Relation Between Dietary Carotenoid Intake, Serum Concentration, and Mortality Risk of CKD Patients Among US Adults: National Health and Nutrition Examination Survey 2001–2014

An Overview on the Effects of Some Carotenoids on Health: Lutein and Zeaxanthin

PURPOSE OF REVIEW

In this review, the chemical properties, nutritional sources, absorption mechanisms, metabolism, biosynthesis and promising health-related benefits of lutein and zeaxanthin were emphasized and some recommendations for the future studies are suggested.

RECENT FINDINGS

Lutein and zeaxanthin are phytochemical compounds in the carotenoid group and are synthesised only by plants. All mammals get lutein and zeaxanthin into their bodies by consuming plant-based foods. Especially leafy green vegetables, broccoli, pumpkin, cabbage, spinach and egg yolk are rich in lutein and zeaxanthin. Lutein and zeaxanthin have potential health effects by preventing free radical formation, exhibiting protective properties against oxidative damage and reducing oxidative stress. These compounds have neuroprotective, cardioprotective, ophthalmological, antioxidant, anti-inflammatory, anti-cancer, anti-osteoporosis, anti-diabetic, anti-obesity, and antimicrobial effects. The preventive properties of lutein and zeaxanthin against numerous diseases have attracted attention recently. Further clinical trials with large samples are needed to make generalisations in the prevention and treatment of diseases and to determine the appropriate doses and forms of lutein and zeaxanthin.

Treatment with Gac Fruit Extract and Probiotics Reduces Serum Trimethylamine N-Oxide in Chronic Kidney Disease Rats

Chronic kidney disease (CKD) affects more than 850 million people worldwide, contributing to morbidity and mortality, particularly through cardiovascular disease (CVD). The altered composition in CKD patients leads to increased production and absorption of uremic toxins such as trimethylamine (TMA) and its oxidized form, trimethylamine N-oxide (TMAO), which are associated with cardiovascular risks. This study investigated the potential of supplementary interventions with high-carotenoid-content gac fruit extract and probiotics to mitigate serum TMAO by modulating the gut microbiota. We conducted an animal study involving 48 male Wistar rats, divided into six groups: the control, CKD control, and four treatment groups receiving gac fruit extract, carotenoid extract, or combinations with Ligilactobacillus salivarius and Lactobacillus crispatus and Lactobacillus casei as a standard probiotic. CKD was induced in rats using cisplatin and they were supplemented with choline to enhance TMA production. The measures included serum creatinine, TMAO levels, gut microbiota composition, and the expression of fecal TMA lyase and intestinal zonula occluden-1 (ZO-1). CKD rats showed increased TMA production and elevated serum levels of TMAO. Treatment with gac fruit extract and selective probiotics significantly altered the composition of the gut microbiota by decreasing Actinobacteriota abundance and increasing the abundance of Bacteroides. This combination effectively promoted ZO-1 expression, reduced fecal TMA lyase, and subsequently lowered serum TMAO levels, demonstrating the therapeutic potential of these interventions. Our results highlight the benefits of gac fruit extract combined with probiotics for the effective reduction in serum TMAO levels in rats with CKD, supporting the further exploration of dietary and microbial interventions to improve outcomes in patients with CKD.

Association between dietary carotenoid intakes and the risk of asthma in children and adolescents: evidence from the National Health and Nutrition Examination Survey 2007-2016

Background

In recent years, the incidence of asthma in children has been increasing. As a chronic disease, in addition to drug treatment, dietary management is also important. However, studies of carotenoids and asthma have shown mixed results. This study aimed to evaluate whether the relationship between carotenoid intake and current asthma holds significant importance.

Methods

We studied 9,118 children aged 6-16 years in the National Health and Nutrition Examination Survey (NHANES) of US from 2007 to 2016, and the relationship of dietary carotenoid and its subgroup with pediatric asthma. Current asthma was assessed by parent-reported, doctor-diagnosed, asthma using a standardized questionnaire. We used multivariate logistic regression to calculate the odds ratio (OR) for current asthma with a 95% confidence interval (CI).

Results

Total carotenoid intake was not associated with the risk of current asthma. Compared with the first quantile, the second quantile of β-cryptoxanthin intake was positively correlated with current asthma (Q2: 1.227; 95% CI: 1.025-1.470; P=0.03). The test of trend showed that, as the α-carotene intake increased, the risk of current asthma showed a decreasing trend, which was very close to the statistic confidence cutoff (Model I: P for trend =0.001; Model II: P for trend =0.003; Model III: P for trend =0.08). In subgroup analysis, family history of asthma interacted with carotenoid intake (P=0.005). The population without a family history of asthma, there were significant negative associations between carotenoid intakes and asthma (quartile 4: Model III: 0.720; 95% CI: 0.549-0.943; P=0.02).

Conclusions

In this study, pediatric current asthma was not related to total carotenoids in our total participants. Total dietary carotenoid intake has a protective effect on children without a family history of asthma. Meanwhile, β-cryptoxanthin intake is positively correlated with asthma.

Chronic Kidney Disease Diets for Kidney Failure Prevention: Insights from the IL-11 Paradigm

Nearly every fifth adult in the United States and many older adults worldwide are affected by chronic kidney disease (CKD), which can progress to kidney failure requiring invasive kidney replacement therapy. In this review, we briefly examine the pathophysiology of CKD and discuss emerging mechanisms involving the physiological resolution of kidney injury by transforming growth factor beta 1 (TGFβ1) and interleukin-11 (IL-11), as well as the pathological consequences of IL-11 overproduction, which misguides repair processes, ultimately culminating in CKD. Taking these mechanisms into account, we offer an overview of the efficacy of plant-dominant dietary patterns in preventing and managing CKD, while also addressing their limitations in terms of restoring kidney function or preventing kidney failure. In conclusion, this paper outlines novel regeneration strategies aimed at developing a reno-regenerative diet to inhibit IL-11 and promote repair mechanisms in kidneys affected by CKD.

Cymbopogon proximus and Petroselinum crispum seed ethanolic extract/Gum Arabic nanogel emulsion: Preventing ethylene glycol and ammonium chloride-induced urolithiasis in rats

Urolithiasis is a prevalent urological disorder that contributes significantly to global morbidity. This study aimed to assess the anti-urolithic effects of Cymbopogon proximus (Halfa Bar) and Petroselinum crispum (parsley) seed ethanolic extract /Gum Arabic (GA) emulsion, and its nanogel form against ethylene glycol (EG) and ammonium chloride (AC)-induced experimental urolithiasis in rats. Rats were divided into four groups: group 1 served as the normal control, group 2 received EG with AC in drinking water for 14 days to induce urolithiasis, groups 3 and 4 were orally administered emulsion (600 mg/kg/day) and nanogel emulsion (600 mg/kg/day) for 7 days, followed by co-administration with EG and AC in drinking water for 14 days. Urolithiatic rats exhibited a significant decrease in urinary excreted magnesium, and non-enzymic antioxidant glutathione and catalase activity. Moreover, they showed an increase in oxalate crystal numbers and various urolithiasis promoters, including excreted calcium, oxalate, phosphate, and uric acid. Renal function parameters and lipid peroxidation were intensified. Treatment with either emulsion or nanogel emulsion significantly elevated urolithiasis inhibitors, excreted magnesium, glutathione levels, and catalase activities. Reduced oxalate crystal numbers, urolithiasis promoters' excretion, renal function parameters, and lipid peroxidation while improving histopathological changes. Moreover, it decreased renal crystal deposition score and the expression of Tumer necrosis factor-α (TNF-α) and cleaved caspase-3. Notably, nanogel emulsion showed superior effects compared to the emulsion. Cymbopogon proximus (C. proximus) and Petroselinum crispum (P. crispum) seed ethanolic extracts/GA nanogel emulsion demonstrated protective effects against ethylene glycol induced renal stones by mitigating kidney dysfunction, oxalate crystal formation, and histological alterations.

Association between dietary carotenoid intakes and abdominal aortic calcification in adults: National Health and Nutrition Examination Survey 2013-2014

OBJECTIVE

Abdominal aortic calcification (AAC) is an important marker of subclinical atherosclerosis and a predictor of cardiovascular disease. This study aims to explore the association between carotenoid intakes and AAC.

METHODS

We included 2889 participants from the National Health and Nutrition Examination Survey (NHANES). Dietary carotenoid intakes were obtained through 24-h dietary recall interviews. Severe AAC was defined as a Kauppila score > 5. The main analysis utilizes logistic and restricted cubic spline models.

RESULT

Severe AAC was detected in 378 (13.08%) participants. In fully adjusted models, the odds ratios (OR) with 95% confidence intervals (CI) of α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin and total carotenoid intakes for individuals with severe AAC were 0.53 (0.23-0.77), 0.39 (0.19-0.80), 0.18 (0.05-0.62), 0.40 (0.20-0.78), 0.53 (0.32-0.88) and 0.38 (0.18-0.77) in the highest versus lowest quartile intake, respectively. Dose-response analyses revealed that all of the carotenoids were associated with decreased risk of severe AAC in a nonlinear trend. Total carotenoid intakes of at least 100ug/kg/day were associated with decreased odds for severe AAC.

CONCLUSION

α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin and total carotenoids were inversely associated with the risk of severe AAC in adults.

Dietary carotenoids intake and sex differences in relation to chronic kidney disease a cross-sectional assessment in the NHANES study

BACKGROUND AND AIMS

Current evidence on the relationship between dietary carotenoids intake (DCI) and chronic kidney disease (CKD) are limited. Moreover, whether there is an association between DCI and prevalence of CKD and how this association might be impacted by sex is not clear.

METHODS AND RESULTS

Overall, 4507 women and 4396 men were included for analysis. The study used data from the National Health and Nutrition Examination Survey (NHANES), a cross-sectional survey carried out in the USA. The exposure factor for this analysis was DCI. The outcome was CKD, defined as eGFR < 60mL/min/1.73 m2. Multivariate logistic regression was used to analyzed the associations of DCI and prevalence of CKD both in men and women. There was a significant inverse association between higher DCI and prevalence of CKD only among females. Per LgDCI unit increment, the multivariable adjusted odd ratio (OR) (95% confidence interval) for prevalence of CKD was 0.72 (0.58, 0.90) in females and 0.95 (0.77, 1.18) in males. When compared with the lowest quartile, the ORs of the highest quartile of DCI for prevalence of CKD were 0.59 (0.40, 0.87) in females and 0.87 (0.60, 1.26) in males. The associations remained similar in the subgroup analyses.

CONCLUSIONS

The findings suggest that a higher intake of dietary carotenoids is associated with a lower prevalence of CKD in women, but not in men.

Association between carotenoid intake and metabolic dysfunction-associated fatty liver disease among US adults: A cross-sectional study

Carotenoids have been recognized for their potential health benefits due to their antioxidant properties. There is limited research on the association between metabolic dysfunction-associated fatty liver disease (MAFLD) and carotenoids. This study aimed to investigate the effect of carotenoid intake on the risk of MAFLD. We retrospectively analyzed 2722 adults aged ≥ 18 from the National Health and Nutrition Examination Survey 2017-2018. Hepatic steatosis was identified by elastography, and carotenoid consumption was evaluated through two 24-hour dietary recall interviews. Weighted logistic regression models, subgroup analyses, and restricted cubic splines were used for analyses. The weighted prevalence of MAFLD was 51.90%. Weighted logistic regression analysis demonstrated that intake of β-carotene, lutein/zeaxanthin, and lycopene was associated with a lower risk of MAFLD after adjusting for various covariates. Compared to the lowest tertile, a significant inverse correlation was observed between the highest total lycopene intake and MAFLD among females in the gender subgroup analysis. Restricted cubic spline regression analysis revealed a U-shaped association between lycopene consumption and MAFLD risk (P < .001), with an inflection point of approximately 9.48 mg/day. Moreover, the nonlinear relationship was particularly significant in females and absent in males. In summary, increased β-carotene, lutein/zeaxanthin, and lycopene consumption was associated with a decreased risk of MAFLD. The relationship between total lycopene intake and MAFLD was nonlinear, primarily in females. These findings have significant implications for the potential prevention and management of MAFLD.

Positive Association between Macular Pigment Optical Density and Glomerular Filtration Rate: A Cross-Sectional Study

Although decreased macular pigment density is associated with the development of age-related macular degeneration (AMD), exactly how this decrease may contribute to the development of AMD is still not fully understood. In this study, we investigated the relationship between macular pigment optical density (MPOD) and estimated glomerular filtration rate (eGFR). MPOD was measured using MPS II (Electron Technology, Cambridge, UK) in 137 participants who showed no clinical signs of AMD at 3 months after cataract surgery, and simple and multiple linear regression analyses were performed to determine the associations with age, sex, abdominal circumference, diabetes, hypertension, smoking, intraocular lens color, visual acuity before and after surgery, and eGFR. The participants were divided into two groups based on the median MPOD (0.58): the high-pigment and low-pigment groups. The mean value of eGFR in the high-pigment group was significantly higher than that in the low-pigment group (64.2 vs. 58.1, p = 0.02). The simple linear regression analysis revealed a significant positive association between MPOD and eGFR (β = 0.0034, 95% confidence interval [CI]: 0.0011-0.0056, p = 0.0038), and this association was independent of age, sex, abdominal circumference, diabetes, smoking, hypertension, best-corrected visual acuity (BCVA) before surgery, BCVA after surgery, and intraocular lens color (β = 0.0033, 95% CI: 0.00090-0.0058, p = 0.0076). These results show a strong association of renal dysfunction with the decrease in MPOD.