Serum antioxidant concentrations and metabolic syndrome are associated among U.S. adolescents in recent national surveys

Mechanistic insights on lycopene usage against diabetes and associated complications

Lycopene is a tetraterpene compound belonging to carotenoids that are widely present in tomatoes and similar products. It is known as a powerful anti-oxidant and a non-provitamin A carotenoid. Lycopene has been found to effectively improve diabetes mellitus and its complications, such as cardiac complications, disorders caused by oxidative stress, and liver and neurological disorders. Furthermore, free radicals have been shown to disrupt the action of insulin by changing the physical state of the target cell membrane, while carotenoids improve insulin secretion and function in blood sugar regulation by neutralizing free radicals. It, therefore, seems that targeted clinical studies are needed to investigate the therapeutic effect of lycopene against metabolic disorders induced by diabetes. This review aims to summarize information on the sources and potential uses of lycopene and the possible mechanisms involved in the reduction of the above diseases. Its protective effects, in terms of toxicity and safety, are also discussed. The literature sources used in this review were PubMed, Google Scholar, Scopus, and Web of Science databases.

The associations between serum carotenoids and hyperuricemia among U.S. National Health and Nutrition Examination Survey

BACKGROUND

Hyperuricemia is a risk factor for various metabolic disorders. We aimed to investigate the association between serum carotenoid levels and hyperuricemia using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

We conducted a cross-sectional analysis utilizing data from three specific NHANES cycles (2003-2004, 2005-2006, 2017-2018), containing the most complete serum carotenoid data from 12,253 participants aged 20 years and older. Serum carotenoids were quantified using high-performance liquid chromatography, while hyperuricemia was defined as serum uric acid levels ≥ 416 μmol/L (7.0 mg/dL) in men and ≥ 357 μmol/L (6.0 mg/dL) in women. Multivariable logistic regression models were employed to assess the relationship between carotenoids and hyperuricemia.

RESULTS

The mean age of participants was 50.1 ± 18.7 years, with a hyperuricemia prevalence of 20.5%. Higher serum carotenoids were associated with a lower prevalence of hyperuricemia, with each 1-unit increase in total carotenoids being inversely associated with hyperuricemia (odds ratio [OR] = 0.77, 95% confidence interval [CI]: 0.72-0.82) in multivariable analyses. Compared to participants with the lowest quartile, reduced ORs for hyperuricemia odds were observed for those with the highest quartile for total carotenoids (0.55 [0.47-0.64]), α-carotene (0.60 [0.52-0.71]), β-carotene (0.56 [0.48-0.65]), β-cryptoxanthin (0.58 [0.49-0.67]), trans-lycopene (0.75 [0.65-0.87]), cis-lycopene (0.83 [0.65-1.06]), total-lycopene (0.75 [0.64-0.87]), and lutein + zeaxanthin (0.66 [0.57-0.77]). Subgroup analyses indicated stronger associations among younger individuals, women, and those without any history of diabetes or cardiovascular disease.

CONCLUSIONS

Higher serum carotenoid levels are associated with reduced odds of hyperuricemia. These results underscore the potential role of carotenoids in managing hyperuricemia and its related health complications.

Association between serum carotenoids levels and endometriosis risk: evidence from the National Health and Nutrition Examination Survey

Background

The relationship between serum levels of carotenoids and endometriosis remains largely unknown. The aim of this study is to assess the association between serum levels of major carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, and trans-lycopene) and the risk of endometriosis in US women.

Methods

The data were obtained from the 2001-2006 National Health and Nutrition Examination Surveys (NHANES), which included a total of 3,636 women aged 20 to 54. Serum levels of α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, and trans-lycopene were measured using high performance liquid chromatography (HPLC) with photodiode array detection. Endometriosis was defined as self-report. Weighted multivariate logistic regression analyses were conducted to evaluate the associations of the serum levels of the major carotenoids with endometriosis risk. Additionally, restricted cubic spline (RCS) was employed to assess the possibility of nonlinear associations. Finally, subgroup analyses were utilized to estimate the influence of several covariates on the associations.

Results

Weighted multivariate logistic regression analyses showed that, after adjusting for all covariates taken into account, there was a significant association between serum lutein/zeaxanthin levels and reduced risk of endometriosis (Quartile 3 vs. Quartile 1: odds ratio [OR] = 0.62, 95% confidence interval [CI]: 0.42-0.90; Quartile 4 vs. Quartile 1: OR = 0.54, 95% CI: 0.36-0.81, P for trend = 0.001). However, no significant associations of serum levels of other carotenoids with endometriosis were found in multivariable-adjusted models that included all covariates. RCS analysis did not reveal any non-linear relationships. Subgroup analyses indicated that the inverse association between serum lutein/zeaxanthin levels and reduced endometriosis risk was significant only in individuals under 40 years of age, in both White and non-White populations, in smokers, and among those who had ever used oral contraceptives.

Conclusion

Serum lutein/zeaxanthin levels may offer protective effects against endometriosis in specific subpopulations. Further prospective research is necessary to validate these findings.

Inverse Relationship Between Serum Carotenoid Levels and Cardiovascular-Kidney-Metabolic Syndrome Among the General Adult Population

OBJECTIVE

To examine the relationship between serum carotenoid levels and cardiovascular-kidney-metabolic (CKM) syndrome in a representative sample of US adults.

METHODS

Data from the fasting subsample of the NHANES 2017-2018 were analyzed using a survey-weighted approach to ensure the findings are representative of the broader US adult population. Serum levels of α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, and lycopene were measured using high-performance liquid chromatography. CKM syndrome stages were defined according to the 2023 American Heart Association guidelines, with advanced CKM syndrome categorized as stages 3 or 4. Associations between serum carotenoids and advanced CKM syndrome were assessed using logistic regression and weighted quantile sum (WQS) regression.

RESULTS

The study included 1671 adults aged 20 years and older, with a mean age of 48.7 years and a gender distribution of 50.9% female and 49.1% male. Higher serum levels of α-carotene, β-carotene, α-cryptoxanthin, lutein/zeaxanthin, and lycopene were inversely associated with advanced CKM syndrome. Specifically, compared to the lowest quartile, the highest quartile of α-carotene had an odds ratio (OR) of 0.29 (95% CI: 0.16-0.55), β-carotene 0.35 (95% CI: 0.16-0.78), α-cryptoxanthin 0.23 (95% CI: 0.11-0.49), lutein/zeaxanthin 0.26 (95% CI: 0.14-0.48), and lycopene 0.58 (95% CI: 0.35-0.98). However, β-cryptoxanthin did not show a significant association. Moreover, the combined effect of all carotenoids was significantly negatively correlated with advanced CKM syndrome (OR = 0.67, 95% CI: 0.53-0.86), with lutein/zeaxanthin contributing the most (44.56%).

CONCLUSIONS

Elevated serum carotenoid levels are inversely associated with the prevalence of advanced CKM syndrome in a dose-dependent manner, with this association remaining consistent across diverse demographic and health subgroups.

Association of dietary and circulating antioxidant vitamins with metabolic syndrome: an observational and Mendelian randomization study

Aims

The objective of this study was to investigate the associations of dietary and circulating antioxidant vitamins with metabolic syndrome (MetS), and to assess causality using Mendelian randomization (MR).

Methods

This study included 10,308 participants from the National Health and Nutrition Examination Survey. The associations of vitamins A, C, E and carotenoids with MetS were assessed using multivariable weighted logistic regression analysis. Subsequently, the MR approach was employed to test the causal associations, with inverse variance weighted (IVW) serving as the primary analysis.

Results

Observationally, dietary vitamin A (OR=0.852, 95%CI: 0.727-0.999), C (OR=0.802, 95%CI: 0.675-0.952), carotene (OR=0.832, 95%CI: 0.706-0.982), and β-carotene (OR=0.838, 95%CI: 0.706-0.995) in quartile 4 had lower incidents of MetS, when compared to quartile 1. Circulating vitamin C and carotene were also present inversely associated with MetS, while the vitamin A and E both increased this risk. IVW-MR confirmed the associations of dietary vitamin A (OR=0.920, 95%CI: 0.861-0.984), vitamin C (OR=0.905, 95%CI: 0.836-0.979) and carotene (OR=0.918, 95%CI: 0.865-0.974) with MetS. However, there was only circulating β-carotene (OR=0.909, 95%CI: 0.857-0.965) was found to be causally associated with MetS.

Conclusions

Observational and MR studies have shown that adequate dietary intake of vitamin A, C and carotenoids may help to reduce the risk of MetS.

Sex and organ specific proteomic responses to vitamin C deficiency in the brain, heart, liver, and spleen of Gulo-/- mice

Recent advances in mass spectrometry have indicated that the water-soluble antioxidant vitamin C differentially modulates the abundance of various proteins in the hepatic tissue of female and male mice. In this study, we performed LC-MS/MS to identify and quantify proteins that correlate with serum vitamin C concentrations in the whole brain, heart, liver, and spleen tissues in mice deficient for the enzyme L-Gulonolactone oxidase required for vitamin C synthesis in mammals. This work shows for the first time that various biological processes affected by a vitamin C deficiency are not only sex specific dependent but also tissue specific dependent even though many proteins have been identified and quantified in more than three organs. For example, the abundance of several complex III subunits of the mitochondrial electron transport chain correlated positively with the levels of serum vitamin C only in the liver and not in the other tissues examined in this study even though such proteins were identified in all the organs analyzed. Western blot analyses on the Uqcrc1 and Uqcrfs1 complex III subunits validated the mass spectrometry results. Interestingly, the ferritin subunits represented the few quantified protein complexes that correlated positively with serum vitamin C in all the organs examined. Concomitantly, serum ferritin light chain 1 was inversely correlated with vitamin C levels in the serum. Thus, our study provides an initial comprehensive atlas of proteins significantly correlating with vitamin C in four organs in mice that will be a useful resource to the scientific community.

The Double-Edged Sword of Total Antioxidant Capacity: Clinical Significance and Personal Experience

Oxidative stress (OS) could be a condition underlying several human diseases, despite the physiological role of reactive oxygen species (oxidative eustress). Therefore, antioxidant compounds could represent a modulatory mechanism for maintaining a proper redox balance and redox signaling. When antioxidants are insufficient or overwhelmed, OS ensues, causing multiple damages at molecular, tissue, and cellular levels. This study focuses on the role of total antioxidant capacity (TAC) as a biomarker to be interpreted according to several clinical scenarios. After a brief description of various assay methods to elucidate terminology and physiopathological roles, we focus on the hormonal influence on TAC in blood plasma and other biological fluids, as different endocrine systems can modulate the antioxidant response. Furthermore, OS characterizes several endocrinopathies through different mechanisms: an inadequate antioxidant response to an increase in reducing equivalents (reductive distress) or a marked consumption of antioxidants (oxidative distress), which leads to low TAC values. An increased TAC could instead represent an adaptive mechanism, suggesting a situation of OS. Hence, the clinical context is fundamental for a correct interpretation of TAC. This review aims to provide the reader with a general overview of oxidative stress in several clinical examples of endocrine relevance, such as metabolic syndrome, non-thyroid illness syndrome, hypopituitarism, and infertility. Finally, the impact of dietary and surgical interventions on TAC in the model of metabolic syndrome is highlighted, along with personal experience.

The association between several serum micronutrients and benign prostatic hyperplasia: Results from NHANES 2003-2006

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common condition that affects the quality of life of older men. Specific micronutrients, including retinol, retinyl esters, carotenoids, vitamin E, and vitamin C, have antioxidant and anti-inflammatory properties. However, the correlation between serum concentrations of these micronutrients and BPH is unclear.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES), which included 2067 representative US men. BPH was assessed using the self-reported questionnaire. This association was explored by adjusting for confounders using multivariate logistic regression.

RESULTS

After fully adjusting for confounders, for every 0.01 μmol/L increase in serum retinyl esters, the risk of BPH increased by 2% (OR = 1.02; 95% CI: 1.01-1.03; p = 0.006). Based on the Bonferroni-corrected p-value, we found this correlation to be significant. One μmol/L increase in total carotenoids was associated with a 22% increase in BPH risk (OR = 1.22; 95% CI: 1.03-1.46; p = 0.025). By analyzing the correlation between different types of carotenoids and BPH, we also found that β-carotenoids (OR = 1.43; 95% CI: 1.03-1.99; p = 0.036) was also positively correlated with BPH. The subgroup analysis revealed a positive correlation between serum vitamin E (OR = 1.02; 95% CI: 1.00-1.04; p = 0.018) and BPH in men under 60 years of age. Serum retinyl ester (OR = 1.02; 95% CI: 1.01-1.04; p = 0.008) and carotenoid (OR = 1.52; 95% CI: 1.22-1.87; p < 0.001) concentrations were positively correlated with BPH in men over 60 years of age.

CONCLUSION

Our study suggests that excessive serum retinyl esters, total carotenoids, and especially β-carotenoids are potential risk factors for BPH, and this association should be further investigated.

A causal relationship between antioxidants, minerals and vitamins and metabolic syndrome traits: a Mendelian randomization study

BACKGROUND

The available evidence regarding the association of antioxidants, minerals, and vitamins with the risk of metabolic syndrome (MetS) traits is currently limited and inconsistent. Therefore, the purpose of this Mendelian randomization (MR) study was to investigate the potential causal relationship between genetically predicted antioxidants, minerals, and vitamins, and MetS.

METHODS

In this study, we utilized genetic variation as instrumental variable (IV) to capture exposure data related to commonly consumed dietary nutrients, including antioxidants (β-carotene, lycopene, and uric acid), minerals (copper, calcium, iron, magnesium, phosphorus, zinc, and selenium), and vitamins (folate, vitamin A, B6, B12, C, D, E, and K1). The outcomes of interest, namely MetS (n = 291,107), waist circumference (n = 462,166), hypertension (n = 463,010), fasting blood glucose (FBG) (n = 281,416), triglycerides (n = 441,016), and high-density lipoprotein cholesterol (HDL-C) (n = 403,943), were assessed using pooled data obtained from the most comprehensive genome-wide association study (GWAS) available. Finally, we applied the inverse variance weighting method as the result and conducted a sensitivity analysis for further validation.

RESULTS

Genetically predicted higher iron (OR = 1.070, 95% CI 1.037-1.105, P = 2.91E-05) and magnesium levels (OR = 1.130, 95% CI 1.058-1.208, P = 2.80E-04) were positively associated with increased risk of MetS. For each component of MetS, higher level of genetically predicted selenium (OR = 0.971, 95% CI 0.957-0.986, P = 1.09E-04) was negatively correlated with HDL-C levels, while vitamin K1 (OR = 1.023, 95% CI 1.012-1.033, P = 2.90E-05) was positively correlated with HDL-C levels. Moreover, genetically predicted vitamin D (OR = 0.985, 95% CI 0.978-0.992, P = 5.51E-5) had a protective effect on FBG levels. Genetically predicted iron level (OR = 1.043, 95% CI 1.022-1.064, P = 4.33E-05) had a risk effect on TG level.

CONCLUSIONS

Our study provides evidence that genetically predicted some specific, but not all, antioxidants, minerals, and vitamins may be causally related to the development of MetS traits.

Nutrient Patterns and Its Association and Metabolic Syndrome among Chinese Children and Adolescents Aged 7-17

This study was designed to explore the associations between nutrient patterns (NPs) and metabolic syndrome (MetS) and its five components among Chinese children and adolescents aged 7-17. The required data of participants were collected from the China National Nutrition and Health Surveillance of Children and Lactating Mothers in 2016-2017. Ultimately, 13,071 participants were included. Nutrient patterns were obtained by means of factor analysis. Multivariate logistic regression analysis was conducted to evaluate the association between nutrient patterns with MetS and its components. After adjusting covariates, the results of logistic regression models revealed that high-carbohydrate patterns were associated with the presence of abdominal obesity. The high-animal protein pattern was negatively associated with high triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C). The high-sodium-and-fat pattern had a negative relationship with elevated blood pressure (BP) and was positively associated with low HDL-C. The high-Vitamin D-and-Vitamin B₁₂ pattern had protective effects on MetS, high TG, and low HDL-C. Further large-scale longitudinal investigations are necessary in the future.

Antioxidative, Anti-Inflammatory, Anti-Obesogenic, and Antidiabetic Properties of Tea Polyphenols-The Positive Impact of Regular Tea Consumption as an Element of Prophylaxis and Pharmacotherapy Support in Endometrial Cancer

Endometrial cancer (EC) is second only to cervical carcinoma among the most commonly diagnosed malignant tumours of the female reproductive system. The available literature provides evidence for the involvement of 32 genes in the hereditary incidence of EC. The physiological markers of EC and coexisting diet-dependent maladies include antioxidative system disorders but also progressing inflammation; hence, the main forms of prophylaxis and pharmacotherapy ought to include a diet rich in substances aiding the organism’s response to this type of disorder, with a particular focus on ones suitable for lifelong consumption. Tea polyphenols satisfy those requirements due to their proven antioxidative, anti-inflammatory, anti-obesogenic, and antidiabetic properties. Practitioners ought to consider promoting tea consumption among individuals genetically predisposed for EC, particularly given its low cost, accessibility, confirmed health benefits, and above all, suitability for long-term consumption regardless of the patient’s age. The aim of this paper is to analyse the potential usability of tea as an element of prophylaxis and pharmacotherapy support in EC patients. The analysis is based on information available from worldwide literature published in the last 15 years.

Association of Serum Retinol Concentrations With Metabolic Syndrome Components in Iranian Children and Adolescents: The CASPIAN-V Study

Background

As a fat-soluble vitamin, vitamin A plays a crucial role in adipogenesis, lipolysis, insulin resistance, and obesity. However, it is still unclear whether they are associated with cardiometabolic risk factors in children and adolescents. The current study aimed to determine the association between serum retinol concentration and the cluster of metabolic syndrome components among children and adolescents.

Methods

This nationwide cross-sectional study was performed on 2,518 students aged 7–18 years from the Childhood and Adolescence Surveillance and Prevention of Adult Non- communicable disease (CASPIAN-V) study. Students were selected via multistage cluster sampling method from 30 provinces of Iran in 2015. Multivariable logistic regression was used to assess the association of serum retinol concentration with metabolic syndrome (MetS) components.

Results

Overall, the mean (SD) age of study participants was 12.16 (3.04) years, and 44.9% (n = 1,166) of them were girls. The mean serum retinol concentration was 1.48 ± 1.55 μmol/L and vitamin A deficiency was observed among 19.7% (95% CI: 18.2–21.3) of study subjects. The results of the logistic regression analysis showed that increasing serum retinol concentrations were associated with an increased likelihood of developing obesity (OR: 1.12, 95% CI: 1.04, 1.20), abdominal obesity (OR: 1.07, 95% CI: 1.01, 1.14), low high-density lipoprotein cholesterol (HDL-C) (OR: 1.10, 95% CI: 1.04, 1.16) and high fasting blood glucose (FBG) (OR: 1.21, 95% CI: 1.10, 1.35), whereas it was associated with a decreased odds of developing high blood pressure (OR: 0.82, 95% CI: 0.73, 0.93). Nevertheless, there was no statistically significant association between metabolic syndrome itself and retinol concentration (OR: 1.02, 95% CI: 0.88, 1.18).

Conclusion

We found that serum retinol concentration was positively associated with metabolic syndrome components such as obesity, low HDL-C, and high FBG, but not with metabolic syndrome itself.

Comparison between Egg Intake versus Choline Supplementation on Gut Microbiota and Plasma Carotenoids in Subjects with Metabolic Syndrome

We previously demonstrated that intake of three eggs/d for 4 weeks increased plasma choline and decreased inflammation in subjects with metabolic syndrome (MetS). The purpose of the current study was to further explore the effects of phosphatidylcholine (PC) provided by eggs versus a choline bitartrate (CB) supplement on the gut microbiota, trimethylamine N-oxide (TMAO) formation, and plasma carotenoids lutein and zeaxanthin in MetS. This randomized, controlled crossover clinical trial included 23 subjects with MetS. Following a washout period of 2 weeks without consuming any choline-containing foods, subjects were randomly allocated to consume either three eggs/d or a CB supplement for 4 weeks (both diets had a choline equivalent of 400 mg/day). DNA was extracted from stool samples to sequence the 16S rRNA gene region for community analysis. Operational taxonomic units (OTUs) and the α-diversity of the community were determined using QIIME software. Plasma TMAO, methionine, betaine, and dimethylglycine (DMG) were quantified by stable isotope dilution liquid chromatography with tandem mass spectrometry. Plasma carotenoids, lutein, and zeaxanthin were measured using reversed-phase high-performance liquid chromatography. There were significant increases in plasma lutein and zeaxanthin after egg intake compared to the baseline or intake of CB supplement (p < 0.01). In contrast, TMAO was not different between treatments compared to the baseline (p > 0.05). Additionally, while diet intervention had no effects on microbiota diversity measures or relative taxa abundances, a correlation between bacterial biodiversity and HDL was observed. Following egg intake, the observed increases in plasma lutein and zeaxanthin may suggest additional protection against oxidative stress, a common condition in MetS.

Serum β-carotene concentrations are associated with self-reported fatty acid intake in United States adults from the National Health and Examination Surveys

Bioavailability of dietary β‐carotene (BC) is dependent on dose, quantity, dispersion, and presence of fat in the diet. Fats are comprised of a variety of fatty acids, which may impact the bioavailability of carotenoids. However, there is a gap in research on whether specific fatty acid classes affect serum BC concentrations in population samples. The primary objective of this study was to assess the association between reported fat and fatty acid intake and serum BC concentrations utilizing data from the National Health and Nutrition Examination Surveys (NHANES) 2003–2006. Data from 3278 NHANES participants 20–85 years old were analyzed to estimate the relationships between serum BC concentrations and reported saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acid intakes. Multiple linear regression estimated ln(serum BC) based on reported fatty acid intakes adjusted for age, sex, race/ethnicity, and reported dietary BC intakes. Mean and standard error (SE) for serum BC concentrations were 14.31 ± 0.05 μg/dl. Means and SE for total fat, SFA, MUFA, and PUFA were 85.7 ± 1.3, 26.9 ± 0.4, 31.1 ± 0.5, and 17.8 ± 0.4 g, respectively. There was a significant trend for association between serum BC and reported total fat intakes (r = −0.002, p < 0.0001), but the association was not strong. Multiple linear regression showed positive associations between serum BC concentrations and higher reported dietary PUFA consumption. PUFA alpha‐linolenic acid intakes are positively associated with serum BC concentrations, while MUFA palmitoleic acid and SFA stearic acid were inversely associated with serum BC. The inverse association between MUFA and SFA suggests there may be multiple post‐digestion factors affecting serum carotenoid concentrations.

β-Carotene stimulates browning of 3T3-L1 white adipocytes by enhancing thermogenesis via the β3-AR/p38 MAPK/SIRT signaling pathway

BACKGROUND

Natural compounds with medicinal properties are part of a strategic trend in the treatment of obesity. The vitamin A agent, β-carotene, is a well-known carotenoid, and its numerous functions in metabolism have been widely studied. The activation of thermogenesis by stimulating white fat browning (beiging) has been identified as a treatment for obese individuals.

PURPOSE

The current study was undertaken to unveil the browning activity of β-carotene in 3T3-L1 white adipocytes.

METHODS

The effects of β-carotene were evaluated in 3T3-L1 white adipocytes, and gene/protein expressions were determined by performing quantitative real-time PCR, immunoblot analysis, immunofluorescence assessment, and molecular docking techniques.

RESULTS

β-carotene strikingly increased the expression levels of brown-fat-specific marker proteins (UCP1, PRDM16, and PGC-1α) and beige-fat-specific genes (Cd137, Cidea, Cited1, andTbx1) in 3T3-L1 cells. Exposure to β-carotene also elevated the expressions of key adipogenic transcription factors C/EBPα and PPARγ in white adipocytes but decreased the expressions of lipogenic marker proteins ACC and FAS. Moreover, lipolysis and fat oxidation were regulated by β-carotene via upregulation of ATGL, pHSL, ACOX, and CPT1. In addition, molecular docking studies revealed β-carotene activation of the adenosine A2A receptor and β3-AR. β-Carotene increased the expressions of mitochondrial biogenic markers, stimulated the β3-AR and p38 MAPK signaling pathways and its downstream signaling molecules (SIRTs and ATF2), thereby inducing browning.

CONCLUSIONS

Taken together, our results indicate the potential of β-carotene as a natural-source therapeutic anti-obesity agent.

Associations between Serum Vitamin A and Metabolic Risk Factors among Eastern Chinese Children and Adolescents

Vitamin A, a fat-soluble essential vitamin, is implicated in a large range of physiological processes. Up to now, the associations between vitamin A and metabolic syndrome (MetS) or other metabolic risk factors are controversial in children and adolescents. Thus, we aimed to dig into the relationship of vitamin A with MetS and many other metabolic risk factors. This was a cross-sectional study derived from the China National Nutrition and Health Surveillance of Children and Lactating Mothers. A total of 3025 school-aged (7–17 years) children and adolescents were selected by applying multistage stratified cluster random sampling methods in the Jiangsu Province of eastern China. Through enquiry survey, anthropometric measurement and laboratory examination, relevant information and blood biochemical indexes of the participants were collected in this study. MetS was identified according to the modified criteria of the National Cholesterol Education Program–Adult Treatment Panel III (NCEP-ATP III). Multivariate logistic analysis and the generalized additive model (GAM) were used to analyze the relationship between vitamin A and various metabolic risk factors. The overweight, obesity and MetS prevalence of children and adolescents in this study was 14.0%, 11.9% and 5.1%, respectively. The risk of prevalent MetS, general obesity, high low-density lipoprotein (LDL), high total cholesterol (TC) and hyperuricemia increased with vitamin A in a dose-dependent way. Logistic regression analysis showed that serum vitamin A Z scores were positively associated with MetS and central obesity, elevated blood pressure (BP) and elevated triglyceride (TG). Sex stratification analysis showed that both in male and female participants, the risk of prevalent MetS, general obesity, high LDL, high TC and hyperuricemia still increased with vitamin A levels. MetS was at a high prevalence level in children and adolescents in Jiangsu that were 7–17 years old. Vitamin A was positively associated with obesity, MetS, dyslipidemia and hyperuricemia. More public health measures and new visions should focus on the effects of retinol on children and adolescents.

Associations of Dietary and Circulating Vitamin E Level With Metabolic Syndrome. A Meta-Analysis of Observational Studies

Objective: The associations of dietary and circulating vitamin E level with metabolic syndrome (MetS) remains conflicting. This meta-analysis of observational study was therefore employed to investigate the issue above. Methods: The PubMed, Web of Science and Embase database were searched up to April 2021. The observational studies on the associations of dietary and circulating vitamin E level with MetS were specified. The pooled relative risk (RR) of MetS for the highest vs. lowest dietary and circulating vitamin E level, and the standard mean difference (SMD) of dietary and circulating vitamin E level for MetS vs. control subjects, were calculated. Results: A total of 25 observational studies with 51,276 participants, were included in this meta-analysis. The overall multi-variable adjusted RR demonstrated that the dietary vitamin E level was inversely associated with MetS (RR = 0.92, 95%CI: 0.85-1.00; P = 0.044). In addition, the dietary vitamin E level in MetS was also lower than that in control subjects according to the overall combined SMD (SMD = -0.08, 95%CI: -0.14 to -0.02; P = 0.024). On the other hand, the overall multi-variable adjusted RR showed no significant relationship between the circulating vitamin E level and MetS (RR = 1.46, 95%CI: 0.85-2.48; P = 0.17). However, the circulating vitamin E level in MetS was lower than that in control subjects according to the overall combined SMD (SMD = -0.58, 95%CI: -1.04 to -0.13; P = 0.013). Conclusions: The results of this meta-analysis suggest that the dietary vitamin E level is inversely associated with MetS. On the other hand, current evidence is still insufficient to conclude a relationship between the circulating vitamin E level and MetS. More well-designed prospective cohort studies are needed to address the issues further.

Vitamin C Differentially Impacts the Serum Proteome Profile in Female and Male Mice

A suboptimal blood vitamin C (ascorbate) level increases the risk of several chronic diseases. However, the detection of hypovitaminosis C is not a simple task, as ascorbate is unstable in blood samples. In this study, we examined the serum proteome of mice lacking the gulonolactone oxidase (Gulo) required for the ascorbate biosynthesis. Gulo^-/- mice were supplemented with different concentrations of ascorbate in drinking water, and serum was collected to identify proteins correlating with serum ascorbate levels using an unbiased label-free liquid chromatography-tandem mass spectrometry global quantitative proteomic approach. Parallel reaction monitoring was performed to validate the correlations. We uncovered that the serum proteome profiles differ significantly between male and female mice. Also, unlike Gulo^-/- males, a four-week ascorbate treatment did not entirely re-establish the serum proteome profile of ascorbate-deficient Gulo^-/- females to the optimal profile exhibited by Gulo^-/- females that never experienced an ascorbate deficiency. Finally, the serum proteins involved in retinoid metabolism, cholesterol, and lipid transport were similarly affected by ascorbate levels in males and females. In contrast, the proteins regulating serum peptidases and the protein of the acute phase response were different between males and females. These proteins are potential biomarkers correlating with blood ascorbate levels and require further study in standard clinical settings. The complete proteomics data set generated in this study has been deposited to the public repository ProteomeXchange with the data set identifier: PXD027019.

Vitamin C and Metabolic Syndrome: A Meta-Analysis of Observational Studies

Background: The association between vitamin C and metabolic syndrome (MetS) has been evaluated in several epidemiological studies with conflicting results. This meta-analysis was therefore employed to further investigate the above issue. Methods: The observational studies on the associations of dietary and circulating (serum and plasma) vitamin C levels with MetS were searched in the PubMed, Web of Science, and Embase database up to April 2021. The pooled relative risk (RR) of MetS for the highest vs. lowest dietary and circulating vitamin C levels and the standard mean difference (SMD) of dietary and circulating vitamin C levels for MetS vs. control subjects were calculated, respectively. Results: A total of 28 observational studies were identified in this meta-analysis. Specifically, 23 studies were related to the dietary vitamin C level. The overall multivariable-adjusted RR demonstrated that the dietary vitamin C level was inversely associated with MetS (RR = 0.93, 95% CI: 0.88-0.97; P = 0.003). Moreover, the overall combined SMD showed that the dietary vitamin C level in MetS was lower than that in control subjects (SMD = -0.04, 95% CI: -0.08 to -0.01; P = 0.024). With regard to the circulating vitamin C level, 11 studies were included. The overall multivariable-adjusted RR demonstrated that the circulating vitamin C level was inversely associated with MetS (RR = 0.60, 95% CI: 0.49-0.74; P < 0.001). In addition, the overall combined SMD showed that the circulating vitamin C level in MetS was lower than that in control subjects (SMD=-0.82, 95%CI: -1.24 to -0.40; P < 0.001). Conclusions: Current evidence suggests that both dietary and circulating vitamin C level is inversely associated with MetS. However, due to the limitation of the available evidence, more well-designed prospective studies are still needed.

Association between Dietary Lutein/Zeaxanthin Intake and Metabolic Syndrome among US Females: An Analysis of National Health and Examination Surveys 2015-2018

The prevalence of metabolic syndrome (MetS) is greater among US females than males, mainly due to higher risks of dyslipidemia and hyperglycemia. Lutein and zeaxanthin (L/Z) are carotenoids that can alter the composition of lipoproteins, which may affect components of MetS. However, little is known about the association between L/Z intake and MetS, especially in females. The purpose of this study was to explore the relation between dietary L/Z or dietary plus supplemental L/Z intakes and MetS in women (n = 630), aged 20-50 y, participating in the NHANES 2015-2018. Compared with the lowest quartile, women in the highest quartile of dietary L/Z intake had significantly lower risk of MetS after adjusting for confounders (OR = 0.46; 95% CI: 0.21, 0.98). No significant relation was noted between dietary plus supplemental L/Z intake and MetS. Future cohort studies should investigate the effects of L/Z on MetS development in women.

Towards a Consensus on Alzheimer's Disease Comorbidity?

Alzheimer's disease (AD) is often comorbid with other pathologies. First, we review shortly the diseases most associated with AD in the clinic. Then we query PubMed citations for the co-occurrence of AD with other diseases, using a list of 400 common pathologies. Significantly, AD is found to be associated with schizophrenia and psychosis, sleep insomnia and apnea, type 2 diabetes, atherosclerosis, hypertension, cardiovascular diseases, obesity, fibrillation, osteoporosis, arthritis, glaucoma, metabolic syndrome, pain, herpes, HIV, alcoholism, heart failure, migraine, pneumonia, dyslipidemia, COPD and asthma, hearing loss, and tobacco smoking. Trivially, AD is also found to be associated with several neurodegenerative diseases, which are disregarded. Notably, our predicted results are consistent with the previously published clinical data and correlate nicely with individual publications. Our results emphasize risk factors and promulgate diseases often associated with AD. Interestingly, the comorbid diseases are often degenerative diseases exacerbated by reactive oxygen species, thus underlining the potential role of antioxidants in the treatment of AD and comorbid diseases.

Association between serum Vitamin E concentrations and the presence of Metabolic Syndrome: A population-based cohort study

BACKGROUND

Metabolic syndrome (MetS) is a cluster of clinical and metabolic features that include central obesity, dyslipidemia, hypertension and impaired glucose tolerance. These features are accompanied by increased oxidative stress and impaired antioxidant defenses. Vitamin E is a major factor in the non-enzymatic antioxidant defenses. The aim of present study was to investigate the association between serum levels of vitamin E and the presence of MetS and its components in a sample population of Mashhad stroke and heart atherosclerotic disorder (MASHAD) cohort study.

METHODS

This cross-sectional study was carried out in 128 subjects with MetS and 235 subjects without MetS. MetS was defined according to the International-Diabetes-Federation criteria. Serum levels of vitamin E were measured using the HPLC method. Anthropometric and biochemical parameters were measured using standard protocols.  Results. MetS patients had significantly lower serum levels of vitamin E (Vit E), Vit E/Total cholesterol (TC), and Vit E/ (TC+triglyceride(TG)) compared to the control group (P < 0.05).  Vit E/ (TG+TC) was also significantly lower in diabetics or those with elevated levels of high sensitive C-reactive protein (hs-CRP). Additionally, there was a significant association between Vit E/ (TG + Total Cho) and the number of components of the metabolic syndrome (p= 0.02) Conclusions. There is a significant inverse association between indices of Vit E status and the presence of MetS. Moreover, a significantly lower Vit E/ (TC+TG) was observed along with individuals with increasing numbers of components of the MetS.

Carotenoids supplementation and inflammation: a systematic review and meta-analysis of randomized clinical trials

The aim of this study was to perform a systematic review and meta-analysis on randomized controlled trials investigating the effects of carotenoids on selected inflammatory parameters. PubMed, SCOPUS, and Web of science were searched from inception until April 2021. The random-effect model was used to analyze data and the overall effect size was computed as weighted mean difference (WMD) and corresponding 95% of confidence interval (CI). A total of 26 trials with 35 effect sizes were included in this meta-analysis. The results indicated significant effects of carotenoids on C-reactive protein (CRP) (WMD: ‒0.54 mg/L, 95% CI: ‒0.71, ‒0.37, P < 0.001), and interleukin-6 (IL-6) (WMD: ‒0.54 pg/mL, 95% CI: ‒1.01, ‒0.06, P = 0.025), however the effect on tumor necrosis factor-alpha (TNF-α) was not significant (WMD: ‒0.97 pg/ml, 95% CI: ‒1.98, 0.03, P = 0.0.059). For the individual carotenoids, astaxanthin, (WMD: ‒0.30 mg/L, 95% CI: ‒0.51, ‒0.09, P = 0.005), lutein/zeaxanthin (WMD: ‒0.30 mg/L, 95% CI: ‒0.45, ‒0.15, P < 0.001), and β-cryptoxanthin (WMD: ‒0.35 mg/L, 95% CI: ‒0.54, ‒0.15, P < 0.001) significantly decreased CRP level. Also, only lycopene (WMD: ‒1.08 pg/ml, 95%CI: ‒2.03, ‒0.12, P = 0.027) led to a significant decrease in IL-6. The overall results supported possible protective effects of carotenoids on inflammatory biomarkers.

Lipolytic Postbiotic from Lactobacillus paracasei Manages Metabolic Syndrome in Albino Wistar Rats

The current study investigates the capacity of a lipolytic Lactobacillus paracasei postbiotic as a possible regulator for lipid metabolism by targeting metabolic syndrome as a possibly safer anti-obesity and Anti-dyslipidemia agent replacing atorvastatin (ATOR) and other drugs with proven or suspected health hazards. The high DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS [2,2'-azino-bis (3-ethyl benzothiazoline-6-sulphonic acid)] scavenging activity and high activities of antioxidant enzyme such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-px) of the Lactobacillus paracasei postbiotic (cell-free extract), coupled with considerable lipolytic activity, may support its action against metabolic syndrome. Lactobacillus paracasei isolate was obtained from an Egyptian cheese sample, identified and used for preparing the postbiotic. The postbiotic was characterized and administered to high-fat diet (HFD) albino rats (100 and 200 mg kg^-1) for nine weeks, as compared to atorvastatin (ATOR; 10 mg kg^-1). The postbiotic could correct the disruption in lipid metabolism and antioxidant enzymes in HFD rats more effectively than ATOR. The two levels of the postbiotic (100 and 200 mg kg^-1) reduced total serum lipids by 29% and 34% and serum triglyceride by 32-45% of the positive control level, compared to only 25% and 35% in ATOR's case, respectively. Both ATOR and the postbiotic (200 mg kg^-1) equally decreased total serum cholesterol by about 40% and 39%, while equally raising HDL levels by 28% and 30% of the positive control. The postbiotic counteracted HFD-induced body weight increases more effectively than ATOR without affecting liver and kidney functions or liver histopathology, at the optimal dose of each. The postbiotic is a safer substitute for ATOR in treating metabolic syndrome.

Mixed carotenoid supplementation and dysmetabolic obesity: gaps in knowledge

Dysmetabolic obesity during childhood and adolescence currently represents one of the greatest therapeutic challenge for healthcare systems worldwide. The global rates of obesity have more than doubled in the last 30 years. Recent meta-analysis from national surveys and food composition studies suggest an inverse association between lower carotenoid levels and the prevalence of Metabolic Syndrome in the general population, independent of serum retinol (vitamin A) levels. In children, two double-blind randomised placebo-controlled studies describing the effects of diet vs. mixed carotenoid supplementation on insulin resistance, adipokines and the rate of accrual of subcutaneous abdominal fat, implicate supplementation of these compounds to achieve targetable levels may be useful in the management of obesity accrual in this population. We will discuss the role of carotenoids and their conversion products (retinoids) in adipogenesis, lipolysis, insulin resistance and the pathophysiology of the metabolic syndrome and review the animal studies, which help support these findings.

Multiple-element exposure and metabolic syndrome in Chinese adults: A case-control study based on the Beijing population health cohort

BACKGROUND

Metabolic syndrome (MetS) patients have a considerably increased risk for noncommunicable diseases, which poses a serious burden on public health. The effects of different elements on MetS have received increasing attention in the field of noncommunicable diseases over the past decade. These elements can exert adverse or favourable effects on human health by synergistic or antagonistic actions. Nevertheless, few studies have explored the relationship between multiple-element exposure and MetS.

METHOD

A total of 2095 MetS patients and 2039 controls free of major cardiovascular disease at baseline and follow-up visits were frequency matched for age (±5 years) and sex. The internal exposure levels of 15 elements in serum were investigated. Logistic regression models were employed to estimate odds ratios (ORs) of MetS for element concentrations categorized according to quartiles in the controls.

RESULT

Magnesium (Mg), selenium (Se), barium (Ba) and mercury (Hg) were significantly associated with MetS in the multi-element exposure model. The ORs for the extreme quartiles of Mg, Se, Ba, and Hg were 0.29 (95% CI: 0.23-0.37, P-trend < 0.001), 0.52 (95% CI: 0.42-0.65, P-trend < 0.001), 1.86 (95% CI: 1.51-2.28, P-trend < 0.001), and 2.61 (95% CI: 2.11-3.22, P-trend < 0.001), respectively. Ba may be antagonistic to Mg and Se in the human body.

CONCLUSIONS

Our study suggested that MetS was negatively associated with Mg and Se and positively associated with Ba and Hg. There were significant dose-response relationships between Mg, Se, Ba and Hg and the prevalence of MetS, suggesting that multiple elements may be involved in MetS.

Associations of Serum Retinol and α-Tocopherol Levels with Uric Acid Concentrations: Analysis of a Population-Based, Nationally Representative Sample

The effects of serum retinol and α-tocopherol on serum uric acid levels have not been established, especially in Asian people. This study evaluated the independent associations of retinol and α-tocopherol with serum uric acid levels in the Korean population. We included 6023 participants aged ≥ 19 years from the Korean National Health and Nutrition Examination Survey (KNHANES). Serum retinol and α-tocopherol levels were divided into quintiles, and a multivariate linear regression model was used to evaluate the association of serum retinol and α-tocopherol levels with uric acid concentration. Additionally, we used multivariate logistic regression to examine the relationships between the levels of these micronutrients and hyperuricemia. Serum retinol levels were positively associated with uric acid concentrations in a dose-dependent fashion in both sexes (p_trend < 0.001); the difference in serum uric acid levels between the highest and lowest quintiles of retinol levels was 0.57 mg/dL in men and 0.54 mg/dL in women. In the multivariable logistic model, the hyperuricemia risk increased linearly with the increase in serum retinol level, regardless of sex (p_trend < 0.001). Although the serum α-tocopherol level appeared to be significantly associated with increased uric acid levels, this association was nullified after adjusting for serum retinol levels. Serum retinol levels were positively associated with serum uric acid levels and hyperuricemia in a dose-response fashion. Maintaining serum retinol concentrations under sub-toxic levels might be necessary to prevent hyperuricemia-related adverse health outcomes.

Diet-derived nutrient patterns and components of metabolic syndrome: a cross-sectional community- based study

BACKGROUND

Metabolic syndrome (MetS) is one of the main public health problems worldwide. Although some relations between dietary intakes and MetS have been found, few studies have focused on association between dietary nutrients interactions and the risk of the MetS and its components. The aim of the present study was to examine the association between nutrient patterns and MetS and its components among Iranian adult population.

METHODS

A total of 588 subjects (aged 18-64 years, 271 males and 317 females) enrolled in the cross sectional study. Dietary consumption was evaluated using an 80-item food frequency questionnaire (FFQ). Biochemical assessments including fasting blood sugar (FBS), aspartate aminotransferase (AST), alanine amino transferase (ALT) and serum lipids were performed by enzymatic methods. Nutrient patterns were obtained by factor analysis procedure using principal component method. Multinational logistic regression analysis was used to evaluate the association between nutrient patterns and MetS and its components.

RESULTS

Three nutrient patterns explaining 53.66% of the variance in dietary nutrients intake, were recognized in the current study. Animal-sourced nutrient pattern was significantly associated with the higher odds of MetS and high triglyceride (TG) levels. Plant-sourced nutrient pattern (high intake of fiber, carbohydrate, vitamins B₆, B₃, C, B₁, E, D, magnesium, potassium, and linoleic acid) was significantly associated with lower risk of MetS and lower blood pressure (p < 0.05). Third nutrient pattern (mixed-source) was significantly related to higher risk of MetS, high waist circumference (WC) and high systolic blood pressure (SBP).

CONCLUSION

This present study confirms the important effect of nutrients and their patterns on MetS risk. Our results suggest that adherence to the nutrient pattern rich in fiber, carbohydrate, vitamins D, B₆, B₃, C, B₁, E, magnesium, potassium, linoleic acid, and docosahexaenoic acid (DHA) is associated with a lower risk of MetS, while animal- and mixed-sourced nutrient patterns are positively associated with greater odds of MetS; However, further longitudinal and interventional studies are required to make a clear conclusion.

Carotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis

Context

Modifiable factors that reduce the burden of the metabolic syndrome (MetS), particularly plant-derived biomarkers, have been a recent focus of rising interest.

Objective

This systematic review and meta-analysis, which follows PRISMA guidelines, evaluates evidence from a period of 20 years that links vitamin A and carotenoids with the occurrence of MetS and following the PRISMA guidelines.

Data Sources

PubMed and Cochrane databases (January 1997 through March 2017) were systematically assessed for studies, including case-control, cross-sectional, and cohort studies, that evaluated the associations of MetS with carotenoids and retinyl esters and retinol (vitamin A).

Data Extraction

Key measures of associations were harmonized into odds ratios (ORs) and 95% confidence intervals (95%CI) of MetS per 1 standard deviation (SD) of exposure using forest plots and random effects models that pooled data points from 11 cross-sectional studies. Begg's funnel and harvest plots were constructed.

Results

An inverse association between total carotenoids and MetS was found [ORpooled, 0.66; 95%CI, 0.56-0.78; 1 SD ∼ 0.82 µmol/L; n = 5 studies]. This association was the strongest for β-carotene, followed by α-carotene and β-crypotoxanthin. No association was detected between retinol and MetS (ORpooled, 1.00; 95%CI, 0.88-1.13; 1 SD ∼ 2.14 µmol/L; n = 6 studies). Publication bias was absent, and harvest plots indicated consistency upon replication for β-carotene and total carotenoid exposures.

Conclusions

This review and meta-analysis suggests that, unlike retinol, total and individual carotenoids were inversely related to MetS.

Vitamin C: A Review on its Role in the Management of Metabolic Syndrome

Oxidative stress and inflammation are two interlinked events that exist simultaneously in metabolic syndrome (MetS) and its related complications. These pathophysiological processes can be easily triggered by each other. This review summarizes the current evidence from animal and human studies on the effects of vitamin C in managing MetS. In vivo studies showed promising effects of vitamin C, but most of the interventions used were in combination with other compounds. The direct effects of vitamin C remain to be elucidated. In humans, the current state of evidence revealed that lower vitamin C intake and circulating concentration were found in MetS subjects. A negative relationship was observed between vitamin C intake / concentration and the risk of MetS. Oral supplementation of vitamin C also improved MetS conditions. It has been postulated that the positive outcomes of vitamin C may be in part mediated through its anti-oxidative and anti-inflammatory properties. These observations suggest the importance of MetS patients to have an adequate intake of vitamin C through food, beverages or supplements in order to maintain its concentration in the systemic circulation and potentially reverse MetS.

Vitamins in diet of patients with metabolic syndrome

Aim - analysis of data on the role of vitamin and carotenoid deficiency in the development of metabolic syndrome (MS), the consumption of individual vitamins and vitamin supplements, as well as estimation of the effectiveness of the use of vitamins in patients with MS. A review of the existing literature has been carried out in the databases of RINC, CyberLeninka, Google Scholar, Pubmed. The lack of vitamins is a risk factor for MS and its components. The diet of people with MS is characterized by excessive caloric content and at the same time contains an inadequate amount of most vitamins. The most frequent in patients with MS is the deficiency (blood level) of vitamin D, E, B vitamins, carotenoids. Among patients with MS, individuals with a reduced concentration of vitamins in the blood plasma are often found. In turn, among those with a deficiency of vitamins, MS is more often found. Low concentrations of 25(OH)D in the serum are associated with an increased risk of MS. An inverse association between the concentration of the hormonal form of vitamin 1.25(OH)2D3 in the serum and the development of MC has been found. In patients with MS, the α-tocopherol concentration associated with lipids is lower than in healthy individuals, and γ-tocopherol, on the contrary, is higher. Taking high doses of one of the vitamin E homologues shifts the balance between tocopherols in the blood plasma. Sufficient supply of the body with all vitamins involved in the formation of metabolically active forms of vitamins (D, B6, PP) is a necessary condition for the exercise of these biological functions by these vitamins. The lack of vitamins is a risk factor for MS and its components. Enrichment of the diet of patients with MS should be considered as a necessary favorable background for its treatment. Since the body has functional connections between vitamins, it is advisable to use not individual vitamins, but their complexes.

The antioxidant status of coenzyme Q10 and vitamin E in children with type 1 diabetes

OBJECTIVE

The purpose of this study was to evaluate the antioxidant status of plasma vitamin E and plasma and intracellular coenzyme Q10 in children with type 1 diabetes.

METHOD

This case-control study was conducted on 72 children with type 1 diabetes and compared to 48 healthy children, who were age, sex, and ethnicity-matched. The diabetic children were divided according to their glycosylated hemoglobin (A1c %) into two groups: poor and good glycemic control groups. All children underwent full history taking, clinical examination, and laboratory measurement of complete blood count, A1c %, plasma cholesterol, triglycerides, and vitamin E levels and coenzyme Q10 levels in plasma, erythrocytes, and platelets.

RESULTS

Children with poor glycemic control showed significantly higher plasma vitamin E, coenzyme Q10, triglycerides, low-density lipoproteins, waist circumference/height ratio, cholesterol levels, and lower high-density lipoproteins and platelet coenzyme Q10 redox status in comparison to those with good glycemic control and the control group (p<0.05). Plasma coenzyme Q10 showed a positive correlation with the duration of type 1 diabetes, triglycerides, cholesterol, vitamin E, and A1c %, and negative correlation with the age of the diabetic group (p<0.05). The platelet redox status showed a negative correlation with the A1c % levels (r=-0.31; p=0.022) and the duration of type 1 diabetes (r=-0.35, p=0.012).

CONCLUSION

Patients with type 1 diabetes, especially poorly controlled, had elevation of plasma vitamin E and coenzyme Q10 levels and decreased platelet redox status of coenzyme Q10, which may be an indicator of increased oxidative stress.

A modified Mediterranean diet score is inversely associated with metabolic syndrome in Korean adults

BACKGROUND/OBJECTIVES

Findings from studies in Western countries showed that Mediterranean diet is inversely associated with metabolic syndrome, but little is known about this association in Asian countries. To evaluate the association between Mediterranean diet and metabolic syndrome in Korean population, this study was conducted.

SUBJECTS/METHODS

A total of 8387 adults 19-64 years of age from the Korea National Health and Nutrition Examination Survey 2012-2015 were assessed. A 112-item dish-based semiquantitative food frequency questionnaire was used to assess dietary intakes. Mediterranean diet was assessed by a modified Mediterranean diet score, which was based on the alternate Mediterranean diet score of Fung et al. Multivariable logistic regression models were used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) adjusted for other dietary and lifestyle variables.

RESULTS

Participants with 5-6 and 7 or higher modified Mediterranean diet scores had a lower prevalence of metabolic syndrome by 27% (OR = 0.73, 95% CI: 0.56-0.96) and 36% (OR = 0.64, 95% CI: 0.46-0.89; P-trend = 0.0031), compared with those with 2 or lower modified Mediterranean diet scores, respectively. Higher modified Mediterranean diet scores were associated with a lower prevalence of abdominal obesity and hypertriglyceridemia, which are components of metabolic syndrome CONCLUSIONS: Our findings suggest that diet rich in fruit, vegetables, whole grains, legumes, peanuts and fish is associated with a lower prevalence of metabolic syndrome in Korean adults.

Disturbed Vitamin A Metabolism in Non-Alcoholic Fatty Liver Disease (NAFLD)

Vitamin A is required for important physiological processes, including embryogenesis, vision, cell proliferation and differentiation, immune regulation, and glucose and lipid metabolism. Many of vitamin A’s functions are executed through retinoic acids that activate transcriptional networks controlled by retinoic acid receptors (RARs) and retinoid X receptors (RXRs).The liver plays a central role in vitamin A metabolism: (1) it produces bile supporting efficient intestinal absorption of fat-soluble nutrients like vitamin A; (2) it produces retinol binding protein 4 (RBP4) that distributes vitamin A, as retinol, to peripheral tissues; and (3) it harbors the largest body supply of vitamin A, mostly as retinyl esters, in hepatic stellate cells (HSCs). In times of inadequate dietary intake, the liver maintains stable circulating retinol levels of approximately 2 μmol/L, sufficient to provide the body with this vitamin for months. Liver diseases, in particular those leading to fibrosis and cirrhosis, are associated with impaired vitamin A homeostasis and may lead to vitamin A deficiency. Liver injury triggers HSCs to transdifferentiate to myofibroblasts that produce excessive amounts of extracellular matrix, leading to fibrosis. HSCs lose the retinyl ester stores in this process, ultimately leading to vitamin A deficiency. Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and is a spectrum of conditions ranging from benign hepatic steatosis to non-alcoholic steatohepatitis (NASH); it may progress to cirrhosis and liver cancer. NASH is projected to be the main cause of liver failure in the near future. Retinoic acids are key regulators of glucose and lipid metabolism in the liver and adipose tissue, but it is unknown whether impaired vitamin A homeostasis contributes to or suppresses the development of NAFLD. A genetic variant of patatin-like phospholipase domain-containing 3 (PNPLA3-I148M) is the most prominent heritable factor associated with NAFLD. Interestingly, PNPLA3 harbors retinyl ester hydrolase activity and PNPLA3-I148M is associated with low serum retinol level, but enhanced retinyl esters in the liver of NAFLD patients. Low circulating retinol in NAFLD may therefore not reflect true “vitamin A deficiency”, but rather disturbed vitamin A metabolism. Here, we summarize current knowledge about vitamin A metabolism in NAFLD and its putative role in the progression of liver disease, as well as the therapeutic potential of vitamin A metabolites.

Nutrient-Derived Dietary Patterns and Their Association With Metabolic Syndrome in a Japanese Population

Background

Nutrients have been proposed to be related to metabolic syndrome (MetS). The aims of this study were to identify dietary patterns that correlated with several nutrients using reduced rank regression (RRR) and to examine the association between extracted dietary patterns and prevalence of MetS in a Japanese population.

Methods

The study population comprised 1,092 Japanese men and women (35–69 years old) who had participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study in Tokushima Prefecture. Dietary patterns were derived with RRR using 46 food items as predictors and six established nutrients (potassium, calcium, vitamin D, vitamin C, insoluble dietary fiber, and carotene) as response variables. Associations between extracted dietary patterns and MetS were then examined with logistic regression models.

Results

Among the six dietary patterns, dietary pattern 1 (DP1) explained the largest proportion (60.1%) of variance in the six nutrients. Therefore, only DP1 was selected for further analysis. DP1 was characterized by high intake frequency of vegetables, fruits, fish and small fish, natto (fermented soybeans), and deep-fried tofu. After adjustment for potential confounders, significant inverse associations were found between DP1 score and MetS (odds ratio [OR] for each quartile: 1.00, 0.58, 0.60, 0.52; P_trend = 0.02); DP1 and high blood pressure (P_trend = 0.0002); and DP1 and high blood glucose (P_trend = 0.02).

Conclusion

A dietary pattern characterized by high intake of vegetables, fruits, fish and small fish, natto, and deep-fried tofu was associated with reduced prevalence of MetS in a Japanese population.

β-Carotene Concentration and Its Association with Inflammatory Biomarkers in Spanish Schoolchildren

AIM

To examine the correlation between inflammatory biomarkers and plasma β-carotene levels in children.

METHODS

A total of 564 Spanish schoolchildren aged 9-12 were observed and studied. Plasma β-carotene levels were assessed by HPLC. A β-carotene level <4.83 µg/dL (0.09 µmol/L) was considered deficient. Plasma tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by immunoenzyme assays. Serum high-sensitivity C-reactive protein (hs-CRP) was tested by immunonephelometry.

RESULTS

Subjects who were β-carotene-deficient (23.1% of the studied children) had higher IL-6 levels than subjects with normal β-carotene concentrations. The log-IL-6 and log-hs-CRP concentrations, but not the log-TNF-α level, were strongly and inversely related to the plasma log-β-carotene level (taking into account log-age, energy intake, log-triglycerides, gender, log-body mass index, log-β-carotene intake, energy from lipids and cholesterol as covariables). When the 3 inflammatory biomarkers were introduced into the regression model along with the corresponding covariables, only the log-IL-6 level was related to the plasma log-β-carotene level (β = -0.505 ± 0.078; p < 0.001).

CONCLUSIONS

Inflammatory status, in particular IL-6 levels, appears to be negatively associated with plasma β-carotene levels in schoolchildren.

Effects of Mixed Carotenoids on Adipokines and Abdominal Adiposity in Children: A Pilot Study

CONTEXT

Carotenoids have been implicated in the regulation of adipocyte metabolism.

OBJECTIVE

To compare the effects of mixed-carotenoid supplementation (MCS) versus placebo on adipokines and the accrual of abdominal adiposity in children with obesity.

DESIGN AND SETTING

Randomized (1:1), double-blind, placebo-controlled intervention trial to evaluate the effects of MCS over 6 months in a subspecialty clinic.

PARTICIPANTS

Twenty (6 male and 14 female) children with simple obesity [body mass index (BMI) > 90%], a mean age (± standard deviation) of 10.5 ± 0.4 years, and Tanner stage I to V were enrolled; 17 participants completed the trial.

INTERVENTION

MCS (which contains β-carotene, α-carotene, lutein, zeaxanthin, lycopene, astaxanthin, and γ-tocopherol) or placebo was administered daily.

MAIN OUTCOME MEASURES

Primary outcomes were change in β-carotene, abdominal fat accrual (according to magnetic resonance imaging), and BMI z-score; secondary outcomes were adipokines and markers of insulin resistance.

RESULTS

Cross-sectional analysis of β-carotene showed inverse correlation with BMI z-score, waist-to-height ratio, visceral adipose tissue, and subcutaneous adipose tissue (SAT) at baseline. MCS increased β-carotene, total adiponectin, and high-molecular-weight adiponectin compared with placebo. MCS led to a greater reduction in BMI z-score, waist-to-height ratio, and SAT compared with placebo. The percentage change in β-carotene directly correlated with the percentage change in SAT.

CONCLUSIONS

The decrease in BMI z-score, waist-to-height ratio, and SAT and the concomitant increase in the concentration of β-carotene and high-molecular-weight adiponectin by MCS suggest the putative beneficial role of MCS in children with obesity.

Vitamin C modulates the metabolic and cytokine profiles, alleviates hepatic endoplasmic reticulum stress, and increases the life span of Gulo-/- mice

Suboptimal intake of dietary vitamin C (ascorbate) increases the risk of several chronic diseases but the exact metabolic pathways affected are still unknown. In this study, we examined the metabolic profile of mice lacking the enzyme gulonolactone oxidase (Gulo) required for the biosynthesis of ascorbate. Gulo^−/− mice were supplemented with 0%, 0.01%, and 0.4% ascorbate (w/v) in drinking water and serum was collected for metabolite measurements by targeted mass spectrometry. We also quantified 42 serum cytokines and examined the levels of different stress markers in liver. The metabolic profiles of Gulo^−/− mice treated with ascorbate were different from untreated Gulo^−/− and normal wild type mice. The cytokine profiles of Gulo^−/− mice, in return, overlapped the profile of wild type animals upon 0.01% or 0.4% vitamin C supplementation. The life span of Gulo^−/− mice increased with the amount of ascorbate in drinking water. It also correlated significantly with the ratios of serum arginine/lysine, tyrosine/phenylalanine, and the ratio of specific species of saturated/unsaturated phosphatidylcholines. Finally, levels of hepatic phosphorylated endoplasmic reticulum associated stress markers IRE1α and eIF2α correlated inversely with serum ascorbate and life span suggesting that vitamin C modulates endoplasmic reticulum stress response and longevity in Gulo^−/− mice.

Nutrient patterns and their relationship to metabolic syndrome in Iranian adults

BACKGROUND

The prevalence of metabolic syndrome (MetS) is increasing globally. It is associated with a significant risk of developing type 2 diabetes mellitus and cardiovascular disease.

MATERIALS AND METHODS

The relationship between adherence to several different dietary patterns and the presence of MetS was explored in an Iranian population sample of 5764 subjects.

RESULTS

We observed that the prevalence of MetS was 13% and 18% in men and women, respectively. There were three main dietary patterns: the first pattern was characterized by protein, carbohydrate, starch, glucose, fructose, sucrose, maltose, dietary fibre, potassium, calcium, magnesium, phosphorus, iron, zinc, manganese, thiamine, riboflavin, carotene, vitamin c and lactose; second representative of fat, saturated fat, monounsaturated fat, polyunsaturated fat, cholesterol, sodium, calcium, zinc, phosphorus, iodine, vitamin D, chloride, betaine, niacin; third consisting of copper, selenium, vitamin A, riboflavin, vitamin B12. In this dietary pattern, individuals in first quintile had a higher consumption of total fat, saturated fatty acid, monounsaturated fatty acid, polyunsaturated fatty acid, cholesterol and vitamin A. In the second pattern, individuals in the fifth quintile ate less carbohydrate, dietary fibre, glucose, Fructose, potassium compared to first quintile. We found that individuals in the first quintile in pattern 3 had higher intakes of protein, zinc and calcium compared to other quintiles.

CONCLUSIONS

We have found that a nutrient pattern which mostly characterized by dietary protein, carbohydrate, starch, glucose, fructose, sucrose, maltose was associated with a higher risk of MetS in both genders, while a pattern which was represent of copper, selenium, Vitamin A, riboflavin, vitamin B12 was associated with greater odds of Mets, in women.

Optimised extraction of β-carotene from Spirulina platensis and hypoglycaemic effect in streptozotocin-induced diabetic mice

BACKGROUND

Spirulina platensis is rich in β-carotene, which possesses many important biological activities. This study investigated the ultrasound-assisted extraction and purification of β-carotene from Spirulina platensis by using response surface methodology (RSM), determined its antioxidant capacity in vitro and explored its hypoglycaemic effect in diabetic mice.

RESULTS

The raw β-carotene extract with a concentration of 1942.14 ± 10.03 µg mL(-1) was obtained at the optimised condition by RSM (0.40 of the solid-liquid ratio, 51% of the extraction power, and 17 min of the extraction time), and the purity of evaporated β-carotene extract reached 816.32 ± 10.57 mg g(-1) after purified by a NKA-9 resin with a sampling and elution rate of 1 mL min(-1) . The β-carotene extract scavenged 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radicals with the highest ratios of 44 ± 0.26% and 35 ± 0.45% respectively, and exhibited strong inhibiting capacity on anti-lipid peroxidation. The blood glucose level of streptozotocin-induced diabetic mice was significantly reduced from 15.81 ± 1.71 mmol L(-1) to 8.10 ± 0.88 mmol L(-1) after 10 d administration of the β-carotene extract [100 mg kg(-1) body weight (BW)], and the increased food and water intakes in the diabetic mice were also significantly relieved after β-carotene treatment.

CONCLUSION

Our results suggested that extraction of β-carotene from Spirulina platensis had potential prospects in scaled-up industrialisation and healthcare applications.

Plasma n-3 polyunsaturated fatty status and its relationship with vitamin E intake and plasma level

PURPOSE

The aim of the study was to investigate habitual vitamin E intake and plasma α-tocopherol concentration and their relationship with plasma fatty acid profile in a healthy adult population.

METHODS

Vitamin E and fatty acid intake data were determined from the National Adult Nutrition Survey. Plasma α- and γ-tocopherol concentrations were quantified by high-performance liquid chromatography and the percentage of fatty acids in plasma by gas chromatography coupled with mass spectrometry. Participants (n = 601) were divided into vitamin E intake quartiles and plasma α-tocopherol quartiles, and differences in fatty acid intake and plasma fatty acid profile were analyzed by a general linear model.

RESULTS

Dietary intake data showed that as vitamin E intake increased, intakes of total polyunsaturated fatty acid (PUFA) and α-linolenic acid increased significantly (p < 0.001), but eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) did not. After adjusting for fatty acid intake, vitamin E intake was positively related to plasma n-3 PUFA (EPA and DHA) levels and plasma n-3/n-6 PUFA ratio. Plasma α-tocopherol concentration was positively related to the percentage of plasma total PUFA, n-3 PUFA and EPA and inversely related to the percentage of plasma n-6 PUFA.

CONCLUSIONS

The study illustrates that there are statistical relationships between plasma fatty acid profile and both vitamin E intake and plasma α-tocopherol concentration. Vitamin E may play a role in the maintenance of plasma n-3 PUFA profile in humans with consequent desirable health effects.

Reduced antioxidant capacity and increased subclinical inflammation markers in prepubescent obese children and their relationship with nutritional markers and metabolic parameters

OBJECTIVE

There are associations between some inflammatory and oxidative markers and obesity in adults, but whether prepubescent children of different weights also have such markers has not been studied. We investigated multiple inflammatory markers and levels of erythrocyte oxidant/antioxidant enzymes in prepubescent children of different weights.

METHODS

Children aged 2-11 years were divided into three groups: 80 were underweight, 90 were obese but otherwise healthy, and 80 were healthy age- and sex-matched children of normal-weight. We analyzed inflammatory markers and the total oxidant status, total antioxidant status (TAS), and total thiol level were also determined, and the oxidative stress index was calculated as an indicator of the degree of oxidative stress.

RESULTS

The obese group exhibited higher levels of fasting glucose, insulin, total cholesterol, triglycerides, the homeostatic model assessment of insulin resistance (HOMA-IR), and the homeostatic model assessment of β-cell function (HOMA-β), C-reactive protein (CRP), neutrophils, and neutrophil/lymphocyte ratio (NLR), as well as lower TAS and total thiol levels than the other two groups (all P < 0.001). Moreover, TAS and total thiols were negatively correlated with age in the obese group (r = -0.212, P = 0.001; r = -0.231, P < 0.001, respectively). CRP levels in plasma were positively correlated with the body mass index (BMI), insulin and glucose levels, HOMA-IR, HOMA-β, WBC and neutrophil counts, and the NLR, and were negatively correlated with TAS and total thiol levels in the overall studied population.

DISCUSSION

The coexistence of increased obesity-related subclinical inflammation and decreased antioxidant capacity can be observed even in prepubescence, and may eventually increase the risk of long-term vascular damage.

A Common Variant in the SETD7 Gene Predicts Serum Lycopene Concentrations

Dietary intake and higher serum concentrations of lycopene have been associated with lower incidence of prostate cancer and other chronic diseases. Identifying determinants of serum lycopene concentrations may thus have important public health implications. Prior studies have suggested that serum lycopene concentrations are under partial genetic control. The goal of this research was to identify genetic predictors of serum lycopene concentrations using the genome-wide association study (GWAS) approach among a sample of 441 Old Order Amish adults that consumed a controlled diet. Linear regression models were utilized to evaluate associations between genetic variants and serum concentrations of lycopene. Variant rs7680948 on chromosome 4, located in the intron region of the SETD7 gene, was significantly associated with serum lycopene concentrations (p = 3.41 × 10⁻⁹). Our findings also provided nominal support for the association previously noted between SCARB1 and serum lycopene concentrations, although with a different SNP (rs11057841) in the region. This study identified a novel locus associated with serum lycopene concentrations and our results raise a number of intriguing possibilities regarding the nature of the relationship between SETD7 and lycopene, both of which have been independently associated with prostate cancer. Further investigation into this relationship might help provide greater mechanistic understanding of these associations.

The effects of lutein on cardiometabolic health across the life course: a systematic review and meta-analysis

BACKGROUND

The antioxidant lutein is suggested as being beneficial to cardiometabolic health because of its protective effect against oxidative stress, but evidence has not systematically been evaluated.

OBJECTIVE

We aimed to evaluate systematically the effects of lutein (intake or concentrations) on cardiometabolic outcomes in different life stages.

DESIGN

This is a systematic review with meta-analysis of literature published in MEDLINE, Embase, Cochrane Central, Web of Science, PubMed, and Google Scholar up to August 2014. Included were trials and cohort, case-control, and cross-sectional studies in which the association between lutein concentrations, dietary intake, or supplements and cardiometabolic outcomes was reported. Two independent investigators reviewed the articles.

RESULTS

Seventy-one relevant articles were identified that included a total of 387,569 participants. Only 1 article investigated the effects of lutein during pregnancy, and 3 studied lutein in children. Furthermore, 31 longitudinal, 33 cross-sectional, and 3 intervention studies were conducted in adults. Meta-analysis showed a lower risk of coronary heart disease (pooled RR: 0.88; 95% CI: 0.80, 0.98) and stroke (pooled RR: 0.82; 95% CI: 0.72, 0.93) for the highest compared with the lowest tertile of lutein blood concentration or intake. There was no significant association with type 2 diabetes mellitus (pooled RR: 0.97; 95% CI: 0.77, 1.22), but higher lutein was associated with a lower risk of metabolic syndrome (pooled RR: 0.75; 95% CI: 0.60, 0.92) for the highest compared with the lowest tertile. The literature on risk factors for cardiometabolic diseases showed that lutein might be beneficial for atherosclerosis and inflammatory markers, but there were inconsistent associations with blood pressure, adiposity, insulin resistance, and blood lipids.

CONCLUSIONS

Our findings suggest that higher dietary intake and higher blood concentrations of lutein are generally associated with better cardiometabolic health. However, evidence mainly comes from observational studies in adults, whereas large-scale intervention studies and studies of lutein during pregnancy and childhood are scarce.

Carotenoids in Adipose Tissue Biology and Obesity

Cell, animal and human studies dealing with carotenoids and carotenoid derivatives as nutritional regulators of adipose tissue biology with implications for the etiology and management of obesity and obesity-related metabolic diseases are reviewed. Most studied carotenoids in this context are β-carotene, cryptoxanthin, astaxanthin and fucoxanthin, together with β-carotene-derived retinoids and some other apocarotenoids. Studies indicate an impact of these compounds on essential aspects of adipose tissue biology including the control of adipocyte differentiation (adipogenesis), adipocyte metabolism, oxidative stress and the production of adipose tissue-derived regulatory signals and inflammatory mediators. Specific carotenoids and carotenoid derivatives restrain adipogenesis and adipocyte hypertrophy while enhancing fat oxidation and energy dissipation in brown and white adipocytes, and counteract obesity in animal models. Intake, blood levels and adipocyte content of carotenoids are reduced in human obesity. Specifically designed human intervention studies in the field, though still sparse, indicate a beneficial effect of carotenoid supplementation in the accrual of abdominal adiposity. In summary, studies support a role of specific carotenoids and carotenoid derivatives in the prevention of excess adiposity, and suggest that carotenoid requirements may be dependent on body composition.

Impact of diet on cardiometabolic health in children and adolescents

The manifestation of cardiovascular risk factors, such as hypertension, diabetes, and particularly obesity begins in children and adolescents, with deleterious effects for cardiometabolic health at adulthood. Although the impact of diet on cardiovascular risk factors has been studied extensively in adults, showing that their cardiometabolic health is strongly lifestyle-dependent, less is known about this impact in children and adolescents. In particular, little is known about the relationship between their dietary patterns, especially when derived a posteriori, and cardiovascular risk. An adverse association of cardiovascular health and increased intake of sodium, saturated fat, meat, fast food and soft drinks has been reported in this population. In contrast, vitamin D, fiber, mono-and poly-unsaturated fatty acids, dairy, fruits and vegetables were positively linked to cardiovascular health.

The aim of this review was to summarize current epidemiological and experimental evidence on the impact of nutrients, foods, and dietary pattern on cardiometabolic health in children and adolescents. A comprehensive review of the literature available in English and related to diet and cardiometabolic health in this population was undertaken via the electronic databases PubMed, Cochrane Library, and Medline.

Lutein intake at the age of 1 year and cardiometabolic health at the age of 6 years: the Generation R Study

Lutein is a carotenoid with strong antioxidant properties. Previous studies in adults suggest a beneficial role of lutein on cardiometabolic health. However, it is unknown whether this relation also exists in children; therefore, we aimed to assess the relation between lutein intake at 13 months of age and cardiometabolic outcomes at the age of 6 years. We included 2044 Dutch children participating in a population-based prospective cohort study. Diet was measured at 13 months of age with an FFQ. Lutein intake was standardised for energy and β-carotene intake. Blood pressure, anthropometrics, serum lipids and insulin were measured at the age of 6 years. Dual-energy X-ray absorptiometry was performed to measure total and regional fat and lean mass. A continuous cardiometabolic risk factor score was created, including the components body fat percentage, blood pressure, insulin, HDL-cholesterol and TAG. Age- and sex-specific standard deviation scores were created for all outcomes. Multivariable linear regression was performed, including socio-demographic and lifestyle variables. Median (energy-standardised) lutein intake was 1317 mcg/d (95% range 87, 6069 mcg/d). There were no consistent associations between lutein intake at 13 months and anthropometrics and body composition measures at 6 years of age. In addition, lutein intake was not associated with a continuous cardiometabolic risk factor score, nor was it associated with any of the individual components of the cardiometabolic risk factor score. Results from this large population-based prospective cohort study do not support the hypothesis that lutein intake early in life has a beneficial role for later cardiometabolic health.

Greater serum carotenoid levels associated with lower prevalence of nonalcoholic fatty liver disease in Chinese adults

Previous studies have suggested that serum carotenoids may be inversely associated with liver injury, but limited data are available from population-based studies. We examined the relationship between serum carotenoid levels and the prevalence of nonalcoholic fatty liver disease (NAFLD) in Chinese adults. A total of 2935 participants aged 40–75 years were involved in this community-based cross-sectional study. General information, lifestyle factors, serum levels of carotenoid and the presence and degree of NAFLD were determined. After adjusting for potential covariates, we observed a dose-dependent inverse association between NAFLD risk and each individual serum carotenoid and total carotenoids (all p-values < 0.001). The ORs of NAFLD for the highest (vs. lowest) quartile were 0.44 (95% CI 0.35, 0.56) for α-carotene, 0.32 (95% CI 0.25, 0.41) for β-carotene, 0.62 (95% CI 0.49, 0.79) for β-cryptoxanthin, 0.54 (95% CI 0.42, 0.68) for lycopene, 0.56 (95% CI 0.44, 0.72) for lutein + zeaxanthin and 0.41 (95% CI 0.32, 0.53) for total carotenoids. Higher levels of α-carotene, β-carotene, lutein + zeaxanthin and total carotenoids were significantly associated with a decrease in the degree of NAFLD (p-trend: < 0.001 to 0.003). Serum carotenoids are inversely associated with prevalence of NAFLD in middle aged and elderly Chinese.