American Journal of Clinical Nutrition最新文献

Background: It's commonly believed that higher nutrient content equates to healthier foods, and food processing lowers nutrient content, although bioavailability studies often indicate otherwise. Blueberries, a rich source of (poly)phenols with proven health benefits, provide a feasible model to evaluate phytochemical bioavailability following consumption of raw and processed fruits.

Objective: This study evaluates the effect of processing on the bioavailability of (poly)phenols following consumption of 4 interventions: 2 blueberry varieties (i.e., Elliott and Olympia) selected based on differing (poly)phenol content and in vitro bioaccessibility, a (poly)phenol-rich protein bar providing an equivalent amount of blueberries, and a control beverage.

Methods: This blinded, randomized, 4-way crossover, controlled trial (n = 18; 42.06±12.53 y; BMI 24.75±2.97 kg/m²) fed one serving (150 g) of Elliott and Olympia blueberries and a (poly)phenol-rich protein bar containing one serving of Elliott blueberries, compared to a macronutrient-matched control beverage. (Poly)phenols and metabolites were analyzed in blood and urine over 48h, with bioavailability and pharmacokinetics assessed via linear mixed-effects repeated measures ANOVA.

Results: Recovery of metabolites was similar following consumption of blueberry varieties of differing (poly)phenol composition, with higher total urinary recovery after Elliott blueberry relative to Olympia blueberry and protein bar (21% and 29%, respectively). Serum area under the curve was similar across berry-derived treatments, while differences in maximum concentration (C_max) and time at maximum concentration (T_max) were observed; for example, urinary recovery of 3-methoxycinnamic acid-4-O-glucuronide was similar following Elliott blueberry and protein bar (p=1.00), while C_max was 1.24 h later after Elliott blueberry vs protein bar (T_max=3.84 vs 2.60 h). Alternatively, C_max for 3-(3-hydroxyphenyl)propanoic acid was higher following Elliott blueberry vs Olympia blueberry and protein bar (26.63 and 25.32 ng/mL, respectively).

Conclusion: Differing berry (poly)phenol content and bioaccessibility only minimally affected bioavailability following consumption of blueberries relative to a blueberry-rich protein bar, suggesting (poly)phenol-dense foods, such as bars and snacks, could provide similar health benefits as raw fruits. Further studies using other crops are required to assess if these findings are translatable.

Clinical trial registry: NCT04175106 (https://clinicaltrials.gov/ct2/show/NCT04175106?term=19138&draw=2&rank=1) CLINICAL TRIAL REGISTRY: NCT04175106 (https://clinicaltrials.gov/study/NCT04175106).

Background: India grapples with a dual burden of child wasting and stunting and stark socio-economic and regional disparities.

Objective: We aimed to better understand trends in the prevalence of childhood stunting and wasting, with an emphasis on its disproportionate effects on marginalized populations, by analyzing National Family Health Surveys (NFHS) data from 2005 to 2020.

Methods: We analyzed trends in the distribution of childhood Height-for-Age Z (HAZ) and Weight-for-Height Z (WHZ) scores using anthropometric data from three surveys, NFHS 3, 4, and 5. We examined disparities by wealth, caste, tribe, area of residence (rural vs. urban), and sex, and mapped trends against India's evolving policy landscape. We also conducted a regression analysis of HAZ and WHZ risk factors.

Results: In the context of an evolving nutrition-centered policy landscape, disparities by level of wealth in both HAZ and WHZ decreased in the study period (HAZ: estimate=0.27, CI= 0.16, 0.38; and WHZ: estimate=0.11, CI=0.01, 0.22), though there were no improvements in disparities for marginalized castes (HAZ: estimate=0.07, CI= 0.00, 0.13; and WHZ: estimate=0.02, CI= -0.04, 0.08). Though they have narrowed, disparities by wealth, caste, tribe and area of residence persist, with undernutrition at birth, as measured by HAZ and WHZ, a particularly acute problem.

Conclusions: Although there have been significant reductions in disparities by wealth in mean HAZ and WHZ scores in India, persistent disparities by caste, tribe, and area of residence necessitate reinvestments in targeted interventions. Further, despite this narrowing of disparities and overall progress against stunting, anthropometric scores in early childhood continue to be low in India, especially with regard to wasting, indicating the importance of not only maternal nutrition and care for newborns, but more comprehensive efforts to address poverty and other factors that contribute to undernutrition, with a focus on vulnerable populations.

Background: The vascular and cardiometabolic effects of pecans are relatively under-studied.

Objectives: The aim was to examine how substitution of usual snack foods with 57 g/day of pecans affects vascular health, risk factors for cardiometabolic diseases and diet quality, compared to continuing usual intake in individuals at risk for cardiometabolic diseases.

Methods: A 12-week single-blinded, parallel, randomized controlled trial was conducted. Adults with ≥1 criterion for metabolic syndrome who were free from cardiovascular disease and type 2 diabetes were included. Participants were provided with 57 g/day of pecans and instructed to replace the snacks usually consumed with the provided pecans. The control group was instructed to continue consuming their usual diet. Flow mediated dilation (FMD; primary outcome), blood pressure, carotid-femoral pulse wave velocity (cf-PWV), lipids/lipoproteins, and glycemic control were measured at baseline and following the intervention. Participants completed three 24-hour recalls at three timepoints (baseline, week 6, and week 12) during the study (9 recalls in total). The Healthy Eating Index-2020 (HEI-2020) was calculated to assess diet quality.

Results: In total, 138 participants (Mean±SD;46±13 years, 29.8±3.7 kg/m²) were randomized (69 per group). No between group differences in FMD, cf-PWV or blood pressure were observed. Compared to the usual diet group, pecan intake reduced total cholesterol (-8.1 mg/dL; 95%CI -14.5, -1.7), LDL-C (-7.2 mg/dL; 95%CI -12.3, -2.1), non-HDL-C (-9.5 mg/dL; 95%CI -15.3, -3.7) and triglycerides (-16.4 mg/dL; 95%CI -30.0, -2.9). Weight tended to increase in the pecan group compared with the usual diet group (0.7 kg; 95%CI -0.1, 1.4). The HEI-2020 increased by 9.4 points (95%CI 5.0, 13.7) in the pecan group compared to the usual diet group.

Conclusions: Replacing usual snacks with 57 g/day of pecans for 12-weeks improved lipids/lipoproteins and diet quality, but did not affect vascular health in adults at risk for cardiometabolic disease.

Clinical trials registration: clinicaltrials.gov NCT05071807.

Background: Industrial processing and storage of milk products can strongly increase protein glycation level. Previously, we have reported that ingestion of highly glycated milk protein attenuates the post-prandial rise in plasma lysine concentrations when compared to the ingestion of an equivalent amount of milk protein with a low glycation level. Whether the attenuated increase in plasma lysine availability is attributed to compromised protein digestion and subsequent lysine absorption remains to be established.

Objective: The present study combined stable isotope methodology with the ingestion of, specifically produced, intrinsically labeled protein to assess protein digestion and amino acid absorption following ingestion of milk protein with a high versus low glycation level in vivo in humans.

Methods: 15 recreationally active, healthy young males participated in this double-blinded, randomized cross-over study. Subjects ingested 40 g intrinsically L-[1-¹³C]-lysine-labeled milk protein with either a low (3%) or high (50%) glycation level. Continuous intravenous infusion of L-[4,4,5,5-²H₄]-lysine was combined with frequent blood sample collection during a 6-h post-prandial period to evaluate dietary protein-derived lysine release into the circulation.

Results: Post-prandial plasma lysine concentrations were lower following the ingestion of milk protein with a high versus low glycation level (time*treatment effect: P=0.002; ƞ²=0.214), resulting in a 23 mmol·L^-1·360 min^-1 [95%-CI:13-32] lower incremental area under the curve (0±12 vs 23±11 mmol·L^-1·360 min^-1, respectively, P<0.001). The post-prandial release of milk protein-derived lysine into the circulation was attenuated following ingestion of the protein with the high versus low glycation level (time*treatment effect: P<0.001; ƞ²=0.640) and was 31% [95%-CI:26-36] lower over the full 6-h post-prandial period (18±4 vs 49±10% of the ingested lysine, respectively, P<0.001).

Conclusions: A high level of milk protein glycation strongly reduces post-prandial plasma lysine availability in vivo in humans. Industrial processing and storage of (milk) protein products can strongly modulate protein bioavailability and, as such, lower the nutritional value of a protein source. This trial was registered at www.

Clinicaltrials: gov as NCT05479916: https://clinicaltrials.gov/study/NCT05479916.

Background: Publishing protocols promotes transparency and reproducibility. The scope and methods of protocols for nutrition- and diet-related randomized controlled trials (RCTs) have not been investigated yet.

Objective: Map the landscape of nutrition- and diet-related interventions research.

Methods: We conducted a meta-research of nutrition-and diet-related RCT protocols published between January 2012 and March 2022, in any language, targeting human participants, evaluating nutrition interventions isolated or combined. A systematic search of the literature was conducted in six online databases. Bibliometric information, study characteristics, and research transparency practices data were collected from the included publications. The instructions for authors of journals with publications in our sample were checked for endorsement of reporting guidelines. Mentions to reporting guidelines in the included protocols were also checked.

Results: Among the 62,319 records retrieved, 1,068 were eligible. The number of published protocols increased annually, with a mean of 103 (range: 32-163) publications/year. Protocols were published in 148 journals, 50 of them (33.8%) endorsed SPIRIT, 111 (75.3%) CONSORT, and 4 (2.7%) TIDieR, while 343 (32.1%) protocols mentioned SPIRIT, 297 (27.8%) CONSORT, and 20 (1.9%) TIDieR. Most protocols reported the RCT registration number (n=1,006; 94.2%) and included statements about conflicts of interest (n=952; 89.1%) and funding (n=994; 93.2%). About one third of protocols focused on adults or elderly participants (n=677; 63.4%). Most protocols described one isolated nutrition- or diet-related intervention (n=724; 67.8%), which were most frequently "supplementation, supplements or fortification" (n=405; 37.9%) or "nutrition education, counselling or coordination of care" (n=354; 33.1%). The most frequent primary outcomes reported were related to clinical status (n=308; 28.8%).

Conclusions: The number of protocols for nutrition- or diet-related RCTs published is increasing, supporting the raising awareness and the importance of promoting these publications. The support and mention of relevant reporting guidelines by journals and researchers, respectively, remain far from ideal.

Background: Rapid infant growth is positively, and breastfeeding inversely, associated with childhood overweight. However, the interplay has only been sparsely investigated.

Objective: We aimed to investigate how exclusive breastfeeding duration modify the effect of infant growth on childhood overweight.

Methods: We included routinely collected data on duration of exclusive breastfeeding and child growth from Aarhus Municipality, Denmark, and on maternal health from the patient records at Aarhus University Hospital, 2008-2013. Infant growth was estimated using latent class analysis. Duration of exclusive breastfeeding was grouped in never, ≤4 months, and >4 months. Childhood overweight was defined as a BMI Z-score of >1 at age 5-9 years. We investigated the risk of overweight dependent on infant growth and breastfeeding duration both independently and combined using logistic regression and adjusting for potential confounders.

Results: In 7,074 infants we identified three growth patterns: average, accelerated, and decelerated. Never or ≤4 months of breastfeeding was associated with being overweight at 5-9 years (adjusted odds ratio (aOR): 1.61 [95% CI: 1.27 -2.03] and aOR: 1.54 [95% CI: 1.28 - 1.85], respectively) compared to >4 months of breastfeeding. Accelerated, as compared to average, infant growth was associated with childhood overweight (aOR: 1.35 [95% CI: 1.01 - 1.79]). In the combined analysis, accelerated infant growth showed no evidence of being associated with overweight if infants were exclusively breastfed >4 months (aOR: 1.20 [0.68-2.10]). Decelerated growth was not associated with overweight regardless of exclusive breastfeeding duration, compared to infants with average growth who were exclusively breastfed >4 months.

Conclusions: Longer duration of exclusive breastfeeding was associated with decreased risk of being overweight, while accelerated infant growth was associated with increased risk. Children with accelerated infant growth who were never breastfed had the highest risk of overweight at 5-9 years of age, while there was no association if the infants were exclusively breastfed >4 months.

Background: High prevalence of urinary tract infections (UTI), including cystitis, and concern for antimicrobial resistance justify safe and effective non-antibiotic therapies for prevention of recurrent UTI (rUTI). This study investigated the effect of a whole cranberry fruit powder supplement on incidence of culture-confirmed UTI (primary outcome) in females with rUTI history.

Methods: This multicenter, 6-month, randomized, placebo-controlled, double-blind study enrolled 150 healthy females (18-65 years, body mass index (BMI) >17.5-<35 kg/m²) with rUTI defined as ≥3 UTIs in the last year or at least 2 UTIs in the last 6 months, excluding those with >5 UTIs in the last 6 months. Participants consumed either 1 capsule 500 mg/day of whole cranberry powder (Pacran®) or placebo. Culture-confirmed UTIs (>10⁸cfu/L) were assessed throughout the intervention period at unscheduled clinic visits whenever participants experienced UTI symptoms, and at baseline, 3- and 6-month clinic visits. Symptomatic suspected UTIs were defined as participant-reported UTI-associated symptoms at unscheduled visits.

Results: Whole cranberry powder capsules reduced culture-confirmed UTI risk compared to placebo by 52% (adjusted relative risk [RR]=0.48, 95% CI=[0.26, 0.87], P=0.01); reduced Escherichia coli UTIs (RR=0.49, 95% CI=[0.24, 1.01], P=0.05); reduced incidence of UTI with urinary frequency and urgency symptomatology (RR=0.29, 95% CI=[0.13, 0.63], P<0.01); delayed time to first UTI episode (adjusted hazard ratio [HR]=0.36, 95% CI=[0.18, 0.74], P=0.01); and reduced the mean total number of UTIs per participant (adjusted incidence rate ratio [IRR]=0.41, 95% CI=[0.21, 0.79], P=0.01). Significant differences between groups in incidence of symptomatic suspected UTIs, and culture-confirmed dysuria were not observed. Exploratory scores for UTI-related female sexual matters, assessed in a sub-set of sexually active, consenting females, did not differ significantly between groups. No safety concerns were reported.

Conclusion: This study showed that whole cranberry powder capsules do not impact safety markers and reduce the incidence of culture-confirmed UTI and several other UTI-related outcomes in healthy females with rUTI history.

Clinical trials registration: Registered with clinicaltrials.gov (NCT03042273).

Background: To improve both human health and the health of our planet, the EAT-Lancet Commission proposed the planetary health diet (PHD).

Objective: We aimed to evaluate associations of PHD with all-cause, cardiovascular disease (CVD), and cancer-specific mortality among U.S. Black females.

Methods: The Black Women's Health Study is a prospective study of self-identified U.S. Black females. In 2001, 33,824 participants free of cancer and CVD completed a validated food frequency questionnaire. PHD Index (PHDI) was calculated based on reported consumption of 15 food groups, such as whole grains, non-starchy vegetables, legumes, soy foods, added fat and trans fat, and red/processed meats. Deaths were identified through linkage to the National Death Index. Cox proportional hazards regression, stratified by age and adjusted for smoking status, body mass index, and other CVD risk factors, was used to calculate hazards ratios (HRs) for quintiles of PHDI in relation to all-cause, CVD-, and cancer-specific mortality.

Results: During 18 years of follow-up, we identified 3537 deaths, including 779 from CVD and 1625 from cancer. Females in the quintile representing highest adherence to PHD were estimated to have a 18% reduction in risk of all-cause mortality (HR=0.82, 95% CI: 0.71, 0.94) and 26% reduction in CVD-specific mortality (HR=0.74, 95% CI: 0.55, 0.98), compared to those in the lowest quintile, with similar reductions observed for quintiles 2, 3, and 4. Among individuals under age 55, there was a significant trend of lower CVD mortality risk with higher level of adherence to PHD (p _trend=0.004) and the HR for the highest versus lowest quintile was 0.43 (95% CI: 0.21, 0.87). PHDI was not associated with cancer-specific mortality.

Conclusions: Adherence to a diet that has been shown to benefit the planet was associated with a lower risk of mortality among Black females, primarily driven by reduction in CVD-specific mortality risk.

Background: Understanding gene-environment interactions associated with vitamin D status may refine nutrition and public health strategies for vitamin D deficiency. Recent methodological advances have enabled the identification of variance quantitative trait loci (vQTLs) where gene-environment interactions are enriched.

Objectives: To identify vQTLs for serum 25-hydroxy vitamin D (25OHD) concentrations and characterize potential gene-environment interactions of vQTLs.

Methods: We conducted vQTL discovery for 25OHD using a newly developed quantile integral linear model in the UK Biobank individuals of European (N = 313,514), African (N = 7,800), East Asian (N = 2,146), and South Asian (N = 8,771) ancestries, respectively. We tested for interactions between the identified vQTL lead variants and 18 environmental, biological, or lifestyle factors, followed by multiple sensitivity analyses.

Results: We identified 19 independent vQTL lead variants (p-value <5x10^-8) in the European ancestry population. No vQTLs were identified in the non-European ancestry populations, likely due to limited sample sizes. A total of 32 interactions were detected with a false discovery rate <0.05. While known gene-season of measurement interactions were confirmed, additional interactions were identified involving modifiable risk factors, including time spent outdoors and body mass index. The magnitudes of these interactions were consistent within each locus upon adjusting for season of measurement and other covariates. We also identified a gene-sex interaction at a vQTL that implicates DHCR7. Integrating transcript- and protein-level evidence, we found that the sex-differentiated genetic associations may act through sex-biased expression of DHCR7 isoforms in skin tissues due to alternative splicing.

Conclusions: Through the lens of vQTLs, we identified additional gene-environment interactions affecting vitamin D status in addition to season of measurement. These findings may provide new insights into the etiology of vitamin D deficiency and encourage personalized prevention and management of associated diseases for at-risk individuals.

Background: Hippuric acid (HA), a host-microbe co-metabolite, normally derives from gut microbial catabolism of dietary polyphenols.

Objectives: We investigated the potential interplay between dietary polyphenols and gut microbiota on circulating HA levels, and examined the associations between serum concentrations of HA and cardiometabolic risk markers.

Methods: In a 1-year cohort of 754 community-dwelling adults, serum HA and its precursor [benzoic acid (BA)] and fecal microbiota were assayed using liquid chromatography-tandem mass spectrometry and 16S ribosomal RNA sequencing, respectively. Diet, blood pressure, blood glucose and lipids were measured twice, 1-year apart. Arterial stiffness [indicated by brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index] and liver fat accumulation [indicated by controlled attenuation parameter (CAP)] were measured after 1 year.

Results: We identified 27 microbial genera whose relative abundance was positively associated with serum HA concentrations (P_FDR<0.05) and constructed a microbial score to reflect the overall HA-producing potential. In multivariate-adjusted linear models, dietary intake of catechins and chlorogenic acids was positively associated with serum HA concentrations among participants with a higher microbial score (β=0.26, P=0.03), but not among those with a lower score (β=-0.13, P=0.30, P_interaction=0.03). Participants with higher intake of dietary catechins and chlorogenic acids had lower triglyceride (Percentage change = -5.9%, P<0.05). Each 1 μmol/L increase in serum HA, but not in BA, was associated with 5.7%, 1.5%, 1.7%, 1.7%, and 1.7% decrease in triglyceride, systolic blood pressure, diastolic blood pressure, baPWV, and CAP, respectively (all P<0.05).

Conclusions: The gut microbial genera that predicted circulating HA levels may modify the association between dietary polyphenol intake and circulating HA levels, and elevated serum HA concentrations are favorably associated with multiple cardiometabolic risk markers.