Provitamin A carotenoid intake and carotid artery plaques: the Atherosclerosis Risk in Communities Study

Dietary antioxidant intake reduces carotid intima-media thickness in coronary heart disease patients: From the CORDIOPREV study

BACKGROUND

Atherosclerosis is the leading underlying cause of coronary heart disease (CHD). In patients with CHD, intima-media thickness of common carotid arteries (IMT-CC) is a reliable, validated, and non-invasive marker of the progression of atherosclerosis. Dietary intervention may affect IMT-CC evolution through different pathways. There is a lack of clinical trials evaluating the effect of total dietary antioxidant content of diets on IMT-CC, especially in patients with CHD.

OBJECTIVE

We evaluated the correlation between the diet's total antioxidant content and the changes in IMT-CC produced after 5 years of dietary intervention following two healthy diet models (Mediterranean diet and low-fat diet). We also evaluated whether the diet's total antioxidant content was related to the total redox capacity of the participants.

METHODS

From the total participants of the CORDIOPREV study (clinical trial register NCT00924937), 805 participants completed the IMT-CC measurement and the dietary antioxidant evaluation at baseline and after 5 years of dietary intervention. IMT-CC was carried out by ultrasound and the dietary antioxidant evaluation was performed by the Dietary Antioxidant Index (DAI). Additionally, direct redox balance was evaluated in a subset of population by the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSH) by colorimetric assay.

RESULTS

We observed an inverse correlation between evolution of DAI and IMT-CC after 5-years of dietary intervention. The mean of the DAI index augmented in the Mediterranean Diet group, whereas it decreased in the Low-fat group. DAI was correlated to the GSH/GSSG ratio, supporting DAI as an adequate estimator of diet's antioxidant content. When looking for individual components of the DAI that were associated to the changes in IMT-CC, an inverse correlation was found for carotenoids, vitamin E, vitamin C, and zinc and the IMT-CC.

CONCLUSIONS

Our study indicates that, after five years of dietary intervention, changes in DAI inversely correlate with changes in IMT-CC in patients with CHD. Overall effect of Mediterranean diet resulted in an increase of DAI, conversely to low-fat. Specific elements included in the DAI index were inversely correlated with IMT-CC.

Changes in Intake and Major Food Sources of Carotenoids among U.S. Adults between 2009-2018

Large epidemiologic studies suggest that diets rich in total or specific carotenoids are associated with a reduced risk of many chronic diseases. However, there are few studies characterizing trends in dietary carotenoid sources and intake among subgroups of the US adult population in the previous decade. This study aimed to assess these trends using data from 22,339 adults who participated in NHANES 2009-2018 cycles. Carotenoid intake and major food sources were calculated by linking food consumption data from the 24 h diet recall to an FNDDS 2009-2018 and the USDA's National Nutrient Database for Standard Reference (Release 28). Among US adults, mean (SE) dietary carotenoid intake was 9687.1 (158.0) mcg/day, and total intake was highest in men, non-smokers, moderate alcohol consumers, supplement users, and those with normal BMI, a PIR ≥ 1.85, and whose physical activity level was considered vigorous (p < 0.05). Carotenoid intake has gradually decreased over the past decade (p-trend: 0.097), especially among White adults (p-trend < 0.05), males (p-trend: 0.062), and those with a PIR of 1.0-1.3 (p-trend: 0.051), as have estimated rates of vitamin A adequacy. Tomatoes, carrots, and spinach were major food sources of carotenoids, and consumption of carrots and tomatoes decreased, while the consumption of lettuce, spinach, and salsa increased from 2009 to 2018. Our results warrant further studies investigating the consequences of the decreased tendencies of carotenoid intake on chronic disease risk, especially focusing on population subgroups exhibiting low or decreasing trends of carotenoid intake status.

The Roles of Carotenoid Consumption and Bioavailability in Cardiovascular Health

Carotenoids are natural pigments generally with a polyene chain consisting of 9-11 double bonds. In recent years, there has been increasing research interest in carotenoids because of their protective roles in cardiovascular diseases (CVDs). While the consumption of carotenoids may have a beneficial effect on CVDs, the literature shows inconsistencies between carotenoid consumption and reductions in the risk of CVDs. Therefore, this review aims to provide a summary of the association between dietary carotenoid intake and the risk of CVDs from published epidemiological studies. Meanwhile, to further elucidate the roles of carotenoid intake in CVD protection, this review outlines the evidence reporting the effects of carotenoids on cardiovascular health from randomized controlled trials by assessing classical CVD risk factors, oxidative stress, inflammatory markers and vascular health-related parameters, respectively. Given the considerable discrepancies among the published results, this review underlines the importance of bioavailability and summarizes the current dietary strategies for improving the bioavailability of carotenoids. In conclusion, this review supports the protective roles of carotenoids against CVDs, possibly by attenuating oxidative stress and mitigating inflammatory response. In addition, this review suggests that the bioavailability of carotenoids should be considered when evaluating the roles of carotenoids in CVD protection.

Non-nutrients and nutrients from Latin American fruits for the prevention of cardiovascular diseases

Non-communicable diseases (NCDs) have been rapidly increasing; among them, cardiovascular diseases (CVDs) are responsible for around 1/3 of deaths in the world. Environmental factors play a central role in their development. Diet is a very important factor in this scenario, and the intake of fruits and vegetables has been considered as one of the critical strategies for reducing the risk of CVDs. Fruits are a source of micronutrients and bioactive compounds that could have cardioprotective effects through several distinct mechanisms, such as antioxidant, antithrombotic and antiplatelet activities, vasodilatation, improvement of plasma lipid profiles, and modulation of inflammatory signaling. Brazil has a very rich and unexplored biodiversity in its different biomes, with several types of fruit, which are a source of bioactive compounds and micronutrients with therapeutic properties. In this sense, this review shows the current knowledge regarding the cardioprotective properties of selected Latin American and Brazilian fruits, including their effects on the activation of platelets and on the inflammation processes involved in atherosclerosis and cardiovascular diseases.

Higher dietary and serum carotenoid levels are associated with lower carotid intima-media thickness in middle-aged and elderly people

Several studies have suggested that higher carotenoid levels may be beneficial for atherosclerosis patients, but few studies have examined this relationship in the Chinese population. This cross-sectional study examined the association between the levels of carotenoids in diet and serum and carotid intima-media thickness (IMT) in Chinese adults aged 50-75 years in Guangzhou, China. Dietary intake was assessed using a FFQ. HPLC was used to assay the serum concentrations of α-carotene, β-carotene, lutein+zeaxanthin, β-cryptoxanthin and lycopene. The IMT at the common carotid artery (CCA) and bifurcation of the carotid artery was measured by B-mode ultrasound. A total of 3707 and 2947 participants were included in the analyses of dietary and serum carotenoids. After adjustment for demographic, socio-economic and lifestyle factors, all the serum carotenoids levels except lycopene were found to be inversely associated with the IMT at the CCA and bifurcation (P trend<0·001 to 0·013) in both men and women. The absolute mean differences in the IMT between the subjects in the extreme quartiles of serum carotenoid levels were 0·034 mm (α-carotene), 0·037 mm (β-carotene), 0·032 mm (lutein+zeaxanthin), 0·030 mm (β-cryptoxanthin), 0·015 mm (lycopene) and 0·035 mm (total carotenoids) at the CCA; the corresponding values were 0·025, 0·053 0·043, 0·050, 0·011 and 0·042 mm at the bifurcation. The favourable associations were also observed between dietary carotenoids (except lycopene) and the CCA IMT. In conclusion, elevated carotenoid levels in diet and serum are associated with lower carotid IMT values (particular at the CCA) in Chinese adults.

Dietary Composition and Cardiovascular Risk: A Mediator or a Bystander?

The role of nutrition in the pathogenesis of cardiovascular disease has long been debated. The established notion of the deleterious effects of fat is recently under question, with numerous studies demonstrating the benefits of low-carbohydrate, high-fat diets in terms of obesity, diabetes, dyslipidemia, and metabolic derangement. Monounsaturated and polyunsaturated fatty acids, especially n-3 PUFAs (polyunsaturated fatty acids), are the types of fat that favor metabolic markers and are key components of the Mediterranean Diet, which is considered an ideal dietary pattern with great cardioprotective effects. Except for macronutrients, however, micronutrients like polyphenols, carotenoids, and vitamins act on molecular pathways that affect oxidative stress, endothelial function, and lipid and glucose homeostasis. In relation to these metabolic markers, the human gut microbiome is constantly revealed, with its composition being altered by even small dietary changes and different microbial populations being associated with adverse cardiovascular outcomes, thus becoming the target for potential new treatment interventions. This review aims to present the most recent data concerning different dietary patterns at both the macro- and micronutrient level and their association with atherosclerosis, obesity, and other risk factors for cardiovascular disease.

Influence of phytosterol and phytostanol food supplementation on plasma liposoluble vitamins and provitamin A carotenoid levels in humans: An updated review of the evidence

Phytosterols and phytostanols (PAP) compete with cholesterol absorption in the intestine, resulting in a 5-15%-reduction in plasma total and LDL cholesterol. An important issue is the PAP potential to reduce the plasma concentrations of fat-soluble vitamins and provitamin A carotenoids. Here, an update of the scientific evidence is reviewed to evaluate plant PAP-enriched foods impact on plasma fat-soluble vitamins and carotenoid levels, and to discuss potential implications in terms of cardiovascular risk. Based on 49 human interventional and 3 bioavailability studies, results showed that regular consumption, particularly over the long term, of foods fortified with PAP as recommended in labeling does not significantly impact plasma vitamins A, D, and K concentration. A 10% significant median reduction was observed for α-tocopherol. Concerning carotenoids, while 13 studies did not demonstrate statistically significant plasma β-carotene reduction, 20 studies showed significant reductions, with median effect size of -24%. This decline can be mitigated or offset by increased fruits and vegetables consumption. Furthermore, higher cardiovascular risk was observed for differences in plasma β-carotene concentration of the same magnitude as the estimated average decrease by PAP consumption. These results are supported by the only study of β-carotene bioavailability showing decrease in absorption by phytosterols daily intake.

Association between Micronutrients Intake/Status and Carotid Intima Media Thickness: A Systematic Review

BACKGROUND

Carotid intima media thickness (IMT) is a noninvasive marker of the extent and severity of subclinical atherosclerosis. Micronutrient intake may affect atherosclerosis and play a major role in the development of cardiovascular diseases (CVDs).

OBJECTIVE

The primary aim of this review was to synthesize the evidence regarding the association between carotid IMT and selected micronutrients.

METHOD

The authors searched PubMed, Cochrane, and EMBASE databases from inception to June 2016 for selected micronutrients, CVD, carotid IMT, and antioxidants. Thirty-five original studies met the inclusion criteria and were reviewed following preferred reporting items for systematic review and meta-analysis guidelines.

RESULTS

Although not all studies found consistent results, the weight of the evidence suggests that high intakes and/or circulatory levels of magnesium, as well as vitamin D and the vitamin B group, may be associated with lower carotid IMT or reduced progression of carotid IMT. The majority of studies did not find any significant association between vitamin E and C and carotid IMT. Less evidence was available for associations of retinol, zinc, and iron with carotid IMT.

CONCLUSIONS

In general, the current evidence concerning micronutrient intake and carotid IMT is largely inconclusive. Pragmatic clinical trials are required to determine whether dietary or supplemental intake of specific micronutrients alters carotid IMT, which is a surrogate measure of cardiovascular risk.

The Multiple Facets of Lutein: A Call for Further Investigation in the Perinatal Period

Lutein may have important antioxidant actions in free-radical-mediated diseases, in addition to its well-known antioxidant and cytoprotective effects on macula and photoreceptors. The peculiar perinatal susceptibility to oxidative stress indicates that prophylactic use of antioxidants as lutein could help to prevent or at least to reduce oxidative stress related diseases in newborns. Since lutein is not synthesized by humans, the intake primarily depends on diet or supplementation. Newborns receive lutein exclusively from breast milk. Lutein supplementation in term newborns has been reported to reduce oxidative stress and increase antioxidant capacities in the first days of life. Innovative frontiers concerning lutein supplementation are orientated toward cardiometabolic health improvement and cognitive benefits. The safety of lutein as an antioxidant agent has been confirmed in experimental and clinical studies, but its routine use is not recommended in perinatal period. This review summarizes what is known about the role of lutein as an antioxidant and anti-inflammatory agent in animal model and humans.

Carotenoids: potential allies of cardiovascular health?

Carotenoids are a class of natural, fat-soluble pigments found principally in plants. They have potential antioxidant biological properties because of their chemical structure and interaction with biological membranes. Epidemiologic studies supported the hypothesis that antioxidants could be used as an inexpensive means of both primary and secondary cardiovascular disease (CVD) prevention. In fact, the oxidation of low-density lipoproteins (LDL) in the vessels plays a key role in the development of atherosclerotic lesions. The resistance of LDL to oxidation is increased by high dietary antioxidant intake, so that carotenoids, as part of food patterns such as the Mediterranean diet, may have beneficial effects on cardiovascular health too. Further properties of carotenoids leading to a potential reduction of cardiovascular risk are represented by lowering of blood pressure, reduction of pro-inflammatory cytokines and markers of inflammation (such as C-reactive protein), and improvement of insulin sensitivity in muscle, liver, and adipose tissues. In addition, recent nutrigenomics studies have focused on the exceptional ability of carotenoids in modulating the expression of specific genes involved in cell metabolism. The aim of this review is to focus attention to this effect of some carotenoids to prevent CVD.

Effect of alcoholic fermentation on the carotenoid composition and provitamin A content of orange juice

Orange juice is considered a rich source of carotenoids, which are thought to have diverse biological functions. In recent years, a fermentation process has been carried out in fruits resulting in products that provide higher concentrations of bioactive compounds than their original substrates. The aim of this study was to evaluate the effect of a controlled alcoholic fermentation process (15 days) on the carotenoid composition of orange juice. Twenty-two carotenoids were identified in samples. The carotenoid profile was not modified as result of the fermentation. Total carotenoid content and provitamin A value significantly increased from day 0 (5.37 mg/L and 75.32 RAEs/L, respectively) until day 15 (6.65 mg/L and 90.57 RAEs/L, respectively), probably due to a better extractability of the carotenoids from the food matrix as a result of processing. Therefore, the novel beverage produced could provide a rich source of carotenoids and exert healthy effects similar to those of orange juice.

Serum carotenoids reduce progression of early atherosclerosis in the carotid artery wall among Eastern Finnish men

BACKGROUND

Several previous epidemiologic studies have shown that high blood levels of carotenoids may be protective against early atherosclerosis, but results have been inconsistent. We assessed the association between atherosclerotic progression, measured by intima-media thickness of the common carotid artery wall, and serum levels of carotenoids.

METHODS

We studied the effect of carotenoids on progression of early atherosclerosis in a population-based study. The association between concentrations of serum carotenoids, and intima-media thickness of the common carotid artery wall was explored in 840 middle-aged men (aged 46-65 years) from Eastern Finland. Ultrasonography of the common carotid arteries were performed at baseline and 7-year follow-up. Serum levels of carotenoids were analyzed at baseline. Changes in mean and maximum intima media thickness of carotid artery wall were related to baseline serum carotenoid levels in covariance analyses adjusted for covariates.

RESULTS

In a covariance analysis with adjustment for age, ultrasound sonographer, maximum intima media thickness, examination year, body mass index, systolic blood pressure, smoking, physical activity, serum LDL cholesterol, family history of coronary heart disease, antihypertensive medication and serum high sensitivity C-reactive protein, 7-year change in maximum intima media thickness was inversely associated with lycopene (p = 0.005), α-carotene (p = 0.002) and β-carotene (p = 0.019), respectively.

CONCLUSIONS

The present study shows that high serum concentrations of carotenoids may be protective against early atherosclerosis.

Provitamin A carotenoids are independently associated with matrix metalloproteinase-9 in plasma samples from a general population

BACKGROUND AND AIM

Carotenoids in plasma are inversely associated with cardiovascular risk. Low levels can be explained by low dietary intake but also by a number of other factors including inflammatory activity. Given that matrix metalloproteinase (MMP)-9 has an important role in inflammation and cardiovascular disease, we hypothesized that circulating MMP-9 levels would be inversely related to total or single carotenoids in a general population cohort.

METHODS

A well-characterized population-based cohort of 285 Swedish men and women (45-69 years) was used for the present study. The intake of carotenoid-rich fruits and vegetables was estimated from a food frequency questionnaire. Levels of MMP-9, C-reactive protein (CRP), interleukin (IL)-6 and six major carotenoids [β-cryptoxanthine, α-carotene, β-carotene, lutein (+zeaxanthin) and lycopene] were determined in plasma.

RESULTS

Lower plasma levels of total and single carotenoids were associated with lower dietary intake of carotenoids, older age, male sex, lower physical activity, higher alcohol consumption, higher body mass index (BMI), higher systolic and diastolic blood pressures, lower levels of total cholesterol and HDL cholesterol and higher levels of CRP, IL-6 and MMP-9. After multivariate adjustments, plasma levels of total carotenoids and provitamin A carotenoids (β-cryptoxanthine, α-carotene and β-carotene) remained independently associated with sex, dietary intake of carotenoids, BMI, HDL cholesterol and MMP-9, whilst associations with CRP and IL-6 were not maintained. Neither dietary intake of carotenoid-rich fruits and vegetables, nor vitamin supplement use was associated with MMP-9, CRP or IL-6 levels.

CONCLUSION

Plasma carotenoids were associated with a variety of factors including age, sex, dietary intake and metabolic variables. A new finding was the independent relationship in plasma between low provitamin A carotenoids and high MMP-9, suggesting a link between these carotenoids, matrix turnover and arterial remodelling.

Determination of carotenoids, total phenolic content, and antioxidant activity of Arazá (Eugenia stipitata McVaugh), an Amazonian fruit

The fruit of Arazá (Eugenia stipitata McVaugh) native to the Colombian Amazon is considered a potentially economically valuable fruit for the Andean economy due to its novel and unique taste. The fruit has an intense yellow color, but its chemical composition and properties have not been well studied. Here we report the identification and quantitation of carotenoids in the ripe fruit using high performance liquid chromatography (HPLC) with photodiode array detector (PDA) and atmospheric pressure chemical ionization (APcI) mass spectrometry (MS/MS). The qualitative carotenoid profile of the fruit according to maturity stage was also observed. Furthermore, antioxidant activity of the peel and pulp were assessed using the ferric reducing ability of plasma (FRAP), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods, in addition to chemical indexes and total phenolic content. Multiple carotenoids were identified in the peel and pulp including four xanthophylls (free and esterified as their mono and diesters) and two carotenes. One of the xanthophylls was tentatively identified as zeinoxanthin, while the others were identified as lutein, zeaxanthin, and β-cryptoxanthin. Carotenes included α-carotene and β-carotene. The total carotenoid content was significantly higher in the peel (2484 ± 421 μg/100 g FW) than in the pulp (806 ± 348 μg/100 g FW) with lutein, β-cryptoxanthin, and zeinoxanthin as the major carotenoid components. The unique carotenoid composition of this fruit can differentiate it from other carotenoid-rich fruits and perhaps be useful in authentication procedures. Overall, results from this study suggest that Colombian Arazá may be a good edible source of carotenoids important in retinal health as well as carotenoids with provitamin A activity. Therefore, Arazá fruit can be used as a nutraceutical ingredient and in production of functional foods in the Colombian diet.

Plasma carotenoids are related to intima--media thickness of the carotid artery wall in men from eastern Finland

BACKGROUND

Several previous epidemiological studies have suggested that high plasma concentrations of carotenoids may slow the development of early atherosclerosis, but results have been inconclusive.

METHODS

We examined the effect of carotenoids on early atherosclerosis in a population-based study. The association between plasma carotenoid concentrations and intima-media thickness of the common carotid artery (CCA-IMT) was investigated in 1212 elderly men (aged 61-80 years) in Eastern Finland. They were examined by B-mode ultrasound to detect early signs of carotid atherosclerosis, and plasma concentrations of carotenoids were measured by high-performance liquid chromatography.

RESULTS

Men in the lowest quartile of CCA-IMT had significantly higher concentrations of plasma β-cryptoxanthin, lycopene and α-carotene than men in the highest quartile (P for the differences: 0.043, 0.045 and 0.046, respectively), after adjustment for age, examination year, body mass index, smoking, alcohol intake, years of education, symptomatic coronary heart disease (CHD) or CHD history, diabetes, low-density lipoprotein cholesterol, medications and season. The concentrations of plasma β-cryptoxanthin, lycopene and α-carotene decreased linearly with increasing CCA-IMT.

CONCLUSIONS

The results of this study suggest that high plasma concentrations of β-cryptoxanthin, lycopene and α-carotene may be associated with decreased carotid atherosclerosis in elderly men from eastern Finland.

High serum level of lutein may be protective against early atherosclerosis: the Beijing atherosclerosis study

OBJECTIVE

We investigated whether early atherosclerosis before calcified plaque appeared as assessed by carotid intima-media thickness (IMT) was associated with levels of the major carotenoids, and assessed the associations among these serum carotenoids, carotid IMT, and arterial stiffness.

METHODS

The case-control study comprised 125 subjects with early atherosclerosis and 107 controls aged 45-68 years. We simultaneously measured common carotid IMT and arterial stiffness by carotid ultrasonography, and serum carotenoids were determined by high-pressure liquid chromatograph (HPLC).

RESULTS

In cases of early atherosclerosis, serum level of lutein was significantly lower than that in controls. Serum lutein was inversely associated with carotid IMT. Zeaxanthin and β-carotene were both negatively correlated with right common carotid artery stiffness β, elastic modulus (E(p)), and pulse wave velocity (PWV). After adjusting for age and gender, the associations remain significantly (P<0.05). However, there is no significant difference for zeaxanthin and β-carotene between the cases and controls.

CONCLUSION

These findings suggest that lutein may play a protective role in the prevention of early atherosclerosis, and the associations between serum carotenoids and arterial stiffness remained to be investigated.

Carotenoids and cardiovascular health

Cardiovascular disease (CVD) is the main cause of death in Western countries. Nutrition has a significant role in the prevention of many chronic diseases such as CVD, cancers, and degenerative brain diseases. The major risk and protective factors in the diet are well recognized, but interesting new candidates continue to appear. It is well known that a greater intake of fruit and vegetables can help prevent heart diseases and mortality. Because fruit, berries, and vegetables are chemically complex foods, it is difficult to pinpoint any single nutrient that contributes the most to the cardioprotective effects. Several potential components that are found in fruit, berries, and vegetables are probably involved in the protective effects against CVD. Potential beneficial substances include antioxidant vitamins, folate, fiber, and potassium. Antioxidant compounds found in fruit and vegetables, such as vitamin C, carotenoids, and flavonoids, may influence the risk of CVD by preventing the oxidation of cholesterol in arteries. In this review, the role of main dietary carotenoids, ie, lycopene, beta-carotene, alpha-carotene, beta-cryptoxanthin, lutein, and zeaxanthin, in the prevention of heart diseases is discussed. Although it is clear that a higher intake of fruit and vegetables can help prevent the morbidity and mortality associated with heart diseases, more information is needed to ascertain the association between the intake of single nutrients, such as carotenoids, and the risk of CVD. Currently, the consumption of carotenoids in pharmaceutical forms for the treatment or prevention of heart diseases cannot be recommended.

Carotenoid actions and their relation to health and disease

Based on extensive epidemiological observation, fruits and vegetables that are a rich source of carotenoids are thought to provide health benefits by decreasing the risk of various diseases, particularly certain cancers and eye diseases. The carotenoids that have been most studied in this regard are beta-carotene, lycopene, lutein and zeaxanthin. In part, the beneficial effects of carotenoids are thought to be due to their role as antioxidants. beta-Carotene may have added benefits due its ability to be converted to vitamin A. Additionally, lutein and zeaxanthin may be protective in eye disease because they absorb damaging blue light that enters the eye. Food sources of these compounds include a variety of fruits and vegetables, although the primary sources of lycopene are tomato and tomato products. Additionally, egg yolk is a highly bioavailable source of lutein and zeaxanthin. These carotenoids are available in supplement form. However, intervention trials with large doses of beta-carotene found an adverse effect on the incidence of lung cancer in smokers and workers exposed to asbestos. Until the efficacy and safety of taking supplements containing these nutrients can be determined, current dietary recommendations of diets high in fruits and vegetables are advised.

Relationship between premenopausal dietary intake and postmenopausal subclinical atherosclerosis

OBJECTIVES

This study examines the association of premenopausal dietary intake with postmenopausal subclinical atherosclerosis.

DESIGN

A prospective population-based cohort of 401 premenopausal women from the Healthy Women Study. Baseline premenopausal dietary intake was determined with the use of single 24-h recall. Coronary and aortic calcium scores were measured by electron beam computed tomography 8 years after menopause, and carotid plaque index was measured by carotid ultrasound scan 5 years after menopause.

RESULTS

Prevalence of coronary, aortic, and carotid subclinical atherosclerosis were 47.3%, 75.4%, and 52.1%, respectively. In unadjusted analysis, the relative risks (RR) of saturated fat intake for coronary calcification in second, third and highest quartile groups compared to the lowest were 1.82 (95% confidence interval, 1.00-3.30), 1.49 (0.82-2.70), and 1.99 (1.09-3.62), while those of carbohydrate intake were 0.48 (95% confidence interval, 0.26-0.88), 0.47 (0.26-0.86), and 0.35 (0.19-0.64), respectively. None of the dietary components were significantly associated with aortic calcification or carotid plaque.

CONCLUSION

The association between premenopausal dietary intake and postmenopausal subclinical atherosclerosis supports the recommended premenopausal dietary intervention for the prevention of cardiovascular disease.

Dietary antioxidants and paraoxonases against LDL oxidation and atherosclerosis development

Oxidative modification of low-density lipoprotein (LDL) in the arterial wall plays a key role in the pathogenesis of atherosclerosis. Under oxidative stress LDL is exposed to oxidative modifications by arterial wall cells including macrophages. Oxidative stress also induces cellular-lipid peroxidation, resulting in the formation of 'oxidized macrophages', which demonstrate increased capacity to oxidize LDL and increased uptake of oxidized LDL. Macrophage-mediated oxidation of LDL depends on the balance between pro-oxidants and antioxidants in the lipoprotein and in the cells. LDL is protected from oxidation by antioxidants, as well as by a second line of defense--paraoxonase 1 (PON1), which is a high-density lipoprotein-associated esterase that can hydrolyze and reduce lipid peroxides in lipoproteins and in arterial cells. Cellular paraoxonases (PON2 and PON3) may also play an important protective role against oxidative stress at the cellular level. Many epidemiological studies have indicated a protective role for a diet rich in fruits and vegetables against the development and progression of cardiovascular disease. A large number of studies provide data suggesting that consumption of dietary antioxidants is associated with reduced risk for cardiovascular diseases. Basic research provides plausible mechanisms by which dietary antioxidants might reduce the development of atherosclerosis. These mechanisms include inhibition of LDL oxidation, inhibition of cellular lipid peroxidation and consequently attenuation of cell-mediated oxidation of LDL. An additional possible mechanism is preservation/increment of paraoxonases activity by dietary antioxidants. This review chapter presents recent data on the anti-atherosclerotic effects and mechanism of action of three major groups of dietary antioxidants-vitamin E, carotenoids and polyphenolic flavonoids.

Distribution of lutein, zeaxanthin, and related geometrical isomers in fruit, vegetables, wheat, and pasta products

Quantitative data with regard to dietary (3R,3'R,6'R)-lutein, (3R,3'R)-zeaxanthin, and their (E/Z)-geometrical isomers are scarce, and in most cases, only the combined concentrations of these two carotenoids in foods are reported. Lutein and zeaxanthin accumulate in the human macula and have been implicated in the prevention of age-related macular degeneration (AMD). The qualitative and quantitative distributions of lutein, zeaxanthin, and their (E/Z)-isomers in the extracts from some of the most commonly consumed fruits, vegetables, and pasta products were determined by HPLC employing a silica-based nitrile-bonded column. Green vegetables had the highest concentration of lutein (L) and zeaxanthin (Z), and the ratios of these carotenoids (L/Z) were in the range 12-63. The yellow-orange fruits and vegetables, with the exception of squash (butternut variety), had much lower levels of lutein in comparison to greens but contained a higher concentration of zeaxanthin. The ratio of lutein to zeaxanthin (L/Z) in two North American bread varieties of wheat (Pioneer, Catoctin) was 11 and 7.6, respectively, while in a green-harvested wheat (Freekeh) imported from Australia, the ratio was 2.5. Between the two pasta products examined, lasagne and egg noodles, the latter had a much higher concentration of lutein and zeaxanthin. The levels of the (E/Z)-geometrical isomers of lutein and zeaxanthin in these foods were also determined.

Vitamin C, provitamin A carotenoids, and other carotenoids in high-pressurized orange juice during refrigerated storage

Vitamin C, provitamin A carotenoids, and other carotenoids were measured in freshly squeezed juices from oranges (Citrus sinensis L. var. Valencia late) that were subjected to high-pressure (HP) treatment. Also, the stability of these compounds was studied during refrigerated storage at 4 degrees C. HP treatment is an alternative to heat preservation methods for foods; therefore, it is essential to assess the impact of HP on bioactive compounds. Several processes that combine HP treatment with heat treatment for various time periods were assayed: T0, fresh juice (without treatment); T1, 100 MPa/60 degrees C/5 min; T2, 350 MPa/30 degrees C/2.5 min; T3, 400 MPa/40 degrees C/1 min. Fresh and treated samples were kept refrigerated (4 degrees C) over 10 days. After application of HP and during the refrigeration period, the qualitative and quantitative determination of vitamin C, provitamin A carotenoids (beta- and alpha-carotene; beta- and alpha-cryptoxanthin), and the xanthophylls zeaxanthin and lutein was achieved by high-performance liquid chromatography. T1 and T3 juices showed a decrease in ascorbic acid and total vitamin C just after HP treatment (D0) compared with T0 juices. On the contrary, T2 juices, just after HP treatment (D0), had the same levels of both compounds compared to untreated juices. T1, T2, and T3 treatments led to an increase in the extraction of carotenoids and provitamin A carotenoids. Total carotenoid content after the 10-day refrigerated storage period resulted in no significant quantitative changes in T1 juices, whereas in T2 and T3 juices small losses were found at the end of the storage period (20.56 and 9.16%, respectively). These losses could be influenced by the depleted protection of vitamin C toward carotenoid oxidation during the same period. A similar trend was found in provitamin A carotenoids for the different treated juices.

Serum lycopene concentrations and carotid atherosclerosis: the Kuopio Ischaemic Heart Disease Risk Factor Study

BACKGROUND

Interest in lycopene is growing rapidly following the recent publication of epidemiologic studies in which high circulating lycopene concentrations were associated with reductions in cardiovascular disease. Lycopene is one of the major carotenoids in the Western diet and is probably one of the protective factors in a vegetable-rich diet.

OBJECTIVE

We studied the hypothesis that the intima-media thickness of the common carotid artery (CCA-IMT) would be greater in men with low serum lycopene concentrations.

DESIGN

We investigated the relation between serum lycopene concentration and CCA-IMT in 1028 middle-aged men (aged 46-64 y) in eastern Finland who were participants in the Kuopio Ischaemic Heart Disease Risk Factor study and who were examined in 1991-1993. The subjects were classified into quarters according to serum lycopene concentration.

RESULTS

In a covariance analysis with adjustment for covariates, the men in the lowest quarter of serum lycopene concentration had a significantly higher mean CCA-IMT and maximal CCA-IMT (P = 0.005 and P = 0.001 for the difference, respectively) than did the other men. The mean and maximal CCA-IMT increased linearly across the quarters of serum lycopene concentration.

CONCLUSIONS

A low serum lycopene concentration is associated with a higher CCA-IMT in middle-aged men from eastern Finland. This finding suggests that the serum lycopene concentration may play a role in the early stages of atherosclerosis. Increased thickness of the intima-media has been shown to predict coronary events; thus, lycopene intakes and serum concentrations may have clinical and public health relevance.

Lycopene, atherosclerosis, and coronary heart disease

Diets rich in fruits and vegetables containing carotenoids have been of interest because of their potential health benefit against chronic diseases such as cardiovascular diseases (CVD) and cancer. Interest particularly in lycopene is growing rapidly following the recent publication of epidemiological studies that have associated high lycopene levels with reductions in CVD incidence. Two studies were conducted. In the first one, we examined the role of lycopene as a risk-lowering factor with regard to acute coronary events and stroke in the prospective Kuopio Ischemic Heart Disease Risk Factor (KIHD) Study. The subjects were 725 middle-aged men free of coronary heart disease and stroke at the study baseline. In a Cox's proportional hazards' model adjusting for covariates, men in the lowest quartile of serum levels of lycopene had a 3.3-fold (P < 0.001) risk of the acute coronary event or stroke as compared with others. In the second study, we assessed the association between plasma concentration of lycopene and intima-media thickness of the common carotid artery wall (CCA-IMT) in a cross-sectional analysis of the Antioxidant Supplementation in the Atherosclerosis Prevention (ASAP) study data in 520 asymptomatic men and women. In a covariance analysis adjusting for common cardiovascular risk factors, low plasma levels of lycopene were associated with an 18% increase of IMT in men as compared with men in whom plasma levels were higher than median (P = 0.003 for difference). In women, the difference did not remain significant after the adjustments. On the basis of these works, it is evident that the circulating levels of lycopene play some role with regard to cardiovascular health in Finland, at least in men. We conclude that circulating levels of lycopene, a biomarker of tomato-rich food, may play a role in early stages of atherogenesis and may have clinical and public health relevance.

Plasma status of retinol, alpha- and gamma-tocopherols, and main carotenoids to first myocardial infarction: case control and follow-up study

OBJECTIVE

Epidemiologic studies have suggested that dietary intake and plasma concentrations of antioxidants have an inverse relation with coronary heart disease. To test whether fat-soluble antioxidants can play a role against the occurrence of myocardial infarction (MI), we measured plasma levels of retinol, tocopherols, and individual carotenoids in MI patients.

METHODS

A case-control and follow-up study of patients in the Móstoles area (Madrid, Spain). One hundred six patients (62 after 1 y) and 104 control subjects participated in the study. Blood samples were collected after overnight fast or during the first 24 h of MI onset for biochemical profiles of retinol, alpha- and gamma-tocopherols, and carotenoid by means of a quality-controlled high-performance liquid chromatography.

RESULTS

During the acute phase after MI onset, plasma levels of retinol, gamma-tocopherol, and xanthophylls (lutein/zeaxanthin and beta-cryptoxanthin) decreased, whereas alpha-tocopherol, alpha-carotene, beta-carotene, and lycopene showed levels similar to those of control subjects. Logistic regression analysis showed low concentrations of gamma-tocopherol (and retinol) in plasma as the only statistically significant factor associated with MI, after adjusting for traditional risk factors. However, 1 y later, the MI patients showed a general improvement in plasma lipids and fat-soluble antioxidant status, and none of the analytes was associated with MI.

CONCLUSIONS

The decreased plasma status of retinol, gamma-tocopherol, and xanthophylls during the acute phase of MI normalized the year after the MI event, suggesting that most subjects had followed an overall healthier lifestyle and dietary pattern. The results also raise concerns on the usefulness of these plasma compounds as specific, relevant, and predictive markers in relation to coronary heart disease.

Antioxidant vitamin status and carotid atherosclerosis in the elderly

BACKGROUND

The oxidative modification of LDL is thought to play a crucial role in the initiation of atherosclerosis. Antioxidant vitamins can protect LDL from oxidation, and high intakes or blood concentrations of these vitamins have been linked with a reduced risk of cardiovascular disease. Few data are available on the importance of antioxidant vitamins in earlier stages of atherogenesis.

OBJECTIVE

We investigated the cross-sectional relation between antioxidant vitamin status and carotid atherosclerosis in a group of elderly persons.

DESIGN

The study sample comprised 468 men and women aged 66-75 y living in Sheffield, United Kingdom. Duplex ultrasonography was used to measure intima-media thickness and the degree of stenosis in the extracranial carotid arteries. Antioxidant vitamin status was assessed by measuring fasting plasma concentrations of vitamin C, vitamin E, and beta-carotene.

RESULTS

In the men, after adjustment for age and cardiovascular disease risk factors, a 20% higher plasma vitamin C concentration was associated with a 0.004-mm smaller intima-media thickness; a 20% higher beta-carotene concentration was associated with a 0.005-mm smaller intima-media thickness. Compared with men with high blood concentrations of beta-carotene or cholesterol-adjusted vitamin E, those with low blood concentrations of these vitamins were 2.5 times as likely to have carotid stenosis of >30%. We found no significant trends between plasma concentrations of antioxidant vitamins and either measure of carotid atherosclerosis in the women.

CONCLUSION

A high antioxidant vitamin status may help to prevent the initiation and progression of early atherosclerotic lesions in men.

Serum carotenoids and cerebral white matter lesions: the Rotterdam scan study

OBJECTIVES

To study the relation between serum levels of carotenoids and white matter lesions (WMLs) on magnetic resonance imaging (MRI).

DESIGN

Evaluation of cross-sectional data from a cohort study.

SETTING

The Rotterdam Scan Study.

PARTICIPANTS

Two hundred and three nondemented older persons, age 60 to 90, from the Rotterdam Scan Study.

MEASUREMENTS

Serum levels of carotenoids were determined. WMLs on MRIs were rated separately into periventricular and subcortical WMLs. Odds ratios (ORs) for the presence of severe WMLs (upper decile) were calculated per standard deviation (SD) increase in serum carotenoid level and per SD increase in overall carotenoid serum level. Effect modification by smoking status was studied through stratified analyses.

RESULTS

Increasing levels of all the separate carotenoids were associated with less severe periventricular WMLs, which reached statistical significance for the overall carotenoid serum level (OR 0.4 per SD; 95% confidence interval (CI) = 0.2-0.9). We found no association between carotenoid levels and the presence of severe subcortical WMLs (OR 1.2 per SD; 95% CI = 0.7-2.0). The association of carotenoid levels with severe periventricular WMLs was more marked in those who ever smoked (OR 0.1 per SD; 95% CI = 0.0-0.9) than in those who had never smoked (OR 0.9 per SD; 95% CI = 0.4-2.1).

CONCLUSIONS

These findings are compatible with the view that high levels of carotenoids may protect against WMLs in the periventricular region, in particular in smokers. Longitudinal studies with repeated measurements of both carotenoids and WMLs are necessary to explore this hypothesis further.

Work-related stress and early atherosclerosis

The purpose of this study was to examine the link between work-related stress and early atherosclerosis as measured by common carotid artery intima-media thickness and focal lesions in the common carotid artery and bifurcation. Four hundred sixty-seven members of an occupational cohort (total N = 573) were examined via questionnaires and B-mode ultrasound. We used multiple linear and logistic models to regress lesion risk and intima-media thickness on work-related stress scores from a questionnaire administered at an 18-month follow-up examination. In an age-adjusted model, the prevalence of carotid lesions among men scoring in the highest stress quintile was 36% compared with 21% among men in the lowest quintile. We also observed an increase in intima-media thickness in the highest quintile relative to the lowest (difference = 0.048 +/- 0.025 mm) among men. Among women, stress was not related to the prevalence of lesions or intima-media thickness. These findings suggest that men with greater work-related stress are at increased risk for atherosclerotic disease. Women in this age group may be protected from such effects, or current work-place questionnaires may not accurately assess stress in women.

Low plasma lycopene concentration is associated with increased intima-media thickness of the carotid artery wall

Although a number of epidemiological studies have evaluated the association between ss-carotene and the risk of cardiovascular diseases, there has been little research on the role of lycopene, an acyclic form of ss-carotene, with regard to the risk of cardiovascular disease. We investigated the relationship between plasma concentrations of lycopene and intima-media thickness of the common carotid artery wall (CCA-IMT) in 520 middle-aged men and women (aged 45 to 69 years) in eastern Finland. They were examined from 1994 to 1995 at the baseline of the Antioxidant Supplementation in Atherosclerosis Prevention (ASAP) study, a randomized trial concerning the effect of vitamin E and C supplementation on atherosclerotic progression. The subjects were classified into 2 categories according to the median concentration of plasma lycopene (0.12 micromol/L in men and 0.15 micromol/L in women). Mean CCA-IMT of the right and left common carotid arteries was 1.18 mm in men and 0.95 mm in women with plasma lycopene levels lower than the median and 0.97 mm in men (P:<0.001 for difference) and 0.89 mm in women (P:=0.027 for difference) with higher levels of plasma lycopene. In ANCOVA adjusting for cardiovascular risk factors and intake of nutrients, in men, low levels of plasma lycopene were associated with a 17.8% increment in CCA-IMT (P:=0.003 for difference). In women, the difference did not remain significant after the adjustments. We conclude that low plasma lycopene concentrations are associated with early atherosclerosis, manifested as increased CCA-IMT, in middle-aged men living in eastern Finland.

Stress proteins as biomarkers of oxidative stress: effects of antioxidant supplements

The potential benefits to health of the supply of antioxidants, either through dietary intake or as supplements, is equivocal. There is a need to develop biomarkers that may act as monitors of cellular defense as influenced by antioxidant status. Thirty-two individuals participated in the project and 19 received supplements for 5 weeks in the form of a capsule containing a defined mixture of antioxidants. No change was noted in levels of superoxide dismutase and glutathione peroxidase following antioxidant supplementation. On the other hand, increase in total antioxidant status and decrease in malondialdehyde, protein carbonyl formation, and erythrocyte hemolysis were noted. In lymphocytes isolated from individuals receiving antioxidant supplements and subjected to a heat shock in the presence of the free radical generator 2, 2'-azobis-(2-amidinopropane)-dihydrochloride, enhanced synthesis of heat shock proteins hsp 105, hsp 90, hsp 70, and hsp 40 by contrast with decreased synthesis of heme oxygenase HO-1 (hsp 32) were noted. We conclude that antioxidant status modulates the synthesis of stress proteins.

A comparative study of dietary intake among urban Japanese and Chinese aged 50∼79

This study examined the difference in dietary intake between middle-aged and elderly Japanese and Chinese. Volunteers aged 50-79 living in two cities in both Japan and China were recruited in local community service centers and were asked to complete a 3-day diet recording. The final results were based on 356 subjects (166 Chinese and 190 Japanese). In men, the Japanese subjects significantly consumed more energy, with a large proportion of the energy coming from carbohydrates, dietary fiber, vitamin A, vitamin B(2), vitamin C and they consumed less iron, and a lower proportion of energy from protein and fat than in the Chinese subjects. In women, the Japanese subjects had significantly higher intakes of energy, the proportion of energy from carbohydrates, dietary fiber, calcium, vitamin A, vitamin B(1), vitamin B(2), vitamin C and they consumed less iron, with the proportion of energy from protein and from fat in comparison with the Chinese women. Fat intake provided more than 29% of the total dietary energy in Chinese subjects. Daily intake of food items was significantly greater in the Japanese participants, both men and women (18.54 ±2.85, 20.11 ± 2.40, respectively), than in the Chinese subjects (14.11 ± 3.62, 15.51 ± 4.15, respectively) (p<0.01 by Mann WhitneyU-test). The present study suggests that the middleaged and elderly Chinese subjects should increase their variety of foods consumed while decreasing their consumption of high-fat foods. For the Japanese subjects, the higher intake of total calories among the woman should also be noted.

Carotid intima-media thickness as a measure of vascular target organ damage

This paper summarizes important investigations published within the past 2 years that use B-mode carotid ultrasound and measurements of intima-media thickness or plaque to elucidate the relationship between traditional or novel risk factors for the development of atherosclerotic or arteriosclerotic disease. This methodology is proposed as an extremely useful, noninvasive tool with proven ability to show cross-sectional associations with cardiovascular risk factors, prevalence of vascular disease, and predictive power. The method appears highly suited to the goal of detecting asymptomatic vascular target organ damage, which may greatly assist with assessment of risk and selection of appropriate, preventive, strategies for management of disease.