Current WHO recommendation to reduce free sugar intake from all sources to below 10% of daily energy intake for supporting overall health is not well supported by available evidence

Associations of diet quality and daily free sugar intake with depressive and anxiety symptoms among Chinese adolescents

BACKGROUND

Assessing diet quality has been challenging, and the associations of diet quality and daily free sugar intake with depressive and/or anxiety symptoms have shown inconsistency.

METHODS

A total of 1749 students aged 12-16 years were recruited using stratified random cluster sampling across three cities in China. The overall Global Dietary Recommendations (GDR) score, a novel indicator of diet quality, was constructed using the low-burden Diet Quality Questionnaire. Free sugar intake, including from beverages and foods, was measured using the Food Frequency Questionnaire. Daily free sugar intake was divided into low, medium, and high categories based on the latest version of the dietary guidelines for Chinese residents. Binomial and multinominal logistic regression analyses were used to examine the associations of the overall GDR score and daily free sugar intake categories or different sources of free sugar intake with depressive and/or anxiety symptoms.

RESULTS

The overall GDR score was negatively associated with depressive symptoms (adjusted odds ratio[aOR] = 0.92, 95%CI: 0.87-0.98) and anxiety symptoms (0.95, 0.90-0.99), particularly with comorbid depression and anxiety (0.90, 0.84-0.97). Conversely, daily free sugar intake was positively associated with symptoms of depression and/or anxiety, the multiple aOR for symptoms depression or anxiety were significantly increased with higher daily free sugar intake (all Ptrend < 0.05). Both free sugar from beverages and from foods were positively associated with depressive and/or anxiety symptoms. These associations were consistent between males and females.

LIMITATIONS

Cross-sectional design and self-reported symptoms.

CONCLUSIONS

Diet quality was negatively associated with symptoms of depression or anxiety, especially with comorbid symptoms among adolescents. Daily free sugar intake, regardless of its sources, was positively associated with symptoms of depression and/or anxiety.

Therapeutic effects of a walnut-derived peptide on NLRP3 inflammasome activation, synaptic plasticity, and cognitive dysfunction in T2DM mice

NLRP3 inflammasome activation plays a key role in the development of diabetes-induced cognitive impairment. However, strategies to inhibit NLRP3 inflammasome activation remain elusive. Herein, we evaluated the impact of a walnut-derived peptide, TWLPLPR (TW-7), on cognitive impairment in high-fat diet/streptozotocin-induced type 2 diabetes mellitus (T2DM) mice and explored its underlying mechanisms in high glucose-induced HT-22 cells. In the Morris water maze test, TW-7 alleviated cognitive deficits in mice; this was confirmed at the level of synaptic structure and dendritic spine density in the mouse hippocampus using transmission electron microscopy and Golgi staining. TW-7 increased the expression of synaptic plasticity-related proteins and suppressed the NEK7/NLRP3 inflammatory pathway, as determined by western blotting and immunofluorescence analysis. The mechanism of action of TW-7 was verified in an HT-22 cell model of high glucose-induced insulin resistance. Collectively, TW-7 could regulate T2DM neuroinflammation and synaptic function-induced cognitive impairment by inhibiting NLRP3 inflammasome activation and improving synaptic plasticity.

Charting the Chronology of Research on Added Sugars: A Scoping Review and Evidence Map

The objective of this study was to conduct a scoping review and produce a publicly available database characterizing the design and reporting elements of the literature on dietary added sugars and select health outcomes. Relevant studies published from 1990 to 2021 were identified to create a database containing information on study and population characteristics, reported added sugars source and concentrations, dietary energy balance, total energy intake, and outcome measures related to body composition, obesity, cardiovascular disease, and diabetes mellitus. There were 245 publications identified, 22% of which describe interventions, and 78% describe observational studies. Publications pertaining to added sugars have risen dramatically since 2010, led by studies primarily assessing body composition (36%) or cardiovascular health (32%), including adults (65%), measuring liquid-only sources of added sugars (56%). Over 65% of studies reported total energy intake, 61% controlled for total energy intake in the design and analysis, and fewer than 5% of studies reported the energy balance of subjects. There has been a significant increase in research on added sugars since 2010, with substantial heterogeneity across all facets of methodology-study designs, exposures and outcomes of interest, terminology, and reporting of dietary intake data-thus limiting the ability to synthesize evidence in this scope of the literature. This evidence map highlights gaps and important areas for improvement to strengthen the state of research and better inform future policies and dietary recommendations on added sugars.

Effect of weight change on the association between overall and source of carbohydrate intake and risk of metabolic syndrome: Tehran lipid and glucose study

BACKGROUND

In this prospective cohort study, we aimed to evaluate the association between dietary carbohydrates, whole grains, refined grains, and simple sugar with the risk of metabolic syndrome (MetS) and assess the effect of weight change on these associations.

METHODS

This study was conducted within the framework of the Tehran Lipid and Glucose Study (TLGS). We included 1915 healthy participants with complete demographic, anthropometric and dietary measurements, among whom 591 developed MetS during 8.9 years of follow-up. Intake of dietary carbohydrates, whole grains, refined grains, and simple sugar was assessed with a validated semi-quantitative food frequency questionnaire. Multivariable adjusted Cox regression was used to estimate hazard ratios (HRs) for MetS events across tertiles of dietary variables. Using joint classification, the effect of weight change on the association between dietary variables and risk of MetS was assessed by Cox regression.

RESULTS

Carbohydrate intake was not associated with the risk of MetS in multivariable-adjusted models. Whole grains intake was inversely associated with the risk of MetS (HR: 0.78, CI: 0.63-0.98), while this association disappeared after adjustment for weight change. The risk of MetS increased by 11% (1.11, 1.09-1.14) for each 3% energy increment from simple sugar, and by 5% (1.05, 1.03-1.08) for each 1 serving/day increment in refined grains. Consumption of refined grains increased the risk of MetS; an effect modification of this association was found by weight change. Among subjects with weight loss, intake of refined grains < median intake decreased the risk of MetS (0.59, 0.41-0.87). However, consumption of refined grains ≥ median intake increased the risk of MetS in individuals with weight gain (1.47, 1.08-2.01). Simple sugar was positively associated with an increased risk of MetS, after adjustment for weight change (3.00, 2.37-3.82). In joint classification, intake of simple sugar greater than median intake increased the risk of MetS, independent of weight change.

CONCLUSION

Our findings suggest an effect modification by weight change on the association between carbohydrates, and refined grains intake and the risk of MetS. Weight loss along with lower consumption of carbohydrates, and refined grains reduced the risk of MetS. However, simple sugar intake, regardless of weight change, was associated with an increased risk of MetS.

Urinary Sucrose and Fructose From Spot Urine May Be Used as a Predictive Biomarker of Total Sugar Intake-Findings From a Controlled Feeding Study

BACKGROUND

Recently, we confirmed 24-h urinary sucrose plus fructose (24 uSF) as a predictive biomarker of total sugar intake. However, the collection of 24-h urine samples has limited feasibility in population studies.

OBJECTIVE

We investigated the utility of the urinary sucrose plus fructose (uSF) biomarker measured in spot urine as a measure of 24 uSF biomarker and total sugar intake.

METHODS

Hundred participants, 18-70 y of age, from the Phoenix Metropolitan Area completed a 15-d feeding study. For 2 of the 8 collected 24-h urine samples, each spot urine sample was collected in a separate container. We considered 4 timed voids of the day [morning (AM) void: first void 08:30-12:30; afternoon (PM) void: first void 12:31-17:30; evening (EVE) void: first void 17:31-12:00; and next-day (ND) void: first void 04:00-12:00]. We investigated the performance of uSF from 1 void, and uSF combined from 2 and 3 voids as a measure of 24 uSF and sugar intake.

RESULTS

The biomarker averaged from PM/EVE void strongly correlated with 24 uSF (partial r = 0.75). The 24 uSF predicted from the PM/EVE combination was significantly associated with observed sugar intake and was selected for building the calibrated biomarker equation (marginal R2 = 0.36). Spot urine-based calibrated biomarker, ie, biomarker-estimated sugar intake was moderately correlated with the 15-d mean-observed sugar intake (r = 0.50).

CONCLUSIONS

uSF measured from a PM and EVE void may be used to generate biomarker-based sugar intake estimate when collecting 24-h urine samples is not feasible, pending external validation.

Effect of lifelong sucrose consumption at human-relevant levels on food intake and body composition of C57BL/6N mice

Introduction

Controversies surround the issue if chronic consumption of a high-sugar diet is detrimental to health or not. This study investigates whether lifelong consumption of a higher sucrose diet will induce overeating, and obesity, and cause metabolic dysfunctions such as hyperglycemia and dyslipidaemia in C57BL/6N mice, compared to a lower sucrose diet.

Methods

Male C57BL/6N mice at 3 weeks of age were randomized into consuming a diet with 25 or 10% kcal from sucrose for the rest of their lives. Body weight, food and water intake, fasting blood glucose, insulin, and lipid levels were measured at regular intervals. At the end of the study, organs and tissues were collected and gene expression was measured.

Results

There was no discernible difference in the impact on food intake, body composition, glucose and lipid homeostasis, liver triglyceride content, life expectancy, as well as gene expression related to intermediary metabolism between mice fed a diet with 10 vs. 25% kcal as sucrose over their lifespan. We also showed that switching from a 25% kcal diet to a 10% kcal diet at different life stages, or vice versa, did not appear to affect these outcomes of interest.

Discussion

The results from our study suggest that lifelong consumption of a higher sugar diet generally did not induce overeating and obesity, disrupt carbohydrate metabolism and lipid homeostasis, and reduce life expectancy compared with a lower sugar diet. Our unorthodox findings disagreed with the popular belief that higher sugar consumption is detrimental to health, which should be confirmed in future studies.

Different Dose of Sucrose Consumption Divergently Influences Gut Microbiota and PPAR-γ/MAPK/NF-κB Pathway in DSS-Induced Colitis Mice

Sugar reduction and sugar control are advocated and gaining popularity around the world. Sucrose, as the widely consumed ingredient in our daily diet, has been reported a relation to gastrointestinal diseases. However, the role of sucrose in inflammatory bowel disease remains controversial. Hence, our study aimed to elucidate the potential role of three doses of sucrose on DSS-induced colitis in C57BL/6 mice and the underlying mechanisms. The results showed that low-dose sucrose intervention alleviated colitis in mice, reducing the expression of inflammatory cytokines and repairing mucosal damages. In contrast, high-dose sucrose intervention exacerbated colitis. Furthermore, three doses of sucrose administration markedly altered gut microbiota composition. Notably, the low-dose sucrose restored microbial dysfunction and enhanced the production of short chain fatty acids (SCFAs). Specifically, the abundance of SCFAs-producing bacteria Faecalibaculum, Bacteroides, and Romboutsia were increased significantly in the LOW group. Consistently, PPAR-γ, activated by SCFAs, was elevated in the LOW group, thereby inhibiting the MAPK/NF-κB pathway. Together, our study demonstrates the differential effects of sucrose on colitis at different doses, providing a scientific basis for measuring and modifying the safe intake level of sugar and providing favorable evidence for implementing sugar reduction policies.