Tagged: AJCN

The effect of zinc-biofortified rice on zinc status of Bangladeshi pre-school children: a randomized, double-masked, household-based controlled trial

Abstract
Background

Zinc biofortification of rice could sustainably improve zinc status in countries where zinc deficiency is common and rice is a staple, but its efficacy has not been tested. Fatty acid desaturases (FADS) are putative new zinc status biomarkers.

Objective

Our objective was to test the efficacy of zinc-biofortified rice in preschool-aged children with zinc-deficiency. Our hypothesis was that consumption of zinc-biofortified rice would increase plasma zinc concentration (PZC).

Design

We conducted a 9-month, double-masked, intervention trial in 12–36 month-old rural Bangladeshi children, most of whem were who were zinc-deficient (PZC < 70 µg/dL) and stunted (n = 520). The children were randomized to receive either control rice (CR) or zinc-biofortified rice (BFR) provided in cooked portions to their households daily, with compliance monitoring. The primary outcome was PZC. Secondary outcomes were zinc deficiency, linear growth, infection-related morbidity, FADS activity indices, intestinal fatty acid binding protein (I-FABP) and fecal calprotectin. We applied sparse serial sampling for midpoint measures and analyzed data by intention-to-treat using mixed-effects models. The trial was registered under NCT03079583.

Results

At baseline, median (IQR) PZC was 60.4 (56.3–64.3) µg/dL, 78.1% of children were zinc deficient and 59.7% were stunted. Mean ± SD daily zinc intakes from the CR and BFR during the trial were 1.20 ± 0.34 and 2.22 ± 0.47 mg/day, respectively (P < 0.001). There were no significant time-by-treatment effects on PZC, zinc deficiency prevalence, FADS activity, I-FABP or fecal calprotectin (all P > 0.05). There was a time-treatment interaction for height-for-age z scores (P < 0.001) favoring the BFR group. The morbidity longitudinal prevalence ratio (LPR) (95% CI) was 1.08 (1.05,1.12) comparing the BFR and CR groups, due to more upper respiratory tract illness in the BFR group.

Conclusions

Consumption of zinc-biofortified rice for 9 months providing ∼1 mg of additional zinc daily to Bangladeshi children did not significantly affect PZC, prevalence of zinc deficiency or FADS activity.Clinical Trial Registry: https://clinicaltrials.gov/ct2/show/NCT03079583

Food system dynamics structuring nutrition equity in racialized urban neighborhoods

Abstract
Background

The food system is a social determinant of health and leverage point for reducing diet-related racial inequities. Yet, food system interventions have not resulted in sustained improvement in dietary outcomes for underrepresented minorities living in neighborhoods with a history of disinvestment. Research is needed to illuminate the dynamics structuring food systems in racialized neighborhoods to inform intervention development.

Objective

Conduct participatory research examining the complexity and inequity of food systems in historically redlined neighborhoods to identify feedback mechanisms to leverage in efforts to transform system outcomes for racial equity.

Methods

We conducted a mixed-methods study in Cleveland, Ohio, USA from 2018–21 using participatory system dynamic modeling with 30 academic and community partners, in-depth qualitative interviews with 22 key stakeholders, and public convenings with 250 local food policy council affiliates. Data were synthesized into causal loop diagrams depicting feedback mechanisms reinforcing or balancing neighborhood-level food system dynamics.

Results

We identified 10 feedback mechanisms structuring nutrition equity, which was identified as a meta-goal for food systems in racialized neighborhoods. Feedback mechanisms were organized in three domains: 1. meeting basic food needs with dignity (i.e., side hustle, government benefits, emergency food assistance, stigma and stereotypes), 2. local food supply and demand dynamics (i.e., healthy food retail, job security, food culture and norms), and 3. community empowerment and food sovereignty (i.e., community power, urban agriculture, risk of gentrification). Five exogenous factors moderate feedback dynamics: neighborhood crisis, neighborhood investments, household costs, government benefit funding, and voter participation.

Conclusions

We identified nutrition equity as an overarching goal for local food systems, which reflects a state of having freedom, agency, and dignity in food traditions resulting in people and communities healthy in body, mind, and spirit. It is a transformative goal designed to spur system-level interventions that further racial equity through improved local food system dynamics.

Genosets for APOE and CYP7A1-rs3808607 variants do not predict low-density lipoprotein cholesterol lowering upon intervention with plant sterols in a randomized, double-blind, placebo-controlled trial

Abstract
Background

The consumption of 2 g/d plant sterols (PS) reduces circulating low-density lipoprotein cholesterol (LDL-C) up to 10%. The degree of LDL-C lowering was associated with specific apolipoprotein E (APOE, rs429358) and cholesterol 7α-hydroxylase (CYP7A1, rs3808607) genosets in previous post hoc analyses of randomized controlled trials. However, since post-hoc analyses do not conform to the randomization model, there is a greater potential that the findings may be due to type I error, thus warranting validation through an a priori-designed intervention trial.

Objective

The GenePredict Plant Sterol study (GPS) was designed to validate associations of LDL-C lowering with specific APOE and CYP7A1 genosets through a priori recruitment of individuals carrying pre-specified genosets.

Methods

A two center, double-blind, placebo-controlled, randomized two-period crossover dietary intervention with 2 g/d of PS for 28 days with a minimum 28 day washout was undertaken from July 2017 to December 2019. A priori recruitment of individuals with slightly elevated LDL-C was based on genosets of APOE isoforms and CYP7A1 rs3808607. Randomization was performed with stratification by sex and genoset.

Results

The recruitment target of 64 participants with pre-specified genosets could not be reached, despite the screening of 477 individuals; 42 participants completed the intervention trial. Reductions in LDL-C were similar across all three genosets (–0.298 ±0.164, –0.357 ±0.115, –0.293 ±0.109 mmol/L, P = 0.0002 overall, P = 0.9126 for treatment*genoset), providing evidence that the shortfall in recruitment may not have stopped the trial from meeting the objective.

Conclusions

APOE and CYP7A1 genotypes did not influence the efficacy of LDL-C reductions upon dietary intervention with PS. Findings of previous post-hoc analyses could not be validated in a trial using a priori genotype-based recruitment. Obtaining adequate numbers of participants is challenging in trials using genoset-based recruitment, even for common variants.Trial Registration: Clinical Trials #NCT02765516 https://clinicaltrials.gov/ct2/show/NCT02765516

The effect of camelina oil on vascular function in essential hypertensive patients with metabolic syndrome: A randomized, placebo-controlled, double-blind study

Abstract
Background

The effects of a dietary supplementation with the vegetable omega-3 α-linolenic acid (ALA) on cardiovascular homeostasis are unclear. In this context, it would be interesting to assess the effects of camelina oil.

Objective

This study aimed to assess the cardiovascular and metabolic effects of camelina oil in hypertensive patients with metabolic syndrome.

Methods

In a double-blind placebo-controlled randomized study, treated essential hypertensive patients with metabolic syndrome received during 6 months either cyclodextrin-complexed camelina oil containing ≈ 1.5 g ALA/day (n = 40), or an isocaloric placebo (n = 41), consisting in the same quantity of cyclodextrins and wheat starch. Anthropometric data, plasma lipids, glycemia, insulinemia, creatininemia, thiobarbituric acid reactive substances, high-sensitivity C-reactive protein, and n-3, n-6 and n-9 fatty acids in erythrocyte membranes were measured. Peripheral and central blood pressures, arterial stiffness, carotid intima-media thickness and brachial artery endothelium-dependent flow-mediated dilatation and endothelium-independent dilatation were assessed.

Results

Compared to placebo, camelina oil increased ALA (mean ± SD: 0 ± 0.04 vs. 0.08 ± 0.06%, P < 0.001), its elongation product eicosapentaenoic acid (EPA; 0 ± 0.5 vs. 0.16 ± 0.65%, P < 0.05), and the n-9 gondoic acid (0 ± 0.04 vs. 0.08 ± 0.04%, P < 0.001). No between-group difference was observed for cardiovascular parameters. However, changes in flow-mediated dilatation were associated with the magnitude of changes in EPA (r = 0.26, P = 0.03). Compared to placebo, camelina oil increased fasting glycemia (–0.2 ± 0.6 vs. 0.3 ± 0.5 mmol/L, P < 0.001) and homeostatic model assessment for insulin resistance (HOMA-IR; –0.8 ± 2.5 vs. 0.5 ± 0.9, P < 0.01) index, without affecting plasma lipids, or inflammatory and oxidative stress markers. Changes in HOMA-IR index were correlated with the magnitude of changes in gondoic acid (r = 0.32, P < 0.01). Nutritional intake remained similar between groups.

Conclusion

ALA supplementation with camelina oil did not improve vascular function but adversely affected glucose metabolism in hypertensive patients with metabolic syndrome Whether this adverse effect on insulin sensitivity is related to gondoic acid enrichment, remains to be elucidated.

Association of Plant-Based Diet Index with Prostate Cancer Risk

ABSTRACT
Background

Plant-based diets are associated with multiple health benefits and a favorable environmental impact. For prostate cancer, previous studies suggest a beneficial role of specific plant-based foods (e.g., tomatoes) and a potentially harmful role of specific animal-based foods (e.g., meat, dairy). However, less is known about plant-based dietary patterns.

Objective

To examine the relationship between Plant-based Diet Indices and prostate cancer risk, including clinically relevant disease.

Design

This was a prospective cohort study including 47,239 men in the Health Professionals Follow-up Study (1986–2014). Overall and healthful Plant-based Diet Indices were calculated from food frequency questionnaires. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) to examine the risk of incident prostate cancer (total and by clinical category), among men ages < 65 and ≥ 65.

Results

6,655 men were diagnosed with prostate cancer over follow-up, including 515 with advanced stage at diagnosis, 956 with lethal disease (metastasis or death) and 806 prostate cancer deaths. Greater overall plant-based consumption was associated with a significantly lower risk of fatal prostate cancer (HR 0.81, 95% CI 0.64,1.01; p-trend = 0.04). In men age < 65, higher Plant-based Diet Index was associated with a lower risk of advanced, lethal and fatal prostate cancer. Moreover, greater consumption of a healthful plant-based diet was associated with lower risks of total (HR 0.84; 95% CI 0.73,0.98; P-trend = 0.046) and lethal prostate cancer (HR 0.56; 95% CI 0.34,0.94; P-trend = 0.03) at age < 65. There were no associations between overall or healthful Plant-based Diet Indices with prostate cancer among men ≥ 65 years. Less than 1% of participants followed a strict vegetarian or vegan diet.

Conclusions and Relevance

This prospective study provides supportive evidence that greater consumption of healthful plant-based foods is associated with a lower risk of aggressive forms of prostate cancer, with stronger benefit among men age < 65.

Enable Notifications    OK No thanks