit pattern" and "vegetable pattern". First and second tertiles of "dried fruit and cruciferous vegetable pattern" lowered MetS risk among educated participants, compared to the reference.

CONCLUSIONS

The reduction in MetS risk caused by fruits and vegetables intake depends on the modifying effect of lifestyle and socioeconomic factors.