Dietary patterns of antioxidant vitamin and carotenoid intake associated with bone mineral density: findings from post-menopausal Japanese female subjects

Association between composite dietary antioxidant and bone mineral density in children and adolescents aged 8-19 years: findings from NHANES

Dietary antioxidants may have beneficial effects on bone health, but it remains uncertain in children and adolescents. This study investigates the association of composite dietary antioxidant index (CDAI) with bone mineral density (BMD) in children and adolescents aged 8-19 years from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. The study assessed the relationship between CDAI and BMD in 2994 individuals aged 8-19 years (average age 13.48 ± 3.32 years) from the NHANES 2007-2010. Multivariate linear regression analyses were utilized to detect the association between CDAI and total spine, femur neck, and total femur BMD, adjusting for confounders including age, race/ethnicity, sex, poverty income ratio (PIR), body mass index (BMI), serum phosphorus and calcium. Stratified analyses and interaction tests were performed to examine the stability of the results. The weighted characteristics showed that subjects in the fourth CDAI quartile were more likely to be older, men, and Non-Hispanic White. They have higher values of serum total calcium and phosphorus. After adjusting all confounders, CDAI was positively associated with the total spine (β = 0.0031 95% CI 0.0021-0.0040), total femur (β = 0.0039 95% CI 0.0028-0.0049), and femur neck BMD (β = 0.0031 95% CI 0.0021-0.0040) in children and adolescents. Furthermore, we found no interaction effects between different race/ethnicity, age, and sex groups. Our findings suggest that dietary intake of multiple antioxidants was positively associated with BMD in children and adolescents. These findings provide valuable evidence for improving bone health in the early stages of life. However, more prospective studies are required to validate our findings and their causal relationship.

Independent and combined associations of dietary antioxidant intake with bone mineral density and risk of osteoporosis among elderly population in United States

BACKGROUND

The influence of dietary antioxidant intake on the occurrence and progression of osteoporosis may be significant. However, to date, evidence on the link between combined effect of dietary antioxidants on bone mineral density (BMD) level and risk of osteoporosis is limited. We aimed to assess the independent and combined association of dietary antioxidant intake with BMD level and risk of osteoporosis among elderly population in United States through analysis of data in the National Health and Nutrition Examination Survey.

METHODS

The dietary antioxidant intake was assessed based on six antioxidants, including vitamin A, vitamin C, vitamin E, zinc, selenium, and total carotenoid. A composite dietary antioxidant index (CDAI) was used to evaluate the combined exposure of dietary antioxidant intake.

RESULTS

A total of 5618 participants were included. Higher dietary vitamin A, vitamin C, vitamin E, zinc, selenium, and total carotenoid, were positively associated with BMD level. Compared with participants in the first quartile, those in the higher quartile of vitamin E (Q4: OR 0.652; 95% CI 0.463-0.918), zinc (Q4: OR 0.581; 95% CI 0.408-0.826), and selenium (Q3: OR 0.673; 95% CI 0.503-0.899) were associated with decreased risk of overall osteoporosis. Furthermore, compared to those in the first quartile, participants in the highest quartile of CDAI were associated with increased total femur (β 0.019; 95% CI 0.007-0.032), femur neck (β 0.020; 95% CI 0.009-0.032), trochanter (β 0.012; 95% CI 0.001-0.023), and intertrochanter BMD level (β 0.022; 95% CI 0.007-0.037); participants in the highest quartile of CDAI were associated with decreased risk of overall osteoporosis (OR 0.536; 95% CI 0.376-0.763). Furthermore, the associations of CDAI with the BMD level and osteoporosis risk were more significant among female participants.

CONCLUSION

Our study provides evidence that a combination of dietary antioxidants intake was associated increased BMD level and decreased osteoporosis risk.

Cytochrome P450 CitCYP97B modulates carotenoid accumulation diversity by hydroxylating β-cryptoxanthin in Citrus

Carotenoids in plant foods provide health benefits by functioning as provitamin A. One of the vital provitamin A carotenoids, β-cryptoxanthin, is typically plentiful in citrus fruit. However, little is known about the genetic basis of β-cryptoxanthin accumulation in citrus. Here, we performed a widely targeted metabolomic analysis of 65 major carotenoids and carotenoid derivatives to characterize carotenoid accumulation in Citrus and determine the taxonomic profile of β-cryptoxanthin. We used data from 81 newly sequenced representative accessions and 69 previously sequenced Citrus cultivars to reveal the genetic basis of β-cryptoxanthin accumulation through a genome-wide association study. We identified a causal gene, CitCYP97B, which encodes a cytochrome P450 protein whose substrate and metabolic pathways in land plants were undetermined. We subsequently demonstrated that CitCYP97B functions as a novel monooxygenase that specifically hydroxylates the β-ring of β-cryptoxanthin in a heterologous expression system. In planta experiments provided further evidence that CitCYP97B negatively regulates β-cryptoxanthin content. Using the sequenced Citrus accessions, we found that two critical structural cis-element variations contribute to increased expression of CitCYP97B, thereby altering β-cryptoxanthin accumulation in fruit. Hybridization/introgression appear to have contributed to the prevalence of two cis-element variations in different Citrus types during citrus evolution. Overall, these findings extend our understanding of the regulation and diversity of carotenoid metabolism in fruit crops and provide a genetic target for production of β-cryptoxanthin-biofortified products.

Elucidating causal relationships of diet-derived circulating antioxidants and the risk of osteoporosis: A Mendelian randomization study

Background

Osteoporosis (OP) is typically diagnosed by evaluating bone mineral density (BMD), and it frequently results in fractures. Here, we investigated the causal relationships between diet-derived circulating antioxidants and the risk of OP using Mendelian randomization (MR).

Methods

Published studies were used to identify instrumental variables related to absolute levels of circulating antioxidants like lycopene, retinol, ascorbate, and β-carotene, as well as antioxidant metabolites such as ascorbate, retinol, α-tocopherol, and γ-tocopherol. Outcome variables included BMD (in femoral neck, lumbar spine, forearm, heel, total body, total body (age over 60), total body (age 45-60), total body (age 30-45), total body (age 15-30), and total body (age 0-15)), fractures (in arm, spine, leg, heel, and osteoporotic fractures), and OP. Inverse variance weighted or Wald ratio was chosen as the main method for MR analysis based on the number of single nucleotide polymorphisms (SNPs). Furthermore, we performed sensitivity analyses to confirm the reliability of the findings.

Results

We found a causal relationship between absolute retinol levels and heel BMD (p = 7.6E-05). The results of fixed effects IVW showed a protective effect of absolute retinol levels against heel BMD, with per 0.1 ln-transformed retinol being associated with a 28% increase in heel BMD (OR: 1.28, 95% CI: 1.13-1.44). In addition, a sex-specific effect of the absolute circulating retinol levels on the heel BMD has been observed in men. No other significant causal relationship was found.

Conclusion

There is a positive causal relationship between absolute retinol levels and heel BMD. The implications of our results should be taken into account in future studies and in the creation of public health policies and OP prevention tactics.

Association Study between Antioxidant Nutrient Intake and Low Bone Mineral Density with Oxidative Stress-Single Nucleotide Variants: GPX1 (rs1050450 and rs17650792), SOD2 (rs4880) and CAT (rs769217) in Mexican Women

Oxidative stress is essential in developing multiple bone metabolism diseases, including osteoporosis. Single-nucleotide variants (SNVs) have been associated with oxidative stress, promoting an imbalance between the production of reactive oxygen species and the ability to neutralize them, and it has been reported that antioxidant nutrient intake can influence bone mineral density (BMD). This work reports the association between oxidative stress-related SNVs (GPX1-rs1050450, rs17650792, SOD2-rs4880, and CAT-rs769217), BMD, and antioxidant nutrient intake. The study included 1269 Mexican women from the Health Workers Cohort Study. Genotyping was performed using predesigned TaqMan assays. Dietary data were collected using a 116-item semi-quantitative food frequency questionnaire. A dietary antioxidant quality score (DAQS) was used to estimate antioxidant-nutrient intake. Association analysis was estimated via linear, logistic, or quantile regression models. The results showed an association of the rs1050450-A and rs17650792-A alleles with femoral neck BMD (p = 0.038 and p = 0.017, respectively) and the SNV rs4880-A allele with total hip BMD (p = 0.026) in respondents aged 45 years or older. In addition, antioxidant-nutrient intake was associated with the rs4880-GG genotype, being significant for fiber (p = 0.007), riboflavin (p = 0.005), vitamin B6 (p = 0.034), and vitamin D (p = 0.002). The study showed an association between oxidative stress-related SNVs, BMD, and antioxidant-nutrient intake in Mexican women. Therefore, treatments for low BMD could be developed based on antioxidant supplementation.

Higher lacto-vegetarian dietary score is associated with reduced risk of postmenopausal osteoporosis: A case-control study in a sample of Iranian postmenopausal women

Osteoporosis is a systemic skeletal disease manifesting as weak and fragile bones. Dietary patterns have been described as an affecting constituent of bone metabolism. There is no consensus on the advantages or harms of vegetarian diets on bone health. This study aimed to design a lacto-vegetarian dietary score (LVDS) to evaluate the similarity of an individual's dietary pattern to the lacto-vegetarian dietary pattern and assess its association with postmenopausal osteoporosis (PMO). We hypothesized that individuals with greater LVDS will have a lower risk for PMO. In this hospital-based, case-control study, 220 cases (definitively diagnosed with osteoporosis) and 220 age-matched controls were registered. Usual dietary intakes were evaluated by a validated 147-item semiquantitative food frequency questionnaire. To design the LVDS, the energy-adjusted intakes of 12 food groups were categorized into quintiles, and positive or reverse points were assigned. To determine the association between the LVDS and PMO, binary logistic regression was used. Those in the top tertile of the LVDS had a lower chance of PMO compared with those in the bottom tertile (odds ratio, 0.11; 95% confidence interval, 0.06-0.22). An inverse relation was obtained between vegetables, fruits, legumes, nuts, dairy, soy protein, and egg consumption and PMO. Higher consumption of vegetable and animal oils significantly increased the risk of PMO. A dietary pattern similar to the lacto-vegetarian dietary pattern and concentrated on greater consumption of legumes, nuts, dairy, fruits, vegetables, and soy protein can be suggested as a protective method against PMO. Further, longitudinal studies are required to confirm these findings.

Association of the composite dietary antioxidant index with bone mineral density in the United States general population: data from NHANES 2005-2010

INTRODUCTION

There is evidence that individual antioxidants may increase bone mineral density (BMD) in patients with low BMD. However, the association between overall dietary antioxidant intake and BMD is unclear. The objective of this study was to examine how overall dietary antioxidant intake is related to BMD.

MATERIALS AND METHODS

A total of 14,069 people participated in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2010. Dietary Antioxidant Index (DAI) was calculated from the intake of vitamins A, C, E, zinc, selenium, and magnesium, which indicates a nutritional tool to assess the overall antioxidant properties of the diet. The correlation between the Composite Dietary Antioxidant Index (CDAI) and BMD was examined using multivariate logistic regression models. In addition to fitting smoothing curves, we fitted generalized additive models as well. Furthermore, to ensure data stability and avoid confounding factors, subgroup analysis was also conducted on gender and body mass index (BMI).

RESULTS

A significant association was demonstrated by the study between CDAI and total spine BMD (β = 0.001, 95% CI 0-0.001, P = 0.00039). And just like that, CDAI was positively correlated with femoral neck (β = 0.003, 95% CI 0.003-0.004, P < 0.00001) and trochanter (β = 0.004, 95% CI 0.003-0.004, P < 0.00001). In the gender subgroup analysis, CDAI maintained a strong positive correlation with femoral neck and trochanter BMD in males and females. Nevertheless, the link with total spine BMD was only observed in males. In addition, in the subgroup analysis stratified by BMI, CDAI showed a significantly positive relation to BMD of the femoral neck and trochanter in each group. However, the significant relationship between CDAI and BMD of the total spine was only maintained when BMI was above 30 kg/m2.

CONCLUSION

This study found that CDAI correlated positively with femoral neck, trochanter, and total spine BMD. This suggests that intake of a diet rich in antioxidants can reduce the risk of low bone mass and osteoporosis.

Association between multiple vitamins and bone mineral density: a cross-sectional and population-based study in the NHANES from 2005 to 2006

BACKGROUND

Bone mineral density (BMD) alterations in response to multivitamin exposure were rarely studied. Our study assessed the association of coexposure to six types of vitamins (i.e., vitamins B12, B9, C, D, A and E) with BMD measurements in adults in the US.

METHODS

Data were collected from participants aged ≥ 20 years (n = 2757) in the U.S. National Health and Nutrition Examination Surveys (NHANES) from 2005 to 2006. Multiple linear regression, restricted cubic splines, principal component analysis (PCA) and weighted quantile sum (WQS) regression were performed for statistical analysis.

RESULTS

The circulating levels of vitamins B12 and C were positively associated with BMDs, and an inverted L-shaped exposure relationship was observed between serum vitamin C and BMDs. PCA identified two principal components: one for 'water-soluble vitamins', including vitamins B12, B9 and C, and one for 'fat-soluble vitamins', including vitamins A, D and E. The former was positively associated with total femur (β = 0.009, 95%CI: 0.004, 0.015) and femoral neck (β = 0.007, 95%CI: 0.002, 0.013) BMDs, and the latter was negatively associated with BMDs with non-statistical significance. The WQS index constructed for the six vitamins was significantly related to total femur (β = 0.010, 95%CI: 0.001, 0.018) and femoral neck (β = 0.008, 95%CI: 0.001, 0.015) BMDs, and vitamins B12 and C weighted the most. The WQS index was inversely related to BMDs with non-statistical significance, and vitamins E and A weighted the most.

CONCLUSION

Our findings suggested a positive association between water-soluble vitamin coexposure and BMD, and the association was mainly driven by vitamins B12 and C. Negative association between fat-soluble vitamin coexposure and BMD was indicated, mainly driven by vitamins E and A. An inverted L-shaped exposure relationship was found between vitamin C and BMD.

Japanese carotenoid database with α- and β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene, and fucoxanthin and intake in adult women

Carotenoid intake is associated with low mortality and cancer risks; data on non-provitamin carotenoid intake is limited especially in Asians. We aimed to estimate carotenoid intake in Japanese adult women. Carotenoid content database comprises 196 food items, including 39 fruits, 87 vegetables and mushrooms, and 11 seaweeds, and was established using data from the literature and analyses of foods available in Japan. We surveyed the intake of these foods in Japanese women aged 21-56 years (n=109). Total intake of 7 carotenoids (mean±SD [range]) was 7,450±3,840 (1,160-21,300) μg/day; α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene, and fucoxanthin represented 4.3%, 23%, 3.4%, 15%, 2.0%, 39%, and 13% of total intake, respectively. Lutein intake was 1,132±686 (294-3,490) μg/day; its best sources were spinach, cucumber, chicken egg, green onion, and Chinese chives, representing 51% of total intake. Lutein can be obtained from a variety of sources. Thus, lutein intake levels did not vary widely among individuals and very few individuals consumed insufficient levels of lutein. Intake of zeaxanthin, lycopene, and fucoxanthin was 149±93 (2-479), 2,890±2,970 (0-17,100), and 980±1,230 (0-5,660) μg/day, respectively. Their intake required rich sources including chicken egg for zeaxanthin (52%); tomato products for lycopene (98%), and wakame seaweed for fucoxanthin (76%). The carotenoid content database including all food items consumed in Japan will be helpful for further investigations on carotenoid intake and its health benefits.

Chemistry, Occurrence, Properties, Applications, and Encapsulation of Carotenoids-A Review

Carotenoids are natural lipophilic pigments and antioxidants that are present in many fruits and vegetables. The consumption of carotenoids is correlated with positive health effects and a decreased risk of several chronic diseases. Provitamin A carotenoids (β-carotene, α-carotene, γ-carotene, and β-cryptoxanthin) are essential for the development and maintenance of sight. β-carotene, α-carotene, zeaxanthin, β-cryptoxanthin, lutein, and lycopene have high antioxidant activity and promote free radical scavenging, which helps protect against chronic diseases. However, carotenoids are chemically unstable and prone to oxidation in the presence of light, heat, oxygen, acids, and metal ions. The use of carotenoids in the food industry is limited due to their poor solubility in water, bioavailability and quick release. Encapsulation techniques, such as microencapsulation, nanoencapsulation and supercritical encapsulation, are used to overcome these problems. The objective of this paper is to describe the characteristics and potential health benefits of carotenoids and advances in encapsulation techniques for protecting and enhancing their solubility or bioavailability.

The effects of β-carotene on osteoporosis: a systematic review and meta-analysis of observational studies

PURPOSE

The aim is to evaluate the effect of β-carotene for osteoporosis and provide quantitative evidence.

METHOD

PubMed, Embase, Web of Science, and Cochrane Library were searched for eligible studies. Fifteen studies were included. Random-effect model was applied to pool the odds ratio (OR). The risk of osteoporosis and fracture were compared between low β-carotene intake group and high β-carotene intake group.

RESULT

The intake of β-carotene was unassociated with the overall risk of osteoporosis [OR = 0.733, 95% Cl (0.528, 1.018), p = 0.064]. Subgroup analysis showed that the intake of β-carotene was negatively associated with the risk of osteoporosis in both male subgroup [OR = 0.7, 95% Cl (0.549, 0.893), I² = 40.40%, p = 0.004] and female subgroup [OR = 0.684, 95% Cl (0.487, 0.960), I² = 86.40%, p = 0.028]. There was also a negative association between β-carotene intake and osteoporosis in Asia subgroup [OR = 0.512, 95% Cl (0.403, 0.650), I² = 0.00%, p = 0], whereas no association was observed in Western subgroup [OR = 1.107, 95% Cl (0.908, 1.350), I² = 2.30%, p = 0.314]. In addition, random-effect model was adopted to pool the standard mean difference (SMD), and the results showed that β-carotene intake was positively associated with overall bone mineral density (BMD) [SMD =  - 0.213, 95% Cl (- 0.391, - 0.034), I² = 87.30%, p = 0.019]. Subgroup analysis showed that β-carotene intake was positively associated with BMD in Asian participants [SMD =  - 0.394, 95% Cl (- 0.461, - 0.328), I² = 0, p = 0], while unassociated in Western participants [SMD =  - 0.047, 95% Cl (- 0.314, 0.219), I² = 78.9%, p = 0.727].

CONCLUSION

β-carotene may improve BMD and reduce the risk of osteoporosis and fracture. However, these effects could vary by gender and race and need to be further validated by longitudinal studies.

Effects of β-Cryptoxanthin on Improvement in Osteoporosis Risk: A Systematic Review and Meta-Analysis of Observational Studies

Many studies have analyzed the effects of β-cryptoxanthin (BCX) on osteoporosis and bone health. This systematic review and meta-analysis aimed at providing quantitative evidence for the effects of BCX on osteoporosis. Publications were selected and retrieved from three databases and carefully screened to evaluate their eligibility. Data from the final 15 eligible studies were extracted and uniformly summarized. Among the 15 studies, seven including 100,496 individuals provided information for the meta-analysis. A random effects model was applied to integrate the odds ratio (OR) to compare the risk of osteoporosis and osteoporosis-related complications between the groups with high and low intake of BCX. A high intake of BCX was significantly correlated with a reduced risk of osteoporosis (OR = 0.79, 95% confidence interval (CI) 0.70–0.90, p = 0.0002). The results remained significant when patients were stratified into male and female subgroups as well as Western and Asian cohorts. A high intake of BCX was also negatively associated with the incidence of hip fracture (OR = 0.71, 95% CI 0.54–0.94, p = 0.02). The results indicate that BCX intake potentially reduces the risk of osteoporosis and hip fracture. Further longitudinal studies are needed to validate the causality of current findings.

Effects of Salicylic Acid and Methyl Jasmonate Treatments on Flavonoid and Carotenoid Accumulation in the Juice Sacs of Satsuma Mandarin In Vitro

Salicylic acid and jasmonic acid are two important plant hormones that trigger the plant defense responses and regulate the accumulation of bioactive compounds in plants. In the present study, the effects of salicylic acid (SA) and methyl jasmonate (MeJA) on flavonoid and carotenoid accumulation were investigated in the juice sacs of Satsuma mandarin in vitro. The results showed that SA treatment was effective to enhance the contents of eriocitrin, narirutin, poncirin, and β-cryptoxanthin in the juice sacs (p < 0.05). In contrast, the MeJA treatment inhibited flavonoid and carotenoid accumulation in the juice sacs (p < 0.05). Gene expression results showed that the changes of flavonoid and carotenoid contents in the SA and MeJA treatments were highly regulated at the transcriptional level. In addition, a transcriptional factor CitWRKY70 was identified in the microarray analysis, which was induced by the SA treatment, while suppressed by the MeJA treatment. In the SA and MeJA treatments, the change in the expression of CitWRKY70 was consistent with that of flavonoid and carotenoid biosynthetic key genes. These results indicated that CitWRKY70 might be involved in the regulation of flavonoid and carotenoid accumulation in response to SA and MeJA treatments in the juice sacs of citrus fruit.

Potential Role of Lycopene in the Prevention of Postmenopausal Bone Loss: Evidence from Molecular to Clinical Studies

Osteoporosis is a metabolic bone disease characterized by reduced bone mineral density, which affects the quality of life of the aging population. Furthermore, disruption of bone microarchitecture and the alteration of non-collagenous protein in bones lead to higher fracture risk. This is most common in postmenopausal women. Certain medications are being used for the treatment of osteoporosis; however, these may be accompanied by undesirable side effects. Phytochemicals from fruits and vegetables are a source of micronutrients for the maintenance of bone health. Among them, lycopene has recently been shown to have a potential protective effect against bone loss. Lycopene is a lipid-soluble carotenoid that exists in both all-trans and cis-configurations in nature. Tomato and tomato products are rich sources of lycopene. Several human epidemiological studies, supplemented by in vivo and in vitro studies, have shown decreased bone loss following the consumption of lycopene/tomato. However, there are still limited studies that have evaluated the effect of lycopene on the prevention of bone loss in postmenopausal women. Therefore, the aim of this review is to summarize the relevant literature on the potential impact of lycopene on postmenopausal bone loss with molecular and clinical evidence, including an overview of bone biology and the pathophysiology of osteoporosis.

Nutrient and Dietary Patterns in Relation to the Pathogenesis of Postmenopausal Osteoporosis-A Literature Review

Postmenopausal women tend to be susceptible to primary osteoporosis due to its association with oestrogen deficiency. There is emerging evidence that an unhealthy dietary pattern drives an increase in the risk of postmenopausal osteoporosis (PO), whereas a healthy dietary pattern may decrease its occurrence. In this narrative literature review, we sought to review the role of nutrient and dietary patterns in the pathogenesis of PO. Therefore, we searched and reported all research articles from 2001 to May 2020 in Web of Science, Cinahl and Scopus that have researched a relationship between nutrient and/or dietary patterns and postmenopausal osteoporosis. Nutrients such as calcium, phosphorus, magnesium and vitamin D have been proven to be beneficial for bone health. Meanwhile, for the dietary patterns, foods such as dairy products especially milk, fibre and protein-rich foods, e.g., meat were directly linked to a positive association with bone mineral density (BMD). Likewise, fruits, vegetables and probiotic and prebiotic foods were reported for its positive relationship with BMD. Therefore, aside from physical activity, nutrition and diet in adequate proportions are suggested to be an important tool for ameliorating osteoporosis and bone health issues in older age.

Role of Vitamin C in Osteoporosis Development and Treatment-A Literature Review

Osteoporosis and associated low energy fractures are a significant clinical problem, especially in the elderly population. The occurrence of a hip fracture is associated with significant mortality and a high risk of disability. For this, apart from the treatment of osteoporosis, effective prevention of both the development of the disease and related fractures is extremely important. One aspect of osteoporosis prevention is proper dietary calcium intake and normal vitamin D3 levels. However, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention, too. This review aims to summarize the current knowledge about the role of vitamin C in osteoporosis development, prevention and treatment. The PubMed/Medline search on the role of vitamin C in bone metabolism database was performed for articles between 2000 and May 2020. Reports from in vitro and animal studies seem promising. Epidemiological studies also indicate the positive effect of high vitamin C content in the daily diet on bone mineral density. Despite promising observations, there are still few observational and intervention studies and their results do not allow for unequivocal determination of the benefits of high daily intake of vitamin C or its long-term supplementation.

Heterologous expression of xanthophyll esterase genes affects carotenoid accumulation in petunia corollas

The majority of carotenoids in petals are xanthophylls and most of these xanthophylls are esterified with fatty acids. Although petunia (Petunia x hybrida) is an important ornamental plant, it cannot accumulate enough carotenoids to have deep-yellow flowers. Our previous study suggested that low esterification activity causes low carotenoid accumulation in petunia corollas. Here, we introduced xanthophyll esterase (XES) from the petals of Ipomoea obscura, tomato (Solanum lycopersicum), and marigold (Tagetes erecta) into a pale-yellow-flowered cultivar of petunia to see whether these affect carotenoid accumulation in petunia corollas. Carotenoid contents and the proportions of esterified xanthophylls were elevated in the corollas of XES-overexpressing (XES-OX) transformants. Expression analysis showed that the transcript levels of endogenous carotenoid biosynthetic genes, which included geranylgeranyl diphosphate synthase 2, ζ-carotene desaturase, and lycopene β-ring cyclase in corolla tubes were upregulated in XES-OX plants. In addition, we discovered a difference in the composition of esterified xanthophylls among XES-OX plants, which may be caused by differences in the substrate specificity of their respective XESs. We conclude that esterification is an important process for carotenoid accumulation and XES is a useful tool for the quantitative and qualitative control of carotenoid accumulation in petals.

Circulatory Levels of RANKL, OPG, and Oxidative Stress Markers in Postmenopausal Women With Normal or Low Bone Mineral Density

Introduction:

Receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and oxidative stress markers are suggested to contribute to bone loss in osteoporosis that occurs in menopause. However, the association between these markers and bone mineral density (BMD) is controversial. The aim of this study was to measure circulatory levels of these parameters in postmenopausal women with normal or low BMD.

Methods:

The study population included 71 postmenopausal women, of whom 25 had normal BMD, 31 had osteopenia, and 15 had osteoporosis. Serum levels of RANKL, OPG, and 5 oxidative stress markers (catalase, peroxiredoxin 2 [PRX2], superoxide dismutase 1 [SOD1], superoxide dismutase 2 [SOD2], and thioredoxin [TRx1]) were measured using the Multiplex system.

Results:

As compared with subjects having normal BMD, subjects with low BMD had significantly lower median serum levels of OPG, catalase, SOD2, and PRX2 (P = .004, .031, .044, and .041 respectively). Although levels of RANKL were not different between the 2 groups, the RANKL/OPG ratio was higher in women with low BMD (P = .027).

Conclusions:

These data provide insights into the possible roles of OPG, RANKL, and oxidative stress in the pathogenesis of postmenopausal osteoporosis. However, the lack of association between these markers and BMD indicates that osteoporosis is complex and multivariate.

Vitamin C effects on 5-hydroxymethylcytosine and gene expression in osteoblasts and chondrocytes: Potential involvement of PHD2

Vitamin C (ascorbic acid, AA) is a well-known regulator of bone and cartilage metabolism. However, the mechanisms of AA’s action in these tissues are only partly understood. In this study, we confirmed that AA contributes to bone and cartilage metabolism by showing decreased articular cartilage and trabecular bone in AA-deficient spontaneous fracture (sfx) mutant mice. In vitro, we found that AA exerts differential effects on chondrocyte and osteoblast differentiation. Since AA is known to increase levels of 5-hydroxymethylcytosine (5-hmC) and induce DNA demethylation via the ten-eleven translocases (TETs), and since prolyl hydroxylase domain-containing protein 2 (PHD2), a known mediator of AA’s effects in these tissues, is part of the same enzyme family as the TETs, we next investigated whether increases in 5-hmC might mediate some of these effects. All TETs and PHDs are expressed in chondrocytes and osteoblasts, and PHD2 is localized in both the cytoplasm and nucleus of the cell, lending plausibility to the hypothesis of altered 5-hmC content in these cells. We found that AA treatment increased levels of 5-hmC in both cell types globally, notably including promoter regions of osteoblast differentiation genes. Furthermore, inhibition of PHD2 decreased 5-hmC levels in chondrocyte differentiation gene promoters, and knockdown of Phd2 in chondrocytes reduced global 5-hmC levels, suggesting for the first time that PHD2 may itself directly mediate increases in 5-hmC in chondrocyte and osteoblast genes. Further investigation of this mechanism could lead to novel therapeutic approaches to treat debilitating diseases such as osteoarthritis and osteoporosis.

Vitamin C intake in relation to bone mineral density and risk of hip fracture and osteoporosis: a systematic review and meta-analysis of observational studies

We aimed to systematically review available data on the association between vitamin C intake and bone mineral density (BMD), as well as risk of fractures and osteoporosis, and to summarise this information through a meta-analysis. Previous studies on vitamin C intake in relation to BMD and risk of fracture and osteoporosis were selected through searching PubMed, Scopus, ISI Web of Science and Google Scholar databases before February 2017, using MeSH and text words. To pool data, either a fixed-effects model or a random-effects model was used, and for assessing heterogeneity, Cochran's Q and I 2 tests were used. Subgroup analysis was applied to define possible sources of heterogeneity. Greater dietary vitamin C intake was positively associated with BMD at femoral neck (pooled r 0·18; 0·06, 0·30) and lumbar spine (pooled r 0·14; 95 % CI 0·06, 0·22); however, significant between-study heterogeneity was found at femoral neck: I 2=87·6 %, P heterogeneity<0·001. In addition, we found a non-significant association between dietary vitamin C intake and the risk of hip fracture (overall relative risk=0·74; 95 % CI 0·51, 1·08). Significant between-study heterogeneity was found (I 2=79·1 %, P heterogeneity<0·001), and subgroup analysis indicated that study design, sex and age were the main sources of heterogeneity. Greater dietary vitamin C intake was associated with a 33 % lower risk of osteoporosis (overall relative risk=0·67; 95 % CI 0·47, 0·94). Greater dietary vitamin C intake was associated with a lower risk of hip fracture and osteoporosis, as well as higher BMD, at femoral neck and lumbar spine.

Effects of French maritime pine bark extract (Oligopin®) supplementation on bone remodeling markers in postmenopausal osteopenic women: A randomized clinical trial

French maritime pine bark extract (FMPBE; Oligopin®), a dietary supplement, is rich in procyanidin. The objective of this study was to determine the effects of FMPBE on bone remodeling in postmenopausal osteopenic women. This randomized, double-blinded, placebo-controlled clinical trial was conducted on 40 postmenopausal osteopenic women. Individuals were randomly assigned to either FMPBE (250 mg/day, n = 21) or placebo (250-mg starch/day, n = 19) for 12 weeks. Biochemical indices, including bone remodeling marker, were assessed before and after the intervention. After the 12-week intervention, that is, FMPBE supplementation, a significant increase in bone alkaline phosphatase (BAP), procollagen type 1 amino-terminal propeptide (P1NP) levels and a significant decrease in C-terminal telopeptide of type I collagen (CTx1) were observed. Compared with the control group, FMPBE supplementation resulted in a significant increase in P1NP (0.015), BAP levels (0.001), and BAP/CTx1 ratio (p = 0.001) and a significant decrease in CTx1 levels (0.006). FMPBE supplementation for 12 weeks in postmenopausal osteopenic women produced favorable effects on bone markers. Meanwhile, further research is needed to determine whether FMPBE supplements can be used as a preventive strategy for bone loss in postmenopausal osteopenic women.

SLAF-Based Construction of a High-Density Genetic Map and Its Application in QTL Mapping of Carotenoids Content in Citrus Fruit

Carotenoids are important antioxidant components in the human diet. To develop carotenoid-rich agricultural products by genetic intervention, understanding the genetic basis of carotenoids variation is essential. In this study, we constructed a high-density integrated genetic map with 3817 molecular markers using specific locus amplified fragment (SLAF) sequencing from a C. reticulata × P. trifoliata F₁ pseudotestcross population. A total of 17 significant quantitative trait loci (QTLs) distributed on Chromosomes (Chr) 2, 3, 5, 6, and 9 were detected to determine the carotenoid variation in the population. In particular, three QTL colocalizations for multiple carotenoid constituents were observed on Chr 2, 3, and 9, one of which was located on Chr2:34,654,608-35430715 accounted for 20.1-25.4% of the variation of luteoxanthin, auroxanthin, lutein, violaxanthin, and total carotenoid content. Overall, this study provides a genetic foundation for marker-assisted selection (MAS) breeding of nutritionally enhanced citrus fruit.

β-Cryptoxanthin Reduces Body Fat and Increases Oxidative Stress Response in Caenorhabditis elegans Model

β-Cryptoxanthin (BCX) is a major dietary pro-vitamin A carotenoid, found mainly in fruits and vegetables. Several studies showed the beneficial effects of BCX on different aspects of human health. In spite of the evidence, the molecular mechanisms of action of BCX need to be further investigated. The Caenorhabditis elegans model was used to analyze in vivo the activity of BCX on fat reduction and protection to oxidative stress. Dose-response assays provided evidence of the efficacy of BCX at very low dose (0.025 µg/mL) (p < 0.001) on these processes. Moreover, a comparative analysis with other carotenoids, such as lycopene and β-carotene, showed a stronger effect of BCX. Furthermore, a transcriptomic analysis of wild-type nematodes supplemented with BCX revealed upregulation of the energy metabolism, response to stress, and protein homeostasis as the main metabolic targets of this xanthophyll. Collectively, this study provides new in vivo evidence of the potential therapeutic use of BCX in the prevention of diseases related to metabolic syndrome and aging.

Intrinsic and Extrinsic Factors Impacting Absorption, Metabolism, and Health Effects of Dietary Carotenoids

Carotenoids are orange, yellow, and red lipophilic pigments present in many fruit and vegetables, as well as other food groups. Some carotenoids contribute to vitamin A requirements. The consumption and blood concentrations of specific carotenoids have been associated with reduced risks of a number of chronic conditions. However, the interpretation of large, population-based observational and prospective clinical trials is often complicated by the many extrinsic and intrinsic factors that affect the physiologic response to carotenoids. Extrinsic factors affecting carotenoid bioavailability include food-based factors, such as co-consumed lipid, food processing, and molecular structure, as well as environmental factors, such as interactions with prescription drugs, smoking, or alcohol consumption. Intrinsic, physiologic factors associated with blood and tissue carotenoid concentrations include age, body composition, hormonal fluctuations, and variation in genes associated with carotenoid absorption and metabolism. To most effectively investigate carotenoid bioactivity and to utilize blood or tissue carotenoid concentrations as biomarkers of intake, investigators should either experimentally or statistically control for confounding variables affecting the bioavailability, tissue distribution, and metabolism of carotene and xanthophyll species. Although much remains to be investigated, recent advances have highlighted that lipid co-consumption, baseline vitamin A status, smoking, body mass and body fat distribution, and genetics are relevant covariates for interpreting blood serum or plasma carotenoid responses. These and other intrinsic and extrinsic factors are discussed, highlighting remaining gaps in knowledge and opportunities for future research. To provide context, we review the state of knowledge with regard to the prominent health effects of carotenoids.

Higher dietary carotenoid intake associated with lower risk of hip fracture in middle-aged and elderly Chinese: A matched case-control study

BACKGROUND

Mechanism studies have suggested that carotenoids may benefit bone health due to their antioxidant properties, but epidemiological data on their effects on risk of hip fracture are sparse.

PURPOSE

To explore the relationships between dietary total and specific carotenoids and the risk of hip fracture in a middle-aged and elderly Chinese population.

DESIGN

A case-control study of 1070 patients with hip fractures (diagnosed within 2 weeks) aged 55-80 years and 1070 age- (within 3 years) and gender-matched controls was conducted in Guangdong, China between 2009 and 2015. Information on dietary carotenoid intake was assessed using a 79-item food frequency questionnaire administered in face-to-face interviews, and general information was collected using structured questionnaires. The univariate and multivariate conditional logistic regression models were applied to analyze the associations.

MAIN RESULTS

Higher intakes of both total and some specific carotenoids (including β-carotene, β-cryptoxanthin and lutein/zeaxanthin) were significantly associated with a lower risk of hip fracture (all p trends <0.01). Compared with the lowest quartile of carotenoids, the multivariate-adjusted odds ratios and 95% confidential intervals of the highest quartile were 0.44 (0.29, 0.68) (total carotenoids), 0.50 (0.29, 0.69) (β-carotene), 0.55 (0.38, 0.80) (β-cryptoxanthin) and 0.40 (0.27, 0.59) (lutein/zeaxanthin), respectively. There were no statistically significant associations between α-carotene and lycopene intakes and hip fracture risk after adjustment for various confounding variables.

CONCLUSION

These results suggest that the consumption of carotenoids may be protective against hip fracture in middle-aged and elderly Chinese adults.

Inferring causal relationships between phenotypes using summary statistics from genome-wide association studies

Genome-wide association studies (GWAS) have successfully identified numerous genetic variants associated with diverse complex phenotypes and diseases, and provided tremendous opportunities for further analyses using summary association statistics. Recently, Pickrell et al. developed a robust method for causal inference using independent putative causal SNPs. However, this method may fail to infer the causal relationship between two phenotypes when only a limited number of independent putative causal SNPs identified. Here, we extended Pickrell's method to make it more applicable for the general situations. We extended the causal inference method by replacing the putative causal SNPs with the lead SNPs (the set of the most significant SNPs in each independent locus) and tested the performance of our extended method using both simulation and empirical data. Simulations suggested that when the same number of genetic variants is used, our extended method had similar distribution of test statistic under the null model as well as comparable power under the causal model compared with the original method by Pickrell et al. But in practice, our extended method would generally be more powerful because the number of independent lead SNPs was often larger than the number of independent putative causal SNPs. And including more SNPs, on the other hand, would not cause more false positives. By applying our extended method to summary statistics from GWAS for blood metabolites and femoral neck bone mineral density (FN-BMD), we successfully identified ten blood metabolites that may causally influence FN-BMD. We extended a causal inference method for inferring putative causal relationship between two phenotypes using summary statistics from GWAS, and identified a number of potential causal metabolites for FN-BMD, which may provide novel insights into the pathophysiological mechanisms underlying osteoporosis.

Carotenoids and risk of fracture: a meta-analysis of observational studies

To quantify the association between dietary and circulating carotenoids and fracture risk, a meta-analysis was conducted by searching MEDLINE and EMBASE databases for eligible articles published before May 2016. Five prospective and 2 case-control studies with 140,265 participants and 4,324 cases were identified in our meta-analysis. Among which 5 studies assessed the association between dietary carotenoids levels and hip fracture risk, 2 studies focused on the association between circulating carotenoids levels and any fracture risk. A random-effects model was employed to summarize the risk estimations and their 95% confidence intervals (CIs). Hip fracture risk among participants with high dietary total carotenoids intake was 28% lower than that in participants with low dietary total carotenoids (OR: 0.72; 95% CI: 0.51, 1.01). A similar risk of hip fracture was found for β-carotene based on 5 studies, the summarized OR for high vs. low dietary β-carotene was 0.72 (95% CI: 0.54, 0.95). However, a significant between-study heterogeneity was found (total carotene: I2 = 59.4%, P = 0.06; β-carotene: I2 = 74.4%, P = 0.04). Other individual carotenoids did not show significant associations with hip fracture risk. Circulating carotene levels had no significant association with any fracture risk, the pooled OR (95% CI) was 0.83 (0.59, 1.17). Based on the evidence from observational studies, our meta-analysis supported the hypothesis that higher dietary total carotenoids or β-carotene intake might be potentially associated with a low risk of hip fracture, however, future well-designed prospective cohort studies and randomized controlled trials are warranted to specify the associations between carotenoids and fracture.

Association between lumbar bone mineral density and serum uric acid in postmenopausal women: a cross-sectional study of healthy Chinese population

Partial correlation and regression analyses were used in this study. We showed that there is a linear relationship between bone mineral density and serum uric acid within the normal physiologic range, and higher serum uric acid levels had a protective effect on bone loss in postmenopausal osteoporosis.

PURPOSE

The significance of the relationship between lumbar bone mineral density ⁽BMD) and serum uric acid (SUA) levels is unclear. The aims of this study were to investigate on a population-level the association between lumbar BMD and SUA within the normal physiologic range and to determine whether SUA plays a protective role in bone loss in healthy postmenopausal Chinese women.

METHODS

This was a community-based cross-sectional study involving 390 healthy postmenopausal women, 47-89 years of age, conducted in Shenyang, China. The BMD was measured at the lumbar spine using dual-energy X-ray absorptiometry (DXA). The SUA levels were obtained at each DXA visit. Partial correlation and regression analyses were applied to determine the associations.

RESULTS

The SUA levels were significantly different between the normal BMD, osteopenia, and osteoporosis groups. The lumbar BMD was positively correlated with SUA in postmenopausal women after adjustment for age (r = 0.212). After adjustment for age, body mass index, systolic blood pressure, diastolic blood pressure, hip circumference, cigarette smoking, alcohol consumption, milk intake, physical exercise, fracture history, total protein, total bilirubin, triglycerides, total cholesterol, high-density lipoprotein cholesterol, fasting blood glucose, serum calcium, and estimated glomerular filtration rate, the lumbar BMD was associated with SUA and the odds ratio of the third SUA quartile was 0.408 (95%CI, 0.198-0.841, P = 0.015), compared to the first quartile of SUA levels.

CONCLUSION

The lumbar BMD was linearly associated with SUA levels within the normal physiologic range of postmenopausal women. Higher SUA levels had a protective effect on bone loss in postmenopausal osteoporosis.

Association between Dietary Carotenoid Intake and Bone Mineral Density in Korean Adults Aged 30-75 Years Using Data from the Fourth and Fifth Korean National Health and Nutrition Examination Surveys (2008-2011)

Age-related bone loss is a major public health problem. This cross-sectional study examined the association between the dietary intake of carotenoids and bone mineral density (BMD). Data from 8022 subjects (3763 males and 4259 females) aged 30–75 years included in the Korean National Health and Nutrition Examination Survey (2008–2011) were analyzed. BMD was measured by dual-energy X-ray absorptiometry. Intake of carotenoids was estimated using 24-h dietary recall. In multiple linear analysis, after adjusting for covariates, lutein + zeaxanthin and β-cryptoxanthin intake was positively associated with total hip BMD in males and premenopausal women respectively, while β-carotene intake was positively correlated with femoral neck, total hip, and whole-body BMD in postmenopausal women. Postmenopausal women in the highest quintile of daily β-carotene intake, showed a lower risk of osteopenia at the lumbar spine (odds ratio (OR): 0.35, 95% CI: 0.16–0.79, P for trend = 0.009) than those in the lowest quintile, after adjusting for covariates. Daily β-cryptoxanthin intake was significantly associated with a lower risk of osteopenia at the total hip (OR per 1 mg/day increase: 0.76; 95% CI: 0.59–0.97), and lumbar spine (OR per 1 mg/day increase: 0.79; 95% CI: 0.70–0.89) in postmenopausal women. These results suggest that the dietary intake of β-carotene and β-cryptoxanthin may have a positive effect on bone health.

Allelic diversity of phytoene synthase gene influences the transcription level in citrus fruit among a citrus F1 hybrid population

Phytoene synthase (PSY) is one of the key regulatory enzyme on the biosynthesis and accumulation of carotenoid in citrus fruits. The transcriptional diversity of PSY is mainly attributed to the structural variation in promoter region among PSY alleles. In aim to clarify how this transcriptional diversity is regulated among them, PSY alleles responsible for carotenoid biosynthesis in the fruits are characterized and their promoter sequences were compared. Based on gene structure and expression pattern of PSY homologues on the clementine mandarin genome sequence, PSY alleles responsible for carotenoid biosynthesis are derived from a single locus in the scaffold 6. AG mapping population possessed four PSY alleles derived from parent lines of A255 and G434, and their F₁ individuals with PSY-g2 allele tended to have low transcription level. From sequence comparison of their promoter regions, the cis-motif alternation from MYBPZM to RAV1AAT might be a candidate to influence the transcription level. Among the ancestral pedigree varieties of AG mapping population, the transcription level of PSY correlated with genotypes of MYBPZM and RAV1AAT motifs in the promoter region of PSY alleles, so that homozygous genotype of MYBPZM showed higher transcription level while heterozygous genotype of MYBPZM and RAV1AAT showed lower transcription level.

Identification and quantitative analysis of β-cryptoxanthin and β-citraurin esters in Satsuma mandarin fruit during the ripening process

In this study, to investigate the xanthophyll accumulation in citrus fruits, the major fatty acid esters of β-cryptoxanthin and β-citraurin were identified, and changes in their contents were investigated in two Satsuma mandarin varieties, 'Miyagawa-wase' and 'Yamashitabeni-wase', during the ripening process. The results showed that β-cryptoxanthin and β-citraurin were mainly esterified with lauric acid, myristic acid, and palmitic acid in citrus fruits. During the ripening process, β-cryptoxanthin laurate, myristate, and palmitate were accumulated gradually in the flavedos and juice sacs of the two varieties. In the flavedo of 'Yamashitabeni-wase', β-citraurin laurate, myristate, and palmitate were specifically accumulated, and their contents increased rapidly with a peak in November. In addition, functional analyses showed that CitCCD1 and CitCCD4 efficiently cleaved the free β-cryptoxanthin, but not the β-cryptoxanthin esters in vitro. The substrate specificity of CitCCDs towards free β-cryptoxanthin indicated that β-cryptoxanthin esters might be more stable than free β-cryptoxanthin in citrus fruits.

Carotenoid dietary intakes and plasma concentrations are associated with heel bone ultrasound attenuation and osteoporotic fracture risk in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort

Carotenoids are found in abundance in fruit and vegetables, and may be involved in the positive association of these foods with bone health. This study aimed to explore the associations of dietary carotenoid intakes and plasma concentrations with bone density status and osteoporotic fracture risk in a European population. Cross-sectional analyses (n 14 803) of bone density status, using calcaneal broadband ultrasound attenuation (BUA) and longitudinal analyses (n 25 439) of fracture cases were conducted on data from the prospective European Prospective Investigation into Cancer and Nutrition-Norfolk cohort of middle-aged and older men and women. Health and lifestyle questionnaires were completed, and dietary nutrient intakes were derived from 7-d food diaries. Multiple regression demonstrated significant positive trends in BUA for women across quintiles of dietary α-carotene intake (P=0·029), β-carotene intake (P=0·003), β-cryptoxanthin intake (P=0·031), combined lutein and zeaxanthin intake (P=0·010) and lycopene intake (P=0·005). No significant trends across plasma carotenoid concentration quintiles were apparent (n 4570). The Prentice-weighted Cox regression showed no trends in fracture risk across dietary carotenoid intake quintiles (mean follow-up time 12·5 years), except for a lower risk for wrist fracture in women with higher lutein and zeaxanthin intake (P=0·022); nevertheless, inter-quintile differences in fracture risk were found for both sexes. Analysis of plasma carotenoid data (mean follow-up time 11·9 years) showed lower hip fracture risk in men across higher plasma α-carotene (P=0·026) and β-carotene (P=0·027) quintiles. This study provides novel evidence that dietary carotenoid intake is relevant to bone health in men and women, demonstrating that associations with bone density status and fracture risk exist for dietary intake of specific carotenoids and their plasma concentrations.

High Vitamin C Intake with High Serum β-Cryptoxanthin Associated with Lower Risk for Osteoporosis in Post-Menopausal Japanese Female Subjects: Mikkabi Cohort Study

Recent epidemiological studies show that antioxidant vitamins and carotenoids might be beneficial to the maintenance of bone health. Recently, we found that serum carotenoids were inversely associated with the risk of developing osteoporosis in post-menopausal Japanese female subjects. However, little is known about the vitamin alone and/or the combination of the vitamin and carotenoid with the risk of osteoporosis. The objective of this study was to investigate longitudinally whether antioxidant vitamins and their combination with carotenoids are associated with the risk of developing of osteoporosis. We conducted a follow-up study on 187 post-menopausal female subjects from the Mikkabi prospective cohort study. Those who participated in previous bone mineral density (BMD) surveys and completed four years of follow-up were examined longitudinally. During a four-year follow-up, fifteen of the post-menopausal female subjects developed new-onset osteoporosis. After adjustment for confounders, the odds ratios (OR) for osteoporosis in the highest tertiles of vitamins C and E and retinol intakes against the lowest tertiles were 0.15 (95% confidence interval (CI): 0.02-0.99), 0.50 (CI: 0.08-3.23), and 1.49 (CI: 0.36-6.22), respectively. Furthermore, a significantly lower odds ratio was observed in the higher vitamin C intake group (169-625 mg/d) with higher serum β-cryptoxanthin (1.88-10.53 μM) against the lower vitamin C intake group (47-168 mg/d) with lower serum β-cryptoxanthin (0.24-1.84 μM) used for the reference group (p<0.05). The combination of β-cryptoxanthin and vitamin C is inversely associated with the risk of developing osteoporosis in post-menopausal Japanese female subjects.

[β-Cryptoxanthin and the risk for lifestyle-related disease: findings from recent nutritional epidemiologic studies]

  Antioxidant micronutrients, such as vitamins and carotenoids, exist in abundance in fruits and vegetables and have been known to contribute to the body's defense against reactive oxygen species. Numerous recent epidemiologic studies have demonstrated that a high dietary consumption of fruit and vegetables rich in carotenoids or with high serum carotenoid concentrations results in lower risks of certain cancers, diabetes, and cardiovascular disease. These epidemiologic studies have suggested that antioxidant carotenoids may have a protective effect against several lifestyle-related diseases. β-Cryptoxanthin is a carotenoid pigment found in Japanese mandarin (Citrus unshiu MARC.) fruit, which is mainly produced in Japan. Our nutritional epidemiologic survey, the Mikkabi Study, utilized data derived from health examinations of inhabitants performed in the town of Mikkabi in Shizuoka, Japan. In this survey, we measured serum β-cryptoxanthin as a specific biomarker to estimate the consumption of Japanese mandarin fruit. From the cross-sectional analyses from the Mikkabi Study, we found inverse associations of serum β-cryptoxanthin with the risks for atherosclerosis, insulin resistance, liver dysfunction, metabolic syndrome, low bone mineral density, and oxidative stress. In this review, recent epidemiologic studies about the associations between serum β-cryptoxanthin with the risk for several lifestyle-related diseases were reviewed.

Current Evidence on the Association of Dietary Patterns and Bone Health: A Scoping Review

Nutrition is an important modifiable factor that affects bone health. Diet is a complex mixture of nutrients and foods that correlate or interact with each other. Dietary pattern approaches take into account contributions from various aspects of diet. Findings from dietary pattern studies could complement those from single-nutrient and food studies on bone health. In this study we aimed to conduct a scoping review of the literature that assessed the impact of dietary patterns (derived with the use of both a priori and data-driven approaches) on bone outcomes, including bone mineral status, bone biomarkers, osteoporosis, and fracture risk. We retrieved 49 human studies up to June 2016 from the PubMed, Embase, and CINAHL databases. Most of these studies used a data-driven method, especially factor analysis, to derive dietary patterns. Several studies examined adherence to a variety of the a priori dietary indexes, including the Mediterranean diet score, the Healthy Eating Index (HEI), and the Alternative Healthy Eating Index (AHEI). The bone mineral density (BMD) diet score was developed to measure adherence to a dietary pattern beneficial to bone mineral density. Findings revealed a beneficial impact of higher adherence to a "healthy" dietary pattern derived using a data-driven method, the Mediterranean diet, HEI, AHEI, Dietary Diversity Score, Diet Quality Index-International, BMD Diet Score, Healthy Diet Indicator, and Korean Diet Score, on bone. In contrast, the "Western" dietary pattern and those featuring some aspects of an unhealthy diet were associated inversely with bone health. In both a priori and data-driven dietary pattern studies, a dietary pattern that emphasized the intake of fruit, vegetables, whole grains, poultry and fish, nuts and legumes, and low-fat dairy products and de-emphasized the intake of soft drinks, fried foods, meat and processed products, sweets and desserts, and refined grains showed a beneficial impact on bone health. Overall, adherence to a healthy dietary pattern consisting of the above-mentioned food groups can improve bone mineral status and decrease osteoporosis and fracture risk.

Association between serum uric acid and bone health in general population: a large and multicentre study

Previous studies proposed that serum uric acid (UA), an endogenous antioxidant, could be a protective factor against bone loss. However, recently, a study with a population of US adults did not note the protective effects of serum UA. Therefore, the exact association between serum UA and bone health remains unclear. We performed a retrospective consecutive cohort study in a Chinese population to examine the association between serum UA and bone health. This cross-sectional study included 17,735 individuals who underwent lumbar spine bone mineral density (BMD) measurements as part of a health examination. In covariance analyses (multivariable-adjusted), a high serum UA level was associated with a high BMD, T-score, and Z-score. In binary logistic regression analyses (multivariable-adjusted), a high serum UA level was associated with low odds ratios (ORs) for at least osteopenia and osteoporosis in male (age ≥50 years) (OR = 0.72-0.60 and OR = 0.49-0.39, respectively) and postmenopausal female participants (OR = 0.61-0.51 and OR = 0.66-0.49, respectively). In conclusion, serum UA is associated with BMD, the T-score, and the Z-score, and has a strong protective effect against at least osteopenia and osteoporosis.

Expression and functional analysis of citrus carotene hydroxylases: unravelling the xanthophyll biosynthesis in citrus fruits

BACKGROUND

Xanthophylls are oxygenated carotenoids and fulfill critical roles in plant growth and development. In plants, two different types of carotene hydroxylases, non-heme di-iron and heme-containing cytochrome P450, were reported to be involved in the biosynthesis of xanthophyll. Citrus fruits accumulate a high amount of xanthophylls, especially β,β-xanthophylls. To date, however, the roles of carotene hydroxylases in regulating xanthophyll content and composition have not been elucidated.

RESULTS

In the present study, the roles of four carotene hydroxylase genes (CitHYb, CitCYP97A, CitCYP97B, and CitCYP97C) in the biosynthesis of xanthophyll in citrus fruits were investigated. Phylogenetic analysis showed that the four citrus carotene hydroxylases presented in four distinct clusters which have been identified in higher plants. CitHYb was a non-heme di-iron carotene hydroxylase, while CitCYP97A, CitCYP97B, and CitCYP97C were heme-containing cytochrome P450-type carotene hydroxylases. Gene expression results showed that the expression of CitHYb increased in the flavedo and juice sacs during the ripening process, which was well consistent with the accumulation of β,β-xanthophyll in citrus fruits. The expression of CitCYP97A and CitCYP97C increased with a peak in November, which might lead to an increase of lutein in the juice sacs during the ripening process. The expression level of CitCYP97B was much lower than that of CitHYb, CitCYP97A, and CitCYP97C in the juice sacs during the ripening process. Functional analysis showed that the CitHYb was able to catalyze the hydroxylation of the β-rings of β-carotene and α-carotene in Escherichia coli BL21 (DE3) cells. Meanwhile, when CitHYb was co-expressed with CitCYP97C, α-carotene was hydroxylated on the β-ring and ε-ring sequentially to produce lutein.

CONCLUSIONS

CitHYb was a key gene for β,β-xanthophyll biosynthesis in citrus fruits. CitCYP97C functioned as an ε-ring hydroxylase to produce lutein using zeinoxanthin as a substrate. The results will contribute to elucidating xanthophyll biosynthesis in citrus fruits, and provide new strategies to improve the nutritional and commercial qualities of citrus fruits.

Absorption, metabolism, and functions of β-cryptoxanthin

β-Cryptoxanthin, a carotenoid found in fruits and vegetables such as tangerines, red peppers, and pumpkin, has several functions important for human health. Most evidence from observational, in vitro, animal model, and human studies suggests that β-cryptoxanthin has relatively high bioavailability from its common food sources, to the extent that some β-cryptoxanthin-rich foods might be equivalent to β-carotene-rich foods as sources of retinol. β-Cryptoxanthin is an antioxidant in vitro and appears to be associated with decreased risk of some cancers and degenerative diseases. In addition, many in vitro, animal model, and human studies suggest that β-cryptoxanthin-rich foods may have an anabolic effect on bone and, thus, may help delay osteoporosis.

Diversity in the carotenoid profiles and the expression of genes related to carotenoid accumulation among citrus genotypes

Carotenoids are not only important to the plants themselves but also are beneficial to human health. Since citrus fruit is a good source of carotenoids for the human diet, it is important to study carotenoid profiles and the accumulation mechanism in citrus fruit. Thus, in the present paper, we describe the diversity in the carotenoid profiles of fruit among citrus genotypes. In regard to carotenoids, such as β-cryptoxanthin, violaxanthin, lycopene, and β-citraurin, the relationship between the carotenoid profile and the expression of carotenoid-biosynthetic genes is discussed. Finally, recent results of quantitative trait locus (QTL) analyses of carotenoid contents and expression levels of carotenoid-biosynthetic genes in citrus fruit are shown.

Cross-sectional and prospective associations between dietary and plasma vitamin C, heel bone ultrasound, and fracture risk in men and women in the European Prospective Investigation into Cancer in Norfolk cohort

BACKGROUND

Vitamin C sufficiency may help prevent osteoporosis and fractures by mediating osteoclastogenesis, osteoblastogenesis, and bone collagen synthesis.

OBJECTIVE

We determined whether dietary intakes and plasma concentrations of vitamin C were associated with a heel ultrasound and hip and spine fracture risks in older men and women.

DESIGN

Participants were recruited from the European Prospective Investigation into Cancer in Norfolk study with 7-d diet diary estimates of vitamin C intake and plasma concentrations. A random subset (4000 of 25,639 subjects) was available for the cross-sectional (ultrasound) study of broadband ultrasound attenuation (BUA) and velocity of sound (VOS), which were determined during the second health examination. The prospective (fracture) study was a case-cohort sample of all participants with a fracture up to March 2009 and the random subset (n = 5319). ANCOVA-determined associations between quintiles of vitamin C intake and plasma status with adjusted BUA and VOS and adjusted Prentice-weighted Cox proportional HRs were calculated for fracture risk.

RESULTS

Women were 58% of the population (39-79 y old), and the median follow-up was 12.6 y (range: 0-16 y). Positive associations across all quintiles of vitamin C intake but not plasma status were significant for VOS in men (β = 2.47 m/s, P = 0.008) and BUA in women (β = 0.82 dB/MHz, P = 0.004). Vitamin C intake was not associated with fracture risk, but there was an inverse association with plasma concentrations in men, with quintile 4 having significantly lower risks of hip fractures (HR: 0.35; 95% CI: 0.16, 0.80) and spine fractures (HR: 0.26; 95% CI: 0.10, 0.69) than quintile 1.

CONCLUSIONS

Higher vitamin C intake was significantly associated with higher heel ultrasound measures in men and women, and higher plasma vitamin C concentrations were significantly associated with reduced fracture risk in men only. Our findings that vitamin C intake and status were inconsistently associated with bone health variables suggest that additional research is warranted.

The Roles and Mechanisms of Actions of Vitamin C in Bone: New Developments

Vitamin C is an important antioxidant and cofactor that is involved in the regulation of development, function, and maintenance of several cell types in the body. Deficiencies in vitamin C can lead to conditions such as scurvy, which, among other ailments, causes gingivia, bone pain, and impaired wound healing. This review examines the functional importance of vitamin C as it relates to the development and maintenance of bone tissues. Analysis of several epidemiological studies and genetic mouse models regarding the effect of vitamin C shows a positive effect on bone health. Overall, vitamin C exerts a positive effect on trabecular bone formation by influencing expression of bone matrix genes in osteoblasts. Recent studies on the molecular pathway for vitamin C actions that include direct effects of vitamin C on transcriptional regulation of target genes by influencing the activity of transcription factors and by epigenetic modification of key genes involved in skeletal development and maintenance are discussed. With an understanding of mechanisms involved in the uptake and metabolism of vitamin C and knowledge of precise molecular pathways for vitamin C actions in bone cells, it is possible that novel therapeutic strategies can be developed or existing therapies can be modified for the treatment of osteoporotic fractures.

Effect of blue LED light intensity on carotenoid accumulation in citrus juice sacs

In the present study, the effects of blue LED light intensity on carotenoid accumulation and expression of genes related to carotenoid biosynthesis were investigated in the juice sacs of Satsuma mandarin (Citrus unshiu Marc.) and Valencia orange (Citrus sinensis Osbeck) in vitro. The results showed that 100 μmol m(-2)s(-1) blue LED light (100B) was effective for increasing carotenoid content, especially β-cryptoxanthin, in Satsuma mandarin after cultured in vitro for four weeks. In Valencia orange, in contrast, 50 μmol m(-2)s(-1) blue LED light (50B) treatment was effective for inducing carotenoid accumulation through increasing the contents of two major carotenoids, all-trans-violaxanthin and 9-cis-violaxanthin. In addition, gene expression results showed that the simultaneous increases in the expression of genes (CitPSY, CitPDS, CitZDS, CitLCYb2, and CitHYb) involved in producing β,β-xanthophylls were well consistent with the accumulation of β-cryptoxanthin in Satsuma mandarin under 100B, and violaxanthin in Valencia orange under 50B. The results presented herein contribute to further elucidating the regulatory mechanism of carotenoid accumulation by blue LED light.

Favorable effect of dietary vitamin C on bone mineral density in postmenopausal women (KNHANES IV, 2009): discrepancies regarding skeletal sites, age, and vitamin D status

Dietary vitamin C intake showed significant positive associations with BMD in postmenopausal women, especially with vitamin D deficiency.

INTRODUCTION

Although there is a positive role of vitamin C in osteoblastogenesis, debate remains about the contribution of vitamin C to bone mineral density (BMD) in humans.

METHODS

Data were derived from the Fourth Korean National Health and Nutrition Examination Survey. Dietary information was assessed using a 24-h dietary recall questionnaire. BMD was measured by dual-energy X-ray absorptiometry at the lumbar and hip.

RESULTS

A total of 1,196 postmenopausal women aged 50 years and older were stratified into tertiles by daily dietary vitamin C intake. After adjusting for traditional confounders, dietary vitamin C intake tertile was significantly positively associated with BMD at all sites (R = 0.513 for lumbar spine (LS) and R = 0.657 for femoral neck (FN), P < 0.05 for each). The subjects with osteoporosis had significantly lower dietary vitamin C intake than did subjects without osteoporosis (74.4 ± 66.2 vs 94.1 ± 78.6 mg/day for LS and 65.5 ± 56.6 vs 94.3 ± 79.2 mg/day for FN, respectively, P < 0.001). The multiple-adjusted odds ratio for osteoporosis for dietary vitamin C <100 mg/day was 1.790 (95 % CI 1.333-2.405, P < 0.001). However, the significant association between vitamin C intake and BMD was only observed in subjects with vitamin D deficiency and aged 50-59 years or >70 years.

CONCLUSION

Dietary vitamin C intake was positively associated with BMD in postmenopausal women, and inadequate vitamin C intake could increase the risk of osteoporosis.

Impact of Dietary Habits and Physical Activity on Bone Health among 40 to 60 Year Old Females at Risk of Osteoporosis in India

Osteoporosis is a disorder of bones with increasing risk among women. However, a number of modifiable factors can help in combating this disorder. Present study examined the relationship of diet and physical activity and risk of osteoporosis through biochemical tests, bone mass density (BMD) scores, and standard questionnaires. Genetic risk for osteoporosis, presence of osteoarthritis, and thyroid problems were found among 8%, 7%, and 3% of participants, respectively; and 78% had onset of menopause between 47 to 55 years of age. Results revealed that less intake of proteins, minerals, and diverse fruit and vegetable consumption was significantly (p≤0.05; 0.01) correlated with decreased BMD score and serum calcium. It was concluded that adequate intake of varied fruits and vegetables, good protein, habit of daily physical activity, adequate sun exposure, and dietary calcium, may play a promising role in decreasing the risk of osteoporosis among women of this age group.