Longitudinal associations between body mass index and serum carotenoids: the CARDIA study

Protective effect of provitamin A dietary carotenoid intake on overweight/obesity and their relation to inflammatory and oxidative stress biomarkers - a case-control study

This investigation assessed associations between dietary carotenoid intake and the odds of overweight/obesity, as well as inflammatory/oxidative stress biomarkers, in 851 participants with overweight/obesity (BMI ≥25 kg m-2) and 754 normal-weight controls. A 124-item food-frequency-questionnaire (FFQ) and food composition databases were employed to estimate carotenoid intake. Binary logistic regressions assessed the association of carotenoid intake with the odds of overweight/obesity, adjusting for several potential confounders. Multiple linear regression models revealed associations between carotenoid intake and biomarkers (anthropometrics, blood lipids, inflammation, antioxidant status). Logistic regression models adjusted for various confounders and fruits and vegetables showed protective associations for provitamin A carotenoids (i.e., β-carotene + α-carotene + β-cryptoxanthin; odds ratio (OR): 0.655, p = 0.041) and astaxanthin (OR: 0.859, p = 0.017). Similarly adjusted multiple linear regressions revealed significant associations between several carotenoids and lower levels of interleukin (IL)-6, IL-1β, and TNF-α and increased IL-10 and total antioxidant capacity. Further analysis revealed that lycopene was significantly associated with increased odds of overweight/obesity (OR: 1.595, p = 0.032) in a model adjusted for various confounders and vegetables (i.e., unadjusted for fruits). A protective association between the sum of provitamin A carotenoid and astaxanthin dietary intake and the odds of having overweight/obesity was found. The findings that carotenoids other than lycopene were not or inversely associated with the odds of overweight/obesity may point toward differentiating effects of various carotenoids or their associations with different food groups. Provitamin A rich food items including fruits and vegetables appear to be a prudent strategy to reduce inflammation and the odds of having overweight/obesity.

The Potential Effects of Dietary Antioxidants in Obesity: A Comprehensive Review of the Literature

Obesity has become a global health concern, with its prevalence steadily increasing in recent decades. It is associated with numerous health complications, including cardiovascular diseases, diabetes, and certain types of cancer. The aetiology of obesity is multifactorial, involving genetic, environmental, and lifestyle factors. In recent years, oxidative stress has emerged as a potential contributor to obesity and its related metabolic disorders. Dietary antioxidants, which can counteract oxidative stress, have gained significant attention for their potential role in preventing and managing obesity. This comprehensive review aims to explore the impact of dietary antioxidants on obesity and its associated metabolic dysregulations, discussing the underlying mechanisms and highlighting the potential therapeutic implications.

Validation of resonance Raman spectroscopy-measured skin carotenoid status as a biomarker for fruit and vegetable intake in Korean adults

Blood carotenoid concentration measurement is considered the gold standard for fruit and vegetable (F&V) intake estimation; however, this method is invasive and expensive. Recently, skin carotenoid status (SCS) measured by optical sensors has been evaluated as a promising parameter for F&V intake estimation. In this cross-sectional study, we aimed to validate the utility of resonance Raman spectroscopy (RRS)-assessed SCS as a biomarker of F&V intake in Korean adults. We used data from 108 participants aged 20-69 years who completed SCS measurements, blood collection and 3-d dietary recordings. Serum carotenoid concentrations were quantified using HPLC, and dietary carotenoid and F&V intakes were estimated via 3-d dietary records using a carotenoid database for common Korean foods. The correlations of the SCS with serum carotenoid concentrations, dietary carotenoid intake and F&V intake were examined to assess SCS validity. SCS was positively correlated with total serum carotenoid concentration (r = 0·52, 95 % CI = 0·36, 0·64, P < 0·001), serum β-carotene concentration (r = 0·60, 95 % CI = 0·47, 0·71, P < 0·001), total carotenoid intake (r = 0·20, 95 % CI = 0·01, 0·37, P = 0·04), β-carotene intake (r = 0·30, 95 % CI = 0·11, 0·46, P = 0·002) and F&V intake (r = 0·40, 95 % CI = 0·23, 0·55, P < 0·001). These results suggest that SCS can be a valid biomarker of F&V intake in Korean adults.

Associations of serum carotenoids with visceral adiposity index and lipid accumulation product: a cross-sectional study based on NHANES 2001-2006

BACKGROUND

Visceral adiposity index (VAI) and lipid accumulation product (LAP) are comprehensive indicators to evaluate visceral fat and determine the metabolic health of individuals. Carotenoids are a group of naturally occurring antioxidants associated with several diseases. The purpose of this investigation was to explore the association between serum carotenoid concentration and VAI or LAP.

METHODS

The data were obtained from the National Health and Nutrition Examination Survey between 2001 and 2006. The levels of serum carotenoids were evaluated using high-performance liquid chromatography. Multivariate linear regression models were employed to investigate the relationship between levels of serum carotenoids and VAI or LAP. The potential non-linear relationship was determined using threshold effect analysis and fitted smoothing curves. Stratification analysis was performed to investigate the potential modifying factors.

RESULTS

In total, 5,084 participants were included in this population-based investigation. In the multivariate linear regressions, compared to the lowest quartiles of serum carotenoids, the highest quartiles were significantly associated with VAI, and the effect size (β) and 95% CI was - 0.98 (- 1.34, - 0.62) for α-carotene, - 1.39 (- 1.77, - 1.00) for β-carotene, - 0.79 (- 1.18, - 0.41) for β-cryptoxanthin, - 0.68 (- 0.96, - 0.39) for lutein/zeaxanthin, and - 0.88 (- 1.50, - 0.27) for trans-lycopene. Using piece-wise linear regression models, non-linear relationships were found between β-carotene and trans-lycopene and VAI with an inflection point of 2.44 (log2-transformed, ug/dL) and 3.80 (log2-transformed, ug/dL), respectively. The results indicated that α-carotene, β-cryptoxanthin, and lutein/zeaxanthin were linearly associated with VAI. An inverse association was also found between serum carotenoids and LAP after complete adjustments.

CONCLUSION

This study revealed that several serum carotenoids were associated with VAI or LAP among the general American population. Further large prospective investigations are warranted to support this finding.

Changes in Plasma Carotenoid Concentrations during the AntioxObesity Weight Reduction Program among Adults with Excessive Body Weight

Plasma carotenoid concentrations are associated with antioxidant defense which might be disturbed in people with excessive body weight (EBW). This study aimed at evaluating the effect of a 6-week weight reduction program on plasma concentration of β-carotene, lycopene, and lutein/zeaxanthin in adults with EBW. A total of 130 adults were recruited for the study; 75 completed the program. Data on food consumption were collected with a 3-day recording method and a semi-quantitative FFQ. Body height, body weight (BW), waist circumference (WC), fat mass (FM), fat-free mass (FFM), abdominal subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) were measured. Lipid profile, β-carotene, lycopene, and lutein/zeaxanthin were analyzed in blood. The AntioxObesity program resulted in a significant reduction in BW, WC, FM, SAT, and VAT. The mean plasma concentrations of β-carotene, lycopene, and lutein/zeaxanthin increased significantly after intervention. A reduction in FM above 4 kg significantly increased the concentration of β-carotene, lutein/zeaxanthin, and total carotenoids. An increase in carotenoid levels correlated with FM reduction, as fruit and vegetable intake remained unchanged. However, this effect may vary due to gender, HDL-cholesterol, body fat content, and obesity status in the weight loss process.

The Contribution of Hippocampal All-Trans Retinoic Acid (ATRA) Deficiency to Alzheimer's Disease: A Narrative Overview of ATRA-Dependent Gene Expression in Post-Mortem Hippocampal Tissue

There is accumulating evidence that vitamin A (VA) deficiency contributes to the pathogenesis and progression of Alzheimer's disease (AD). All-trans retinoic acid (ATRA), a metabolite of VA in the brain, serves distinct roles in the human hippocampus. Agonists of retinoic acid receptors (RAR), including ATRA, promote activation of the non-amyloidogenic pathway by enhancing expression of α-secretases, providing a mechanistic basis for delaying/preventing amyloid beta (Aβ) toxicity. However, whether ATRA is actually deficient in the hippocampi of patients with AD is not clear. Here, using a publicly available human transcriptomic dataset, we evaluated the extent to which ATRA-sensitive genes are dysregulated in hippocampal tissue from post-mortem AD brains, relative to age-matched controls. Consistent with ATRA deficiency, we found significant dysregulation of many ATRA-sensitive genes and significant upregulation of RAR co-repressors, supporting the idea of transcriptional repression of ATRA-mediated signaling. Consistent with oxidative stress and neuroinflammation, Nrf2 and NfkB transcripts were upregulated, respectively. Interestingly, transcriptional targets of Nrf2 were not upregulated, accompanied by upregulation of several histone deacetylases. Overall, our investigation of ATRA-sensitive genes in the human hippocampus bolsters the scientific premise of ATRA depletion in AD and that epigenetic factors should be considered and addressed as part of VA supplementation.

A Review of the Anti-Obesity Effects of Wild Edible Plants in the Mediterranean Diet and Their Active Compounds: From Traditional Uses to Action Mechanisms and Therapeutic Targets

Obesity is a long-term condition resulting from a continuous imbalance between the amount of energy consumed and expended. It is associated with premature mortality and contributes to a large portion of the global chronic disease burden, including diabesity, cardiovascular disease, hypertension, and some cancers. While lifestyle changes and dietary adjustments are the primary ways to manage obesity, they may not always be sufficient for long-term weight loss. In these cases, medication may be necessary. However, the options for drugs are limited due to their potential side effects. As a result, there is a need to identify safe and effective alternative treatments. Recently, dietary compounds, plants, and bioactive phytochemicals have been considered as promising sources for discovering new pharmacological agents to treat obesity and its related complications. These natural products can function independently or synergistically with other plants to augment their effects at various levels of the body. They can modulate appetite, lipase activity, thermogenesis and fat synthesis and degradation, satiation, adipogenesis, and adipocyte apoptosis. Additionally, targeting adipocyte growth and differentiation with diverse medicinal plants/diet is a significant strategy for devising new anti-obesity drugs that can intervene in preadipocytes, maturing preadipocytes, and mature adipocytes. Clinical trials have shown that the wild edible plants in the Mediterranean diet can reduce the risk of obesity and its related diseases. This review examines the effectiveness of the common components of the Mediterranean diet in managing obesity and its associated health issues. We conducted a comprehensive literature review using PubMed, Science Direct, Google Scholar, and Medline Plus to gather data on the therapeutic effects of the Mediterranean diet and phytochemicals in treating obesity and its associated diseases.

Safety, Tolerability, and Pharmacokinetics of β-Cryptoxanthin Supplementation in Healthy Women: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

β-cryptoxanthin is a dietary carotenoid for which there have been few studies on the safety and pharmacokinetics following daily oral supplementation.

METHODS

90 healthy Asian women between 21 and 35 years were randomized into three groups: 3 and 6 mg/day oral β-cryptoxanthin, and placebo. At 2, 4, and 8 weeks of supplementation, plasma carotenoid levels were measured. The effects of β-cryptoxanthin on blood retinoid-dependent gene expression, mood, physical activity and sleep, metabolic parameters, and fecal microbial composition were investigated.

RESULTS

β-cryptoxanthin supplementation for 8 weeks (3 and 6 mg/day) was found to be safe and well tolerated. Plasma β-cryptoxanthin concentration was significantly higher in the 6 mg/day group (9.0 ± 4.1 µmol/L) compared to 3 mg/day group (6.0 ± 2.6 µmol/L) (p < 0.03), and placebo (0.4 ± 0.1 µmol/L) (p < 0.001) after 8 weeks. Plasma all-trans retinol, α-cryptoxanthin, α-carotene, β-carotene, lycopene, lutein, and zeaxanthin levels were not significantly changed. No effects were found on blood retinol-dependent gene expression, mood, physical activity and sleep, metabolic parameters, and fecal microbial composition.

CONCLUSIONS

Oral β-cryptoxanthin supplementation over 8 weeks lead to high plasma concentrations of β-cryptoxanthin, with no impact on other carotenoids, and was well tolerated in healthy women.

Maternal High-Fat Diet Consumption in Sprague Dawley Rats Compromised the Availability and Altered the Tissue Distribution of Lutein in Neonatal Offspring

Lutein, the most abundant carotenoid in the infant eye and brain, is critical for their visual and cognitive development. Due to its lipophilic nature, a high adiposity may affect the tissue distribution of lutein. The aim of the study was to determine the impacts of a maternal high-fat diet (HFD) consumption on the status of lutein in the neonatal offspring. Female Sprague Dawley rats (n = 6) were fed a normal fat diet (NFD) or a HFD for 8 weeks before mating, and they were switched to an NFD or an HFD containing the same concentration of lutein ester during gestation and lactation. Rat pups (n = 7/group/time) were euthanized on postnatal day 2 (P2), P6, P11, and P20 for measuring tissue lutein concentrations. No significant difference in maternal lutein intake was found between the two groups. At both P6 and P11, a significantly lower lutein concentration was noted in the milk samples separated from the stomach of HFD pups than the concentration in the samples from the NFD pups; the HFD group showed a significantly lower lutein concentration in the liver. At P11, the HFD pups exhibited a significantly lower lutein concentration in the eye, brain, and brown adipose tissue accompanied with a significantly higher lutein concentration and mass in the visceral white adipose tissue. The study was the first to provide evidence that maternal HFD consumption resulted in a compromised availability and altered distribution of lutein in the neonatal offspring.

Associations of dietary antioxidant micronutrients with the prevalence of obesity in adults

Background

Antioxidant micronutrients have a therapeutic potential for clinical treatment of obesity. NO research, however, has examined the connection between the complex level of dietary antioxidants and obesity.

Materials and methods

We mainly aimed to investigate the relationship between a combination of antioxidants and obesity using the database of the national health and nutrition examination survey (NHANES). This cross-sectional study contains a survey of 41,021 people (≥18 years) in total ranging from 2005 to 2018. Multivariate logistic and weighted quantile sum (WQS) regression were performed to investigate the associations between these antioxidants, both individually and collectively, and the prevalence of obesity. The restricted cubic spline (RCS) regression was also utilized to analyze the linearity of these associations.

Results

According to multivariate logistic models, we found that the levels of most antioxidants in the highest quartile were independently related to a lower prevalence of obesity, while a reverse result was observed in selenium (p for trend &lt;0.05). The WQS index revealed that a total of the 11 antioxidants is negatively related to the prevalence of obesity and abdominal obesity (all p&lt;0.001), and iron/vitamin C have the greatest weight in the negative associations between antioxidant complex and obesity, as well as abdominal obesity. In addition, the RCS regression showed that retinol, vitamin A, α-carotene, β-carotene, β-cryptoxanthin, vitamin C, iron, and copper all had a non-linear association with obesity. Threshold effect analysis demonstrated that the inflection points of retinol, vitamin A, α-carotene, β-carotene, β-cryptoxanthin, vitamin C, iron, and cooper were 235.57, 374.81, 58.89, 891.44, 30.70, 43,410.00, 11,240.00, and 990.00 μg/day, respectively.

Conclusion

Our study found that a high level of a complex of 11 dietary antioxidants is related to a lower prevalence of obesity and abdominal obesity, among this inverse associations iron and vitamin C have the greatest weight.

A, Bhardwaj S, Yadav NK, Patel A, Patel A. Gut Microbiota Interventions for the Management of Obesity: A Literature Review

The gut microbiota (GM) has been recognized as an important factor in the development of metabolic diseases such as obesity; it has been reported that the composition of the GM differs in obese and lean subjects, suggesting that microbiota dysbiosis can contribute to changes in body weight. Dysbiosis occurs due to an imbalance in the composition of gut bacteria, changes in the metabolic process, or changes in the distribution of microbiota within the gut. Dysbiosis can change the functioning of the intestinal barrier and the gut-associated lymphoid tissues (GALT). Microbial manipulation may help with preventing or treating weight gain and associated comorbidities. Approaches to this may range from dietary manipulation, which is suitable to treat the individual’s microflora, to probiotics, prebiotics, synbiotics, and fecal microbiota transplant (FMT).

Pre-Operative Assessment of Micronutrients, Amino Acids, Phospholipids and Oxidative Stress in Bariatric Surgery Candidates

Obesity has been linked to lower concentrations of fat-soluble micronutrients and higher concentrations of oxidative stress markers as well as an altered metabolism of branched chain amino acids and phospholipids. In the context of morbid obesity, the aim of this study was to investigate whether and to which extent plasma status of micronutrients, amino acids, phospholipids and oxidative stress differs between morbidly obese (n = 23) and non-obese patients (n = 13). In addition to plasma, malondialdehyde, retinol, cholesterol and triglycerides were assessed in visceral and subcutaneous adipose tissue in both groups. Plasma γ-tocopherol was significantly lower (p < 0.011) in the obese group while other fat-soluble micronutrients showed no statistically significant differences between both groups. Branched-chain amino acids (all p < 0.008) and lysine (p < 0.006) were significantly higher in morbidly obese patients compared to the control group. Malondialdehyde concentrations in both visceral (p < 0.016) and subcutaneous (p < 0.002) adipose tissue were significantly higher in the morbidly obese group while plasma markers of oxidative stress showed no significant differences between both groups. Significantly lower plasma concentrations of phosphatidylcholine, phosphatidylethanolamine, lyso-phosphatidylethanolamine (all p < 0.05) and their corresponding ether-linked analogs were observed, which were all reduced in obese participants compared to the control group. Pre-operative assessment of micronutrients in patients undergoing bariatric surgery is recommended for early identification of patients who might be at higher risk to develop a severe micronutrient deficiency post-surgery. Assessment of plasma BCAAs and phospholipids in obese patients might help to differentiate between metabolic healthy patients and those with metabolic disorders.

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.

Lutein and Zeaxanthin Distribution in the Healthy Macula and Its Association with Various Demographic Factors Examined in Pseudophakic Eyes

The macular pigment consisting of lutein (L) and zeaxanthin (Z) protects photoreceptors via its antioxidative and barrier activities. This study aimed to determine L and Z distribution in the healthy macula and their association with various demographic factors. Macular pigment optical density (MPOD) was measured using fundus autofluorescence spectroscopy in 352 pseudophakic eyes with no fundus diseases. Pseudophakia was chosen to avoid the influence of cataract in the measurement of fundus autofluorescence. The mean patient age was 72.3 ± 8.6 years. MPOD was analyzed separately in three zones, i.e., A: a central area within a radius of 0.5°, mainly containing Z; B: a ring area with radii from 0.5° to 1.3°, containing Z and L; C: a ring area with radii from 1.3° to 9°, containing L. Multivariate analyses were performed with MPOD as the dependent variable and sex, supplement intake, smoking habits, glaucoma, diabetes, age, body mass index (BMI), skin carotenoid levels, retinal thickness, retinal volume, axial length as the independent variables. The mean total MPOD volume within 9° eccentricity was 20,121 ± 6293. Age was positively associated with MPOD in all zones. Supplement and BMI were positively and negatively associated with MPOD in zones B and C. Smoking was negatively associated with MPOD in zone A. This study revealed the standard MP values of aged Japanese, which resulted to be higher than the previously reported values in other races. Age was found to have a positive association with MP values. L in the outer foveola was affected by BMI and supplements, but Z in the foveola was not. The amount of Z in the Müller cell cone may not be changed easily by factors such as hunger and satiety in the context of preservation of homeostasis in the human body, but tobacco had a negative effect on Z.

Virtual Grocery Store: Fostering Healthy Nutrition among Seniors

AtlantiCare Health System provides health care services to residents in Atlantic City, an urban food desert in southern New Jersey. The purpose of this study is to explore baseline data on the first four months of the program to better understand participants purchasing behaviors. To improve the health of Atlantic City seniors, AltantiCare established a Virtual Grocery Store Program (VGSP). The program covers fees associated with online grocery shopping for 300 residents in Jeffries Towers, a low-income housing complex. Over the course of 4 months, 28 participants placed a total of 151 orders, with a range from 1 to 14 orders each. Out of the 151 orders, that yielded 1,771 items, the top three types of food purchased were fruits and vegetables, dairy and eggs, and meat and fish; one-third of the items were prepared, two-thirds were perishable, and while almost half the items had no nutritional value, out the half that did, the majority had the high nutrition; and less than a third of participants used NJ SNAP funds to purchase their groceries online. Future efforts need to uncover the explanation for these purchases along with identifying potential strategies to increase consumption of healthier food options.

Carrot Consumption Frequency Associated with Reduced BMI and Obesity through the SNP Intermediary rs4445711

It is unclear whether genetic interactions are involved in the association between vegetable intake and reduced body mass index (BMI) or obesity. We conducted a comprehensive search for single nucleotide polymorphisms (SNPs) which are associated with the interaction between vegetable intake frequency and BMI or obesity. We performed a genome-wide association analysis to evaluate the genetic interactions between self-reported intake of vegetables such as carrot, broccoli, spinach, other green vegetables (green pepper and green beans), pumpkin, and cabbage with BMI and obesity, which is defined as a BMI ≥ 25.0 kg/m2 in the Japanese population (n = 12,225). The mean BMI and prevalence of obesity was 23.9 ± 3.4 kg/m2 and 32.3% in men and 22.1 ± 3.8 kg/m2 and 17.3% in in women, respectively. A significant interaction was observed between rs4445711 and frequency of carrot intake on BMI (p = 4.5 × 10-8). This interaction was slightly attenuated after adjustment for age, sex, alcohol intake, smoking, physical activity and the frequency of total vegetable intake (p = 2.1 × 10-7). A significant interaction was also observed between rs4445711 and frequency of carrot intake on obesity (p = 2.5 × 10-8). No significant interactions that were the same as the interaction between frequency of carrot intake and rs4445711 were observed between the intake frequency of broccoli, spinach, other green vegetables, pumpkin or cabbage and BMI or obesity. The frequency of carrot consumption is implicated in reducing BMI by the intermediary of rs4445711. This novel genetic association may provide new clues to clarify the association between vegetable intake and BMI or obesity.

A Role of Stress Sensor Nrf2 in Stimulating Thermogenesis and Energy Expenditure

During chronic cold stress, thermogenic adipocytes generate heat through uncoupling of mitochondrial respiration from ATP synthesis. Recent discovery of various dietary phytochemicals, endogenous metabolites, synthetic compounds, and their molecular targets for stimulating thermogenesis has provided promising strategies to treat or prevent obesity and its associated metabolic diseases. Nuclear factor E2 p45-related factor 2 (Nrf2) is a stress response protein that plays an important role in obesity and metabolisms. However, both Nrf2 activation and Nrf2 inhibition can suppress obesity and metabolic diseases. Here, we summarized and discussed conflicting findings of Nrf2 activities accounting for part of the variance in thermogenesis and energy metabolism. We also discussed the utility of Nrf2-activating mechanisms for their potential applications in stimulating energy expenditure to prevent obesity and improve metabolic deficits.

Plasma Concentrations and Maternal-Umbilical Cord Plasma Ratios of the Six Most Prevalent Carotenoids across Five Groups of Birth Gestational Age

Carotenoids are antioxidant nutrients with the potential to provide protection against oxidative stress. Plasma carotenoid concentrations are lower in newborn infants compared to their mothers; however, limited information is available regarding how concentrations differ by gestational age. The objective of this research is to assess maternal and umbilical cord plasma carotenoid concentrations and maternal-umbilical cord plasma ratios across five groups of birth gestational age. Mother-infant dyads were enrolled at delivery for collection of maternal and umbilical cord blood. Plasma carotenoids were analyzed by HPLC and LC-MS/MS. Birth gestational age was categorized into five groups, and the Kruskal–Wallis test compared carotenoid concentrations and maternal-umbilical cord plasma ratios between these groups. A p-value of < 0.05 was considered statistically significant. 370 mother-infant dyads were included, with most infants delivered at early term (20.3%) or term (64.6%). Though maternal plasma concentrations increased with birth gestational age, we observed less variability in umbilical cord plasma concentrations, thus the maternal-umbilical cord plasma ratio also increased with birth CGA groups for lutein + zeaxanthin (p = 0.008), β-cryptoxanthin (p = 0.027), α-carotene (p = 0.030); β-carotene approached significance (p = 0.056). Additional research is needed to determine if carotenoid concentrations were physiologic to varying gestational ages or if they were impacted by factors associated with preterm birth.

Use of the Spectroscopy-Based Veggie Meter® to Objectively Assess Fruit and Vegetable Intake in Low-Income Adults

Reflection spectroscopy is an emerging approach for noninvasively assessing dermal carotenoids as a biomarker of fruit and vegetable (FV) intake. This study sought to profile and identify determinants of scores from a reflection spectroscopy device (the Veggie Meter (VM)®) among 297 urban, primarily Hispanic low-income adults served by the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). The repeatability of the scores and bi- and multivariate relationships between VM scores, self-reported FV intake measured by a brief screener, and participant characteristics were examined. The mean VM score was 270 (range 0-695); 3- and 6-month test-retest correlations were positive and strong (r = 0.79 and 0.55, respectively). VM scores were negatively associated with body mass index (BMI; r = -0.22) and were higher among participants of Ecuadorian, Dominican, and Mexican Hispanic origin relative to those of Puerto Rican origin; foreign- vs. US-born participants, breastfeeding vs. non-breastfeeding participants, nonsmokers vs. smokers, and participants who consumed three or more cups of FV/day relative to those who consumed less than three cups of FV/day. Foreign-born nativity, consumption of three or more cups of FV/day, and smaller body size were determinants of increased VM scores. Although replication studies are needed to confirm these findings, investigators working with similar populations are encouraged to use the VM to longitudinally track FV intake and to target determinants of the scores in observational and intervention studies of FV intake as measured by the VM.

From carotenoid intake to carotenoid blood and tissue concentrations - implications for dietary intake recommendations

There is uncertainty regarding carotenoid intake recommendations, because positive and negative health effects have been found or are correlated with carotenoid intake and tissue levels (including blood, adipose tissue, and the macula), depending on the type of study (epidemiological vs intervention), the dose (physiological vs supraphysiological) and the matrix (foods vs supplements, isolated or used in combination). All these factors, combined with interindividual response variations (eg, depending on age, sex, disease state, genetic makeup), make the relationship between carotenoid intake and their blood/tissue concentrations often unclear and highly variable. Although blood total carotenoid concentrations <1000 nmol/L have been related to increased chronic disease risk, no dietary reference intakes (DRIs) exist. Although high total plasma/serum carotenoid concentrations of up to 7500 nmol/L are achievable after supplementation, a plateauing effect for higher doses and prolonged intake is apparent. In this review and position paper, the current knowledge on carotenoids in serum/plasma and tissues and their relationship to dietary intake and health status is summarized with the aim of proposing suggestions for a "normal," safe, and desirable range of concentrations that presumably are beneficial for health. Existing recommendations are likewise evaluated and practical dietary suggestions are included.

Weight Status and Visceral Adiposity Mediate the Relation between Exclusive Breastfeeding Duration and Skin Carotenoids in Later Childhood

BACKGROUND

Breastfeeding is associated with healthier weight and nutrient status in early life. However, the impact of breastfeeding on carotenoid status beyond infancy, and the influence of adiposity, are unknown.

OBJECTIVES

The aim of the study was to retrospectively investigate the relation between breastfeeding and carotenoid status, and the mediating effect of weight status and adiposity on this relation, among school-age children.

METHODS

This was a secondary analysis of baseline data collected from a randomized-controlled clinical trial. Children 7-12 y old (n = 81) were recruited from East-Central Illinois. DXA was used to assess visceral adipose tissue (VAT) and whole-body total fat percentage (%Fat; i.e., whole-body adiposity). Weight was obtained to calculate children's BMI percentiles. Skin carotenoids were assessed via reflection spectroscopy. Macular carotenoids were assessed as macular pigment optical density (MPOD). Dietary, birth, and breastfeeding information was self-reported by parents.

RESULTS

Skin carotenoids were inversely related to %Fat (P < 0.01), VAT (P < 0.01), and BMI percentile (P < 0.01). VAT and BMI percentile significantly mediated this relation between exclusive breastfeeding duration and skin carotenoids, after adjustment for dietary carotenoids, energy intake, and mother education.

CONCLUSIONS

Weight status and adipose tissue distribution mediate the positive correlation between exclusive breastfeeding duration and skin carotenoids among children aged 7-12 y. The results indicate the need to support breastfeeding and healthy physical growth in childhood for optimal carotenoid status.This trial was registered at clinicaltrials.gov as NCT03521349.

Reduced plasma carotenoids in individuals suffering from metabolic diseases with disturbances in lipid metabolism: a systematic review and meta-analysis of observational studies

This review summarises the association between serum carotenoids, serum retinoids and dietary intake outcomes with obesity/overweight and individuals with metabolic diseases with disturbances in lipid metabolism. Observational studies reporting dietary intakes and serum concentrations of carotenoids and retinol were collected from Medline and Web of Science. Mean differences were calculated between "cases" (classified as obese, overweight or having a metabolic disease with disturbances in lipid metabolism; i.e. non-alcoholic fatty liver disease, type 2 diabetes, dyslipidaemia or metabolic syndrome) and "comparator group" (classified as normal weight healthy individuals) and summarised in meta-analyses. Significant summary measures were observed for most serum provitamin A and non-provitamin A carotenoids. Studies reporting total serum carotenoids had shown the greatest decrease (-0.28 µmol/l [-0.33, -0.23], p<.001, I²=62.5%, n = 7). There were no significant summary measures for dietary outcomes, suggesting a physiological role of low serum carotenoids in the development of obesity and associated diseases.

A new approach to study human perivascular adipose tissue of the internal mammary artery by fiber-optic Raman spectroscopy supported by spectral modelling

Perivascular adipose tissue (PVAT) regulates vascular function and represents a novel therapeutic target in vascular diseases. In this work, a new approach based on fiber-optic Raman spectroscopy and spectral modelling was used to characterize the chemical content of the PVAT of the internal mammary artery (IMA) of patients with advanced coronary atherosclerosis (n = 10) undergoing coronary bypass surgery. Our results showed a high degree of lipid unsaturation and low carotenoid content in the PVAT of the IMA of patients with more advanced coronary artery disease. Moreover, the spectral modelling of the IMA's PVAT composition indicated that glyceryl trioleate was a major PVAT lipid and for patients with relatively low levels of β-carotene, it was accompanied by arachidonic acid and glyceryl trilinolenate. In summary, our proof-of-concept study suggests that carotenoid content and lipid unsaturation degree may reflect the PVAT functional status and a Raman-based assessment of the PVAT of the IMA could prove useful as a novel diagnostic tool to rapidly define the PVAT phenotype in a grafted artery in patients undergoing coronary bypass.

The association between carotenoids and subjects with overweight or obesity: a systematic review and meta-analysis

BACKGROUND

Excess body weight, including overweight and obesity, is one of the major factors influencing human health, and plays an important role in the global burden of disease. Carotenoids serve as precursors of vitamin A-related retinoids, and are considered to have potential effects on many diseases. However, the influence of carotenoids on people with excess body weight is unclear.

METHODS

This meta-analysis was conducted to assess the effects of carotenoids on overweight or obese subjects utilizing the available evidence. We searched PubMed, Medline, Cochrane Library, Web of Science and EMBASE databases up to September 2020. Random effects models were used to calculate the standard mean differences (SMDs) and odds ratios (ORs) with their 95% confidence intervals (95% CIs).

RESULTS

A total of seven randomized controlled trials and eight observational studies met the inclusion criteria and contained 28 944 subjects and data on multiple carotenoid subgroups, including lycopene, astaxanthin, cryptoxanthin, α-carotene, and β-carotene. In all included Randomized Controlled Trial (RCT), the intervention duration was 20 days at the shortest and 16 weeks at the longest, and the range of intervention doses was 1.2-60 mg d-1. Our study found that the insufficiency of serum carotenoids was a risk factor for overweight and obesity (OR = 1.73, 95% CI [1.57, 1.91], p < 0.001). Moreover, carotenoid supplementation was significantly associated with body weight reductions (SMD = -2.34 kg, 95% CI [-3.80, -0.87] kg, p < 0.001), body mass index decrease (BMI, SMD = -0.95 kg cm-2, 95% CI [-1.88, -0.01] kg cm-2, p < 0.001) and waist circumference losses (WC, SMD = -1.84 cm, 95% CI [-3.14, -0.54]cm, p < 0.001).

CONCLUSION

In summary, the carotenoids show promising effects in overweight or obese subjects. Additional data from large clinical trials are needed.

Micronutrients and Markers of Oxidative Stress and Inflammation Related to Cardiometabolic Health: Results from the EHES-LUX Study

Metabolic syndrome (MetS) characteristics include chronic inflammation and elevated oxidative stress. This study assessed associations between circulating concentrations of micronutrients/phytochemicals and inflammatory/oxidative stress markers with MetS and MetS components. Adults (N = 606) from the European Health Examination Survey in Luxembourg (2013-2015) were randomly selected. We performed a multivariable logistic regression model using the least absolute shrinkage and selection operator to identify MetS-associated variables. Participants with MetS had higher concentrations of C-reactive protein (CRP), 8-iso-prostaglandin F2α, leptin, insulin, and vitamins E/A, but lower concentrations of adiponectin, beta-carotene, and oxidized low-density lipoprotein. A one-unit increase in log-CRP was associated with 51% greater odds of MetS (OR = 1.51 (95% CI: 1.16, 1.98)). Adults with a one-unit increase in log-leptin were 3.1 times more likely to have MetS (3.10 (2.10, 4.72)). Women with a one-unit increase in vitamin A were associated with 3% increased odds of MetS (1.03 (1.01, 1.05)), while those with a one-unit increase in log-adiponectin were associated with 82% decreased odds (0.18 (0.07, 0.46)). Chronic inflammation best characterized adults with MetS, as CRP, adiponectin, and leptin were selected as the main MetS determinants. Micronutrients did not seem to affect MetS, except for vitamin A in women.

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.

Lutein supplementation combined with a low-calorie diet in middle-aged obese individuals: effects on anthropometric indices, body composition and metabolic parameters

Lutein is considered as a major biologically active carotenoid, with potential benefits for obesity and cardiometabolic health. This double-blind, randomised controlled trial aimed to assess whether the consumption of lutein along with a low-calorie diet (LCD) can influence anthropometric indices, body composition and metabolic parameters in obese middle-aged individuals. After a 2-week run-in period with an LCD, forty-eight participants aged 45–65 years were randomly assigned to consume 20 mg/d lutein or placebo along with the LCD for 10 weeks. Dietary intake, anthropometric indices, body composition, lipid profile, glucose homoeostasis parameters, NEFA and appetite sensations were assessed at the beginning and end of the study. After 10 weeks, body weight and waist circumference significantly decreased in both groups, although between-group differences were not significant. There was more of a decrease in the percentage of body fat in the lutein group v. the placebo group. Moreover, the placebo group experienced a significant reduction in fat-free mass (FFM), whereas the lutein group preserved FFM during calorie restriction, although the between-group difference did not reach statistical significance. Visceral fat and serum levels of total cholesterol (TC) and LDL-cholesterol were significantly decreased only in the lutein group, with a statistically significant difference between the two arms only for TC. No significant changes were observed in the TAG, HDL-cholesterol, glucose homoeostasis parameters, NEFA and appetite sensations. Lutein supplementation in combination with an LCD could improve body composition and lipid profile in obese middle-aged individuals.

A review of factors that affect carotenoid concentrations in human plasma: differences between Mediterranean and Northern diets

Carotenoids are naturally occurring pigments of autotroph organisms that have been related to many health benefits and this is not only because some of them are precursors of vitamin A. Individual or whole carotenoid consumption has been associated with a lower risk of developing cancer, cardiovascular and metabolic diseases among others. However, the blood levels of carotenoids vary largely from person to person due to different factors. Diet is the most important one because of the dietary patterns that different populations follow, the time of the year of consumption or the personal preferences. Nevertheless, the intrinsic host factors such as the absorption, distribution, metabolism and excretion genetic polymorphisms, the volume of distribution and the person's microbiota and others such as carotenoid interactions are also inducing this so called inter-individual variability. Besides, culinary methods and processing produce changes in the foods that directly affect carotenoid content and hence their blood profile. Different types of studies have been performed to understand the between-subject variation of the carotenoid profile in human plasma. This research is focused on this matter as levels of carotenoids in human plasma could be useful for the prediction of some diseases. The Mediterranean diet is probably the most carotenoid rich diet stemming from its high proportion of fruits and vegetables. Its differences with other diets and the effect on the carotenoid blood profile of the consumers are currently a very interesting topic of study.

Systemic and Adipose Tissue Redox Status in Sprague-Dawley Rats Fed Normal- and High-Fat Diets Supplemented with Lycopene

Dietary patterns high in fat influence local and systemic oxidative stress through adipose tissue (AT) accrual and increased reactive oxygen species generation. Lycopene, a carotenoid with antioxidant functionality, may mitigate excess oxidative stress, yet the lipophilic nature of this compound may limit its functionality if sequestered by AT. Thus, it is critical to elucidate whether lycopene's efficacy is limited based on adiposity. The purpose of this study was to investigate the influence of lycopene-supplemented normal- and high-fat diets on systemic and AT redox status. Male Sprague-Dawley rats (n = 18) were fed a 30% normal-fat (NFD) or 60% high-fat (HFD) purified diet supplemented with 100 mg of lycopene/day. Body weight and visceral AT mass, as well as serum and AT lycopene, lipid peroxides, and antioxidant capacity (AC), were assessed after 3, 7, and 10 weeks of supplementation. At week 10, AT mass was significantly higher (P = .028) in the HFD group, yet there were no significant differences in serum or AT lycopene concentrations or lipid peroxides between groups. Additionally, AT in the HFD group exhibited significantly greater lipophilic AC (27.6% higher, P = .031). Results suggest that excess adiposity did not negatively influence circulating lycopene, nor did it limit its antioxidant functionality.

Association of Carotenoids Concentration in Blood with Physical Performance in Korean Adolescents: The 2018 National Fitness Award Project

Adolescent physical performance is not only dependent on exercise but also on the role of antioxidants obtained through a healthy diet. However, few studies have specifically identified the relationship between carotenoids, a common antioxidant, and physical performance. This cross-sectional study aims to investigate the association between the level of carotenoids in the blood and physical performance among Korean adolescents aged 13 to 18 years. The study sample consisted of 450 participants (190 males, 260 females) from the 2018 National Fitness Award project. In boys, multiple regression analysis after adjustment for age, body mass index (BMI), smoking, drinking, and physical activity revealed that the α-carotene level was positively associated with a 20-m progressive aerobic cardiovascular endurance run (PACER) (β = 5.350, p < 0.05) and estimated maximal oxygen consumption (VO_2max) (β = 1.049, p < 0.05). In girls, after adjustment for age, BMI, smoking, drinking, and physical activity, the levels of α-carotene were positively associated with a 20-m PACER (β = 3.290, p < 0.05), VO_2max (β = 0.644, p < 0.05) and curl-up (β = 5.782, p < 0.05), and β-carotene (β = 2.983, p < 0.05) and total carotenoids (β = 4.248, p < 0.05) were positively associated with curl-up. Our results suggest that an increased level of carotenoids in the blood may be associated with better physical performance among adolescents in Korea.

Associations of Serum Carotenoids with DXA-Derived Body Fat and Fat Distribution in Chinese Adults: A Prospective Study

BACKGROUND

Most previous studies have examined the associations between carotenoids and anthropometrics with cross-sectional designs. Few studies have investigated the associations between serum carotenoids and fat mass and fat distribution (general vs central type).

OBJECTIVE

This study aimed to explore the associations of serum carotenoids with body fat and fat distribution in Chinese adults.

DESIGN

Cross-sectional and longitudinal analyses of a prospective, community-based cohort were performed.

PARTICIPANTS/SETTING

There were 4,048 participants aged 40 to 75 years recruited in the Guangzhou Nutrition and Health Study from 2008 to 2013.

MAIN OUTCOME MEASURES

Serum carotenoids were assessed at baseline. Anthropometrics, fat mass (FM), and percentage FM (%FM) over the total body, trunk, limbs, and android and gynoid regions were obtained by dual-energy x-ray absorptiometry for 3,002 participants between 2011 and 2013 and for 2,537 participants after 3.1 years.

STATISTICAL ANALYSIS

Cross-sectional and longitudinal analyses were performed to compare the mean differences in adiposity indices among the quartiles of carotenoids.

RESULTS

Covariance analyses showed significant inverse associations between serum total carotenoid levels and adiposity indices cross-sectionally (all P trends<0.05). The percentage mean differences in quartile 4 (vs 1) in FM and %FM were much more pronounced in the trunk (-15.4% and -7.74%) and android area (-16.6% and -8.59%) than those in the limbs (-8.31% and -4.51%) and gynoid area (-7.76% and -2.71%) (all P<0.001). Longitudinal results revealed that higher total carotenoids were associated with significantly lower 3-year increases in body mass index (calculated as kg/m²); waist circumference; waist-to-hip ratio; body FM in the limbs and android and gynoid area; and %FM in total body, trunk, and limbs (all P trends<0.05). Regarding individual carotenoids, β-carotene tended to have the most notable beneficial associations with the majority of fat indices, especially for cross-sectional analyses.

CONCLUSIONS

Serum carotenoid concentrations are inversely associated with body fat, especially in the abdominal region, in Chinese adults.

Effects of lutein supplementation on inflammatory biomarkers and metabolic risk factors in adults with central obesity: study protocol for a randomised controlled study

Background

The prevalence of central obesity is constantly increasing, and visceral fat is associated with increased production of inflammatory factors and metabolic risk factors. Lutein might retard the development of metabolic disease through its antioxidant and anti-inflammatory properties. Furthermore, epidemiological studies have associated higher dietary intake and serum levels of lutein with decreased adiposity. However, few randomised controlled trials have shown the effects of lutein supplementation on inflammatory biomarkers and metabolic risk factors, especially in adults with central obesity.

Methods

This study will be conducted as a double-blind, parallel placebo-controlled clinical trial in which 120 people who have central obesity, are 18 to 60 years old and are willing to provide informed consent will be randomly assigned to the intervention or placebo group in a 1:1 ratio according to sex, age and waist circumference. The intervention group will receive 10 mg daily lutein supplementation for 12 weeks to explore the effect of lutein supplementation on serum lutein, glycaemic and lipid profiles, inflammatory factors and body composition. Two populations (intention-to-treat population and per-protocol population) will be used in the data analyses.

Discussion

Our findings from this trial will contribute to the knowledge of the association between lutein supplementation and inflammatory biomarkers and metabolic risk factors in people with central obesity and will offer a possibility for the prevention of inflammatory diseases.

Trial registration

Chinese Clinical Trial Registry: ChiCTR1800018098. Registered on 30 August 2018.

Serum carotenoids are strongly associated with dermal carotenoids but not self-reported fruit and vegetable intake among overweight and obese women

Background

Accurate assessment of fruit and vegetable intake (FVI) is essential for public health nutrition research and surveillance. Blood carotenoid concentrations are robust biomarkers of FVI, but collecting blood samples typically is not feasible in population-based studies. Understanding how well non-invasive measures compare to blood estimates is important for advancing surveillance and evaluation. The objective of this study was to examine the associations between serum carotenoids and four non-invasive measures of FVI in overweight and obese women.

Methods

This study utilized baseline data from 157 overweight or obese women (95.5% white, mean age 58.56 years ± 9.49 years) enrolled in the Strong Hearts, Healthy Communities randomized trial, including two direct measures of carotenoids and three self-reported measures of FVI. Participants completed a fasting blood draw, dermal carotenoid scans using resonance Raman spectroscopy (RRS), a two-item FVI screener modeled after the American Heart Association’s Life’s Simple 7 “My Life Check” tool (modified AHA tool), the National Cancer Institute’s All-Day Fruit and Vegetable Screener (FVS), multiple 24-h dietary recalls, physical measurements, and demographic and health behavior questions. We analyzed blood for total carotenoids and derived total FVI estimates from self-report tools. We used multivariate linear regression models to examine associations between each non-invasive tool and serum carotenoids under four scenarios analogous to different research contexts in which varying breadths of participant data are available. We also calculated adjusted Pearson’s correlations between serum carotenoids, dermal carotenoids, and the self-reported measures.

Results

Dermal carotenoids were strongly correlated with serum carotenoids (0.71, P < 0.00067) and associated with serum carotenoids in all regression models (0.42–0.43, P < 0.002). None of the self-reported FVI measures were significantly associated with serum or dermal carotenoids in adjusted regression models or correlation analyses.

Conclusions

Compared to self-reported FVI, we found dermal carotenoids measured by RRS to be a superior method to approximate serum carotenoids among overweight and obese women. More research is needed to investigate these assessment methods in diverse populations.

Trial registration

ClinicalTrials.gov Identifier: NCT02499731, registered July 16, 2015.

Anti-Obesity Effect of Carotenoids: Direct Impact on Adipose Tissue and Adipose Tissue-Driven Indirect Effects

This review summarizes current knowledge on the biological relevance of carotenoids and some of their metabolites in obesity management. The relationship between carotenoids and obesity is considered in clinical studies and in preclinical studies. Adipose tissue is a key organ in obesity etiology and the main storage site for carotenoids. We thus first describe carotenoid metabolism in adipocyte and adipose tissue and the effects of carotenoids on biological processes in adipose tissue that may be linked to obesity management in in vitro and preclinical studies. It is also now well established that the brain is strongly involved in obesity processes. A section is accordingly devoted to the potential effect of carotenoids on obesity via their direct and/or adipose tissue-driven indirect biological effects on the brain.

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.

The Association of Serum Carotenoids, Tocopherols, and Ascorbic Acid With Rapid Kidney Function Decline: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

Nutritional intervention targeting dietary intake modification is a major component of treatment for chronic kidney disease; however, little is known about the relationship between dietary intake and kidney function decline in individuals with preserved kidney function.

DESIGN AND METHODS

In this prospective cohort study we examined the association of biomarkers of dietary intake with kidney function decline over a 5-year interval in 2,152 men and women with cystatin-C-based estimated glomerular filtration rate > 60 mL/minute/1.73 m² from the Coronary Artery Risk Development in Young Adults study. The biomarkers of interest included carotenoids, tocopherols, and ascorbic acid. Multivariable logistic regression was used to explore the relationship between serum concentrations of the sum of 4 carotenoids (α-carotene, β-carotene, β-cryptoxanthin, and lutein/zeaxanthin), lycopene, α-tocopherol, γ-tocopherol, and ascorbic acid and rapid kidney function decline, defined as .15% decline in cystatin-C-based estimated glomerular filtration rate over 5 years.

RESULTS

During the 5-year follow-up, 290 participants (13.5%) experienced rapid kidney function decline. Relative to individuals in the lowest quartile of serum carotenoids, those in the highest quartile had significantly lower odds of rapid kidney function decline in the fully adjusted model (odds ratio, 0.51; 95% confidence interval [CI], 0.32-0.80; P trend, .02). No association of levels of serum tocopherols, ascorbic acid, or lycopene with kidney function decline was found. There was no evidence that results differed for individuals with hypertension or diabetes.

CONCLUSIONS

These results demonstrate that higher serum carotenoid levels, reflective of a fruit- and vegetable-rich dietary pattern, inversely associate with rapid kidney function decline in early middle adulthood and provide insight into how diet might play a role in chronic kidney disease prevention.

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.

Serum carotenoid interactions in premenopausal women reveal α-carotene is negatively impacted by body fat

Increasing body mass indices (BMIs) across the globe reflect pandemic shifts towards habitual positive energy imbalances. Excess body fat in individuals is often associated with high-energy and high-fat diets scanty in fresh produce. Carotenoids are fat-soluble pigments plentiful in many fruits and vegetables. They are well-known for provitamin A and antioxidant functions, but little research has been done related to carotenoid-body mass interactions. Serum carotenoids were analyzed relative to body fat to determine correlations between major serum carotenoids, retinol, BMI, fat mass, and lean mass. Healthy women ( n = 76), 19-50 years old, were categorized into two comparison groups determined by percent body fat measured by air displacement plethysomography (BOD POD®), i.e. <31% and ≥31% fat mass. Anthropometric and three-day diet records were completed for BMI and nutrient intake calculations, respectively. Serum α-carotene concentrations were strongly inversely associated with all measures of body composition ( P < 0.001 α-carotene) controlling for dietary intake and age, while β-carotene, lutein, and lycopene were not ( P > 0.05). Dietary intake between groups did not differ, including carrot consumption (a high dietary source of α-carotene). These results confirm previous carotenoid-health research and propose the need for further investigation of potential protective roles that α-carotene may perform for optimal health. Serum α-carotene may provide a deeper and clinically relevant purpose, beyond previous suggestions for its use as a biomarker for fruit and vegetable consumption, in that α-carotene may be a biomarker for chronic disease risk frequently linked with obesity. Impact statement Carotenoids are important pigments in fruit and vegetables and found in human serum. This study isolated a negative relationship between serum α-carotene and body fatness. As humans begin to live over a century, determining biomarkers of ultimate health is important. α-Carotene does not have the same distribution in the food supply as β-carotene and therefore is often overlooked in surveys. In part, this is due to the fact that β-carotene provides two molecules of vitamin A, while α-carotene provides one upon central cleavage. This study shows a very clear association between α-carotene and body fatness, which appears to go beyond its fat-soluble nature. Dietary intake data were not able to explain the association. Further work is needed to determine what dietary components infer health benefits.

Association Between Antioxidant Intake/Status and Obesity: a Systematic Review of Observational Studies

The global prevalence of obesity has doubled in recent decades. Compelling evidences indicated that obesity was associated with lower concentrations of specific antioxidants which may play a role in the development of obesity-related diseases such as cardiovascular disease. The present review aimed to synthesize the evidence from studies on the association between obesity and antioxidant micronutrients in a systematic manner. Data bases including MEDLINE, Science Direct, and Cochrane were searched from inception to October 2015. Thirty-one articles were reviewed using the MOOSE checklist. Lower concentrations of antioxidants have been reported in obese individuals among age groups worldwide. Circulatory levels of carotenoids, vitamins E and C, as well as zinc, magnesium, and selenium were inversely correlated with obesity and body fat mass. However, studies demonstrated inconsistencies in findings. Lower status of carotenoids, vitamins E and C, zinc, magnesium, and selenium appears to be associated with adiposity. Intervention studies may be needed to establish the causality of these associations.

Role of vitamin A metabolism in IIH: Results from the idiopathic intracranial hypertension treatment trial

INTRODUCTION

Vitamin A and its metabolites (called retinoids) have been thought to play a role in the development of idiopathic intracranial hypertension (IIH). The IIH Treatment Trial (IIHTT) showed the efficacy of acetazolamide (ACZ) in improving visual field function, papilledema grade, quality of life and cerebrospinal fluid (CSF) pressure. We postulated that IIH patients would demonstrate elevated measures of vitamin A metabolites in the serum and CSF.

METHODS

Comprehensive measures of serum vitamin A and its metabolites were obtained from 96 IIHTT subjects, randomly assigned to treatment with ACZ or placebo, and 25 controls with similar gender, age and body mass index (BMI). These included retinol, retinol binding protein, all-trans retinoic acid (ATRA), alpha- and beta-carotenes, and beta-cryptoxanthin. The IIHTT subjects also had CSF and serum vitamin A and metabolite measurements obtained at study entry and at six months.

RESULTS

At study entry, of the vitamin A metabolites only serum ATRA was significantly different in IIHTT subjects (median 4.33nM) and controls (median 5.04nM, p=0.02). The BMI of IIHTT subjects showed mild significant negative correlations with serum ATRA, alpha- and beta-carotene, and beta-cryptoxanthin. In contrast, the control subject BMI correlated only with serum ATRA. At six months, the serum retinol, alpha-carotene, beta-carotene, and CSF retinol were increased from baseline in the ACZ treated group, but only increases in alpha-carotene (p=0.02) and CSF ATRA (p=0.04) were significantly greater in the ACZ group compared with the placebo group. No other vitamin A measures were significantly altered over the six months in either treatment group. Weight loss correlated with only with the change in serum beta-carotene (r=-0.44, p=0.006) and the change in CSF retinol (r=-0.61, p=0.02).

CONCLUSION

Vitamin A toxicity is unlikely a contributory factor in the causation of IIH. Our findings differ from those of prior reports in part because of our use of more accurate quantitative methods and measuring vitamin A metabolites in both serum and CSF. ACZ may alter retinoid metabolism in IIH patients.

Plasma Carotenoids, Tocopherols, and Retinol in the Age-Stratified (35-74 Years) General Population: A Cross-Sectional Study in Six European Countries

Blood micronutrient status may change with age. We analyzed plasma carotenoids, α-/γ-tocopherol, and retinol and their associations with age, demographic characteristics, and dietary habits (assessed by a short food frequency questionnaire) in a cross-sectional study of 2118 women and men (age-stratified from 35 to 74 years) of the general population from six European countries. Higher age was associated with lower lycopene and α-/β-carotene and higher β-cryptoxanthin, lutein, zeaxanthin, α-/γ-tocopherol, and retinol levels. Significant correlations with age were observed for lycopene (r = -0.248), α-tocopherol (r = 0.208), α-carotene (r = -0.112), and β-cryptoxanthin (r = 0.125; all p < 0.001). Age was inversely associated with lycopene (-6.5% per five-year age increase) and this association remained in the multiple regression model with the significant predictors (covariables) being country, season, cholesterol, gender, smoking status, body mass index (BMI (kg/m²)), and dietary habits. The positive association of α-tocopherol with age remained when all covariates including cholesterol and use of vitamin supplements were included (1.7% vs. 2.4% per five-year age increase). The association of higher β-cryptoxanthin with higher age was no longer statistically significant after adjustment for fruit consumption, whereas the inverse association of α-carotene with age remained in the fully adjusted multivariable model (-4.8% vs. -3.8% per five-year age increase). We conclude from our study that age is an independent predictor of plasma lycopene, α-tocopherol, and α-carotene.

Carotenoid intake and adipose tissue carotenoid levels in relation to prostate cancer aggressiveness among African-American and European-American men in the North Carolina-Louisiana prostate cancer project (PCaP)

BACKGROUND

Associations between carotenoid intake and prostate cancer (CaP) incidence have varied across studies. This may result from combining indolent with aggressive disease in most studies. This study examined whether carotenoid intake and adipose tissue carotenoid levels were inversely associated with CaP aggressiveness.

METHODS

Data on African-American (AA, n = 1,023) and European-American (EA, n = 1,079) men with incident CaP from North Carolina and Louisiana were analyzed. Dietary carotenoid intake was assessed using a detailed-food frequency questionnaire (FFQ), and abdominal adipose tissue samples were analyzed for carotenoid concentrations using high-performance liquid chromatography. Multivariable logistic regression was used in race-stratified analyses to calculate odds ratios (ORs) and 95% confidence intervals (95%CI) comparing high aggressive CaP with low/intermediate aggressive CaP.

RESULTS

Carotenoid intake differed significantly between AAs and EAs, which included higher intake of lycopene among EAs and higher β-cryptoxanthin intake among AAs. Comparing the highest and lowest tertiles, dietary lycopene was associated inversely with high aggressive CaP among EAs (OR = 0.55, 95%CI: 0.34-0.89, Ptrend  = 0.02), while an inverse association was observed between dietary β-cryptoxanthin intake and high aggressive CaP among AAs (OR = 0.56, 95%CI: 0.36-0.87, Ptrend  = 0.01). Adipose tissue α-carotene and lycopene (cis + trans) concentrations were higher among EAs than AAs, and marginally significant inverse linear trends were observed for adipose α-carotene (Ptrend  = 0.07) and lycopene (Ptrend  = 0.11), and CaP aggressiveness among EAs only.

CONCLUSIONS

These results suggest that diets high in lycopene and β-cryptoxanthin may protect against aggressive CaP among EAs and AAs, respectively. Differences in dietary behaviors may explain the observed racial differences in associations. Prostate 76:1053-1066, 2016. © 2016 Wiley Periodicals, Inc.

Obesity, Oxidative Stress, Adipose Tissue Dysfunction, and the Associated Health Risks: Causes and Therapeutic Strategies

Obesity is gaining acceptance as a serious primary health burden that impairs the quality of life because of its associated complications, including diabetes, cardiovascular diseases, cancer, asthma, sleep disorders, hepatic dysfunction, renal dysfunction, and infertility. It is a complex metabolic disorder with a multifactorial origin. Growing evidence suggests that oxidative stress plays a role as the critical factor linking obesity with its associated complications. Obesity per se can induce systemic oxidative stress through various biochemical mechanisms, such as superoxide generation from NADPH oxidases, oxidative phosphorylation, glyceraldehyde auto-oxidation, protein kinase C activation, and polyol and hexosamine pathways. Other factors that also contribute to oxidative stress in obesity include hyperleptinemia, low antioxidant defense, chronic inflammation, and postprandial reactive oxygen species generation. In addition, recent studies suggest that adipose tissue plays a critical role in regulating the pathophysiological mechanisms of obesity and its related co-morbidities. To establish an adequate platform for the prevention of obesity and its associated health risks, understanding the factors that contribute to the cause of obesity is necessary. The most current list of obesity determinants includes genetic factors, dietary intake, physical activity, environmental and socioeconomic factors, eating disorders, and societal influences. On the basis of the currently identified predominant determinants of obesity, a broad range of strategies have been recommended to reduce the prevalence of obesity, such as regular physical activity, ad libitum food intake limiting to certain micronutrients, increased dietary intake of fruits and vegetables, and meal replacements. This review aims to highlight recent findings regarding the role of oxidative stress in the pathogenesis of obesity and its associated risk factors, the role of dysfunctional adipose tissue in development of these risk factors, and potential strategies to regulate body weight loss/gain for better health benefits.

The influence of BMI on the association between serum lycopene and the metabolic syndrome

Overweight and obese individuals have an increased risk of developing the metabolic syndrome because of subsequent chronic inflammation and oxidative stress, which the antioxidant nutrient lycopene can reduce. However, studies indicate that different BMI statuses can alter the positive effects of lycopene. Therefore, the purpose of this study was to examine how BMI influences the association between serum lycopene and the metabolic syndrome. The tertile rank method was used to divide 13 196 participants, aged 20 years and older, into three groups according to serum concentrations of lycopene. The associations between serum lycopene and the metabolic syndrome were analysed separately for normal-weight, overweight and obese participants. Overall, the prevalence of the metabolic syndrome was significantly higher in the first tertile group (OR 38·6%; 95% CI 36·9, 40·3) compared with the second tertile group (OR 29·3%; 95% CI 27·5, 31·1) and the third tertile group (OR 26·6%; 95% CI 24·9, 28·3). However, the associations between lycopene and the metabolic syndrome were only significant for normal-weight and overweight participants (P0·05), even after adjusting for possible confounding variables. In conclusion, BMI appears to strongly influence the association between serum lycopene and the metabolic syndrome.

Oxidative stress, inflammation, endothelial dysfunction and incidence of type 2 diabetes

BACKGROUND

Oxidative stress, inflammation and endothelial dysfunction are interrelated factors in the etiology of cardiovascular disease, but their linkage to type 2 diabetes is less clear. We examined the association of these biomarkers with incident type 2 diabetes (T2D).

METHODS

Analysis of 2339 participants in the community-based coronary artery risk development in young adults (CARDIA) study. Participants (age 40.1 ± 3.6 years, 44 % Black, 58 % women) were free of diabetes, and were followed 10 years. Cox regression was used to estimate hazard ratios (HRs) for incident T2D adjusting for the other biomarkers under study, demographic and lifestyle measures, dietary biomarkers, BMI (kg/m(2)) and metabolic syndrome components.

RESULTS

F2-isoprostanes and oxidized LDL (oxidative stress) were positively associated with incident T2D, but the associations were attenuated by adjustment for BMI. C-reactive protein was positively associated with T2D even with full adjustment: HR (95 % CI) = 2.21 (1.26-3.88) for quartile 4 (Q4) v. quartile 1 (Q1). The HR (95 % CI) for T2D for biomarkers of endothelial dysfunction ICAM-1 and E-selectin for Q4 v. Q1 were 1.64 (0.96-2.81) and 1.68 (1.04-2.71) respectively, with full adjustment. Including these two markers in a common risk score incorporating BMI and clinical measures improved the prediction probability of T2D: relative risk for the average person classified up compared to the average person classified down: 1.09, (1.06-1.13), P < 0.0001.

CONCLUSIONS

Biomarkers of inflammation and endothelial dysfunction were positively associated with incident T2D. ICAM-1 and E-selectin add to the prediction of T2D beyond a common risk score.

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.

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.