American Journal of Clinical Nutrition最新文献

Background: Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder; however, evidence regarding its association with early-life factors is lacking.

Objectives: We aimed to examine the association between early-life factors, including maternal smoking and lactation, and risk of incident IBS in offspring within a large prospective cohort.

Methods: Participants free of IBS at baseline and with available data on maternal smoking and lactation were included. Maternal smoking was defined as regular cigarette smoking during the perinatal period, and lactation was defined as any breastfeeding during the infant period. Participants exposed to maternal smoking or to lactation during infancy were defined as exposure groups. The primary outcome was incident IBS. Cox proportional hazards model was conducted to estimate the associated risk.

Results: Among 290,962 participants, 81,186 (27.90%) participants were exposed to maternal smoking and 211,954 (72.85%) were exposed to lactation as infants. Over a median of 14.6 y of follow-up, 6222 incident IBS cases were identified. After multivariable adjustment, participants with maternal smoking had a 16.0% higher risk of incident IBS compared with those without maternal smoking [hazard ratio (HR): 1.16; 95% confidence interval (CI): 1.09, 1.22], whereas those exposed to lactation had a 9% lower risk of IBS than those not exposed to lactation (HR: 0.91; 95% CI: 0.86, 0.97). Notably, participants exposed to both maternal smoking and no lactation exhibited an even higher risk of developing IBS compared with those with lactation exposure but without maternal smoking (HR: 1.23; 95% CI: 1.14, 1.34). Additionally, an evidently higher IBS risk was observed in those with both maternal smoking and individual previous/current smoking (HR: 1.30; 95% CI: 1.21, 1.41).

Conclusions: Maternal smoking is associated with a higher risk of incident IBS, whereas exposure to lactation is associated with a lower risk. These findings underscore the potential impact of early-life exposures on gastrointestinal health.

Background: Dietary choices are shaped by both genetic predisposition and environmental exposures, yet the relative influence of these factors remains insufficiently understood across populations and age groups. Young adulthood represents a critical period when long-term eating habits take form, and clarifying the determinants of dietary behavior in this life stage may inform strategies to promote sustained health.

Objectives: This twin study aimed to estimate genetic and environmental contributions to food, energy, and nutrient intakes, and taste preferences in young adults in Sweden.

Methods: The study included 2832 Swedish twins (858 monozygotic and 1974 dizygotic; mean age 24 y; 59.5% female). Participants completed a validated dietary questionnaire assessing food intake frequencies and taste preferences. Additive genetic (A), shared environmental (C), and nonshared environmental (E) influences on a priori dietary indices, specific food and nutrient intakes, and taste preferences were estimated using classical ACE twin models and nested models fitted in OpenMx.

Results: Heritability estimates across dietary traits ranged from 20% to 61%. Genetic influences on overall dietary pattern indices exceeded 40%. Heritability varied across food groups (e.g., 61% for venison; 24% for potatoes) and nutrient intakes (50% for fiber; 20% for sodium), indicating differing degrees of genetic impact across dietary components. Taste preferences also showed substantial genetic contributions (21%-61%), with the strongest effects observed for bitter foods (e.g., black coffee, grapefruit), followed by sweet foods (e.g., jam/marmalade).

Conclusions: This large-scale twin study provides a comprehensive overview of genetic and environmental influences on dietary behavior in young adults, showing substantial genetic and nonshared environmental contributions across diverse dietary traits. These results provide a foundation for future research on diet-disease relationships and may support the development of prevention and intervention strategies, including emerging precision-nutrition approaches.

Background: Pregestational diabetes increases the risk of adverse outcomes including congenital malformations, stillbirth, developmental disabilities, and maternal morbidity. Periconceptional glycemic control and folic acid (FA) supplementation are 2 of the most effective birth defects prevention strategies.

Objectives: The objectives are to describe the proportion of and risk factors for diabetes and prediabetes and assess the association of folate status and diabetes among a nationally representative sample of nonpregnant women of reproductive age (WRA).

Methods: WRA (12‒49 y) from the NHANES 2011‒March 2020 (n = 3731) were included. Diabetes status was defined by glycated hemoglobin (HbA1c) ≥6.5%, fasting plasma glucose (FPG) ≥126 mg/dL, or self-report. Prediabetes was defined as HbA1c ≥5.7 <6.5% or FPG ≥100 <126 mg/dL. The associations were assessed by multivariate regression models.

Results: Among all WRA, 32.3% [95% confidence interval (CI): 30.0%, 34.7%] had prediabetes and 5.3% (95% CI: 4.4%, 6.3%) had diabetes [1.8% undiagnosed, 95% CI: 1.4%, 2.3%; 3.1% diagnosed but uncontrolled (HbA1c ≥5.7), 95% CI: 2.5, 4.0; 0.4% diagnosed but controlled (HbA1c<5.7), 95% CI: 0.2, 0.6]. The prevalence of diabetes was associated with increased age, BMI, serum pyrazino-s-triazine, an oxidation form of 5'-methyltetrahydrofolate (MeFox), and red blood cell (RBC) folate concentrations (all P < 0.0001) but not unmetabolized FA. Among WRA ≥35 y, 10.5% (95% CI: 8.5%, 12.8%) had diabetes and 40.3% (95% CI: 37.1%, 43.5%) had prediabetes. In adjusted regression models, diabetes was associated with altered folate metabolism [i.e., high (>90th %) RBC folate concentrations with lower (<400 μg/d) FA intake; adjusted odds ratio 2.28 (95% CI: 1.23, 4.24)]. Among those with diabetes, high serum MeFox and RBC folate concentrations were lower with euglycemia.

Conclusions: Diabetes and prediabetes were common among WRA. Diabetes was associated with high RBC folate concentration and high MeFox despite low FA intake; however, these associations were reduced among those with good glycemic control. Screening for and preventing the progression of prediabetes, diagnosis, and glycemic control among those with diabetes has the potential to prevent adverse outcomes.

Background: Nutrient-specific front-of-package (FOP) schemes are expanding internationally, but no validated, population-level measures exist to monitor adherence or link adherence to healthcare burden. Leveraging Canada's FOP thresholds, we introduce reproducible alignment indexes designed for surveillance and evaluate their predictive validity using hospital bed-day outcomes.

Objectives: This study aims to construct a priori dietary indexes reflecting alignment with Canadian FOP thresholds and assess their ability to predict all-cause hospital bed-day rates over 5 and 10 y among Canadian adults aged 20-79.

Methods: Data from the Canadian Community Health Survey-Nutrition linked longitudinally with individual hospital records (n = 14,249 after exclusions) were used. Food items were classified according to FOP nutrition labeling regulations to create the FOP-compliance index (FOP-CI) dietary index. A 10-y follow-up sensitivity analysis and 2 policy scenarios were included: 1 removing exemptions (FOP-compliance index without policy exemptions) and 1 including fast food and restaurant items (FOP-compliance index including fast food and restaurant items). The Dietary Approaches to Stop Hypertension index served as a reference. Weighted multivariable zero-inflated negative binomial models estimated the relative rate (RR) of hospital bed-days across alignment quintiles.

Results: Quintile 5 (lower FOP-CI alignment) had a higher rate of all-cause hospital bed-days than quintile 1 [RR: 1.52; 90% confidence interval (CI): 1.05, 2.19] over 5 y. After accounting for the probability of hospitalization across the entire cohort, this corresponds to an estimated difference of 500,108 annual bed-days. The increased bed-day rate for nonalignment held across policy scenarios and a 10-y follow-up (RR: 1.34; 90% CI: 1.02,1.77). Sex-stratified models showed consistent directions, with stronger and significant associations for males at 10 y of follow-up (FOP-CI, RR: 1.50; 90% CI: 1.00, 2.25).

Conclusions: In this exploratory analysis, greater alignment with FOP policy was associated with a lower hospital bed-day rate over5 and 10 y. Sex-tailored risk-reduction strategies may be warranted with the strongest association in males. These findings reinforce the value of the "high-in" symbol; however, the nutrient-specific focus may still miss broader dimensions of diet quality. Complementary, whole-diet guidance remains essential to maximize population-level benefits and health-system savings.

Background: Consumer interest in grass-finished meat and plant-based meat alternatives is growing because of concerns about health and environmental sustainability. Although these options differ in nutrient composition, their acute effects on postprandial inflammation remain unclear.

Objectives: This study aimed to compare acute postprandial inflammatory responses after the consumption of grass-finished beef, a plant-based meat alternative, and grain-finished beef. Secondary outcomes included subjective measures of hunger, fullness, and thirst.

Methods: In a randomized crossover trial, 36 middle-aged adults [mean ± standard deviation (SD): 46.5 ± 8 y; 47% male, 53% female] with a body mass index (BMI) 25-35 kg/m² (mean ± SD: 29.6 ± 3) consumed 3 dietary interventions: ground grass-finished beef, plant-based meat alternative, and ground grain-finished beef. Blood was collected at baseline and multiple time points over 5 h after eating to measure C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Hunger, fullness, and thirst were assessed using visual analog scales. Data were analyzed using linear mixed models, adjusting for baseline inflammation.

Results: No significant differences in postprandial inflammatory markers were observed across interventions (P = 0.64). CRP increased slightly (+0.05 to +0.38 mg/L), TNF-α decreased moderately (-0.75 to -1.08 pg/mL), and IL-6 increased slightly (+1.29 to +1.92 pg/mL) across interventions (all P > 0.05). Exploratory analyses indicated a marginal association between age and inflammatory responses (P = 0.12), with no effects of BMI or sex (P = 0.60 and 0.56). Subjective ratings of hunger, fullness, and thirst did not differ between interventions.

Conclusions: Despite differences in nutrient composition, acute consumption of grass-finished beef, a plant-based meat alternative, and grain-finished beef did not elicit significantly different postprandial inflammatory responses. These findings suggest that, in the short term, the choice between these protein sources may not meaningfully impact inflammation. Further research is needed to explore potential long-term health implications.

Clinical trial registry: This was registered at https://clinicaltrials.gov/study/NCT05690061.