Measures of carbohydrate quality and their association with diet quality and cardiometabolic health outcomes in Singapore middle-aged and older adults.

BACKGROUND AND AIMS: Carbohydrate quality may play a key role in cardiometabolic health and disease risk. This study aimed to assess the dietary carbohydrate quality of the free-living middle-aged and older adults in Singapore, and its association with overall diet quality and cardiometabolic health. METHODS AND RESULTS: This cross-sectional study examined the diet and cardiometabolic disease risk indicators of middle-aged and older adults in Singapore (n = 104). Dietary carbohydrate quality was assessed as the pass and fail rate of the population to four measures of carbohydrate quality: (i) dietary fiber recommended daily allowance (RDA), (ii) whole-grain recommendation, (iii) free sugar recommendation, and (iv) carbohydrate metrics. The association between each carbohydrate quality measure and diet quality, as well as cardiometabolic health, was assessed. Except for free sugar recommendation, the carbohydrate quality of the population was found to be poor with a low adherence (20-36%) to three measures. Subjects meeting these measures had generally higher intakes of fiber, protein, and most micronutrients compared with subjects who failed. Meeting different variants of the carbohydrate metrics was associated with 60% lower odds of pre-hypertensive blood pressure (p = 0.037; p = 0.047), and meeting the dietary fiber RDA was associated with lower waist circumference (p = 0.021). CONCLUSION: An improvement in carbohydrate quality is warranted among free-living middle-aged and older adults in Singapore. Not all measures of carbohydrate quality were equally effective in preserving overall diet quality; the carbohydrate metrics and dietary fiber RDA can be identified as effective measures in relation to cardiometabolic disease risk. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ CLINICAL TRIAL REGISTRATION: NCT03554954, 13 Sept. 2018.

Skin carotenoid status and plasma carotenoids: biomarkers of dietary carotenoids, fruits and vegetables for middle-aged and older Singaporean adults.

Skin carotenoid status (SCS) measured by resonance Raman spectroscopy (RRS) may serve as an emerging alternative measurement for dietary carotenoid, fruit and vegetable (FV) intake although its application had not been assessed in a middle-aged and older population in Asia. This cross-sectional study aims to concurrently examine the use of SCS and plasma carotenoids to measure FV and carotenoid intake in a middle-aged and older population, taking into consideration potential socio-demographic and nutritional confounders. The study recruited 103 middle-aged and older adults (mean age: 58 years) in Singapore. Dietary carotenoids and FV, plasma carotenoid concentration and SCS were measured using 3-d food records, HPLC and a biophotonic scanner which utilised RRS, respectively. Adjusted for statistically defined socio-demographic covariates sex, age, BMI, prescription medication and cigarette smoking, plasma carotenoids and SCS showed positive associations with dietary total carotenoids (ßplasma: 0·020 (95 % CI 0·000, 0·040) µmol/l/mg, P = 0·05; ßskin: 265 (95 % CI 23, 506) arbitrary units/mg, P = 0·03) and FV (ßplasma: 0·076 (95 % CI 0·021, 0·132) µmol/l per FV serving, P = 0·008; ßskin: 1036 (95 % CI 363, 1708) arbitrary units/FV serving, P = 0·003). The associations of SCS with dietary carotenoid and FV intake were null with the inclusion of dietary PUFA, fibre and vitamin C as nutritional covariates (P > 0·05). This suggests a potential influence of these nutritional factors on carotenoid circulation and deposition in the skin. In conclusion, SCS, similar to plasma carotenoids, may serve as a biomarker for both dietary carotenoid and FV intake in a middle-aged and older Singaporean population.

The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: A randomized controlled trial.

BACKGROUND & AIMS: Sleep quality is a pivotal part of health and there is growing evidence on the association between gut microbiota composition and sleep quality. 5-Hydroxytryptophan (5-HTP) is known as a precursor of the sleep regulating neurotransmitter and hormone. However, efficacy of 5-HTP supplementation for improving sleep quality in older adults is unclear. Hence, the aim of this study is to assess the impact of 5-HTP supplementation on sleep quality and gut microbiota composition in older adults. METHODS: This is a single-blinded, 12-week parallel randomized controlled trial. Thirty older adults (66 ± 3 years) in Singapore were randomly assigned to either consume or not consume 100 mg 5-HTP daily. Every 4 weeks, sleep quality was assessed via both subjective (Pittsburg Sleep Quality Index) and objective (actigraphy watch) measures. A global sleep score (GSS) was obtained from the PSQI, where a GSS>5 defines as poor sleeper while a GSS≤5 defines as good sleeper. Blood serotonin level, urine melatonin concentration, gut microbiota composition and stool short chain fatty acids (SCFA) content were assessed at week 0 and 12. This study was registered in clinicaltrials.gov as NCT04078724 (https://clinicaltrials.gov/ct2/show/NCT04078724). RESULTS: 5-HTP supplementation showed an overall favorable effect on certain sleep quality components and an increase in serum serotonin concentration. In particular, at week 12, not good sleepers but poor sleepers with 5-HTP supplementation were able to significantly improve subjective GSS (ΔSL5-HTP: -2.80 ± 1.10 min, p-value = 0.005). In addition, they showed an increase in microbiota diversity (Simpson5-HTP vs. SimpsonControl: 0.037 ± 0.032 a.u. vs. -0.007 ± 0.022 a.u.; pinteraction: 0.013) and relative abundance of SCFA producing bacteria in the gut. CONCLUSIONS: 5-HTP supplementation can improve certain sleep quality components in older adults and this benefit was more prominently observed in poor sleepers. 5-HTP was also able to improve the gut microbiota composition in poor sleepers.

Association Between Dietary Protein Intake and Sleep Quality in Middle-Aged and Older Adults in Singapore.

Poor sleep has been associated with the increased risk of developing detrimental health conditions. Diet and certain nutrients, such as dietary protein (PRO) may improve sleep. This cross-sectional study aimed to investigate the relationship between PRO intake, their amino acid components, and sources with sleep quality in middle-aged and older adults residing in Singapore. A dataset of 104 healthy subjects between the age of 50 and 75 years old were used. Collected data included 3-day food record and sleep quality [sleep duration, global sleep score (GSS), sleep latency (SL), and sleep efficiency (SE)]. The collected 3-day food records were extracted for PRO, tryptophan (Trp), and large neutral amino acid (LNAA) intake. PRO intake was further categorized into plant and animal PRO. A multivariate multiple linear regression (MLR) was performed to assess the association between PRO intake and sleep quality. Dietary Trp:LNAA ratio was positively associated with sleep duration (ßtotal: 108.234 h; p: 0.005) after multiple covariates adjustment. Similarly, plant Trp (ßplant: 2.653 h/g; p: 0.020) and plant Trp:LNAA (ßplant: 54.006 h; p: 0.008) was positively associated with sleep duration. No significant associations were observed for both SL and SE. Sleep duration in middle-aged and older Singaporean adults was positively associated with dietary Trp and Trp:LNAA, especially when obtained from plant sources.

Postprandial glycemic and circulating SCFA concentrations following okara- and biovalorized okara-containing biscuit consumption in middle-aged and older adults: a crossover randomized controlled trial.

Okara is a high-fiber food by-product that can be biotransformed with Rhizopus oligosporus to improve its nutritional value and palatability. This research aims to assess postprandial changes in glycemic-related and lipid-related outcomes in middle-aged and older Singaporeans following okara- and biovalorized okara-containing biscuit consumption. Fifteen participants (58 ± 6 years old, mean ± SD) completed the randomized crossover study. Participants were provided control (C), okara (AOK)-, and biovalorized okara (RO)-containing biscuits in separate 4 h mixed meal tolerance tests. Serum glucose and insulin, insulin indices, serum short-chain fatty acids (SCFA) and lipid-lipoprotein panels, and sensory analysis were assessed. Glucose-stimulated insulin secretion was significantly lower for RO than for C (p: 0.035) while log insulin incremental area under the curve (AUC) was significantly lower for AOK compared to that for C (p: 0.023). The estimated insulin sensitivity index and estimated metabolic clearance rate were significantly higher for AOK compared to that for C (p: 0.025 and 0.016 respectively). Normalized AUC for total SCFA was significantly higher for RO compared to that for C (p: 0.038). Normalized AUC for LDL-cholesterol was significantly higher for AOK than for C (p: 0.010). No significant difference was noted for glucose, total cholesterol, HDL-cholesterol, and triglyceride concentrations. RO had greater flavor and overall liking than AOK (p: 0.007 and 0.017 respectively). Biscuits incorporated with okara or biovalorized okara can attenuate postprandial insulin responses. RO offered a greater SCFA response than C, indicating improved SCFA concentrations upon consumption of okara improved with fermentation. The trial was registered under https://www.clinicaltrials.gov (NCT03978104, 25 May 2019).

Wolfberry (Lycium barbarum) Consumption with a Healthy Dietary Pattern Lowers Oxidative Stress in Middle-Aged and Older Adults: A Randomized Controlled Trial.

Incorporating zeaxanthin-rich wolfberry (Lycium barbarum) into a healthy dietary pattern may augment its antioxidant potential. The present 16-week, parallel design randomized controlled trial aimed to investigate the impact of adhering to a healthy dietary pattern, either with or without whole dried wolfberry (15 g/d) on oxidative stress status (plasma malondialdehyde and 8-iso-prostaglandin F2α) in middle-aged and older adults. Changes to carotenoids status (plasma and skin carotenoids) and body composition were further evaluated to explore potential mechanisms which underlie the antioxidant properties of wolfberry. Plasma 8-iso-prostaglandin F2α, plasma zeaxanthin and skin carotenoids status were significantly raised in the wolfberry consuming group (n = 22; p < 0.05) compared to the control group which showed no changes (n = 18). Likewise in the wolfberry group only, inverse association was observed between the change values of plasma zeaxanthin and plasma 8-iso-prostaglandin F2α (-0.21 (-0.43, 0.00) ng/µmol, regression coefficient (95% CI); p = 0.05). Wolfberry consumption with a healthy dietary pattern may serve as a dietary strategy to attenuate lipid peroxidation among middle-aged and older adults who are at a heightened risk of oxidative stress induced age-related disorders. The antioxidant properties of wolfberry may be attributed to its rich zeaxanthin content.

Animal Protein versus Plant Protein in Supporting Lean Mass and Muscle Strength: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Although animal protein is usually considered to be a more potent stimulator of muscle protein synthesis than plant protein, the effect of protein source on lean mass and muscle strength needs to be systematically reviewed. This study aimed to examine potential differences in the effect of animal vs. plant protein on lean mass and muscle strength, and the possible influence of resistance exercise training (RET) and age. The following databases were searched: PubMed, Embase, Scopus and CINAHL Plus with Full Text, and 3081 articles were screened. A total of 18 articles were selected for systematic review, of which, 16 were used for meta-analysis. Total protein intakes were generally above the recommended dietary allowance at the baseline and end of intervention. Results from the meta-analyses demonstrated that protein source did not affect changes in absolute lean mass or muscle strength. However, there was a favoring effect of animal protein on percent lean mass. RET had no influence on the results, while younger adults (<50 years) were found to gain absolute and percent lean mass with animal protein intake (weighted mean difference (WMD), 0.41 kg; 95% confidence interval (CI) 0.08 to 0.74; WMD 0.50%; 95% CI 0.00 to 1.01). Collectively, animal protein tends to be more beneficial for lean mass than plant protein, especially in younger adults.

Enhancing the cardiovascular protective effects of a healthy dietary pattern with wolfberry (Lycium barbarum): A randomized controlled trial.

BACKGROUND: The consumption of wolfberry (Lycium barbarum), a rich source of carotenoids and bioactive polysaccharides, may serve as a potential dietary strategy for cardiovascular disease (CVD) risk management although limited studies examined its effects as whole fruits. OBJECTIVES: To investigate the impact of wolfberry consumption as part of a healthy dietary pattern on vascular health-related outcomes and classical CVD risk factors in middle-aged and older adults in Singapore. METHODS: This is a 16-week, parallel design, randomized controlled trial. All participants (n = 40) received dietary counselling to follow healthy dietary pattern recommendations with the wolfberry group given additional instructions to cook and consume 15 g/d whole, dried wolfberry with their main meals. Biomarkers of vascular function (flow-mediated dilation, plasma total nitrate/nitrite, endothelin-1, and intercellular adhesion molecule-1), vascular structure (carotid intima-media thickness) and vascular regeneration (endothelial progenitor cell count, plasma angiopoietin 1 and angiopoietin 2), were assessed at baseline and postintervention. Serum lipid-lipoproteins and blood pressure were evaluated every 4 weeks. RESULTS: All participants showed an improved compliance toward the healthy dietary pattern. This was coupled with marked rises in total nitrate/nitrite concentrations (mean change wolfberry: 3.92 ± 1.73 nmol/mL; control: 5.01 ± 2.55 nmol/L) and reductions in endothelin-1 concentrations (wolfberry: -0.19 ± 0.06 pg/mL; control: -0.15 ± 0.08 pg/mL). Compared with the control which depicted no changes from baseline, the wolfberry group had a significantly higher HDL cholesterol (0.08 ± 0.04 mmol/L), as well as lower Framingham predicted long-term CVD risk (-0.8 ± 0.5%) and vascular age (-1.9 ± 1.0 y) postintervention. No differences were observed in the other vascular health-related outcomes. CONCLUSIONS: In middle-aged and older adults, adherence to a healthy dietary pattern improves vascular tone. Incorporating wolfberry to the diet further improves blood lipid-lipoprotein profile and may lower long-term CVD risk. This study was registered at clinicatrials.gov as NCT03535844.

Association of Sleep Quality and Macronutrient Distribution: A Systematic Review and Meta-Regression.

Sleep is involved in metabolic, emotional and cognitive regulation and is therefore an essential part of our health. Although an association between sleep quality and macronutrient intake has been reported, studies on the effect of macronutrient distribution with sleep quality are limited, and available results are inconsistent. In this study, we aim to assess the association between sleep quality and macronutrient distribution in healthy adults from systematically reviewed cross-sectional studies and randomized controlled trials (RCTs). A total of 19 relevant articles were selected and it was observed that good sleepers (sleep duration ≥ 7 h, global sleep score ≤ 5, sleep latency ≤ 30 min and sleep efficiency >85%) had a higher energy distribution from dietary protein than poor sleepers. On the other hand, good sleepers showed a relatively lower percentage of energy from dietary carbohydrate and fat than poor sleepers. However, meta-regression analysis revealed no dose-dependent association between the macronutrient distributions and sleep duration. These results suggest that consuming a greater proportion of dietary protein may benefit on improving sleep quality in healthy adults. However, findings may be susceptible to reverse causality and additional RCTs are needed.