Analysis of Repeated Measurements of Serum Carotenoid Levels and All-Cause and Cause-Specific Mortality in Japan

Low Serum Total Carotenoids and β-Cryptoxanthin Are Associated with Low Lean Body Mass in Older Community-Dwellers in the National Institute for Longevity Sciences-Longitudinal Study of Aging: A 4-Y Longitudinal Study

BACKGROUND

Although diets rich in carotenoids are associated with muscle health and a reduced risk of disability, the relationship between carotenoids and low lean body mass has not been fully elucidated.

OBJECTIVES

This study aimed to clarify the relationship between serum carotenoid concentrations and low lean body mass over 4 y in older Japanese community-dwellers.

METHODS

A total of 750 adults aged ≥60 y participated in the National Institute for Longevity Sciences-Longitudinal Study of Aging. Individuals with a low lean body mass and muscle strength or gait speed at baseline were excluded. Baseline serum α-carotene, β-carotene, β-cryptoxanthin, zeaxanthin, lutein, and lycopene were measured. Low lean body mass was defined as appendicular lean mass relative to the measured height (ALM/ht2) of <7.0 kg/m2 in males and <5.4 kg/m2 in females, according to the criteria of the Asian Working Group for Sarcopenia 2019. A generalized estimating equation was used to estimate the odds ratio and 95% confidence interval for low lean body mass according to tertiles of total and individual carotenoids at baseline, adjusted for sex, age, season, follow-up months, education years, economic status, current smoking status, a history of ischemic heart disease, stroke, hypertension, dyslipidemia, diabetes mellitus, and metabolic equivalents.

RESULTS

Low serum total carotenoids were associated with low ALM/ht2, and the odds ratios of low ALM/ht2 in the third tertile of total carotenoids were significantly lower than those in the first tertile after adjusting for covariates. The odds ratios of low ALM/ht2 in the third tertile of β-cryptoxanthin were significantly associated with those in the first tertile after adjusting for covariates (P = 0.03); however, no trend was observed for this relationship.

CONCLUSIONS

These findings indicate that low serum total carotenoids and serum β-cryptoxanthin are associated with low lean body mass in older Japanese community-dwellers.

Associations of serum carotenoids with all-cause and cardiovascular mortality in adults with MAFLD

BACKGROUND AND AIMS

The associations between serum carotenoids and mortality are contradictory in various metabolic-associated diseases. This study aimed to examine the associations of five major serum carotenoids with mortality among adults with metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS AND RESULTS

This analysis included 3040 individuals with MAFLD from the Third National Health and Nutrition Examination Survey (NHANES III). All-cause and cardiovascular mortality were ascertained by linkage to the National Death Index through December 31, 2019. Cox proportional hazards regression models were employed to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), and restricted cubic spline (RCS) analyses were performed to assess the linearity of the associations. During a follow-up period of 826,547 person-years, 1325 all-cause and 429 cardiovascular deaths occurred. For all-cause mortality, compared with those in the lowest quartiles, the multivariable-adjusted HRs (95% CIs) in the highest quartiles were 0.63 (0.49-0.81) for α-carotene; 0.65 (0.52-0.80) for β-carotene; 0.64 (0.51-0.81) for β-cryptoxanthin; 0.73 (0.56-0.95) for lycopene; and 0.69 (0.52-0.91) for lutein/zeaxanthin. For cardiovascular mortality, the multivariable-adjusted HRs (95% CIs) in the highest quartiles were 0.51 (0.33-0.78) for α-carotene; 0.54 (0.35-0.82) for β-carotene; 0.52 (0.34-0.80) for β-cryptoxanthin; 0.63 (0.44-0.90) for lycopene; and 0.62 (0.39-0.99) for lutein/zeaxanthin. Besides, serum α-carotene, β-cryptoxanthin, and lycopene exhibited linear correlations with all-cause mortality in MAFLD adults, and four serum carotenoids, except β-carotene, were linearly correlated with cardiovascular mortality.

CONCLUSIONS

Lower serum α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein/zeaxanthin concentrations were associated with higher risk of all-cause and cardiovascular mortality in US adults with MAFLD.

Associations of multiple carotenoid co-exposure with all-cause and cause-specific mortality in US adults: a prospective cohort study

Background

Epidemiological evidence regarding circulating carotenoids and mortality risk remains conflicting, and most studies focus on the impact of individual carotenoids. This study aimed to elucidate the effects of co-exposure to multiple serum carotenoids on mortality risk.

Methods

We enrolled 22,472 participants aged ≥20 from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 2003-2006. Baseline serum levels of five major carotenoids (α-carotene, β-carotene, lycopene, β-cryptoxanthin, and lutein/zeaxanthin) were measured, and individuals were followed up until December 31, 2019. Carotenoid co-exposure patterns were identified using the K-means method. Cox proportional hazard models were used to investigate the associations between carotenoid exposure and mortality risk.

Results

During a median follow-up of 16.7 years, 7,901 deaths occurred. K-means clustered participants into low-level, low-lycopene, high-lycopene, and high-level exposure groups. In the fully adjusted model, low-lycopene, high-lycopene, and high-level exposure groups had significantly lower all-cause mortality risks compared to the low-level exposure group, with hazard ratios (HRs) and 95% confidence intervals (CIs) of 0.79 (0.72, 0.87), 0.75 (0.67, 0.84), and 0.67 (0.61, 0.74), respectively. For cardiovascular disease mortality, the high-lycopene exposure group had a 27% reduced risk (HR: 0.73, 95% CI: 0.61-0.86), and the high-level exposure group had a 21% reduced risk (HR: 0.79, 95% CI: 0.67-0.93). For cancer mortality, the high-lycopene and high-level exposure groups had 30% and 35% lower risks, with HRs (95% CIs) of 0.70 (0.57, 0.86) and 0.65 (0.54, 0.79), respectively.

Conclusion

This study revealed that co-exposure to multiple serum carotenoids was associated with reduced mortality risk, highlighting the potential health benefits of increased carotenoid intake. Further investigation is warranted to elucidate the underlying mechanisms of interactions among different carotenoids.

Serum carotenoid levels are positively associated with DNA methylation of thioredoxin-interacting protein

Background: Carotenoids have been reported to exert protective effects against age-related diseases via changes in DNA methylation. Although lower thioredoxin-interacting protein (TXNIP) DNA methylation is associated with age-related diseases, only a few studies have investigated the factors influencing TXNIP DNA methylation. Carotenoids may be a factor linking TXNIP to specific pathophysiological functions. The aim of this study was to examine whether serum carotenoid levels are associated with TXNIP DNA methylation levels. Methods: We conducted a cross-sectional study using 376 health examination participants (169 men). DNA methylation levels were determined using a pyrosequencing assay. Serum carotenoid levels were determined by high-performance liquid chromatography. Multivariable regression analyses were performed to examine the associations between TXNIP DNA methylation levels and serum carotenoid levels with adjustment for age, BMI, HbA1c, CRP, smoking habits, alcohol consumption, exercise habits, and percentage of neutrophils. Results: Multiple linear regression analyses showed that TXNIP DNA methylation levels were positively associated with serum levels of zeaxanthin/lutein (β [95%CI]: 1.935 [0.184, 3.685]), β-cryptoxanthin (1.447 [0.324, 2.570]), α-carotene (1.061 [0.044, 2.077]), β-carotene (1.272 [0.319, 2.226]), total carotenes (1.255 [0.040, 2.469]), total xanthophylls (2.133 [0.315, 3.951]), provitamin A (1.460 [0.402, 2.519]), and total carotenoids (1.972 [0.261, 3.683]) in men (all p<0.05). Of these, provitamin A showed the stronger association (standardized β=0.216). No significant association of TXNIP DNA methylation and serum carotenoid was observed in women. Conclusions: The findings of this study suggest that carotenoid intake may protect against age-related diseases by altering TXNIP DNA methylation status in men.

Higher serum carotenoid concentrations were associated with the lower risk of cancer-related death: Evidence from the National Health and Nutrition Examination Survey

The study focuses on the association between serum carotenoids and cancer-related death. Using data from the National Health and Nutrition Examination Survey (2001-2006 and 2017-2018), the study encompasses 10,277 participants older than age 20 years, with recorded baseline characteristics and serum carotenoid concentrations (including α-carotene, trans-β-carotene, cis-β-carotene, β-cryptoxanthin, trans-lycopene, and lutein/zeaxanthin). We hypothesized that serum carotenoid concentrations were negatively associated with cancer-related death. The weighted chi-square analyses indicate significant negative correlations between higher serum concentrations of α-carotene, β-cryptoxanthin, trans-lycopene, and total carotenoids, and the risk of cancer-related deaths. Using weighted Cox regression analysis, this study confirms that α-carotene, β-cryptoxanthin, trans-lycopene, and total carotenoids, as continuous or categorical variables, are inversely related to cancer mortality (P < .0001). Furthermore, considering competitive risk events, lower concentrations of serum β-cryptoxanthin (Fine-Gray P = 1.12e-04), trans-lycopene (P = 5.68e-14), and total carotenoids (P = .03) are associated with an increased risk of cancer-related deaths. The research reveals a crucial inverse relationship between serum carotenoid concentrations and cancer-related death.

Association between atherosclerotic cardiovascular disease score and skin carotenoid levels estimated via refraction spectroscopy in the Japanese population: a cross-sectional study

Carotenoids play a role in preventing and impeding the progression of atherosclerotic cardiovascular diseases (ASCVDs) through their anti-oxidative effects. This study evaluated associations between ASCVD risk and skin carotenoid (SC) levels, reflecting dietary carotenoid intake. Participants' ASCVD risk was assessed using the Hisayama ASCVD risk prediction model, and SC levels were measured through a reflection spectroscope (Veggie Meter). The associations between high ASCVD risk and SC levels were analyzed using logistic regression analysis and a restricted cubic spline (RCS) model. A total of 1130 men and women (mean age: 56 years) from participants who underwent a health examination in Seirei Center for Health Promotion and Prevention Medicine in 2019 and 2022 were analyzed. Of these, 4.6% had moderate or high ASCVD risk. Mean SC values were 236, 315, 376, 447, and 606 in quintile Q1 to Q5, respectively. The adjusted odds ratios (95% confidence intervals) of SC quintile for moderate- or high-risk ASCVD was 0.24 (0.12-0.51) in Q5 (495 ≤), 0.42 (0.23-0.77) in Q4, 0.50 (0.29-0.88) in Q3, and 0.68 (0.41-1.12) in Q2 compared to Q1 (< 281). High SC values continuously showed non-linear inverse association with moderate- or high-risk for ASCVD in Japanese adults. Non-invasive SC measurements may be a good indicator for recommending carotenoids to prevent cardiovascular disease.

Associations of Serum Carotenoids With Risk of All-Cause and Cardiovascular Mortality in Hypertensive Adults

Background Systemic oxidative stress is involved in the development of hypertension, whereas carotenoids are a group of natural antioxidants. Our study aims to evaluate the relationships between the serum concentrations of major carotenoids and mortality in hypertensive adults. Methods and Results Data on 5 serum carotenoids from the National Health and Nutrition Examination Survey (NHANES) III and NHANES 2001-2006 were included. Outcome measures (all-cause and cardiovascular mortality) were identified from the National Death Index through December 31, 2019. Multiple Cox proportional hazards regression and restricted cubic spline analyses were performed to determine the association between carotenoid levels and outcomes. A total of 8390 hypertensive adults were included in the analysis. At a median follow-up duration of 16.6 years, all-cause and cardiovascular mortality occurred in 4005 (47.74%) and 1205 (14.36%) participants, respectively. Compared with the lowest quartiles, the highest quartiles of 5 major serum carotenoids were associated with lower risk of all-cause mortality, with multivariable-adjusted hazard ratios (HRs) of 0.63 (95% CI, 0.56-0.71) for α-carotene, 0.70 (95% CI, 0.61-0.80); for β-carotene, 0.67 (95% CI, 0.58-0.76); for β-cryptoxanthin, 0.74 (95% CI, 0.64-0.86) for lycopene; and 0.72 (95% CI, 0.63-0.83) for lutein/zeaxanthin. For cause-specific mortality, this association with the fourth quartile of serum carotenoids was evident for a reduced rate of cardiovascular mortality, with a 32% reduction for α-carotene (HR, 0.68 [95% CI, 0.55-0.86]), a 29% reduction for β-cryptoxanthin (HR, 0.71 [95% CI, 0.56-0.89]), and a 26% reduction for lycopene (HR, 0.74 [95% CI, 0.59-0.94]), but not for β-carotene and lutein/zeaxanthin. In addition, we found that serum α-carotene, β-carotene, β-cryptoxanthin, and lutein/zeaxanthin levels were nonlinearly related to all-cause mortality with inflection points of 2.43, 8.49, 5.12, and 14.17 μg/dL, respectively. Serum α-carotene, β-cryptoxanthin, and lutein/zeaxanthin concentrations showed nonlinear associations with cardiovascular mortality with inflection points of 2.31, 5.26, and 15.40 μg/dL, respectively. Conclusions Findings suggest that higher serum carotenoid concentrations were associated with lower risks of all-cause and cardiovascular mortality in hypertensive adults.

Intake of vegetables and fruits rich in provitamin A is positively associated with aryl hydrocarbon receptor repressor DNA methylation in a Japanese population

DNA methylation can be affected by numerous lifestyle factors, including diet. Tobacco smoking induces aryl hydrocarbon receptor repressor (AHRR) DNA hypomethylation, which increases the risk of lung and other cancers. However, no lifestyle habits that might increase or restore percentage of AHRR DNA methylation have been identified. We hypothesized that dietary intakes of vegetables/fruits and serum carotenoid concentrations are related to AHRR DNA methylation. A total of 813 individuals participated in this cross-sectional study. A food frequency questionnaire was used to assess dietary intake of vegetables and fruits. AHRR DNA methylation in peripheral blood mononuclear cells were measured using pyrosequencing method. In men, dietary fruit intake was significantly and positively associated with AHRR DNA methylation among current smokers (P for trend = .034). A significant positive association of serum provitamin A with AHRR DNA methylation was observed among current smokers (men: standardized β = 0.141 [0.045 to 0.237], women: standardized β = 0.570 [0.153 to 0.990]). However, compared with never smokers with low provitamin A concentrations, percentages of AHRR DNA methylation were much lower among current smokers, even those with high provitamin A concentrations (men: β = -19.1% [-33.8 to -19.8], women: β = -6.0% [-10.2 to -1.7]). Dietary intake of vegetables and fruits rich in provitamin A may increase percentage of AHRR DNA methylation in current smokers. However, although we found a beneficial effect of provitamin A on AHRR DNA methylation, this beneficial effect could not completely remove the effect of smoking on AHRR DNA demethylation.

Association between serum carotenoids and premature mortality in a population-based case-control study

Carotenoids are abundant pigments mainly contained in vegetables and fruits, and show antioxidant properties by quenching free radicals in human body. Few studies have investigated associations between serum carotenoid levels and premature mortality. The objective of this study was to investigate the association between serum carotenoid level and premature mortality in a Japanese population. This study included 446 Japanese adults (174 men, aged of 40-64) recruited as participants in the Japan Collaborative Cohort (JACC) Study. Serum carotenoid level was measured by high-performance liquid chromatography. Premature mortality was defined as death before 65 years old during the follow-up period. Premature mortality was ascertained in 60 men (34.5%) and 65 women (23.9%). In men, compared to the 1^st tertile of serum β-cryptoxanthin and provitamin A, those who were in the 3^rd tertile had lower risks of premature all-cause mortality (OR, 95% CI: 0.19, 0.07-0.47 for β-cryptoxanthin, and 0.24, 0.09-0.61 for provitamin A). In women, compared to the 1^st tertile of serum β-cryptoxanthin, those who were in the 3^rd tertile had higher risks of premature all-cause mortality (OR, 95% CI: 1.94, 1.00-4.03). These significant associations were observed in analyses for premature cancer mortality. We found significant associations between higher levels of serum β-cryptoxanthin and provitamin A and lower risks of premature mortality among Japanese men, while a different directional association was found in women. Although these findings suggest roles of serum carotenoids on premature mortality, further studies are needed to validate this association in other populations.

Effect of Carotenoids on Paraoxonase-1 Activity and Gene Expression

Paraoxonase 1 (PON1) is an antioxidant enzyme attached to HDL with an anti-atherogenic potential. It protects LDL and HDL from lipid peroxidation. The enzyme is sensitive to various modulating factors, such as genetic polymorphisms as well as pharmacological, dietary (including carotenoids), and lifestyle interventions. Carotenoids are nutritional pigments with antioxidant activity. The aim of this review was to gather evidence on their effect on the modulation of PON1 activity and gene expression. Carotenoids administered as naturally occurring nutritional mixtures may present a synergistic beneficial effect on PON1 status. The effect of carotenoids on the enzyme depends on age, ethnicity, gender, diet, and PON1 genetic variation. Carotenoids, especially astaxanthin, β-carotene, and lycopene, increase PON1 activity. This effect may be explained by their ability to quench singlet oxygen and scavenge free radicals. β-carotene and lycopene were additionally shown to upregulate PON1 gene expression. The putative mechanisms of such regulation involve PON1 CpG-rich region methylation, Ca(2+)/calmodulin-dependent kinase II (CaMKKII) pathway induction, and upregulation via steroid regulatory element-binding protein-2 (SREBP-2). More detailed and extensive research on the mechanisms of PON1 modulation by carotenoids may lead to the development of new targeted therapies for cardiovascular diseases.

Associations of Serum Biomarkers of Fruit and Vegetable Intake With the Risk of Cause–Specific Mortality and All–Cause Mortality: A National Prospective Cohort Study

Objective

The purpose of this study was to evaluate the associations of serum biomarkers of fruit and vegetable intake (vitamin C and carotenoids) with cause–specific mortality and all–cause mortality in a nationally representative sample of US adults.

Methods

We analyzed data from 12,530 participants from the National Health and Nutrition Examination Survey III (1988–1994). The Cox proportional hazards models with restricted cubic spline were used for the analysis.

Results

During 246,027 person–years of follow–up, 4,511 deaths occurred, including 1,395 deaths from cardiovascular disease, 1,072 deaths from heart disease, 323 deaths from cerebral disease, and 954 deaths from cancer. The serum vitamin C was significantly associated with the cancer and all–cause mortality, with hazard ratios (HRs) (95% CIs) for each one SD of 0.80 (0.71–0.91) and 0.91 (0.86–0.96). The serum alpha–carotene was significantly associated with the cancer mortality, with HRs (95% CIs) of 0.70 (0.54–0.90), 0.68 (0.48–0.95), 0.64 (0.43–0.95), and 0.44 (0.33–0.60) for comparisons of groups 2–5 with group 1 in model 2, respectively. The change for each one SD in the composite biomarker score, equivalent to a 0.483 times/month difference in total fruits and vegetables intake, gave an HR of 0.79 (0.69–0.90) for cancer mortality.

Conclusion

Inverse associations were found between serum vitamin C, carotenoids, and composite biomarker score and outcomes expect for cerebral disease, heart disease, and cardiovascular disease mortality. This finding supports an increase in dietary fruit and vegetable intake as a primary prevention strategy for cancer and all–cause mortality.