Urinary Excretion of Sodium, Nitrogen, and Sugar Amounts Are Valid Biomarkers of Dietary Sodium, Protein, and High Sugar Intake in Nonobese Adolescents

Dietary biomarkers-an update on their validity and applicability in epidemiological studies

The aim of this literature review was to identify and provide a summary update on the validity and applicability of the most promising dietary biomarkers reflecting the intake of important foods in the Western diet for application in epidemiological studies. Many dietary biomarker candidates, reflecting intake of common foods and their specific constituents, have been discovered from intervention and observational studies in humans, but few have been validated. The literature search was targeted for biomarker candidates previously reported to reflect intakes of specific food groups or components that are of major importance in health and disease. Their validity was evaluated according to 8 predefined validation criteria and adapted to epidemiological studies; we summarized the findings and listed the most promising food intake biomarkers based on the evaluation. Biomarker candidates for alcohol, cereals, coffee, dairy, fats and oils, fruits, legumes, meat, seafood, sugar, tea, and vegetables were identified. Top candidates for all categories are specific to certain foods, have defined parent compounds, and their concentrations are unaffected by nonfood determinants. The correlations of candidate dietary biomarkers with habitual food intake were moderate to strong and their reproducibility over time ranged from low to high. For many biomarker candidates, critical information regarding dose response, correlation with habitual food intake, and reproducibility over time is yet unknown. The nutritional epidemiology field will benefit from the development of novel methods to combine single biomarkers to generate biomarker panels in combination with self-reported data. The most promising dietary biomarker candidates that reflect commonly consumed foods and food components for application in epidemiological studies were identified, and research required for their full validation was summarized.

Development and validation of a UPLC-MS/MS method for the quantification of sugars and non-nutritive sweeteners in human urine

High-intensity sweeteners ('sweeteners'), such as sucralose, saccharine, acesulfame, cyclamate and steviol, are replacing sugars in many food products, but biomarker-based data on their population-wide exposure, as well as analytical methods that can quantify urinary concentrations of sugars and sweeteners simultaneously, are lacking. Here, we developed and validated an ultra-pressure liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) method to quantify glucose, sucrose, fructose, sucralose, saccharine, acesulfame, cyclamate and steviol glucuronide in human urine. Urine samples were prepared by a simple dilution step containing the internal standards in water and methanol. Separation was achieved on a Shodex Asahipak NH2P-40 hydrophilic interaction liquid chromatography (HILIC) column using gradient elution. The analytes were detected using electrospray ionization in negative ion mode, and selective reaction monitoring was optimized using the [M-H]- ions. Calibration curves ranged between 34 and 19,230 ng/mL for glucose and fructose, and 1.8 to 1,026 ng/mL for sucrose and the sweeteners. The method has acceptable accuracy and precision, which depends on the application of appropriate internal standards. Storage of urine samples in lithium monophosphate gives the best overall analytical performance, and storage at room temperature without any preservatives should be avoided since this leads to reduced glucose and fructose concentrations. With the exception of fructose, all analytes were stable throughout 3 freeze-thaw cycles. The validated method was applied to human urine samples, demonstrating quantifiable concentrations of the analytes which were in the expected range. It is concluded that the method has acceptable performance to quantitatively determine dietary sugars and sweeteners in human urine.

Sugars measured enzymatically in a fasting overnight urine sample are not sensitive biomarkers of dietary added sugar intake in postmenopausal women

BACKGROUND

Restricting dietary sugar is a leading recommendation, but limited biomarkers assessing intake exist. Although 24-h urinary sucrose (U-Suc) and urinary fructose (U-Fruc) excretion has been used with mixed success, collection is burdensome.

AIM

This study aimed to test the sensitivity of an enzymatic assay of U-Suc and U-Fruc to detect changing added sugar intake using low-burden overnight urine samples in 30 postmenopausal women.

METHODS

Women consumed usual dietary intake during day 1 and usual intake plus a sugar sweetened beverage during day 2. Weighed, photographed food records assessed intake. Enzymatic assay measured U-Suc and U-Fruc from fasting overnight samples; liquid chromatography mass spectrometry (LC-MS) validated U-Suc findings.

RESULTS

Dietary added sugars increased significantly during day 2 (p < 0.001), but urinary sugars were not significantly increased. Enzymatic assay detected urinary sugars in 75% (U-Suc) and 35% (U-Fruc) of samples. Dietary sucrose was not associated with U-Suc, however dietary fructose was significantly associated with U-Fruc [β = 0.031; p < 0.05] among women with detectable urinary sugars. Participants with detectable U-Fruc consumed more energy from added sugars [12.6% kcal day 1; 21.5% kcal day 2] than participants with undetectable U-Fruc [9.3% kcal day 1; 17.4% kcal day 2], p < 0.05. Using LC-MS, U-Suc predicted sucrose and added sugar intake [β = 0.017, β = 0.013 respectively; both p < 0.05].

CONCLUSIONS

Urinary sugars measured enzymatically from overnight urine samples were not sensitive biomarkers of changing added sugar intake in postmenopausal women. However, urinary fructose measured by enzymatic assay or LC-MS may differentiate low versus high added sugar consumers.

Nutritional therapy can reduce the burden of depression management in low income countries: A review

Depression is a serious mental and mood disorder with global health and economic burden. This burden may be overwhelming in low income countries, although there are insufficient data. Most antidepressant formulations are predicated on the monoamine, neuroendocrine and neuro-inflammation hypotheses, with little or no cognizance to other neurochemicals altered in depression. A nutritional strategy with or without conventional antidepressants is recommended, as nutrition plays vital roles in the onset, severity and duration of depression, with poor nutrition contributing to its pathogenesis. This review discusses nutritional potentials of utilizing omega-3 fatty acids, proteins, vitamins, minerals and herbs or their phytochemicals in the management of depression with the aim of reducing depression burden. Literature search of empirical data in books and journals in data bases including but not limited to PubMed, Scopus, Science Direct, Web of Science and Google Scholar that might contain discussions of sampling were sought, their full text obtained, and searched for relevant content to determine eligibility. Omega-3 fatty and amino acids had significant positive anti-depression outcomes, while vitamins and minerals although essential, enhanced omega-3 fatty and amino acids activities. Some herbs either as whole extracts or their phytochemicals/metabolites had significant positive anti-depression efficacy. Nutrition through the application of necessary food classes or herbs as well as their phytochemicals, may go a long way to effectively manage depression. This therefore will provide inexpensive, natural, and non-invasive therapeutic means with reduced adverse effects that can also be applied alongside clinical management. This nutritional strategy should be given more attention in research, assessment and treatment for those with depression and other mental illness in low income countries, especially in Africa.

Validity of FFQ Estimates of Total Sugars, Added Sugars, Sucrose and Fructose Compared to Repeated 24-h Recalls in Adventist Health Study-2 Participants

Sugar intake is a potentially important aspect of diet which has not previously been validated in the Adventist Health Study-2 (AHS-2). We sought to validate the food frequency questionnaire (FFQ) measurement of total sugars, added sugars, sucrose, and fructose against multiple 24-h dietary recalls (recalls) in AHS-2 participants. Food consumption data from a self-administered FFQ and six recalls from 904 participants were combined with nutrient profile data to estimate daily sugar intake. Validity was evaluated among all participants and by race. FFQ and recall means were compared and correlation coefficients (Spearman’s, energy-adjusted log-transformed Pearson’s, deattenuated Pearson’s) were calculated. Mean total energy, total sugars, and fructose intake were higher in the FFQ, whereas added sugars and sucrose were higher in recalls. The energy-adjusted (log-transformed) deattenuated correlations among all participants were: total sugars (r = 0.42, 95% CI 0.32–0.52), added sugars (r = 0.50, 95% CI 0.36–0.59), sucrose (r = 0.32, 95% CI 0.23–0.42), and fructose (r = 0.50, 95% CI 0.40–0.59). We observed moderate validity for added sugars and fructose and low-moderate validity for total sugars and sucrose measured by the AHS-2 FFQ in this population. Dietary sugar estimates from this FFQ may be useful in assessing possible associations of sugars intake with health outcomes.

Validity Coefficient of Repeated Measurements of Urinary Marker of Sugar Intake Is Comparable to Urinary Nitrogen as Marker of Protein Intake in Free-living Subjects

BACKGROUND

Studies do not show consistent relationships between self-reported intake of sugar and outcome of disease. To overcome the drawbacks of self-reported intake methods, we investigated whether there is an agreement in ranking of individuals between their self-reported sugar intake and urinary sucrose and fructose.

METHODS

We used data of 198 Dutch adults (106 women) from the DUPLO study. Sugar intake of all foods and drinks consumed over 24-hour period was estimated by collecting duplicate portions (DP) and 24-hour recalls (24hR), telephone (24hRT) and Web-based (24hRW), while sugar excretion was based on 24-hour urine samples. Sugar content of 24hR was calculated using a newly developed sugar database and sugar content of DPs and urine samples was calculated using high-performance liquid chromatography-atomic emission spectrometry and LC/MS-MS, respectively. Measurement error models assessed validity coefficients (VC) and attenuation factors (AF). Coefficients were compared with those of protein biomarker.

RESULTS

The VC for the marker, using DP as reference, showed comparability with substantially better ranking of participants (0.72 for women and 0.93 for men), than 24hRT (0.57 and 0.78) or 24hRW (0.70 and 0.78) as reference in the sucrose models. The VC of the sucrose models was within 10% of the protein models, except for the model with 24hRT as reference, among women. The AF started at higher values and increased by a greater factor compared with the VC.

CONCLUSIONS

Repeated measurements of urinary sucrose and fructose as a marker of daily sucrose intake had a ranking performance comparable to urinary nitrogen as marker of protein intake in free-living Dutch adults.

IMPACT

The validation of the sugar biomarker in a free-living population with three different dietary assessment methods and its comparable ranking ability with a good recovery biomarker (i.e., protein biomarker) have important research applications. The biomarker may be used for validating dietary assessment methods, for monitoring compliance in human feeding studies, for monitoring the effect of public health interventions, and as a surrogate for ranking subjects according to sucrose intake when information on sucrose in food composition databases is lacking.

Sodium and potassium excretion predict increased depression in urban adolescents

This study examined the prospective role of urinary sodium and potassium excretion in depressive symptoms among urban, low-income adolescents, and whether these relationships vary by gender. A total of 84 urban adolescents (mean age 13.36 years; 50% male; 95% African American) self-reported on their depressive symptoms at baseline and 1.5 years later. At baseline, the youth also completed a 12-h (overnight) urine collection at home which was used to measure sodium and potassium excretion. After adjusting for baseline depressive symptoms, age, BMI percentile, and pubertal development, greater sodium excretion and lower potassium excretion predicted more severe depressive symptoms at follow-up, with no significant gender differences. The results suggest that consumption of foods high in sodium and low in potassium contributes to the development of depressive symptoms in early adolescence, and that diet is a modifiable risk factor for adolescent depression. Interventions focusing on diet may improve mental health in urban adolescents.

An iodine balance study to explore the recommended nutrient intake of iodine in Chinese young adults

Data on average iodine requirements for the Chinese population are limited following implementation of long-term universal salt iodisation. We explored the minimum iodine requirements of young adults in China using a balance experiment and the 'iodine overflow' hypothesis proposed by our team. Sixty healthy young adults were enrolled to consume a sequential experimental diet containing low, medium and high levels of iodine (about 20, 40 and 60 μg/d, respectively). Each dose was consumed for 4 d, and daily iodine intake, excretion and retention were assessed. All participants were in negative iodine balance throughout the study. Iodine intake, excretion and retention differed among the three iodine levels (P < 0·01 for all groups). The zero-iodine balance derived from a random effect model indicated a mean iodine intake of 102 μg/d, but poor correlation coefficients between observed and predicted iodine excretion (r 0·538 for μg/d data) and retention (r 0·304 for μg/d data). As iodine intake increased from medium to high, all of the increased iodine was excreted ('overflow') through urine and faeces by males, and 89·5 % was excreted by females. Although the high iodine level (63·4 μg/d) might be adequate in males, the corresponding level of 61·6 μg/d in females did not meet optimal requirements. Our findings indicate that a daily iodine intake of approximately half the current recommended nutrient intake (120 μg/d) may satisfy the minimum iodine requirements of young male adults in China, while a similar level is insufficient for females based on the 'iodine overflow' hypothesis.

Relative Validity of an Online Herb and Spice Consumption Questionnaire

Culinary herbs and spices contribute bioactives to the diet, which act to reduce systemic inflammation and associated disease. Investigating the health effects of herb/spice consumption is hampered, however, by a scarcity of dietary assessment tools designed to collect herb/spice data. The objective of this study was to determine the relative validity of an online 28-item herb/spices intake questionnaire (HSQ). In randomized order, 62 volunteers residing in Idaho, USA, completed the online Diet History Questionnaire III + the HSQ followed one week later by one of two comparative methods: 7-day food records or three telephone-administered 24-h dietary recalls. Relative validity of the HSQ was tested two ways: (1) by comparing herb/spice intakes between the HSQ and comparator, and (2) by determining the correlation between herb/spice data and Healthy Eating Index 2015 score. The HSQ and both comparators identified black pepper, cinnamon and garlic powder as the three most commonly used herbs/spices. The HSQ captured significantly higher measures of the number and amount of herbs/spices consumed than the comparators. The number of herbs/spices consumed was significantly directly correlated with diet quality for the HSQ. These results support the ability of the HSQ to record general herb/spice use, yet suggest that further validation testing is needed.

Sugar intake among German adolescents: trends from 1990 to 2016 based on biomarker excretion in 24-h urine samples

Trend analyses based on dietary records suggest decreases in the intakes of total sugar (TS), added and free sugar since 2005 among children and adolescents in Germany. In terms of age trends, TS intake decreased with increasing age. However, self-reported sugar intake in epidemiological studies is criticised, as it may be prone to bias due to selective underreporting. Furthermore, adolescents are more susceptible to underreporting than children. We thus analysed time and age trends in urinary fructose excretion (FE), sucrose excretion (SE) and the sum of both (FE + SE) as biomarkers for sugar intake among 8·5-16·5-year-old adolescents. Urinary sugar excretion was measured by UPLC-MS/MS in 997 24-h urine samples collected from 239 boys and 253 girls participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study cohort between 1990 and 2016. Time and age trends of log-transformed FE, SE and FE + SE were analysed using polynomial mixed-effects regression models. Between 1990 and 2016, FE as well as FE + SE decreased (linear time trend: P = 0·0272 and P < 0·0001, respectively). A minor increase in excretion during adolescence was confined to FE (linear age trend: P = 0·0017). The present 24-h excretion measurements support a previously reported dietary record-based decline in sugar intake since 2005. However, the previously seen dietary record-based decrease in TS from childhood to late adolescence was not confirmed by our biomarker analysis, suggesting a constant sugar intake for the period of adolescence.

Advances in Nutrition Science and Integrative Physiology: Insights From Controlled Feeding Studies

Nutrition science is a highly impactful but contentious area of biomedical science. Establishing cause and effect relationships between the nutrients and/or diets we consume and the avoidance of or risk of disease is extremely challenging. As such, evidence-based nutrition is best served by considering the totality of evidence across multiple study types including nutritional epidemiological studies, randomized controlled trials of behavioral interventions, and controlled feeding studies. The purpose of the present review is to provide an overview for those conducting research outside of clinical nutrition on how controlled feeding studies can be used to gain insight into integrative physiology/metabolism as well as to inform dietary guidelines. We discuss the rationale, basic elements, and complexities of conducting controlled feeding studies and provide examples of contributions of controlled feeding studies to advances in nutrition science and integrative physiology. Our goal is to provide a resource for those wishing to leverage the experimental advantage provided by controlled feeding studies in their own research programs.

Metabolic Trajectories Following Contrasting Prudent and Western Diets from Food Provisions: Identifying Robust Biomarkers of Short-Term Changes in Habitual Diet

A large body of evidence has linked unhealthy eating patterns with an alarming increase in obesity and chronic disease worldwide. However, existing methods of assessing dietary intake in nutritional epidemiology rely on food frequency questionnaires or dietary records that are prone to bias and selective reporting. Herein, metabolic phenotyping was performed on 42 healthy participants from the Diet and Gene Intervention (DIGEST) pilot study, a parallel two-arm randomized clinical trial that provided complete diets to all participants. Matching single-spot urine and fasting plasma specimens were collected at baseline, and then following two weeks of either a Prudent or Western diet with a weight-maintaining menu plan designed by a dietician. Targeted and nontargeted metabolite profiling was conducted using three complementary analytical platforms, where 80 plasma metabolites and 84 creatinine-normalized urinary metabolites were reliably measured (CV < 30%) in the majority of participants (>75%) after implementing a rigorous data workflow for metabolite authentication with stringent quality control. We classified a panel of metabolites with distinctive trajectories following two weeks of food provisions when using complementary univariate and multivariate statistical models. Unknown metabolites associated with contrasting dietary patterns were identified with high-resolution MS/MS, as well as co-elution after spiking with authentic standards if available. Overall, 3-methylhistidine and proline betaine concentrations increased in both plasma and urine samples after participants were assigned a Prudent diet (q < 0.05) with a corresponding decrease in the Western diet group. Similarly, creatinine-normalized urinary imidazole propionate, hydroxypipecolic acid, dihydroxybenzoic acid, and enterolactone glucuronide, as well as plasma ketoleucine and ketovaline increased with a Prudent diet (p < 0.05) after adjustments for age, sex, and BMI. In contrast, plasma myristic acid, linoelaidic acid, linoleic acid, α-linoleic acid, pentadecanoic acid, alanine, proline, carnitine, and deoxycarnitine, as well as urinary acesulfame K increased among participants following a Western diet. Most metabolites were also correlated (r > ± 0.30, p < 0.05) to changes in the average intake of specific nutrients from self-reported diet records reflecting good adherence to assigned food provisions. Our study revealed robust biomarkers sensitive to short-term changes in habitual diet, which is needed for accurate monitoring of healthy eating patterns in free-living populations, and evidence-based public health policies for chronic disease prevention.

Validity and Reproducibility of a Self-Administered Food Frequency Questionnaire for the Assessment of Sugar Intake in Middle-Aged Japanese Adults

We evaluated the validity and reproducibility of estimated sugar intakes using a food frequency questionnaire (FFQ) among middle-aged Japanese adults in the Japan Public Health Centre-Based Prospective (JPHC) study. In subsamples of the JPHC study (Cohorts I and II in multiple areas), we computed Spearman's correlations of FFQ results with urine sugar concentrations and dietary records (DR) for validity; we evaluated correlations between two FFQs for reproducibility. During 1994⁻1998, participants (Cohort I: n = 27 [men], n = 45 [women]) provided two (spring and fall) 24-h urine samples and completed 7-consecutive-day DR per season (I: n = 99, n = 113; II: n = 168, n = 171) and two FFQs (147 food items) at yearly intervals (I: n = 101, n = 108; II: n = 143, n = 146). Sugar intakes from FFQ were correlated with urinary sugar (de-attenuated correlations: 0.40; 95%CI: 0.19, 0.58). After adjustment for sociodemographic and lifestyle variables, correlations between FFQ and DR for men and women were 0.57 (0.42, 0.69) and 0.41 (0.24, 0.55) (I) and 0.56 (0.44, 0.65) and 0.34 (0.20, 0.47) (II), respectively. Correlations between FFQs for men and women were 0.63 (0.49, 0.73) and 0.55 (0.41, 0.67) (I) and 0.66 (0.55, 0.74) and 0.63 (0.52, 0.72) (II). In conclusion, our study showed moderate FFQ validity and reproducibility for sugar intake evaluation.

Adolescents perceive a low added sugar adequate fiber diet to be more satiating and equally palatable compared to a high added sugar low fiber diet in a randomized-crossover design controlled feeding pilot trial

BACKGROUND

High added sugar (AS) intake is associated with obesity and poor diet quality. Guidelines recommended limiting AS to 5-10% of total energy intake, but palatability and feasibility of this AS intake level is uncertain.

OBJECTIVE

To compare adolescents' perceptions of hunger, fullness, and palatability in response to a low AS adequate fiber (LASAF; 5% total energy from AS and 13.5 g fiber/1000 kcal) and a high AS low fiber (HASLF; 25% total energy form AS and 8.2 g/1000 kcal) diet.

DESIGN

Adolescents (n = 32, age: 15.3 ± 1.6 yrs., BMI percentile: 47 ± 4, 15 male) completed a randomized, crossover, controlled feeding study. Participants consumed calorie-matched LASAF and HASLF diets for 7 days, separated by a 4 week washout. Body weight was monitored daily on each diet. Hunger, fullness, and palatability were assessed via 100 mm visual analogue scales at the end of each feeding period. Differences were assessed with paired sample t-tests. Data are expressed as mean ± SD.

RESULTS

Participants remained weight stable, and no difference in weight change between diet conditions was detected (LASAF: -0.06 ± 0.7 vs. HASLF: -0.02 ± 0.6 kg, p = 0.751). Less hunger (LASAF: 24.1 ± 14.6 vs. HASLF: 32.1 ± 17.6 mm, p = 0.024) and greater fullness (LASAF: 70.2 ± 12.3 vs. HASLF: 61.3 ± 18.1 mm, p = 0.006) were reported on the LASAF compared to the HASLF. Participants reported the diets to be equally palatable (LASAF: 39.6 ± 12.9 vs. HASLF: 37.2 ± 17.8 mm, p = 0.440).

CONCLUSIONS

Adolescents perceive a LASAF diet to be as palatable as a HASLF diet, but more satiating. LASAF diets should be investigated as a strategy for weight control in adolescents.