Alpha-linolenic acid (ALA) is inversely related to development of adiposity in school-age children

Differential Association of Dietary Linoleic Acid and Alpha-linolenic Acid with Adipose Tissue in a Sample of Iranian Adults; A Cohort-based Cross-sectional Study

BACKGROUND

Overweight and obesity are the most critical risk factors for chronic diseases. The quality of dietary fatty acids as one of the factors affecting fat accumulation has received little attention. This study investigates the association between dietary linoleic acid (LA) and alpha-linolenic acid (ALA) with body fat indices in a sample of healthy Iranian adults.

MATERIALS AND METHODS

In this cohort-based cross-sectional study, 3,195 individuals aged 20 to 60 who participated in the Shiraz University of Medical Science Employees Health Cohort study were included. Dietary intake was assessed using a validated 118-item Food Frequency Questionnaire (FFQ), and body composition was assessed by the bioelectrical impedance analysis method. Multiple linear regression adjusted for relevant confounders was used to determine the associations.

RESULTS

Mean dietary intake of LA was 14.20 ± 7.01 mg/day for men and 13.90 ± 6.71 mg/day for women. Additionally, the daily intake of ALA was 0.18 ± 0.18 mg/day in men and 0.17 ± 0.19 mg/day in women. Dietary intake of ALA for men had an inversely significant association with body fat mass (BFM) (β: -0.585, 95% CI: -1.137, -0.032, P=0.038), percentage of body fat (PBF) (β: -0.537, 95% CI: -0.945, -0.129, P=0.010), Visceral Fat Area (VFA) (β: -2.998, 95% CI: -5.695, -0.302, P=0.029), and Waist to Hip Ratio (WHR) (β: -0.689, 95% CI: -1.339, -0.040, P=0.038).

CONCLUSION

Higher dietary ALA intake was associated with lower BFM, BFP, VAF, and WHR in men. The present study confirms that ALA intake should be considered a preventive treatment to improve body composition. However, further research is recommended in this regard.

New Perspectives on the Associations between Blood Fatty Acids, Growth Parameters, and Cognitive Development in Global Child Populations

Malnutrition is prevalent in low-middle-income countries (LMICs), but it is usually clinically diagnosed through abnormal anthropometric parameters characteristic of protein energy malnutrition (PEM). In doing so, other contributors or byproducts of malnutrition, notably essential fatty acid deficiency (EFAD), are overlooked. Previous research performed mainly in high-income countries (HICs) shows that deficiencies in essential fatty acids (EFAs) and their n-3 and n-6 polyunsaturated fatty acid (PUFA) byproducts (also known as highly unsaturated fatty acids or HUFAs) lead to both abnormal linear growth and impaired cognitive development. These adverse developmental outcomes remain an important public health issue in LMICs. To identify EFAD before severe malnutrition develops, clinicians should perform blood fatty acid panels to measure levels of fatty acids associated with EFAD, notably Mead acid and HUFAs. This review demonstrates the importance of measuring endogenous fatty acid levels for measuring fatty acid intake in various child populations in LMICs. Featured topics include a comparison of fatty acid levels between global child populations, the relationships between growth and cognition and PUFAs and the possible mechanisms driving these relationships, and the potential importance of EFAD and HUFA scores as biomarkers of overall health and normal development.

Implications of Nutritional Management on Fatty Acid Profiles of Southern White Rhinoceroses (Ceratotherium simum simum) Housed at Two Zoological Institutions

Southern white rhinoceroses (Ceratotherium simum simum) are African megaherbivores that are considered near threatened by the International Union for the Conservation of Nature. The fatty acid circulating values of these animals have not been thoroughly investigated. Fatty acids are critical for immune, heart, skin, and reproductive health, and may have a significant impact on the management and conservation of this species. Published data on fatty acids in this species is limited to incomplete profiles with very few animals in managed environments. The objectives of this research were to provide novel fatty acid percentage profiles for managed healthy southern white rhinoceroses, as well as to provide comparisons between two zoological institutions with differences in diet and climate during two distinct pasture growth periods. Whole blood samples were collected as dried blood spots from six rhinoceroses at the North Carolina Zoo (NC Zoo) and five rhinoceroses at Busch Gardens Tampa (BGT) in the low growth period (February to April) of 2019 and during the high growth period (July to September) of 2020. Fatty acid results indicated numerous differences when comparing the institutions within the same growth period and when comparing the same institution between its two growth periods. Most noteworthy were the higher levels of α-linolenic acid (18:3w3) and total omega-3 fatty acids and the lower linoleic acid (18:2w6), total omega-6 fatty acids, and omega-6 to omega-3 ratio found in the BGT population in both growth periods. This study provides novel percentages of fatty acids in managed southern white rhinoceroses and data on how fatty acid profiles may be altered between two housing locations via dietary differences in hay type and quantity, pasture availability via season, and pellet inclusion levels.

Plasma lipids and growth faltering: A longitudinal cohort study in rural Gambian children

Growth faltering in children arises from metabolic and endocrine dysfunction driven by complex interactions between poor diet, persistent infections, and immunopathology. Here, we determined the progression of the plasma lipidome among Gambian children (n = 409) and assessed its association with growth faltering during the first 2 years of life using the panel vector autoregression method. We further investigated temporal associations among lipid clusters. We observed that measures of stunting, wasting, and underweight are dynamically associated with each other and that lipid groups containing polyunsaturated fatty acids (PUFAs) and phosphatidylcholines consistently predict future growth outcomes. Linear growth was dynamically associated with the majority of lipids, indicating a higher nutritional demand to improve height compared to weight among growth-restricted children. Our results indicate a critical role for PUFAs and choline in early life dietary interventions to combat the child growth faltering still so prevalent in low-income settings.

Effects of hemodialysis on blood fatty acids

Omega‐3 (n‐3) fatty acids have beneficial cardiovascular effects, perhaps also in chronic kidney disease (CKD) patients. A low omega‐3 index is an independent cardiovascular risk factor in end‐stage renal disease (ESRD) dialysis patients. However, the plasma measurements invariably ignore circulating blood cells, including the preponderant erythrocytes (RBCs). We measured fatty acids (HPLC‐MS lipidomics) in all components of the circulating blood, since RBC n‐3 fatty acid status has been linked to cardiovascular disease and mortality. We studied 15 healthy persons and 15 CKD patients undergoing regular hemodialysis treatments. While total fatty acid levels differed significantly in RBCs from healthy controls and CKD patients, the hemodialysis treatment had no effect on plasma or RBC fatty acid levels. No changes occurred in the percentage of eicosapentaenoic acid (C20:5 n‐3, EPA) and docosahexaenoic acid (C22:6 n‐3; DHA) (omega‐3 quotient) in RBC membrane fatty acids. Nonetheless, hemodialysis treatments increased plasma levels of various total fatty acids, namely C12:0, C14:0, C16:0, C20:2 n‐6, C20:4 n‐6, and C22:6 n‐3 (DHA), while plasma levels of free fatty acids were unchanged. These data suggest that despite significant changes in fatty acids signatures between healthy persons and CKD patients, hemodialysis does not alter RBC n‐3 fatty acid status, including the omega‐3 quotient. The dialysis treatment per se does not appear to be responsible for a lower omega‐3 index in CKD patients.

Metabolite Profiles of the Relationship between Body Mass Index (BMI) Milestones and Metabolic Risk during Early Adolescence

Early growth is associated with future metabolic risk; however, little is known of the underlying biological pathways. In this prospective study of 249 boys and 227 girls, we sought to identify sex-specific metabolite profiles that mark the relationship between age and magnitude of the infancy body mass index (BMI) peak, and the childhood BMI rebound with a metabolic syndrome z-score (MetS z-score) during early adolescence (median age 12.8 years). Thirteen consensus metabolite networks were generated between male and female adolescents using weighted correlation network analysis. In girls, none of the networks were related to BMI milestones after false discovery rate (FDR) correction at 5%. In boys, age and/or magnitude of BMI at rebound were associated with three metabolite eigenvector (ME) networks comprising androgen hormones (ME7), lysophospholipids (ME8), and diacylglycerols (ME11) after FDR correction. These networks were also associated with MetS z-score in boys after accounting for age and race/ethnicity: ME7 (1.43 [95% CI: 0.52, 2.34] units higher MetS z-score per 1 unit of ME7), ME8 (-1.01 [95% CI: -1.96, -0.07]), and ME11 (2.88 [95% CI: 2.06, 3.70]). These findings suggest that alterations in sex steroid hormone and lipid metabolism are involved in the relationship of early growth with future metabolic risk in males.

In utero exposure to gestational diabetes mellitus and cardiovascular risk factors in youth: A longitudinal analysis in the EPOCH cohort

OBJECTIVE

To examine associations of maternal gestational diabetes mellitus (GDM) with offspring cardiovascular biomarkers from late childhood through adolescence.

METHODS

We used mixed effects linear regression models to examine associations of maternal GDM (n = 92 cases of 597) with average offspring levels of serum lipids (total cholesterol, high-density lipoprotein [HDL], low-density lipoprotein [LDL], and triglycerides) and systolic blood pressure (SBP) across two research visits spanning approximately 10.6 and 16.9 years of age. In sex-stratified analysis, we evaluated the impact of adjustment for sociodemographic characteristics, pubertal status, physical activity and total energy intake, maternal body mass index (BMI), GDM treatment, and child's BMI.

RESULTS

After adjusting for child's age, pubertal status, race/ethnicity, and maternal education and smoking, GDM exposure was associated with higher total (0.38 [95% CI, 0.16-0.61] mmol/L) and LDL cholesterol (0.34 [95% CI, 0.14-0.53] mmol/L) in girls. These estimates were robust to adjustment for lifestyle characteristics and maternal BMI but were attenuated after accounting for GDM treatment with no appreciable change following further adjustment for current BMI. In boys, maternal GDM corresponded with 4.50 (1.90-7.10) mmHg higher SBP. This association persisted after accounting for sociodemographic/lifestyle characteristics, maternal BMI, and GDM treatment but was attenuated after adjusting for current BMI.

CONCLUSIONS

Maternal GDM is related to offspring lipid profile and SBP in a sex-specific manner.

Screening of potential biomarkers for Yin-deficiency-heat syndrome based on UHPLC-MS method and the mechanism of Zhibai Dihuang granule therapeutic effect

BACKGROUND

Yin-deficiency-heat (YDH) syndrome is a subhealth state of the individual, mainly manifested as oral ulcers, dry mouth, constipation, and other symptoms. Zhibai Dihuang granule (ZDG), as a classic traditional Chinese medicine, is effective in treating YDH syndrome. We screened the potential biomarkers for diagnosing YDH syndrome, and explored the mechanisms of the therapeutic effect of ZDG.

METHODS

Plasma samples from the Pinghe (PH, healthy control) group, the Shanghuo (SH, YDH syndrome) group, and the ZDG treated group (therapeutic group) were analyzed by using metabolomics profiling. The data were analyzed by multivariate statistical and bioinformatics analyses.

RESULTS

We screened four differential metabolites such as, decanoylcarnitine, dodecanoylcarnitine, phosphatidylcholine (PC), and Aspartate (Asp) Arginine (Arg) Proline (Pro) in the SH group and the PH group. The results showed that the combination of above four metabolites could serve as a potential biomarker for the early diagnosis of YDH syndrome. The metabolites decanoylcarnitine and glucose were found to be differentially expressed in the YDH syndrome group and tended to be normalized after ZDG treatment.

CONCLUSION

The increased levels of four differential metabolites (decanoylcarnitine, dodecanoylcarnitine, PC, and Asp Arg Pro) revealed that individuals with YDH syndrome may have increased energy metabolism in the body, which could lead to disorders of fatty acids β-oxidation and immune function. The levels of two differential metabolites including decanoylcarnitine and glucose returned to normal after ZDG treatment, indicating that ZDG could treat YDH syndrome by regulating glucose metabolism and fatty acids β-oxidation. Our study provides a new method for the diagnosis of YDH syndrome, and may provide theoretical basis for novel therapeutic strategies of YDH syndrome.

Food-Intake Normalization of Dysregulated Fatty Acids in Women with Anorexia Nervosa

Anorexia nervosa (AN) is a psychiatric disorder affected by psychological, environmental, and biological factors. Individuals with AN avoid high-fat, high-calorie diets and have shown abnormal metabolism of fatty acids (FAs), which are essential for brain and cognitive/neuropsychiatric health. To clarify the relationship between FAs and AN, fasting and postprandial plasma FAs in AN patients and age-matched control women were analyzed via mass-spectrometry. Clinical phenotypes were assessed using Becker Anxiety Inventory and Becker Depression Inventory. AN patients and controls exhibited different FA signatures at both fasting and postprandial timepoints. Lauric acid, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and alpha-linoleic acid (ALA) were higher in AN than in controls (lauric acid: 15,081.6 ± 14,970.2 vs. 8257.4 ± 4740.2 pmol/mL; ALA at fasting: 2217.7 ± 1587.6 vs. 1087.9 ± 821.2 pmol/mL; ALA at postprandial: 1830.9 ± 1115.6 vs. 1159.4 ± 664.7 pmol/mL. EPA: 33,788.3 ± 17,487.5 vs. 22,860.6 ± 12,642.4 pmol/mL; DPA: 32,664.8 ± 16,215.0 vs. 20,969.0 ± 12,350.0 pmol/mL. FDR-adjusted p-values < 0.05). Food intake and AN status modified the correlations of FAs with body mass index (BMI), depression, and anxiety. Desaturases SCD-18 and D6D showed lower activities in AN compared to controls. Altered FA signature, specifically correlations between elevated n-3 FAs and worsened symptoms, illustrate metabolic underpinnings in AN. Future studies should investigate the mechanisms by which FA dysregulation, specifically elevated n-3 FAs, affects AN risk and outcome.

Serum Polyunsaturated Fatty Acids in Middle Childhood and Body Mass Index Change Through Adolescence

BACKGROUND

Polyunsaturated fatty acids (PUFA) status in childhood may be associated with adiposity development.

OBJECTIVE

To assess associations of serum PUFA biomarkers in childhood with change in body mass index (BMI)-for-age Z scores (BMIZ) through adolescence.

METHODS

We quantified serum PUFA at ages 5 and 10 years among 418 children from Santiago, Chile. BMI was measured at 5, 10, and 16 years. We compared BMIZ change through age 16 years between quartiles of PUFA at 5 and 10 years and PUFA change 5-10 years by fitting growth curves from mixed effects models.

RESULTS

At age 5 years, serum docosahexaenoic acid was inversely associated with BMIZ change from ages 5 to 16 years. At age 10 years, arachidonic acid (AA) was nonlinearly positively related to BMIZ change from ages 10 to 16 years. Change in AA and the Δ5-desaturase (D5D) activity index between 5 and 10 years were each positively associated with BMIZ change from ages 10 to 16 years. Change in eicosapentaenoic acid was inversely associated with change in BMIZ.

CONCLUSIONS

Serum long-chain n-3 PUFA in middle childhood were associated with less BMI gain through adolescence, whereas AA and D5D activity was related to greater BMI gain.

Polyunsaturated fatty acids in middle childhood and externalizing and internalizing behavior problems in adolescence

BACKGROUND/OBJECTIVES

We sought to determine the associations of n-3 and n-6 polyunsaturated fatty acids (PUFA) in middle childhood with externalizing and internalizing behavior problems in adolescence.

SUBJECTS/METHODS

Using gas-liquid chromatography, we quantified n-3 and n-6 PUFA in serum samples of 444 Colombian schoolchildren aged 5-12 years at the time of enrollment into a cohort study. After a median 6 years, adolescent externalizing and internalizing behavior problems were determined with the Youth Self Report (YSR) questionnaire. We estimated adjusted mean behavior problem score differences with 95% confidence intervals (CIs) between quartiles of each PUFA using multivariable linear regression. We also considered as exposures the Δ6-desaturase (D6D) and Δ5-desaturase (D5D) enzyme activity indices.

RESULTS

Docosahexaenoic acid (DHA) was positively associated with externalizing problems; every standard deviation (SD) of DHA concentration was associated with an adjusted one unit higher externalizing problem score (95% CI: 0.1, 1.9). The D5D enzyme activity index was inversely related to externalizing problem scores. Alpha-linolenic acid concentration was positively associated with internalizing problem scores, whereas adrenic acid was inversely related to this outcome.

CONCLUSIONS

Serum PUFA in middle childhood were related to behavior problems in adolescence. Some of these associations might reflect the role of D5D enzyme activity.

Maximal exercise and erythrocyte fatty-acid status: a lipidomics study

Omega-3 fatty acids have long been ascribed a positive cardiovascular function. However, the plasma measurements invariably ignore 40% of the blood specimen, cells that engage in continuous exchange with their environment. In our study, we included all components of the circulating blood. Erythrocyte or red-blood-cell (RBC) n-3 fatty acid status has been linked to cardiovascular disease and death. A low omega-3 index is an independent risk factor for cardiovascular disease and mortality. We tested the hypothesis that acute, maximal exercise would influence the relationship between RBC and serum fatty acids. RBC fatty acids profiling was achieved using targeted HPLC-MS mass spectrometry. Healthy volunteers performed maximal treadmill exercise testing using the modified Bruce protocol. Central hemodynamics were monitored and maximal workload was assessed in metabolic equivalents (METs). Venous blood was obtained for RBC lipidomics. With the incremental exercise test, no fatty acid-level variations were found in RBCs, while heart rate and arterial blood pressure increased significantly. No changes occurred in the omega-3 quotient, namely the percentage of eicosapentaenoic acid and docosahexaenoic acid in RBC fatty acids in the RBC membrane. Nonetheless, maximal (13.50 ± 1.97 METs) exercise intensity led to a decrease of RBC lauric acid (C12:0) in the recovery period. These data suggest that despite significant hemodynamic effects, short-term maximal exercise is insufficient to alter RBC n-3 and other fatty-acid status, including the omega-3 quotient, in healthy individuals. RBC lauric acid deserves further scrutiny as a potential regulator of cardiovascular and metabolic functions.

Integrated analysis of transcriptomic and proteomic data from tree peony (P. ostii) seeds reveals key developmental stages and candidate genes related to oil biosynthesis and fatty acid metabolism

Tree peony (Paeonia section Moutan DC.) seeds are an excellent source of beneficial natural compounds that promote health, and they contain high levels of alpha-linolenic acid (ALA). In recent years, tree peony has been emerging as an oil crop. Therefore, combined analysis of the transcriptome and proteome of tree peony (P. ostii) seeds at 25, 32, 39, 53, 67, 81, 88, 95, and 109 days after pollination (DAP) was conducted to better understand the transcriptional and translational regulation of seed development and oil biosynthesis. A total of 38,482 unigenes and 2841 proteins were identified. A total of 26,912 differentially expressed genes (DEGs) and 592 differentially expressed proteins (DEPs) were clustered into three groups corresponding to the rapid growth, seed inclusion enrichment and conversion, and late dehydration and mature stages of seed development. Fifteen lipid metabolism pathways were identified at both the transcriptome and proteome levels. Pathway enrichment analysis revealed that a period of rapid fatty acid biosynthesis occurred at 53-88 DAP. Furthermore, 211 genes and 35 proteins associated with the fatty acid metabolism pathway, 63 genes and 11 proteins associated with the biosynthesis of unsaturated fatty acids (UFAs), and 115 genes and 24 proteins associated with ALA metabolism were identified. Phylogenetic analysis revealed that 16 putative fatty acid desaturase (FAD)-encoding genes clustered into four FAD groups, eight of which exhibited the highest expression at 53 DAP, suggesting that they play an important role in ALA accumulation. RT-qPCR analysis indicated that the temporal expression patterns of oil biosynthesis genes were largely similar to the RNA-seq results. The expression patterns of fatty acid metabolism- and seed development-related proteins determined by MRM were also highly consistent with the results obtained in the proteomic analysis. Correlation analysis indicated significant differences in the number and abundance of DEGs and DEPs but a high level of consistency in expression patterns and metabolic pathways. The results of the present study represent the first combined transcriptomic and proteomic analysis of tree peony seeds and provide insight into tree peony seed development and oil accumulation.

Sociodemographic, Anthropometric, and Dietary Predictors of Polyunsaturated Fatty Acids in Adipose Tissue Among Mesoamerican Children and Their Parents

BACKGROUND

Polyunsaturated fatty acid (PUFA) intake is low throughout Latin America. Improving PUFA status could be an effective intervention against chronic disease, but information on sociodemographic and dietary patterning of PUFA status in the region is limited.

OBJECTIVE

To characterize sociodemographic, anthropometric, and dietary predictors of PUFA status biomarkers in adipose tissue among children and their parents from Mesoamerica.

METHODS

This was a cross-sectional study of 220 children aged 7 to 12 years and 471 parents from capital cities of Guatemala, El Salvador, the Dominican Republic, Honduras, Nicaragua, Panama, Costa Rica, and Belize, as well as Tuxtla Gutiérrez in Mexico. The PUFA from gluteal adipose tissue was quantified using gas chromatography. Participants reported sociodemographic information and the type of vegetable oil used for cooking. We estimated percent mean differences in linoleic acid (LA), total long-chain n-6 PUFA (n-6 LCPUFA), α-linolenic acid (ALA), and total long-chain n-3 PUFA (n-3 LCPUFA) between levels of predictors using multivariable-adjusted linear regression models.

RESULTS

Country was the strongest predictor of any PUFA, whereas body mass index was positively associated with n-6 LCPUFA in children and adults. Cooking primarily with soybean oil was positively associated with LA in children and adults and ALA in adults. Cooking with canola oil was positively related to n-6 LCPUFA in adults and n-3 LCPUFA in children and adults. Cooking with palm oil was associated with low adipose tissue levels of all n-6 and n-3 PUFA.

CONCLUSIONS

Adipose tissue PUFA status in Mesoamerica is associated with country of origin and the type of oil used for cooking.

Rosa Mosqueta Oil Prevents Oxidative Stress and Inflammation through the Upregulation of PPAR-α and NRF2 in C57BL/6J Mice Fed a High-Fat Diet

Background: Rosa mosqueta (RM) oil is characterized by high concentrations of antioxidants and α-linolenic acid (ALA; 18:3n-3). We have previously demonstrated in male C57BL/6J mice that RM decreases hepatic steatosis, a condition strongly associated with oxidative stress and inflammation.Objective: We studied the molecular mechanisms that underlie the role of RM in preventing high-fat diet (HFD)-induced oxidative stress and inflammation.Methods: Male C57BL/6J mice aged 28 d and weighing 12-14 g were divided into the following groups and fed for 12 wk: control diet (CD; 10% fat, 20% protein, and 70% carbohydrates); CD + RM (1.94 mg ALA ⋅ g body weight^-1 ⋅ d^-1 administered by oral gavage); HFD (60% fat, 20% protein, and 20% carbohydrates); and HFD + RM. General parameters (body weight, visceral fat, and histology); glucose metabolism [homeostasis model assessment and blood glucose area under the curve (AUC)]; oxidative stress [hepatic nuclear factor (erythroid-derived 2)-like-2 (NRF2) and heme oxygenase 1 (HO-1) concentrations]; and inflammation [hepatic peroxisome proliferator-activated receptor α (PPAR-α) and acyl-coenzyme A oxidase 1 (ACOX1) concentrations, blood tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) concentrations, and Tnfa and Il1b mRNA expression in liver and visceral adipose tissue] were evaluated.Results: In the HFD + RM mice, the final body weight (24.8 ± 1.1 g) was 19% lower than in the HFD mice (30.6 ± 2.8 g) (P < 0.05). Visceral fat was 34% lower in the HFD + RM mice than in the HFD mice (P < 0.05). The blood glucose AUC was 29% lower and Tnfa and Il1b expression levels were 47% and 59% lower, respectively, in the HFD + RM mice than in the HFD mice (P < 0.05). HFD + RM mice had 40% less hepatic steatosis (P < 0.05) and lower upregulation of PPAR-α (33%), ACOX1 (50%), NRF2 (39%), and HO-1 (68%) protein concentrations than did the HFD mice (P < 0.05).Conclusions: Our findings suggest that RM supplementation prevents the obese phenotype observed in HFD-fed mice by downregulating inflammatory cytokine expression and secretion and stimulating hepatic antioxidant and fatty acid oxidation markers.

Alternating or continuous exposure to cafeteria diet leads to similar shifts in gut microbiota compared to chow diet

SCOPE

Overconsumption of energy-rich food is a major contributor to the obesity epidemic. The eating habits of many people are characterized by the cycling between overconsumption of energy-rich foods and dieting, the effects of which on the microbiota are currently unknown.

METHODS AND RESULTS

We compared the fecal microbiota of rats either continuously fed chow or palatable cafeteria diet to a "cycled" group switched between the two diets (chow for 4, cafeteria for 3 days/wk, n = 12/group) over 16 wk. Enriched bacterial metabolic pathways were predicted, and a range of metabolic parameters was correlated to microbial taxa and pathways. Cycled rats showed large excursions in food intake on each diet switch. When switched from chow to cafeteria, they overconsumed, and when switched back to chow they underconsumed relative to those maintained on the two diets. Metabolic parameters of cycled rats were intermediate between those of the other diet groups (p < 0.05). The microbiota of cycled rats was nearly indistinguishable from rats under constant cafeteria diet, and both groups were significantly different to the chow group. Correlation analyses identified microbial metabolic pathways associated with an obese phenotype.

CONCLUSION

These data suggest that continuous or intermittent exposure to palatable foods have similar effects on the gut microbiota.

Serum Trans Fatty Acids Are Not Associated with Weight Gain or Linear Growth in School-Age Children

BACKGROUND

Animal and human adult studies indicate that long-term intake of trans fatty acids (TFAs) may be associated with weight gain. High intake of fast foods and snacks, which are rich in TFAs, is linked to overweight status among school-age children. However, the specific effects of TFAs in this population are unknown.

OBJECTIVE

We examined whether serum TFAs, used as biomarkers of intake, are associated with faster weight gain and linear growth during school years.

METHODS

We quantified TFAs by GLC in serum samples of 668 children aged 5-12 y at the time of recruitment into an ongoing cohort study performed in Bogota (Colombia) since 2006. Serum proportions of trans palmitoleic acid (16:1t), trans oleic acid (18:1t), trans linoleic acid (18:2t), and total TFAs were used as biomarkers of intake. Anthropometric characteristics were measured periodically for a median of 30 mo. Body mass index-for-age z scores (BAZs) and height-for-age z scores (HAZs) were calculated with the use of the WHO reference. We estimated mean changes in BAZs and HAZs over follow-up according to quartiles of each TFA at baseline by using mixed-effects regression models with restricted cubic splines.

RESULTS

Proportions of trans palmitoleic acid, trans oleic acid, trans linoleic acid, and total TFAs (mean ± SD, % of total serum FAs), were 0.22 ± 0.06, 0.91 ± 0.37, 0.96 ± 0.27, and 2.10 ± 0.59, respectively. Serum TFAs were not associated with changes in BAZs and HAZs after adjusting for sex, baseline age, and socioeconomic status. In a subgroup analysis by sex, serum trans palmitoleic acid was positively associated with the estimated change in HAZs from ages 6 to 14 y in boys (with use of the first quartile as the reference, differences in HAZs for trans palmitoleic acid quartiles were 0.73, 0.53, and 0.70, P-trend = 0.03).

CONCLUSIONS

Proportions of serum TFAs, used as biomarkers of TFA intake, were not associated with weight gain in children aged 6-14 y in low- and middle-income populations in Bogota. The proportion of trans palmitoleic acid was positively associated with linear growth in boys. Longer follow-up and studies in diverse cohorts with wider ranges of TFA intake are warranted.

Higher Childhood Red Meat Intake Frequency Is Associated with Earlier Age at Menarche

BACKGROUND

Early age at menarche is associated with increased breast cancer risk. Red meat consumption in adolescence predicts breast cancer risk, but it is unknown whether it is also related to earlier menarche.

OBJECTIVE

We studied the association between intake of red meat at ages 5-12 y and age at menarche in a prospective study.

METHODS

We assessed usual diets with a food-frequency questionnaire in a group of 456 girls aged 8.4 ± 1.7 y and followed them for a median 5.6 y in Bogotá, Colombia. Girls were asked periodically about the occurrence and date of menarche. Median age at menarche was estimated with use of Kaplan-Meier survival probabilities by categories of red meat intake frequency. Cox proportional hazards models were used to compare the incidence of menarche by red meat intake frequency, adjusting for potential sociodemographic and dietary confounders including total energy intake and intake frequency of other animal food groups (dairy, poultry, freshwater fish, tuna/sardines, eggs, and innards).

RESULTS

Median age at menarche was 12.4 y. After adjustment for total energy intake, maternal parity, and socioeconomic status, red meat intake frequency was inversely associated with age at menarche. When compared with girls with red meat intake <4 times/wk, those consuming it ≥2 times/d had a significantly earlier age at menarche (HR: 1.64; 95% CI: 1.11, 2.41; P-trend = 0.0009). Incidentally, we found that girls with tuna/sardine intake >1 time/wk had a significantly later age at menarche (HR: 0.62; 95% CI: 0.42, 0.90; P = 0.01) than those with intake <1 time/mo. Intake frequency of other animal food groups was not significantly associated with age at menarche.

CONCLUSION

Higher red meat intake frequency during childhood is associated with an earlier age at menarche, whereas greater fatty fish intake frequency is associated with a later menarcheal age.