Flavonoid intake from fruit and vegetables during adolescence is prospectively associated with a favourable risk factor profile for type 2 diabetes in early adulthood

Cohort profile update-overview of over 35 years of research in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study

PURPOSE

To provide an update on the cohort profile of the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study, including objectives, study design, methods and description of the comprehensive data pool, as well as to summarize the most important research findings of recent years.

METHODS

In 1985, the open (dynamic) cohort started to collect information on diet, growth, development, and metabolism of healthy children and adolescents in Dortmund, Germany. Detailed data are collected annually during infancy, childhood, and adolescence of the participants, including a 3-day weighed dietary record, a 24-h urine sample, anthropometric and medical examinations as well as interviews on lifestyle.

RESULTS

Even if the basic examination modules have not changed since the start over 35 years ago, the DONALD study has been continuously further developed by introducing new modules. As such, participants are also invited for follow-up examinations during adulthood since 2005, including an additional fasting blood withdrawal. Overall, 2375 (♂: 1177; ♀: 1198) participants were recruited in the DONALD study between 1985 and 2022. Data from ~ 30,700 anthropometric measurements, ~ 19,200 dietary records, ~ 10,600 24-h urine and ~ 1300 blood samples are available from an observation period of over 35 years.

CONCLUSION

The DONALD study provides a large data pool for longitudinal studies on nutrition, growth, and health in childhood and adolescence, its impact on the development of diseases in early adult life as well as dietary intake trends over more than three decades.

The association between dairy intake in adolescents on inflammation and risk markers of type 2 diabetes during young adulthood: results of the DONALD study

OBJECTIVE

The aim of this analysis was to investigate whether habitual intake of total dairy (TD) or different dairy types (liquid, solid, fermented, non-fermented, low-fat, high-fat, low-sugar and high-sugar dairy) during adolescence is associated with biomarkers of low-grade inflammation as well as risk factors of type 2 diabetes in young adulthood.

DESIGN

Multivariable linear regression analyses were used to investigate prospective associations between estimated TD intake as well as intake of different types of dairy and a pro-inflammatory score, based on high-sensitivity C-reactive protein, IL-6, IL-18, leptin and adiponectin, and insulin resistance assessed as Homeostasis Model Assessment Insulin Resistance in an open-cohort study.

SETTING

Dortmund, Germany.

PARTICIPANTS

Data from participants (n 375) of the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study were included, for whom at least two 3-d weighed dietary records during adolescence (median age: 11 years) and one blood sample in young adulthood (>18 years) were available.

RESULTS

There was no statistically significant association between TD intake or intake of any dairy type and the pro-inflammatory score (all P > 0·05). TD intake as well as each dairy type intake and insulin resistance also showed no association (all P > 0·05).

CONCLUSIONS

The habitual intake of dairy or individual types of dairy during adolescence does not seem to have a major impact on low-grade systemic inflammation and insulin resistance in the long term. There was no indication regarding a restriction of dairy intake for healthy children and adolescents in terms of diabetes risk reduction.

Alignment between timing of 'highest caloric intake' and chronotype in relation to body composition during adolescence: the DONALD Study

PURPOSE

Our aim was to assess alignment in timing of 'highest caloric intake' with individual chronotype and its association with body composition in adolescents.

METHODS

We used repeatedly collected data from n = 196 adolescents (age 9-16 years, providing N = 401 yearly questionnaires) of the DONALD open cohort study. Chronotype was assessed by the Munich Chronotype Questionnaire from which midpoint of sleep (MSFsc) was derived. A sex- and age-specific diet-chrono-alignment score (DCAS) was calculated as the difference in hours between the chronotype-specific median timing of highest caloric intake of the studied population and the individual timing of 'highest caloric intake' or vice versa. Repeated-measures regression models were applied to study cross-sectional and longitudinal associations between the DCAS and body composition, e.g., Fat Mass Index (FMI) or Fat Free Mass Index (FFMI).

RESULTS

DCAS ranged from -6:42 h to + 8:01 h and was not associated with body composition. Among adolescents with a later chronotype (N = 201) a 1 h increase in DCAS (later consumption of 'highest caloric intake' in comparison to the median intake of that group), increased FFMI by 1.92 kg/m2 (95% CI: 0.15, 3.69, p value = 0.04) over a median follow-up of 0.94 year.

CONCLUSION

Alignment of energy intake with individual chronotype appears beneficial for FFMI among those with a late chronotype.

Chronic disease outcome metadata from German observational studies - public availability and FAIR principles

Metadata from epidemiological studies, including chronic disease outcome metadata (CDOM), are important to be findable to allow interpretability and reusability. We propose a comprehensive metadata schema and used it to assess public availability and findability of CDOM from German population-based observational studies participating in the consortium National Research Data Infrastructure for Personal Health Data (NFDI4Health). Additionally, principal investigators from the included studies completed a checklist evaluating consistency with FAIR principles (Findability, Accessibility, Interoperability, Reusability) within their studies. Overall, six of sixteen studies had complete publicly available CDOM. The most frequent CDOM source was scientific publications and the most frequently missing metadata were availability of codes of the International Classification of Diseases, Tenth Revision (ICD-10). Principal investigators' main perceived barriers for consistency with FAIR principles were limited human and financial resources. Our results reveal that CDOM from German population-based studies have incomplete availability and limited findability. There is a need to make CDOM publicly available in searchable platforms or metadata catalogues to improve their FAIRness, which requires human and financial resources.

Phytochemical-Based Study of Ethanolic Extract of Saraca asoca in Letrozole-Induced Polycystic Ovarian Syndrome in Female Adult Rats

Polycystic ovarian syndrome (PCOS) is a complex metabolic and endocrine disorder which affects women of reproductive age. It is a condition in which ovaries produce an excessive amount of androgen (the male sex hormone). Saraca asoca (Roxb.) Willd. is a plant of the Fabaceae family. This plant has been traditionally used as a uterine tonic in leucorrhea and dysmenorrhea due to its various pharmacological activities. In this study, the ethanolic extract of S. asoca (EESA) was evaluated for its potential to be used for the management of PCOS. HPLC analysis revealed the presence of various phytoconstituents: kaempferol, rutin, (-)-epicatechin, salicylic acid, and gallic acid. For PCOS induction, 30 adult female rats were randomly divided into two groups: the control group (n = 5) and the PCOS group (n = 25). Letrozole (1 mg/kg/day) was administered per orally (p.o.) for a period of 7 weeks for the induction of disease. Weekly body weight measurements and daily vaginal cytology examinations were performed for disease confirmation. After disease induction, the PCOS group was further divided into five groups (n = 5), that is, disease control, metformin, and EESA (200, 400, and 600 mg/kg) groups, respectively, and given treatment doses for next 5 weeks. After the treatment period, all animals were weighed and euthanized humanly. Blood samples were collected for hormonal assays, lipid profiles, and liver function tests. For histological assessment of ovarian cysts, ovaries were dissected. Livers were preserved to evaluate EESA's antioxidant properties. Histopathology analysis revealed that EESA reduced body weight and the number of cystic follicles. Furthermore, it also lowered the elevated levels of serum testosterone, luteinizing hormone, insulin, and malonaldehyde in PCOS rats while increasing the levels of follicle-stimulating hormone, estradiol, progesterone, prolactin, and other antioxidant enzymes such as superoxide dismutase, glutathione, and catalase. It can be concluded that EESA exhibited beneficial effects in normalizing the perturbed hormonal profile and improved the ovary status by decreasing the cystic follicle and improving the ovulation status in a dose-dependent manner.

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.

Disentangling the Complexity of Nutrition, Frailty and Gut Microbial Pathways during Aging: A Focus on Hippuric Acid

Hippuric acid (HA) is a metabolite resulting from the hepatic glycine conjugation of benzoic acid (BA) or from the gut bacterial metabolism of phenylalanine. BA is generally produced by gut microbial metabolic pathways after the ingestion of foods of vegetal origin rich in polyphenolic compounds, namely, chlorogenic acids or epicatechins. It can also be present in foods, either naturally or artificially added as a preservative. The plasma and urine HA levels have been used in nutritional research for estimating the habitual fruit and vegetable intake, especially in children and in patients with metabolic diseases. HA has also been proposed as a biomarker of aging, since its levels in the plasma and urine can be influenced by the presence of several age-related conditions, including frailty, sarcopenia and cognitive impairment. Subjects with physical frailty generally exhibit reduced plasma and urine levels of HA, despite the fact that HA excretion tends to increase with aging. Conversely, subjects with chronic kidney disease exhibit reduced HA clearance, with HA retention that may exert toxic effects on the circulation, brain and kidneys. With regard to older patients with frailty and multimorbidity, interpreting the HA levels in the plasma and urine may result particularly challenging because HA is at the crossroads between diet, gut microbiota, liver and kidney function. Although these considerations may not make HA the ideal biomarker of aging trajectories, the study of its metabolism and clearance in older subjects may provide valuable information for disentangling the complex interaction between diet, gut microbiota, frailty and multimorbidity.

A healthy lifestyle during adolescence was inversely associated with fatty liver indices in early adulthood: findings from the DONALD cohort study

A healthy lifestyle during adolescence is associated with insulin sensitivity or liver enzyme levels and thus might contribute to the prevention of non-alcoholic fatty liver disease (NAFLD). Therefore, we examined the association between adherence to a hypothesis-based lifestyle score including dietary intake, physical activity, sedentary behaviour, sleep duration and BMI in adolescence and fatty liver indices in early adulthood. Overall, 240 participants of the DOrtmund Nutritional and Anthropometric Longitudinally Designed study completed repeated measurements of lifestyle score factors during adolescence (females: 8·5-15·5 years, males: 9·5-16·5 years). Multivariable linear regression models were used to investigate the association between adolescent lifestyle scores and NAFLD risk (hepatic steatosis index (HSI) and fatty liver index (FLI)) in early adulthood (18-30 years). Participants visited the study centre 4·9 times during adolescence and achieved on average 2·8 (min: 0·6, max: 5) out of five lifestyle score points. Inverse associations were observed between the lifestyle score and fatty liver indices (HSI: ß=-5·8 % (95 % CI -8·3, -3·1), P < 0·0001, FLI: ß=-32·4 % (95 % CI -42·9, -20·0), P < 0·0001) in the overall study population. Sex-stratified analysis confirmed these results in men, while inverse but non-significant associations were observed in women (P > 0·05). A higher lifestyle score was associated with lower HSI and FLI values, suggesting that a healthy lifestyle during adolescence might contribute to NAFLD prevention, predominantly in men. Our findings on repeatedly measured lifestyle scores in adolescents and their association with NAFLD risk in early adulthood warrant confirmation in larger study populations.

Smartphone Usage Patterns and Dietary Risk Factors in Adolescents

BACKGROUND

Whereas earlier studies have shown that traditional screen time such as TV watching influences dietary behaviors in adolescents, little is known about the effects of modern screen time such as smartphone use.

OBJECTIVES

We examined the associations of smartphone usage duration and content type with dietary risk factors among adolescents.

METHODS

We conducted a cross-sectional analysis using a nationally representative sample of 54,601 middle- and high-school students (aged 12-18 y; 26,928 boys and 27,673 girls) in the Korea Youth Risk Behavior Web-Based Survey 2017. Smartphone use (average duration and most frequently used content type) and dietary intakes [frequent breakfast skipping; less frequent intakes of fruits and vegetables; more frequent intakes of instant noodles, fast food, chips/crackers, and sugar-sweetened beverages (SSBs)] were self-reported via an online-based questionnaire. Multivariable logistic regression was performed to estimate ORs and 95% CIs for the associations of smartphone usage duration and content type with prevalence of dietary risk factors, adjusting for potential confounders. All analyses accounted for complex survey sampling.

RESULTS

Prolonged smartphone use (≥300 compared with 1-59 min/d) was associated with (OR; 95% CI) higher prevalence of frequent breakfast skipping (1.60; 1.45, 1.76); frequent intakes of instant noodles (1.65; 1.47, 1.84), fast food (1.36; 1.20, 1.53), and SSBs (1.92; 1.75, 2.11); and less frequent intakes of fruits (1.44; 1.30, 1.59) and vegetables (1.32; 1.18, 1.47). Adjusting for usage duration, using smartphones mainly for messenger/e-mail, social networking service (SNS)/forum, and games were associated with less frequent intakes of fruits (OR: 1.21; 95% CI: 1.12, 1.31; OR: 1.28; 95% CI: 1.17, 1.40; and OR: 1.20; 95% CI: 1.10, 1.32, respectively) and vegetables (OR: 1.24; 95% CI: 1.12, 1.37; OR: 1.26; 95% CI: 1.13, 1.40; and OR: 1.25; 95% CI: 1.12, 1.40, respectively) than was using smartphones for education/information search. Using smartphones mainly for messenger/e-mail (OR: 1.24; 95% CI: 1.14, 1.35) and SNS/forum (OR: 1.18; 95% CI: 1.08, 1.29) were also associated with more frequent intake of SSBs.

CONCLUSIONS

Our data suggest that both duration and content type of smartphone use are independently associated with dietary risk factors among adolescents.

Leisure-time and study-time Internet use and dietary risk factors in Korean adolescents

BACKGROUND

Prolonged screen time is associated with an increased risk of obesity in adolescents. However, little is known about whether Internet use is also associated with dietary risk factors including consumption of obesogenic foods.

OBJECTIVES

In this study, we examined the associations of leisure-time and study-time Internet use with dietary risk factors in Korean adolescents using nationally representative survey data.

METHODS

We conducted a cross-sectional analysis among 54,416 middle and high school students in the Korea Youth Risk Behavior Web-based Survey 2015. Participants were asked to report the average duration of leisure-time and study-time Internet use, days of skipping breakfast, and frequency of fruit, vegetable, instant noodle, fast-food, chip/cracker, and sugar-sweetened beverage (SSB) intakes. We performed multivariable logistic regression to estimate ORs and 95% CIs for the relations between duration of Internet use and dietary risk factors, accounting for complex survey sampling and adjusting for potential confounders.

RESULTS

Prolonged leisure-time Internet use (≥241 compared with 1-60 min/d) was associated with higher prevalence of frequent skipping breakfast (OR: 1.39; 95% CI: 1.29, 1.49), low intakes of fruits (OR: 1.27; 95% CI: 1.18, 1.36) and vegetables (OR: 1.43; 95% CI: 1.33, 1.55), and high intakes of instant noodles (OR: 1.87; 95% CI: 1.74, 2.02), fast-food (OR: 1.63; 95% CI: 1.49, 1.78), chips/crackers (OR: 1.37; 95% CI: 1.24, 1.52), and SSBs (OR: 1.63; 95% CI: 1.52, 1.75). Prolonged study-time Internet use (≥121 compared with 1-60 min/d) was inversely associated with prevalence of low fruit (OR: 0.94; 95% CI: 0.88, 1.00) and vegetable (OR: 0.91; 95% CI: 0.85, 0.98) intakes but was positively associated with high intakes of instant noodles (OR: 1.10; 95% CI: 1.03, 1.19) and chips/crackers (OR: 1.13; 95% CI: 1.04, 1.23). The overall associations remained consistent in analyses stratified by sex, grade, region, parental co-residence, perceived household income, perceived stress level, physical activity, and obesity status.

CONCLUSIONS

Our data suggest that prolonged Internet use, particularly during leisure time, is associated with less healthful dietary behaviors in Korean adolescents.

A lifestyle pattern during adolescence is associated with cardiovascular risk markers in young adults: results from the DONALD cohort study

Lifestyle score approaches combining individual lifestyle factors, e.g. favourable diet, physical activity or normal body weight, showed inverse associations with cardiovascular disease (CVD) risk. However, research mainly focussed on adult behaviour and is scarce for vulnerable time windows for adult health like adolescence. We investigated associations between an adolescent lifestyle score and CVD risk markers in young adulthood. Overall, we analysed 270 participants of the open DONALD cohort study with 1–6 complete measurements of five lifestyle factors (healthy diet, moderate-to-vigorous physical activity, sedentary behaviour, sleep duration and BMI standard deviation score) during adolescence (females: 8⋅5–15⋅5 years and males: 9⋅5–16⋅5 years). Multivariable linear regression models were used to investigate the prospective association between the adolescent lifestyle score (0–5 points) and CVD risk markers in young adulthood (18–30 years). On average, participants obtained a mean adolescent lifestyle score of 2⋅9 (0–5) points. Inverse associations between the adolescent lifestyle score and waist circumference, waist-to-height ratio and percentage of body fat were observed (4⋅1, 4⋅1 and 9⋅2 % decrease per 1 point increase in adolescent lifestyle score, respectively, P < 0⋅05). For the remaining CVD risk markers (glucose, blood lipids, blood pressure and a proinflammatory score), no associations were observed. A healthy adolescent lifestyle is particularly associated with CVD risk-related favourable anthropometric markers in adulthood. A more comprehensive understanding of lifestyle patterns in the life course might enable earlier, targeted preventive measures to assist vulnerable groups in prevention of chronic diseases.

Early life factors and their relevance for markers of cardiometabolic risk in early adulthood

BACKGROUND AND AIMS

Early life exposures could be pertinent risk factors of cardiometabolic diseases in adulthood. We assessed the prospective associations of early life factors with markers of cardiometabolic risk among healthy German adults.

METHODS AND RESULTS

We examined 348 term-born DONALD Study participants with measurement of fasting blood at the age of 18-24 years to assess metabolic indices: fatty liver index (FLI), hepatic steatosis index (HSI), pro-inflammatory score and insulin sensitivity (HOMA2-%S). Early life factors (maternal weight in early pregnancy, maternal early pregnancy BMI, gestational weight gain (GWG), maternal age, birth weight and full breastfeeding (>17 weeks)) were assessed at enrolment of the offspring into the study. Multivariable linear regression models were used to analyze associations between early life factors and markers of cardiometabolic risk in early adulthood with adjustment for potential confounders. A higher early pregnancy BMI was related to notably higher levels of offspring FLI, HSI, pro-inflammatory score and a lower HOMA2-%S (all p < 0.0001). Similarly, a higher gestational weight gain was associated with a higher FLI (p = 0.044), HSI (p = 0.016), pro-inflammatory score (p = 0.032) and a lower HOMA2-%S among females (p = 0.034). Full breastfeeding was associated with a lower adult FLI (p = 0.037). A casual mediation analysis showed that these associations were mediated by offspring adult waist circumference (WC).

CONCLUSION

This study suggests that early pregnancy BMI, gestational weight gain, and full breastfeeding are relevant for offspring markers of cardiometabolic risk which seems to be mediated by body composition in young adulthood.

Roles of Gut Microbial Metabolites in Diabetic Kidney Disease

Diabetes is a highly prevalent metabolic disease that has emerged as a global challenge due to its increasing prevalence and lack of sustainable treatment. Diabetic kidney disease (DKD), which is one of the most frequent and severe microvascular complications of diabetes, is difficult to treat with contemporary glucose-lowering medications. The gut microbiota plays an important role in human health and disease, and its metabolites have both beneficial and harmful effects on vital physiological processes. In this review, we summarize the current findings regarding the role of gut microbial metabolites in the development and progression of DKD, which will help us better understand the possible mechanisms of DKD and explore potential therapeutic approaches for DKD.

The Prospective Association of Dietary Sugar Intake in Adolescence With Risk Markers of Type 2 Diabetes in Young Adulthood

Purpose: To examine the prospective relevance of dietary sugar intake (based on dietary data as well as urinary excretion data) in adolescent years for insulin sensitivity and biomarkers of inflammation in young adulthood.

Methods: Overall 254 participants of the DONALD study who had at least two 3-day weighed dietary records for calculating intakes of fructose, glucose, sucrose, total, free, added sugars, total sugars from sugar-sweetened beverages (SSB), juice, and sweets/sugar or at least two complete 24 h urine samples (n = 221) for calculating sugar excretion (urinary fructose and urinary fructose + sucrose) in adolescence (females: 9–15 years, males: 10–16 years) and a fasting blood sample in adulthood (18–36 years), were included in multivariable linear regression analyses assessing their prospective associations with adult homeostasis model assessment insulin sensitivity (HOMA2-%S) and a pro-inflammatory score (based on CRP, IL-6, IL-18, leptin, chemerin, adiponectin).

Results: On the dietary intake level, no prospective associations were observed between adolescent fructose, sucrose, glucose, added, free, total sugar, or total sugar from SSB, juice or sweets/sugar intake and adult HOMA2-%S (p > 0.01). On the urinary level, however, higher excreted fructose levels were associated with improved adult HOMA2-%S (p = 0.008) among females only. No associations were observed between dietary or urinary sugars and the adult pro-inflammatory score (p > 0.01).

Conclusion: The present study did not provide support that dietary sugar consumed in adolescence is associated with adult insulin sensitivity. The one potential exception was the moderate dietary consumption of fructose, which showed a beneficial association with adult fasting insulin and insulin sensitivity.

Dietary profile and phenolics consumption in university students from the Ningxia Hui Autonomous Region of China

Background

Polyphenol intake assessment is a first step for evaluating relationships between polyphenols and health-related outcomes. Ningxia Hui Autonomous Region is one of the minority areas in China, which is primarily consists of arid, dry desert.

Objectives

This study was to make assessment about phenolics intake by university students from Ningxia of China.

Methods

This study employed data from a cross-sectional survey conducted from February to June 2018 in Ningxia Hui Autonomous Region of Northwest China. A total of 413 undergraduate students (143 boys, 270 girls), mean age 20.6 years, participated in the study. Food-frequency consumption and anthropometric measurements were included in the survey. According to phenol-explorer website, the amount of different classes of phenolic compounds were established. Statistics analyses were conducted with IBM SPSS 20.0.

Results

Profile of the student subjects showed low weight (19.1%), overweight (6.8%) and obesity (0.5%). The mean value about phenolics intake was 1378 mg/day. The main polyphenols consumed were flavonoids (58.7% of total polyphenols), followed by phenolic acids (38.1%). Vegetables, fruits and cereals products were the most consumed foods, while infusions and sugar products were lower. Fruit was the main food sources of total polyphenols, especially apple (22.95%), orange juice (19.03%) and apple juice (3.93%).

Conclusions

This is the first study on the polyphenol intake of university students in Ningxia of China. The present results will be benefit for further investigation on the role of polyphenol intake against disease occurrence for this adults group.

Inflammatory mediators in the adipo-renal axis: leptin, adiponectin, and soluble ICAM-1

A lower 24-h urine pH (24h-pH), i.e., a higher renal excretion of free protons, at a given acid load to the body, denotes a reduction in the kidney's capacity for net acid excretion (NAE). There is increasing evidence, not only for patients with type 2 diabetes but also for healthy individuals, that higher body fatness or waist circumference (WC) has a negative impact on renal function to excrete acids (NAE). We hypothesized that adiposity-related inflammation molecules might mediate this relation between adiposity and renal acid excretion function. Twelve biomarkers of inflammation were measured in fasting blood samples from 162 adult participants (18-25 yr old) of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study who had undergone anthropometric measurements and collected 24-h urine samples. Both Baron and Kenny's (B&K's) steps to test mediation and causal mediation analysis were conducted to examine the potential mediatory roles of biomarkers of inflammation in the WC-24-h pH relationship after strictly controlling for laboratory-measured NAE. In B&K's mediation analysis, leptin, soluble intercellular adhesion molecule 1 (sICAM-1), and adiponectin significantly associated with the outcome 24-h pH and attenuated the WC-pH relation. In agreement herewith, causal mediation analysis estimated the "natural indirect effects" of WC on 24-h pH via leptin (P = 0.01) and adiponectin (P = 0.03) to be significant, with a trend for sICAM-1 (P = 0.09). The calculated proportions mediated by leptin, adiponectin, and sICAM-1 were 64%, 23%, and 12%, respectively. Both mediation analyses identified an inflammatory cytokine (leptin) and an anti-inflammatory cytokine (adiponectin) along with sICAM-1 as being potentially involved in mediating adiposity-related influences on renal acid excretion capacity.

Forecasting Your Future: Nutrition Matters Curriculum with Teacher Training Promotes Students to Try New Fruits and Vegetables

BACKGROUND

Many high school students do not consume the recommended amounts of fruits and vegetables.

OBJECTIVE

This study evaluated student outcomes from a new nutrition curriculum that includes messages from the 2015-2020 Dietary Guidelines for Americans with a teacher training component for high school Family and Consumer Sciences (FACS) teachers.

METHODS

A cluster-randomized controlled study was conducted with 1104 students in FACS classes from 35 schools, taught by teachers trained in implementing a new curriculum (intervention) and teachers using their usual curricula (control). Students completed online surveys at the beginning and end of the semester, that is, pre- and postexposure to the nutrition curricula. Intention-to-treat analyses as hierarchical linear modeling were performed to determine if the intervention students had significant changes compared with the control students for knowledge of nutrition concepts, familiarity of, preferences for, affinity toward, number of times trying new, and daily times eating fruits and vegetables. Per-protocol analyses used the same hierarchical linear model but instead of control and intervention groups, students were split into 3 levels describing the amount of the new curriculum they received (0%, 1-50%, and 51-100%).

RESULTS

Students exposed to 51-100% of the new curriculum tried more fruits and vegetables than both the control students and the students that received 1-50% of the curriculum (P = 0.009 for fruits and P = 0.002 for vegetables). Additionally, there were higher increases in the number of times intervention students tried a new fruit (P = 0.027) and vegetable (P = 0.022) compared with the control students, regardless of the amount of curriculum received.

CONCLUSIONS

Our findings show that the curriculum, Forecasting Your Future: Nutrition Matters, has promise for increasing exposure to new fruits and vegetables for students. If teachers use most of the curriculum, students are likely to try more new fruit and vegetables, which could ultimately contribute to improved health.

Dietary flavonoids among children and adolescents in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study: intake, food sources and trends from 1985 until 2016

Flavonoids are suggested to reduce disease risk. Since dietary habits are acquired during early life, describing age and time trends of flavonoid intake and major food sources are important for monitoring and disease prevention in later life. We aimed to describe total flavonoid intake and food sources and to investigate age and time trends of flavonoid intake in 3-18-year-olds, from the Dortmund Nutritional and Anthropometric Longitudinally Designed study from 1985 to 2016. Intake was assessed annually using 3-d weighed food records (WFR). Flavonoid values were assigned using the United States Department of Agriculture database. Foods contributing to intake were determined. Age and time trends in total flavonoid and isoflavone density were analysed by sex with PROC MIXED. In total, 1312 children completed 10 758 WFR. Across all ages, daily mean total flavonoid density was lower in boys compared with girls (134 v. 146 mg/4184 kJ) and no difference in median isoflavone density (0·04 mg/4184 kJ per d) was found. The top five foods contributing to total flavonoid intake were apple with peel (15·0/17·1 %), strawberries (5·9/6·1 %), chocolate spread (3·9/3·5 %), orange juice (3·5/3·4 %) and pasta (3·5/3·4 %) for boys and girls, respectively. Overall, in boys, total flavonoid density decreased over the course of age and time. In girls, there was no association with age or time. In both sexes, isoflavone density followed a U-shaped age trend with no change over time. From a public health perspective, the overall observed downwards trend of flavonoid intake in boys deserves attention. Future initiatives should be tailored at maintaining a high flavonoid density as children age, specifically among boys.

Total Polyphenol Intake Is Inversely Associated with a Pro/Anti-Inflammatory Biomarker Ratio in European Adolescents of the HELENA Study

BACKGROUND

Although high dietary polyphenol intake is negatively associated with risk of certain inflammation-associated chronic diseases, the underlying mechanisms are not fully understood and few studies have explored this in adolescents.

OBJECTIVE

This study aimed to evaluate the association between intakes of total polyphenols, polyphenol classes, and the 10 most commonly consumed individual polyphenols with inflammatory biomarkers in the blood of European adolescents.

METHODS

In the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study, 526 adolescents (54% girls; 12.5-17.5 y) had data on inflammatory biomarkers and polyphenol intake from 2 nonconsecutive 24-h recalls via matching with the Phenol-Explorer database. Inflammatory biomarkers in serum were IL-1, IL-2, IL-4, IL-5, IL-6, IL-10, transforming growth factor β1 (TGF-β1), TNF-α, IFN-γ, soluble vascular adhesion molecule 1 (sVCAM-1), soluble intercellular adhesion molecule 1 (sICAM-1), soluble E-selectin (sE-selectin), white blood cells, lymphocytes, T cells, and C-reactive protein. Multilevel linear models were used to test associations of polyphenol intake with a pro/anti-inflammatory biomarker ratio [(zTNF-α + zIL-6 + zIL-1)/3/zIL-10] as well as with separate inflammatory biomarkers, adjusted for sociodemographic variables, diet inflammation index, BMI z score, and serum triglycerides.

RESULTS

The pro/anti-inflammatory biomarker ratio was linearly inversely associated with the intake of total polyphenols (β = -0.11, P = 0.040). When other inflammation biomarkers were considered, the serum IL-10 concentration was inversely associated with total polyphenol (β = -0.12, P = 0.017) and flavonoid (β = -0.12, P = 0.013) intakes, findings that were inconsistent with the biomarker ratio results. However, the anti-inflammatory capacity of polyphenols was confirmed by positive associations of IL-4 with phenolic acid (β = 0.09 P = 0.049) and stilbene (β = 0.13, P = 0.019) intakes and the negative association of IL-1, IL-2, and IFN-γ with lignan intake (β = -0.10, P = 0.034; β = -0.09, P = 0.049; β = -0.11, P = 0.023).

CONCLUSIONS

The negative relation with the overall pro/anti-inflammatory biomarker ratio suggests a potential anti-inflammatory role of high polyphenol intakes among European adolescents. Nevertheless, associations are dependent on polyphenol type and the inflammatory biomarker measured.

Estimated intake and major food sources of flavonoids among Australian adolescents

PURPOSE

The consumption of dietary flavonoids from plant-based foods has been related to the prevention of multiple chronic diseases. However, intake data from adolescents are lacking. We aimed to characterise the intake and major sources of dietary flavonoids among Australian adolescents and investigate changes during adolescence.

METHODS

The Raine Study Gen 2 participants completed a 212-item food frequency questionnaire at age 14 years and 17 years, with repeated measures for n = 883. Items were assigned a content for six flavonoid subclasses using the Phenol-Explorer database, which were summed for total flavonoid intake. Daily intakes and sources of flavonoids and flavonoid-subclasses were determined, and change assessed between 14 and 17 years, for males and females.

RESULTS

Major food sources of flavonoids and each subclass were similar at 14 and 17 years, with fruit juice the major contributor to total flavonoid intake at both time points (providing 44% and 38%, respectively). Citrus flavanones (predominantly hesperitin) were the major subclass at 14 years, while tea flavan-3-ols were a major subclass (predominantly procyanidin dimers) at 17 years. The mean intake of total flavonoids at 14 years was 210 ± 133 mg/day, reducing by 5% (10 mg/day) by 17 years. Females consumed a more flavonoid-dense diet compared to males (104.5 ± 71.5 mg/1000 kcal vs 80.4 ± 50.3 mg/1000 kcal per day; p < 0.001).

CONCLUSION

This study provides a comprehensive estimation of flavonoid intake and their major food sources in a sample of Australian adolescents, which may be useful in the development of practical dietary recommendations.

Is there a soft drink vs. alcohol seesaw? A cross-sectional analysis of dietary data in the Australian Health Survey 2011-12

PURPOSE

Previous studies in older Australians have reported higher alcohol intake in those with low added sugar intake, yet the relationship between energy in liquid form [alcoholic beverages vs. sugar-sweetened beverages (SSB)] and measures of obesity has not been evaluated. We aimed to assess the association between the energy derived from SSB and alcoholic beverages, and to model the association between the substitution of SSB with alcoholic beverages and waist circumference.

METHODS

In this cross-sectional analysis, dietary data from the Australian Health Survey 2011-12 were analyzed. Participants with implausible dietary intake were excluded by applying the Goldberg cut-off. Usual SSB intake of adults ≥ 19 years old was estimated using the Multiple Source Method and participants were classified into zero-, low- or high-SSB consumers according to their usual SSB intake. Energy from alcoholic beverages in the three SSB consumption groups was compared using multivariable general linear models. A substitution model was used to assess the association between the replacement of SSB with alcoholic beverages and waist circumference.

RESULTS

Zero-SSB consumers made up 33% of the included participants. In all age groups, zero-SSB consumers had significantly higher energy intakes from alcoholic beverages than low- and high-SSB consumers. Low- and high-SSB consumers had similar consumption of alcoholic beverages. Substituting SSB intake with alcoholic beverage intake was not associated with significant differences in waist circumference in most age groups.

CONCLUSIONS

Australian adults who avoid SSB are common but consume substantially more energy in the form of alcoholic beverages. An increase in alcoholic beverage intake could be an 'unintended consequence' of strictly discouraging SSB consumption.

Polyphenol intake and metabolic syndrome risk in European adolescents: the HELENA study

PURPOSE

The role of polyphenol intake during adolescence to prevent metabolic syndrome (MetS) is little explored. This study aimed to evaluate the association between intake of total polyphenols, polyphenol classes and the 10 most consumed individual polyphenols with MetS risk in European adolescents.

METHODS

Of the cross-sectional HELENA study, 657 adolescents (54% girls; 14.8% overweight; 12.5-17.5 year) had a fasting blood sample and polyphenol intake data from two non-consecutive 24-h recalls matched with the Phenol-Explorer database. MetS was defined via the pediatric American Heart Association definition. Multilevel linear regressions examined the associations of polyphenol quartiles with MetS components, while logistic regression examined the associations with MetS risk.

RESULTS

After adjusting for all potential confounders (socio-demographics and nine nutrients), total polyphenol intake, polyphenol classes and individual polyphenols were not associated with MetS risk. From all MetS components, only BMI z-score was modestly inversely associated with total polyphenol intake. Further sub analyses on polyphenol classes revealed that flavonoid intake was significantly associated with higher diastolic blood pressure and lower BMI, and phenolic acid intake was associated with higher low-density cholesterol. For individual polyphenols, the above BMI findings were often confirmed (not independent from dietary intake) and a few associations were found with insulin resistance.

CONCLUSION

Higher intakes of total polyphenols and flavonoids were inversely associated with BMI. No consistent associations were found for other MetS components.

Insights about urinary hippuric and citric acid as biomarkers of fruit and vegetable intake in patients with kidney stones: The role of age and sex

OBJECTIVES

Urinary hippuric acid (HA) and citrate can represent useful biomarkers of fruit and vegetable (FAV) intake in nephrolithiasis. However, their clinical significance across the life span has been poorly investigated. The aim of this study was to investigate the association between the two biomarkers with FAV intake across different age groups and sexes in a large group of stone formers (SFs).

METHODS

SFs undergoing baseline 24-h urinary collection for metabolic profile of lithogenic risk at our institution were consecutively enrolled for a 6-y time span (N = 1185; 625 men). HA and citrate excretions were determined by ion chromatography and ultraviolet method, respectively. SFs completed a food frequency questionnaire on the intake of FAV. Stepwise logistic regression was applied to investigate factors associated with very low FAV (≤1 servings/d) and analysis of covariance to compare citrate and HA excretion across age groups and sexes.

RESULTS

Very low FAV intake prevalence declined with age (P_trend < 0.001), and was inversely associated with HA and citrate excretion (P < 0.001) in a stepwise logistic regression model. A significant increasing trend was verified for both biomarkers across age groups until the age of 65 for HA (P < 0.001) and 55 for citrate (P < 0.001). Citrate excretion significantly declined after the age of 65, and was higher in women than men in adult age groups, regardless of FAV intake.

CONCLUSIONS

Both urinary citrate and HA were positively associated with FAV intake in SFs. However, unlike HA, citrate excretion was significantly influenced by the female sex and by older age.

Habitual Flavonoid Intake from Fruit and Vegetables during Adolescence and Serum Lipid Levels in Early Adulthood: A Prospective Analysis

Flavonoids have been implicated in the prevention of cardiovascular diseases (CVD). In a prospective approach, we investigated whether habitual flavonoid intake from fruit, vegetables and juices (FlavFVJ) during adolescence is associated with adult levels of serum lipids, one of the main CVD risk factors. This analysis included healthy participants from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study, who had provided a fasting blood sample in adulthood (aged 18–39 years), data on FlavFVJ intake during adolescence (females: 9–15 years, males: 10–16 years)—estimated either from multiple 3-day weighed dietary records (n = 257), or from validated biomarker hippuric acid (uHA) excretion from multiple 24-h urine samples (n = 233)—together with information on relevant covariates. In multivariable linear regression analyses, a higher FlavFVJ intake during adolescence was independently associated with higher serum high-density lipoprotein cholesterol (HDL-C) levels among males (P_trend = 0.038); however, the inclusion of adult waist circumference attenuated this association (P_trend = 0.053). FlavFVJ was not associated with triglycerides (TG), total cholesterol (TC) or low-density lipoprotein cholesterol (LDL-C; all P_trend ≥ 0.1), nor was uHA excretion with any serum lipid outcome among males (all P_trend ≥ 0.5). Neither FlavFVJ intake nor uHA excretion was associated with serum lipids among women (all P_trend ≥ 0.1). However, a higher flavonoid intake from fruit and vegetables was independently related to lower LDL-C levels (P_trend = 0.021), while a higher intake from juices was associated with higher LDL-C levels (P_trend = 0.016) among females. In conclusion, a higher flavonoid intake from fruit, vegetables and/or juices during adolescence may be linked to cholesterol levels in early adulthood in a sex- and food source-specific manner.