Nutrition Research最新文献

This study aimed to investigate the effects of prenatal docosahexaenoic acid (DHA) supplementation on pregnancy outcomes through a systematic review and meta-analysis. We hypothesized that prenatal DHA intake through supplements will improve pregnancy outcomes. Detailed literature search was performed using online databases such as PubMed, EMBASE, and Google Scholar till November 2022, to identify the randomized controlled trials (RCT) with maternal intake of DHA supplementation during the latter half of pregnancy compared to the placebo/control. Based on the inclusion and exclusion criteria, nine RCTs involving 5710 subjects were included. This meta-analysis showed that DHA supplementation (450-800 mg/day) was associated with a significantly higher birth weight of infants (Inverse variance [IV]: 101.71 [57.36-146.06] at 95% CI, P = .00001, I² = 0%), and fewer low birth weights (LBWs) (Mantel–Haenszel [M–H]: 0.53 [0.33-0.86] at 95% CI, P = .01, I² = 72%), with lesser but statistically insignificant pre-term births (PTB) (M–H: -0.02 [-0.04 to 0.00] at 95% CI, P = .07, I² = 0%) compared to the placebo. However, the DHA supplementation has no effect on gestational length (IV: -2.26 [-9.64 to 5.12] at 95% CI, P = .55, I² = 100%) compared to the placebo. In conclusion, the outcomes of this meta-analysis showed that prenatal DHA supplementation (450-800 mg/day) may reduce the risk of preterm births and increase infant birth weight.

Animal studies showed a detrimental effect of dietary branched chain amino acids (BCAAs) on metabolic health, while epidemiological evidence on dietary BCAAs and obesity is limited and inconclusive. We hypothesized that high dietary and circulating BCAAs are unfavorably associated with obesity in community-dwelling adults. We evaluated the 1-year longitudinal associations of dietary BCAA intake and circulating BCAAs with body fat measures. Body weight, height, and circumferences of the waist (WC) and hip (HC) were measured at baseline and again after 1-year. Body composition and liver fat [indicated by controlled attenuation parameter (CAP)] were also assessed after 1-year. Serum BCAA concentrations at baseline were quantified by liquid chromatography mass spectrometry. Diet was collected using 4 quarterly 3-day recalls during the 1-year. The correlation coefficients between dietary and serum BCAAs were 0.12 (P = .035) for total dietary BCAAs, and ranged from -0.02 (soy foods, P = .749) to 0.18 (poultry, P = .001). Total dietary BCAA intake was associated with increase in body weight (β = 0.044, P = .022) and body mass index (BMI, β = 0.047, P = .043). BCAAs from animal foods were associated with increase in HC, while BCAAs from soy foods were associated with weight gain and higher CAP (all P < .05). Serum BCAAs were associated with higher WC, HC, BMI, body fat mass, visceral fat level, and CAP (all P < .05). These results support that dietary and circulating BCAAs are positively associated with the risk of obesity. More cohort studies with validated dietary assessment tools and long-term follow-up among diverse populations are needed to confirm our findings.

Weight variations are common in sporting life, with important inter-individual variability in the degree of an athlete's habitual weight loss. As a part of the WAVE study (NCT04107545), the main objective of this preliminary study was to determine whether the habitual degree of weight loss was associated with anthropometric, body composition, nutritional or psychometric profiles during a period of weight maintenance in athletes accustomed to weight variations. We hypothesized that athletes accustomed to a higher habitual degree of weight loss may have a higher body weight and body fat mass, and may present a more controlled diet regimen and cognitive restriction than athletes with a lower habitual degree of weight loss. During a period of weight maintenance, 62 athletes (24.0 ± 5.3 years; 26 women) completed anthropometry and body composition measurements, a 48-hours food diary and self-reported questionnaires to determine their weight variation practice, nutritional profile and mood state. Athletes were stratified within inter- and intra-quartile groups according to their habitual degree of weight loss. Athletes with a higher habitual degree of weight loss were those who consumed more protein (P < .001) and less fat (P = .01) as a proportion of total energy compared with those losing less weight, without any difference in body composition between the groups. The rapid weight loss score was significantly higher in individuals losing more weight (P < .001) and no difference was observed for the mood state profile. The present results suggest a potential control of nutritional regulation during a period of weight maintenance in order to spare fat-free mass and favor fat mass loss in athletes who are routinely losing more weight. Fat-free mass may be the main nutritional driver due to low body fat mass in athletes, which may limit the “catch-up fat” phenomenon commonly observed in nonathletic population.

Yogurt consumption may help reduce chronic inflammation associated with obesity. However, the underlying mechanism(s) by which yogurt consumption modulates the immune system have not been validated in human intervention studies. We hypothesized that 4-week yogurt consumption (12 oz/day) attenuates systemic inflammation by modulating the proportion of circulating T helper (Th) 17 and regulatory T (Treg) cells in adult women with elevated body mass index (BMI). To test the hypothesis, we conducted a randomized crossover dietary intervention study consisted of a 4-week dietary intervention in which participants consumed 12 oz of either low-fat dairy yogurt or a soy pudding control snack per day, with a 4-week washout between treatments. Thirty-nine healthy adult women with a BMI between 25 and 40 kg/m² were enrolled and 20 completed the study. Changes in the biometrics, circulating T cells, and markers of systemic and colonic inflammation were assessed between the 2 treatment groups, as well as 24-hour diet recalls were conducted at baseline and following each treatment. The primary study outcome, the change in the proportion of circulating Th17 cells, was unaffected by the treatments. Secondary outcome measures, circulating Treg, Th17, and markers of chronic inflammation, were maintained by yogurt treatment, whereas circulating Treg was increased and interleukin-10 was reduced by control snack treatment. However, circulating Treg changes were not associated with changes to other biomarkers of inflammation, implying other immune cells and/or tissues may mediate circulating biomarkers of chronic inflammation. This study was approved by the University of Wisconsin-Madison institutional review board and registered at ClinicalTrials.gov NCT04149418.

Excess visceral adipose tissue (VAT) plays a crucial role in leading to obesity-related diseases. However, the association between fruit intake (excluding fruit juice) and VAT is not well-known. We aim to further explore this association in a large population. We hypothesized that higher intact fruit intake would be inversely associated with VAT. A total of 9582 adult participants from the National Health and Nutrition Examination Survey and the Food Patterns Equivalents Database 2011-2018 were included. Weighted linear regression models were utilized to evaluate the association between intact fruit intake (from two 24-hour dietary recalls) and VAT area (measured by dual-energy X-ray absorptiometry). Subgroup analysis was conducted to test the robustness of the results. Restricted cubic spline analysis was performed to find the nonlinear association. The median of intact fruit intake was 0.32 cup-equivalent (eq)/d, and the mean of VAT was 104.87 ± 1.23 cm². Intact fruit intake (increased by 1 cup-eq/d) demonstrated an inverse association with VAT area across three adjusted models, with β(95% confidence interval) values of –7(–8.49, –5.51), –6(–7.50, –4.51), and –3.02(–4.11, –1.94) in model 1, model 2, and model 3, respectively. Subgroup analysis revealed no interactions were found among age, sex, ethnicity, body mass index, and physical activity subgroups. Restricted cubic spline revealed the inverse association was more significant when intact fruit intake was less than 1.7 cups-eq/d. These findings suggest that increasing intact fruit consumption could be an effective public health strategy to mitigate VAT accumulation and associated health risks, advancing our understanding of dietary impacts on adiposity.

Colorectal cancer (CRC) is one of the leading causes of cancer-related death. Currently, dietary factors are being emphasized in the pathogenesis of CRC. There is strong evidence that fatty acids (FAs) and free FA receptors (FFARs) are involved in CRC. This comprehensive review discusses the role of FAs and their receptors in CRC pathophysiology, development, and treatment. In particular, butyrate and n-3 polyunsaturated fatty acids have been found to exert anticancer properties by, among others, inhibiting proliferation and metastasis and inducing apoptosis in tumor cells. Consequently, they are used in conjunction with conventional therapies. Furthermore, FFAR gene expression is down-regulated in CRC, suggesting their suppressive character. Recent studies showed that the FFAR4 agonist, GW9508, can inhibit tumor growth. In conclusion, natural as well as synthetic FFAR ligands are considered promising candidates for CRC therapy.

Type 2 diabetes mellitus negatively affects the immune system, resulting in reduced natural killer (NK) cell activity. Vitamin D has been shown to regulate innate and adaptive immune cells. However, the effects of vitamin D on NK cells remain inconclusive, especially in the context of diabetes. We hypothesized that dietary vitamin D₃ supplementation can enhance NK cell activity in diabetic mice. Therefore, we investigated the effects of dietary vitamin D₃ on NK cell activity in control and diabetic mice and explored the mechanisms of NK cell activity modulation by vitamin D₃. Control (CON) and diabetic mice (db/db) were randomly divided into 2 groups, then fed either a control diet (948 IU vitamin D₃/kg diet, vDC) or a diet supplemented with vitamin D₃ (9,477 IU vitamin D₃/kg diet, vDS) for 8 weeks. Diabetic mice exhibited lower NK cell activity than control mice. The vDS group had significantly higher NK cell activity than the vDC group in both control and diabetic mice. The vDS group had a higher percentage of CD11b single-positive NK cells than the vDC group (CON-vDS 34%; db/db-vDS 30%; CON-vDC 27%; db/db-vDC 22%). The intracellular expression of splenic TGF-β was significantly higher in the db/db group than in the CON group. Overall, vDS group had higher Bcl2 and Tbx21 mRNA expressions than the vDC group. In conclusion, the present study shows that NK cell activity is impaired under diabetic conditions, possibly due to the reduced percentage of mature NK cells. Moreover, NK activity is enhanced by dietary supplementation in both control and diabetic mice that may be associated with changes in the proportion of mature NK cells.