The effects of serum beta-carotene concentration and burden of inflammation on all-cause mortality risk in high-functioning older persons: MacArthur studies of successful aging

The association between serum vitamin A concentrations and virus hepatitis among U.S. adults from the NHANES database: a cross-sectional study

Objective

According to the present study, the relationship between vitamin A (VA) levels and hepatitis virus carriage has been unclear and controversial. This study aimed to determine the potential relationship between serum VA levels and viral hepatitis and to provide ideas for future clinical treatments.

Methods

A cross-sectional study was performed using the 2005-2006 and 2017-2018 National Health and Nutrition Examination Survey (NHANES) datasets. Multiple linear regression and logistic regression were adopted to analyze the association between serological hepatitis B surface antigen (HBsAg) or hepatitis C RNA (HCV-RNA) positivity and VA levels. There were 5,351 HBsAg-related responders and 242 HCV-RNA-related responders, including 52 HBsAg (+) and 104 HCV-RNA (+) responders.

Results

Compared with HBsAg (-) and HCV-RNA (-) respondents, HBsAg (+) and HCV-RNA (+) respondents tended to have lower serum VA levels, respectively [1.63 (1.33 ~ 2.01) vs. 1.92 (1.57 ~ 2.34), P < 0.001; 1.54 (1.25 ~ 1.83) vs. 1.78 (1.46 ~ 2.26), P < 0.001]. A greater percentage of responders in the subclinical VA deficiency (SVAD) group were HBsAg (+) and HCV-RNA (+) than were those in the normal VA (VAN) group [2.4% (9/374) vs. 0.9% (43/4977), p = 0.003; 61.5% (16/26) vs. 40.7% (88/215), p = 0.043]. According to the results of the multiple regression analyses of the different models, the serum VA concentration was negatively correlated with HBsAg (+) and HCV-RNA (+) status (β = -0.14, 95% CI = -0.30 to -0.01, p = 0.066; β = -0.29, 95% CI = -0.50 ~ -0.09, p = 0.005, respectively). Compared to those with SVAD, patients with VAN were less likely to be serologically HBsAg (+) or HCV-RNA (+) (OR = 0.53, 95% CI = 0.25 ~ 1.10, p = 0.089; OR = 0.39, 95% CI = 0.18 ~ 0.84, p = 0.016, respectively).

Conclusion

Our study provides evidence that patients who are HBsAg (+) or HCV-RNA (+) have a high incidence of SVAD. Moreover, HBsAg and HCV-RNA positivity are negatively correlated with VA levels, and patients with SVAD are more likely to carry HBsAg (+) or HCV-RNA (+). These findings suggest that the relationship between hepatitis viruses and vitamin A needs to be validated by more basic studies and clinical large-sample randomized controlled trials to provide ideas for new therapeutic targets.

Influence of Vitamin A supplementation on inflammatory biomarkers in adults: a systematic review and meta-analysis of randomized clinical trials

Vitamin A is an anti-oxidant which has been presumed to act as an anti-infective vitamin in many studies. This study aimed to evaluate the association between vitamin A supplementation and c-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) levels in randomized control trials (RCTs) studies on adults. A systematic search was performed on databases including PUBMED, SCOPUS, and the Cochrane library. The studies included were considered for data extraction and subsequently assessed for effect. Weighted mean differences (WMD) and 95% confidence intervals (CIs) were evaluated. Among 13,219 articles 13 studies were included for analysis of CRP and TNF-α, as well as 9 studies included for IL-6 in quality and quantity. The pooled WMD analysis of CRP demonstrated that vitamin A supplementation significantly increased CRP concentration with (WMD: 0.84 mg/L; 95% CI 0.29-1.39, I² = 0.96.2% and p value < 0.003). However, there was no significant correlation between vitamin A supplementation and lower plasma TNF-α (p < 0.45)). Subgroup analysis by dosage demonstrate significant association between vitamin A supplementation and IL-6 in dosage with 50,000 with (WMD: - 1.53 mg/L; 95% CI - 2.36 to - 0.71, p value < 0.00001) as well as a negative significant association was seen at 44 weeks of supplementation with 50,000 IU/day retinyl palmitate and TNF-a in chronic hepatitis B conditions with (- 0.94 (- 1.19, - 0.69) p < 0.0001). The result of this study demonstrates that supplementation of vitamin A at low and high dosages for short and long durations increases the CRP plasma concentrations on adults and vitamin A supplementation decreases the TNF-α concentrations in chronic hepatitis B on adults. Therefore, there is an inverse association between vitamin A supplementation and plasma and fecal IL-6 concentrations in many infection conditions.

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

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

What Do We Know about Diet and Markers of Cardiovascular Health in Children: A Review

Chronic diseases such as cancer, diabetes, and cardiovascular diseases (CVD) are the main health concerns in the 21st century, with CVD as the number one cause of mortality worldwide. Although CVD hard endpoints such as stroke or heart attack do not usually occur in children, evidence shows that the manifestation of CVD risk factors begins in childhood, preceding clinical complications of CVD in adulthood. Dietary intake is a modifiable risk factor that has been shown to make a substantial contribution to the risk of CVD in adulthood. However, less is known about the association between dietary intake and markers of cardiovascular health in children. This review summarises the current evidence on the relationship between dietary intake and markers of cardiovascular health including traditional CVD risk factors, physical fitness, and indices of arterial stiffness and wave reflection in children. Original research published in English, between January 2008 and December 2018 fulfilling the objective of this review were screened and included. Findings show that adaptation of a healthy lifestyle early in life can be beneficial for reducing the risk of CVD later in life. Furthermore, keeping arterial stiffness low from a young age could be a potential CVD prevention strategy. However, limited studies are available on diet-arterial stiffness relationship in children, and future research is required to better understand this association to aid the development and implementation of evidence-based strategies for preventing CVD-related complications later in life.

Raman spectroscopic screening of high and low molecular weight fractions of human serum

This study explores the suitability of Raman spectroscopy as a bioanalytical tool, when coupled with ultra-filtration and multivariate analysis, to detect imbalances in both high molecular weight and low molecular weight fractions of the same samples of human patient serum, in the native liquid form.

Dietary intake and blood concentrations of antioxidants and the risk of cardiovascular disease, total cancer, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective studies

Background

High dietary intake or blood concentrations (as biomarkers of dietary intake) of vitamin C, carotenoids, and vitamin E have been associated with reduced risk of cardiovascular disease, cancer, and mortality, but these associations have not been systematically assessed.

Objective

We conducted a systematic review and meta-analysis of prospective studies of dietary intake and blood concentrations of vitamin C, carotenoids, and vitamin E in relation to these outcomes.

Design

We searched PubMed and Embase up to 14 February 2018. Summary RRs and 95% CIs were calculated with the use of random-effects models.

Results

Sixty-nine prospective studies (99 publications) were included. The summary RR per 100-mg/d increment of dietary vitamin C intake was 0.88 (95% CI: 0.79, 0.98, I2 = 65%, n = 11) for coronary heart disease, 0.92 (95% CI: 0.87, 0.98, I2 = 68%, n = 12) for stroke, 0.89 (95% CI: 0.85, 0.94, I2 = 27%, n = 10) for cardiovascular disease, 0.93 (95% CI: 0.87, 0.99, I2 = 46%, n = 8) for total cancer, and 0.89 (95% CI: 0.85, 0.94, I2 = 80%, n = 14) for all-cause mortality. Corresponding RRs per 50-μmol/L increase in blood concentrations of vitamin C were 0.74 (95% CI: 0.65, 0.83, I2 = 0%, n = 4), 0.70 (95% CI: 0.61, 0.81, I2 = 0%, n = 4), 0.76 (95% CI: 0.65, 0.87, I2 = 56%, n = 6), 0.74 (95% CI: 0.66, 0.82, I2 = 0%, n = 5), and 0.72 (95% CI: 0.66, 0.79, I2 = 0%, n = 8). Dietary intake and/or blood concentrations of carotenoids (total, β-carotene, α-carotene, β-cryptoxanthin, lycopene) and α-tocopherol, but not dietary vitamin E, were similarly inversely associated with coronary heart disease, stroke, cardiovascular disease, cancer, and/or all-cause mortality.

Conclusions

Higher dietary intake and/or blood concentrations of vitamin C, carotenoids, and α-tocopherol (as markers of fruit and vegetable intake) were associated with reduced risk of cardiovascular disease, total cancer, and all-cause mortality. These results support recommendations to increase fruit and vegetable intake, but not antioxidant supplement use, for chronic disease prevention.

Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies

The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. A systematic search was performed in PubMed and Scopus, from their inception up to October 2017. Prospective observational studies reporting risk estimates of all-cause mortality in relation to dietary intake and/or circulating concentrations of antioxidants were included. Random-effects meta-analyses were conducted. Forty-one prospective observational studies (total n = 507,251) involving 73,965 cases of all-cause mortality were included. The RRs of all-cause mortality for the highest compared with the lowest category of circulating antioxidant concentrations were as follows: total carotenes, 0.60 (95% CI: 0.46, 0.74); vitamin C, 0.61 (95% CI: 0.53, 0.69); selenium, 0.62 (95% CI: 0.45, 0.79); β-carotene, 0.63 (95% CI: 0.57, 0.70); α-carotene, 0.68 (95% CI: 0.58, 0.78); total carotenoids, 0.68 (95% CI: 0.56, 0.80); lycopene, 0.75 (95% CI: 0.54, 0.97); and α-tocopherol, 0.84 (95% CI: 0.77, 0.91). The RRs for dietary intakes were: total carotenoids, 0.76 (95% CI: 0.66, 0.85); total antioxidant capacity, 0.77 (95% CI: 0.73, 0.81); selenium, 0.79 (95% CI: 0.73, 0.85); α-carotene, 0.79 (95% CI: 0.63, 0.94); β-carotene, 0.82 (95% CI: 0.77, 0.86); vitamin C, 0.88 (95% CI: 0.83, 0.94); and total carotenes, 0.89 (95% CI: 0.81, 0.97). A nonsignificant inverse association was found for dietary zinc, zeaxanthin, lutein, and vitamin E. The nonlinear dose-response meta-analyses demonstrated a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C, and total carotenoids. The association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C. The present study indicates that adherence to a diet with high antioxidant properties may reduce the risk of all-cause mortality. Our results confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.

Inverse association between serum antioxidant levels and inflammatory markers is moderated by adiposity: a report based on a large representative population sample of American adults

We examined the association between plasma antioxidant levels and markers of inflammation, including C-reactive protein (CRP) and fibrinogen (FG) in US adults. National Health and Nutrition Examination Survey participants examined between 2001 and 2002 were included, if data on CRP or FG levels. Serum vitamins A and E, two retinyl esters, and six carotenoids were measured using HPLC with photodiode array detection. Multivariable-adjusted linear regression analyses accounted for the survey design and sample weights. A total of 784 eligible participants were included; 47·5 % (n 372) were men. In multivariable linear regression models, serum α-carotene, trans-β-carotene, cis-β-carotene, β-cryptoxanthin, combined lutein/zeaxanthin, trans-lycopene, retinyl palmitate, α-tocopherol, retinol and 25-hydroxy vitamin D were negatively associated with serum CRP (P3 mg/l, decreased with increasing levels of antioxidants (α-carotene, trans-β-carotene, cis-β-carotene, vitamins A and E). Furthermore, we found a moderate impact of adiposity on the link between antioxidants and CRP. Our results suggest that the lower the antioxidants levels, the higher the inflammatory burden, based on CRP and FG levels. Adiposity moderately affects this association. Furthermore, an inverse relationship between CVD risk and antioxidant levels was observed. This finding suggests that reduced levels of vitamins with antioxidant properties may predispose to increased CVD risk.

Dietary, circulating beta-carotene and risk of all-cause mortality: a meta-analysis from prospective studies

Observational studies evaluating the relation between dietary or circulating level of beta-carotene and risk of total mortality yielded inconsistent results. We conducted a comprehensive search on publications of PubMed and EMBASE up to 31 March 2016. Random effect models were used to combine the results. Potential publication bias was assessed using Egger’s and Begg’s test. Seven studies that evaluated dietary beta-carotene intake in relation to overall mortality, indicated that a higher intake of beta-carotene was related to a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.83, 95%CI: 0.78–0.88) with no evidence of heterogeneity between studies (I² = 1.0%, P = 0.416). A random-effect analysis comprising seven studies showed high beta-carotene level in serum or plasma was associated with a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.69, 95%CI: 0.59–0.80) with low heterogeneity (I² = 37.1%, P = 0.145). No evidence of publication bias was detected by Begg’s and Egger’s regression tests. In conclusion, dietary or circulating beta-carotene was inversely associated with risk of all-cause mortality. More studies should be conducted to clarify the dose-response relationship between beta-carotene and all-cause mortality.

Serum Vitamin A and Inflammatory Markers in Individuals with and without Chronic Obstructive Pulmonary Disease

BACKGROUND

Vitamin A is essential for the preservation and integrity of the lung epithelium and exerts anti-inflammatory effects.

OBJECTIVE

Evaluating vitamin A in the serum and sputum and testing its correlation with inflammatory markers in individuals with or without COPD. Methods. We evaluated dietary intake, serum and sputum vitamin A, tumor necrosis factor alpha, interleukin- (IL-) 6, IL-8, and C-reactive protein in 50 COPD patients (age = 64.0 ± 8.8 y; FEV1 (forced expiratory volume in the first second) (%) = 49.8 ± 16.8) and 50 controls (age = 48.5 ± 7.4 y; FEV1 (%) = 110.0 ± 15.7).

RESULTS

COPD exhibited lower serum vitamin A (1.8 (1.2-2.1) versus 2.1 (1.8-2.4) μmol/L, P < 0.001) and lower vitamin A intake (636.9 (339.6-1349.6) versus 918.0 (592.1-1654.6) RAE, P = 0.05) when compared with controls. Sputum concentration of vitamin A was not different between groups. Sputum vitamin A and neutrophils were negatively correlated (R (2) = -0.26; P = 0.03). Smoking (0.197, P = 0.042) exhibited positive association with serum vitamin A. COPD was associated with lower serum concentrations of vitamin A without relationship with the systemic inflammation.

CONCLUSIONS

Serum concentration of vitamin A is negatively associated with the presence of COPD and positively associated with smoking status. Sputum retinol is quantifiable and is negatively influenced by neutrophils. Although COPD patients exhibited increased inflammation it was not associated with serum retinol.

Association of vegetables and fruits consumption with sarcopenia in older adults: the Fourth Korea National Health and Nutrition Examination Survey

BACKGROUND

several studies have found nutrients, including antioxidants, to be associated with sarcopenia. However, whether specific foods, such as vegetables and fruits, are associated with sarcopenia has not been studied.

OBJECTIVE

to examine the association of the frequency of vegetables and fruits consumption with sarcopenia in older people.

METHODS

this study used cross-sectional data from the Fourth Korea National Health and Nutrition Examination Survey in 2008-09. Subjects were community-dwelling 823 men and 1,089 women aged ≥65 years. Frequency of food group consumption was obtained by using the food frequency questionnaire. Body composition was measured with the dual-energy X-ray absorptiometry and sarcopenia was defined as appendicular lean mass adjusted for height and fat mass. Logistic regression was used to assess the association of the frequency of food group consumption with sarcopenia, controlling for sociodemographics and health-related variables.

RESULTS

dietary intake of vegetables, fruits and both vegetables and fruits was associated with a significantly reduced risk of sarcopenia after controlling for covariates in men (P = 0.026 for trend, P = 0.012 for trend, P = 0.003 for trend, respectively). Men in the highest quintile, compared with those in the lowest quintile, of vegetables [odds ratio (OR) = 0.48; 95% confidence interval (CI): 0.24-0.95], fruits (OR = 0.30; 95% CI: 0.13-0.70) and vegetables and fruits consumption (OR = 0.32; 95% CI: 0.16-0.67) demonstrated a lower risk of sarcopenia. In women, high consumption of fruits demonstrated a lower risk of sarcopenia (OR = 0.39; 95% CI: 0.18-0.83).

CONCLUSION

frequent vegetables and fruits consumption was inversely associated with sarcopenia in older adults.

Associations between antioxidants and all-cause mortality among US adults with obstructive lung function

Chronic obstructive pulmonary disease is characterised by oxidative stress, but little is known about the associations between antioxidant status and all-cause mortality in adults with this disease. The objective of the present study was to examine the prospective associations between concentrations of α- and β-carotene, β-cryptoxanthin, lutein/zeaxanthin, lycopene, Se, vitamin C and α-tocopherol and all-cause mortality among US adults with obstructive lung function. Data collected from 1492 adults aged 20-79 years with obstructive lung function in the National Health and Nutrition Examination Survey III (1988-94) were used. Through 2006, 629 deaths were identified during a median follow-up period of 14 years. After adjustment for demographic variables, the concentrations of the following antioxidants modelled as continuous variables were found to be inversely associated with all-cause mortality among adults with obstructive lung function: α-carotene (P= 0·037); β-carotene (P= 0·022); cryptoxanthin (P= 0·022); lutein/zeaxanthin (P= 0·004); total carotenoids (P= 0·001); vitamin C (P< 0·001). In maximally adjusted models, only the concentrations of lycopene (P= 0·013) and vitamin C (P= 0·046) were found to be significantly and inversely associated with all-cause mortality. No effect modification by sex was detected, but the association between lutein/zeaxanthin concentrations and all-cause mortality varied by smoking status (P interaction= 0·048). The concentrations of lycopene and vitamin C were inversely associated with all-cause mortality in this cohort of adults with obstructive lung function.

Resonance Raman spectroscopic evaluation of skin carotenoids as a biomarker of carotenoid status for human studies

Resonance Raman spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status has been suggested as a promising biomarker for human studies. This manuscript describes research done relevant to the development of this biomarker, including its reproducibility, validity, feasibility for use in field settings, and factors that affect the biomarker such as diet, smoking, and adiposity. Recent studies have evaluated the response of the biomarker to controlled carotenoid interventions, both supplement-based and dietary [e.g., provision of a high-carotenoid fruit and vegetable (F/V)-enriched diet], demonstrating consistent response to intervention. The totality of evidence supports the use of skin carotenoid status as an objective biomarker of F/V intake, although in the cross-sectional setting, diet explains only some of the variation in this biomarker. However, this limitation is also a strength in that skin carotenoids may effectively serve as an integrated biomarker of health, with higher status reflecting greater F/V intake, lack of smoking, and lack of adiposity. Thus, this biomarker holds promise as both a health biomarker and an objective indicator of F/V intake, supporting its further development and utilization for medical and public health purposes.

Race differences in the relation of vitamins A, C, E, and β-carotene to metabolic and inflammatory biomarkers

Using archival data, we conducted a secondary analysis to examine race differences in the relation of serum vitamins A, C, E and β-carotene to insulin resistance (IR), fasting insulin and glucose, high sensitivity C-reactive protein (hs-CRP), and leukocyte count in 176 non-smoking, healthy, white, and African American (AA) adults aged 18 to 65 years (48% women, 33% AA). We hypothesized that micronutrient concentrations would be associated with early risk markers of cardiometabolic diseases in a race-dependent manner. Fasting blood samples were analyzed for micronutrients, insulin, glucose, hs-CRP, and leukocyte count. Insulin resistance was estimated using the homeostatic model assessment. After adjusting for age, body mass index, gender, educational level, use of vitamin supplements, alcohol intake, leisure time physical activity, menopausal status, and total cholesterol, we observed that β-carotene was significantly associated with insulin resistance and fasting insulin in a race-dependent manner. Among AA, lower β-carotene levels were associated with higher estimates of insulin resistance and fasting insulin; whereas, these same associations were not significant for whites. Race also significantly moderated the relation of vitamin C to leukocyte count, with lower vitamin C being associated with higher leukocyte count only in AA but not whites. For all subjects, lower β-carotene was associated with higher hs-CRP. In AA, but not whites, lower levels of β-carotene and vitamin C were significantly associated with early risk markers implicated in cardiometabolic conditions and cancer. Whether or not lower levels of micronutrients contribute uniquely to racial health disparities is a worthwhile aim for future research.

Serum antioxidant nutrients, vitamin A, and mortality in U.S. Adults

BACKGROUND

Observational studies have suggested that antioxidant nutrients may reduce cancer and overall mortality risks. However, most randomized trials have failed to show survival benefits. Examining nonlinear associations between antioxidant levels and health outcomes may help to explain these discrepant findings.

METHODS

We evaluated all-cause, cancer, and cardiovascular mortality risks associated with quintiles (Q1-Q5) of serum antioxidant (vitamins C and E, β-carotene, and selenium) and vitamin A levels, in 16,008 adult participants of The Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994).

RESULTS

Over a median follow-up period of 14.2 years, there were 4,225 deaths, including 891 from cancer and 1,891 from cardiovascular disease. We observed a dose-response decrease in cancer and overall mortality risks with higher vitamin C levels. In contrast, for vitamin A, risk of cancer death decreased from Q1-Q2, with no further decline in risk at higher levels. For vitamin E, having levels in Q4 was associated with the lowest cancer mortality risk. Both vitamin A and E had U-shaped associations with all-cause mortality. Cancer mortality risks decreased from Q1-Q2 for β-carotene and from Q1-Q4 for selenium. However, for β-carotene and selenium, overall mortality risks decreased from Q1-Q2 but then did not change significantly with higher levels.

CONCLUSIONS

Antioxidant supplement use should be studied in the context of overall mortality and other competing mortality risks.

IMPACT

These data suggest the need for novel intervention studies where doses of these agents are individualized based on their serum levels, and possibly, markers of oxidative stress and systemic inflammatory response.

Relationship between human aging muscle and oxidative system pathway

Ageing is a complex process that in muscle is usually associated with a decrease in mass, strength, and velocity of contraction. One of the most striking effects of ageing on muscle is known as sarcopenia. This inevitable biological process is characterized by a general decline in the physiological and biochemical functions of the major systems. At the cellular level, aging is caused by a progressive decline in mitochondrial function that results in the accumulation of reactive oxygen species (ROS) generated by the addition of a single electron to the oxygen molecule. The aging process is characterized by an imbalance between an increase in the production of reactive oxygen species in the organism and the antioxidant defences as a whole. The goal of this review is to examine the results of existing studies on oxidative stress in aging human skeletal muscles, taking into account different physiological factors (sex, fibre composition, muscle type, and function).

Rationale for antioxidant supplementation in sarcopenia

Sarcopenia is an age-related clinical condition characterized by the progressive loss of motor units and wasting of muscle fibers resulting in decreased muscle function. The molecular mechanisms leading to sarcopenia are not completely identified, but the increased oxidative damage occurring in muscle cells during the course of aging represents one of the most accepted underlying pathways. In fact, skeletal muscle is a highly oxygenated tissue and the generation of reactive oxygen species is particularly enhanced in both contracting and at rest conditions. It has been suggested that oral antioxidant supplementation may contribute at reducing indices of oxidative stress both in animal and human models by reinforcing the natural endogenous defenses. Aim of the present paper is to discuss present evidence related to possible benefits of oral antioxidants in the prevention and treatment of sarcopenia.

Drinking carrot juice increases total antioxidant status and decreases lipid peroxidation in adults

BACKGROUND

High prevalence of obesity and cardiovascular disease is attributable to sedentary lifestyle and eating diets high in fat and refined carbohydrate while eating diets low in fruit and vegetables. Epidemiological studies have confirmed a strong association between eating diets rich in fruits and vegetables and cardiovascular health. The aim of this pilot study was to determine whether drinking fresh carrot juice influences antioxidant status and cardiovascular risk markers in subjects not modifying their eating habits.

METHODS

An experiment was conducted to evaluate the effects of consuming 16 fl oz of daily freshly squeezed carrot juice for three months on cardiovascular risk markers, C-reactive protein, insulin, leptin, interleukin-1α, body fat percentage, body mass index (BMI), blood pressure, antioxidant status, and malondialdehyde production. Fasting blood samples were collected pre-test and 90 days afterward to conclude the study.

RESULTS

Drinking carrot juice did not affect (P > 0.1) the plasma cholesterol, triglycerides, Apo A, Apo B, LDL, HDL, body fat percentage, insulin, leptin, interleukin-1α, or C-reactive protein. Drinking carrot juice decreased (P = 0.06) systolic pressure, but did not influence diastolic pressure. Drinking carrot juice significantly (P < 0.05) increased the plasma total antioxidant capacity and decreased (P < 0.05) the plasma malondialdehyde production.

CONCLUSION

Drinking carrot juice may protect the cardiovascular system by increasing total antioxidant status and by decreasing lipid peroxidation independent of any of the cardiovascular risk markers measured in the study.

Characteristics of physical measurement consent in a population-based survey of older adults

BACKGROUND

Collecting physical measurements in population-based health surveys has increased in recent years, yet little is known about the characteristics of those who consent to these measurements.

OBJECTIVE

To examine the characteristics of persons who consent to physical measurements across several domains, including one's demographic background, health status, resistance behavior toward the survey interview, and interviewer characteristics.

RESEARCH DESIGN, SUBJECTS, AND MEASURES

We conducted a secondary data analysis of the 2006 Health and Retirement Study, a nationally-representative panel survey of older adults aged 51 and older. We performed multilevel logistic regressions on a sample of 7457 respondents who were eligible for physical measurements. The primary outcome measure was consent to all physical measurements.

RESULTS

Seventy-nine percent (unweighted) of eligible respondents consented to all physical measurements. In weighted multilevel logistic regressions controlling for respondent demographics, current health status, survey resistance indicators, and interviewer characteristics, the propensity to consent was significantly greater among Hispanic respondents matched with bilingual Hispanic interviewers, patients with diabetes, and those who visited a doctor in the past 2 years. The propensity to consent was significantly lower among younger respondents, those who have several Nagi functional limitations and infrequently participate in "mildly vigorous" activities, and those interviewed by black interviewers. Survey resistance indicators, such as number of contact attempts and interviewer observations of resistant behavior in prior wave iterations of the Health and Retirement Study were also negatively associated with physical measurement consent. The propensity to consent was unrelated to prior medical diagnoses, including high blood pressure, cancer (excluding skin), lung disease, heart abnormalities, stroke, and arthritis, and matching of interviewer and respondent on race and gender.

CONCLUSIONS

Physical measurement consent is not strongly associated with one's health status, though the findings are somewhat mixed. We recommend that physical measurement results be adjusted for characteristics associated with the likelihood of consent, particularly functional limitations, to reduce potential bias. Otherwise, health researchers should exercise caution when generalizing physical measurement results to the population at large, including persons with functional limitations that may affect their participation.

Low dietary intake of β-carotene, α-tocopherol and ascorbic acid is associated with increased inflammatory and oxidative stress status in a Swedish cohort

Fruit and vegetable consumption has been associated with a reduced risk of several diseases including CVD. A part of these effects seen could be linked to anti-inflammatory and antioxidative effects, although this has not been thoroughly investigated. The present study was designed to investigate the effects of the dietary intake of β-carotene, α-tocopherol and ascorbic acid on in vivo biomarkers of inflammation (PGF2α, high-sensitive C-reactive protein (hsCRP) and IL-6 formation) and oxidative stress (F2-isoprostane formation), the two important factors associated with accelerated atherosclerosis. The dietary intake of 704 participants in the Uppsala Longitudinal Study of Adult Men (ULSAM) at age 70 years was registered and inflammatory and oxidative stress biomarkers were quantified 7 years later. The registered dietary intakes of ascorbic acid and α-tocopherol were negatively associated linearly and in quartiles with both PGF2α, hsCRP, IL-6 and F2-isoprostanes, where ascorbic acid intake generally was more strongly associated. Dietary intake of β-carotene was only significantly negatively associated with F2-isoprostanes. In conclusion, the present study is the first to suggest that the intake of food rich in antioxidants is associated with reduced cyclo-oxygenase- and cytokine-mediated inflammation and oxidative stress at 7 years of follow-up. These associations could be linked to the beneficial effects of fruit and vegetables observed on CVD.

Low total plasma carotenoids are independent predictors of mortality among older persons: the InCHIANTI study

BACKGROUND

Plasma carotenoids are considered a valid biological marker for fruit and vegetable dietary intake. Recent studies show that low carotenoid levels are associated with a high risk of inflammation, cancer, and cardiovascular disease.

AIM OF THE STUDY

To determine whether low plasma carotenoids are associated with increased mortality among older adults.

METHODS

Longitudinal study among 1,043 adults, 65 years and older, in the InCHIANTI study, a population-based cohort of adults living in the community in the Tuscany region, Italy.

RESULTS

Mean total carotenoid concentration was 1.80 micromol/l. During eight years of follow-up, 310 (29.7%) of participants died. Eight-year survival was lower in the lowest compared with the highest tertile of total serum carotenoids (P < 0.0001 by Mantel-Haenszel chi-square). In a multivariate Cox proportional hazards model adjusted for age, education, smoking, body mass index, energy intake, and chronic diseases, adults in the highest tertile of plasma carotenoids at enrollment had lower mortality compared to those in the lowest tertile (Hazards Ratio obtained by considering carotenoids level as an ordinal variable 0.81, 95%; CI 0.65-0.99; P for trend = 0.046).

CONCLUSIONS

Low plasma carotenoids are an independent risk factor for mortality among older adults living in the community.

The role of selenium in chronic disease

Selenium functions as a part of proteins known as selenoproteins. Through these selenoproteins, selenium functions as a defensive mechanism for oxidative stress, for the regulation of thyroid hormone activity, and for the redox status of vitamin C and other molecules. In several of its roles, selenium functions as a dietary antioxidant and thus has been studied for its possible role in chronic diseases. This article reviews recent studies regarding selenium status or supplementation in hypertension, cardiovascular disease, cancer, and diabetes mellitus. A few studies regarding aging and mortality are also included. What can be ascertained from this current review is that the maintenance of adequate selenium nutriture and, at minimum, the prevention of a deficiency in selenium would be advisable for all individuals. In addition, the indiscriminant use of selenium supplements should be approached with caution until further randomized, controlled trials monitor the effects of such supplementation, especially on a long-term basis.

Correlation between two markers of inflammation, serum C-reactive protein and interleukin 6, and indices of oxidative stress in patients with high risk of cardiovascular disease

As evidence of the involvement of inflammation and oxidative damage in pathogenesis of age-related chronic diseases is growing, epidemiologists need to develop measures of both conditions to study their relationships in human populations. One way of searching for appropriate biomarkers is to examine correlations between different inflammatory markers and oxidative indices. We examined cross-sectional correlations between two inflammatory markers, serum C-reactive protein (CRP) and interleukin (IL)-6, and three oxidative indices, plasma levels of alpha-tocopherol and beta-carotene, and urinary levels of 2,3-dinor-5,6-dihydro-15-F2t-isoprostane (F2-IsoP), in 60 individuals at high risk of cardiovascular disease. Correlations between the biomarkers were examined graphically and using the Pearson correlation coefficient. No correlation was found between plasma levels of alpha-tocopherol and either of the inflammatory markers. Plasma beta-carotene inversely correlated with IL-6 (r = -0.46, p=0.0002) and CRP (r = -0.41, p = 0.001). Although urinary F2-IsoP did not correlate with IL-6, this biomarker positively correlated with CRP (r = 0.31, p = 0.002). As only urinary F2-IsoP levels have been validated against known oxidative assaults, their positive association with CRP levels is interpreted as evidence of an interconnection between low-level inflammation and oxidative status. Urinary levels of F2-IsoP and serum levels of CRP represent appropriate biomarkers for future studies of inflammation and oxidative status in humans.

Total plasma carotenoids and mortality in the elderly: results of the Epidemiology of Vascular Ageing (EVA) study

Carotenoids are pigments found in fruits and vegetables. While high intakes of fruits and vegetables have been found to be associated with lower mortality, our objective is to investigate if total plasma carotenoids, via their antioxidant properties, are associated with mortality risk in a free-living elderly population. The 'Epidemiology of Vascular Ageing' (EVA) study (n 1389; 59-71 years) is a 9-year longitudinal study with six waves of follow-up. The association between baseline total plasma carotenoids and mortality was determined by Cox proportional hazards regression analyses. Low total plasma carotenoid level was significantly associated with all-cause mortality in men but not in women. After controlling for potential confounding factors, mortality risk increased significantly in men (P = 0.03) with plasma carotenoids in the lowest quintile compared with men with plasma carotenoids in the highest (relative risk 2.94 (95% CI 1.21, 7.17)). A significant association between mortality by cancer and low plasma carotenoid level variable was also found in men (unit = 1 micromol/l; relative risk 1.72 (95% CI 1.02, 2.86); P = 0.01). Associations between total plasma carotenoids and mortality risk remained statistically significant after taking into account: (1) plasma Se level, which previously was found associated with mortality in this population and (2) thiobarbituric acid-reactive substances level considered as an indicator of oxidative stress. By showing, prospectively, in a general healthy elderly population, that total plasma carotenoid levels were independently associated with mortality risk in men, the present study suggests that total plasma carotenoid levels could be a health indicator in elderly populations.

Biomarkers of inflammation and malnutrition associated with early death in healthy elderly people

OBJECTIVES

To determine whether malnutrition and biomarkers of inflammation predict all-cause, cancer, and cardiovascular mortality in healthy elderly subjects.

DESIGN

Population-based study, prospective cohort.

SETTING

Sète, on the French Mediterranean coast.

PARTICIPANTS

Five hundred and fifty-three men and 888 women aged 60 and older from the Pathologies Oculaires Liées à l'Age cohort free of known comorbidities.

MEASUREMENTS

Plasma levels of cholesterol, albumin, transthyretin (TTR), C-reactive protein (CRP), and alpha 1-acid glycoprotein (AAG) were measured at baseline. To investigate the risks of 5-year (early) and 5- to 9-year (late) mortality, hazard ratios (HR) were evaluated using Cox models.

RESULTS

In men, early death was associated with high CRP and AAG and low albumin and TTR. In women, early death was associated with high AAG, low TTR and low cholesterol. For late death, the only significant association was with CRP in men. A synergistic effect was observed between biomarkers of inflammation and malnutrition. In men, the adjusted HR of early death was 4.98 (95% confidence interval (CI)=2.25-11.01) for both CRP in the highest quartile and albumin in the lowest. In men, this risk was greatest for both AAG in the highest quartile and TTR in the lowest (HR=6.86, 95% CI=3.20-14.71). In women, this risk was greatest for both AAG in the highest quartile and TTR in the lowest (HR=4.64, 95% CI=1.79-12.05). Cancer mortality was greater for high CRP and AAG and for low albumin and TTR in men but not in women.

CONCLUSION

Biomarkers of inflammation and malnutrition together predict early mortality. In healthy elderly subjects, TTR and AAG could be helpful in identifying elderly subjects at higher risk of death.

Oxidative damage and platelet activation as new predictors of mobility disability and mortality in elders

Mobility disability is an early phase of the disablement process in older adults, and represents a major risk factor for physical disability and mortality. Pathophysiological mechanisms responsible for the onset of mobility limitation are still largely unknown. Oxidative damage, responsible for the disruption of the equilibrium of biological systems by damaging major constituent molecules, might play an important role in the pathway leading to major health-related events. It has been suggested the existence of a vicious cycle involving oxidative damage, platelet activation, and inflammation as promoter of pathophysiological changes occurring with aging. This hypothesis is based on the following observations: (a) oxidative damage is associated with diseases and clinical conditions potentially leading to disability and mortality; (b) oxidative damage is associated with platelet activation, and a vicious cycle involving oxidative damage, platelet activation, and inflammation has been demonstrated in several metabolic disorders potentially leading to mobility disability; (c) the age-related physical decline may be associated to the oxidative damage due to the excess of free radicals; (d) antioxidant defense and behavioral factors (e.g., physical activity, dietary restriction, smoking cessation) play an important role in the reduction of oxidative damage levels and are associated with improved physical performance and muscle strength.

Low serum selenium and total carotenoids predict mortality among older women living in the community: the women's health and aging studies

Selenium and the carotenoids play an important role in antioxidant defenses and in the redox regulation involved in inflammation. We tested the hypothesis that low selenium and carotenoids predict mortality in older women living in the community. Women who were enrolled in the Women's Health and Aging Studies I and II in Baltimore, MD (n = 632; 70-79 y old) had serum selenium and carotenoids measured at baseline and were followed for mortality over 60 mo. Median (minimum, maximum) serum selenium and carotenoids were 1.53 (0.73, 2.51) micromol/L and 1.67 (0.13, 9.10) micromol/L; 14.1% of the women died. The 5 major causes of death were heart disease (32.6%), cancer (18.0%), stroke (9.0%), infection (6.7%), and chronic obstructive pulmonary disease (5.6%). Adjusting for age, education, smoking, BMI, poor appetite, and chronic diseases, higher serum selenium [hazard ratio (HR) 0.71, 95% CI 0.56-0.90/1 SD increase in log(e) selenium; P = 0.005] and higher serum total carotenoids (HR 0.77, 95% CI 0.64-0.84/1 SD increase in log(e) total carotenoids; P = 0.009) were associated with a lower risk of mortality. Women living in the community who have higher serum selenium and carotenoids are at a lower risk of death.

Plasma carotene and alpha-tocopherol in relation to 10-y all-cause and cause-specific mortality in European elderly: the Survey in Europe on Nutrition and the Elderly, a Concerted Action (SENECA)

BACKGROUND

Only a few observational studies have related plasma carotene and alpha-tocopherol to mortality in elderly subjects.

OBJECTIVE

The objective was to study the association of plasma carotene (alpha-and beta-carotene) and alpha-tocopherol with all-cause and cause-specific mortality in elderly subjects who participated in a European prospective study.

DESIGN

Plasma concentrations of carotene and alpha-tocopherol were measured in 1168 elderly men and women. After a follow-up period of 10 y, 388 persons had died. The association between plasma antioxidants and mortality was analyzed by using Cox proportional hazard models. To put our results in context, we performed a meta-analysis of 5 studies on plasma antioxidants and all-cause mortality in elderly populations.

RESULTS

Plasma carotene concentrations were associated with a lower mortality risk [adjusted rate ratio (RR) for an increment of 0.39 micromol/L: 0.79; 95% CI: 0.70, 0.89]. This lower mortality risk was observed for both cancer (RR: 0.59; 95% CI: 0.44, 0.79) and cardiovascular disease (RR: 0.83; 95% CI: 0.70, 1.00). The lower risk of cardiovascular death was confined to those with a body mass index (in kg/m2) <25 (RR: 0.67; 95% CI: 0.49, 0.94). Plasma concentrations of alpha-tocopherol were not associated with all-cause or cause-specific mortality. The results for both plasma antioxidants and all-cause mortality were confirmed by the meta-analysis.

CONCLUSIONS

This prospective study suggests that high plasma concentrations of carotene are associated both with lower mortality from all causes and with cancer in the elderly. For cardiovascular mortality, the inverse association was confined to elderly with body mass indexes <25.

Different effect of beta-carotene on proliferation of prostate cancer cells

It was shown that high doses of beta-carotene (>30 microM) decrease proliferation of prostate cancer cells in vitro. However, it is rather doubtful whether such concentration of beta-carotene is really accessible at cellular level. We studied the effect of 3 and 10 microM beta-carotene on proliferation and gene expression in LNCaP and PC-3 prostate cancer cell lines. Beta-carotene--more efficiently absorbed from medium by androgen-sensitive LNCaP cells--increased proliferation of LNCaP cells whereas it had weaker effect on PC-3 cells. Initial global analysis of expression of genes in both cell lines treated with 10 microM beta-carotene (Affymetrix HG-U133A) showed remarkable differences in number of responsive genes. Their recognition allows for conclusion that differences between prostate cancer cell lines in response to beta-carotene treatment are due to various androgen sensitivities of LNCaP and PC-3 cells. Detailed analysis of expression of selected genes in beta-carotene treated LNCaP cells at the level of mRNA and protein indicated that the observed increase of proliferation could have been the result of slight induction of a few genes affecting proliferation (c-myc, c-jun) and apoptosis (bcl-2) with no significant effect on major cell cycle control genes (cdk2, RB, E2F-1).