Natural Carotenoids

C. Heart Protection and Atherosclerosis Properties

• 1. High plasma levels of alpha-and beta carotene are associated with lower risk of atherosclerosis

  Willeit, L. et al. (2000). High plasma levels of alpha-and beta carotene are associated with lower risk of atherosclerosis. Atherosclerosis. 153(1):231-9.

  A large number of studies have contributed to the hypothesis that carotenoids, vitamins A and E are protective against atherosclerosis by acting as antioxidants. The aim of this study was to assess the relationship between plasma levels of carotenoids (alpha- and beta- carotene, lutein, lycopene, zeaxanthin, beta-cryptoxanthin), vitamins A and E, and atherosclerosis in the carotid and femoral arteries. This prospective and cross sectional study involved a randomly selected population sample of 392 men and women aged 45-65 years. Carotid and femoral artery atherosclerosis was assessed by high-resolution duplex ultrasound. alpha- and beta- carotene plasma levels were inversely associated with the prevalence of atherosclerosis in the carotid and femoral arteries (P=0.004) and with the 5-year incidence of atherosclerotic lesions in the carotid arteries (P=0.04). These findings were obtained after adjustment for other cardiovascular risk factors (sex, age, LDL (low density lipoproteins), ferritin, systolic blood pressure, smoking, categories of alcohol consumption, social status, C-reactive protein). Atherosclerosis risk gradually decreased with increasing plasma alpha- and beta-carotene concentrations (P=0.004). No associations were found between vitamin A and E plasma levels and atherosclerosis.

• 2. Serum carotenoids and coronary heart dieseace. The Lipid Research Clinics Coronary Primary Prevention Trial and Follow-up Study

  Morris, DL. et al. (1994). Serum carotenoids and coronary heart dieseace. The Lipid Research Clinics Coronary Primary Prevention Trial and Follow-up Study. Journal of the American Medical Association. 2(18):1439-41.

  New analysis of a cohort from the Lipid Research Clinics Coronary Primary Prevention Trial and Follow-up Study (LRC-CPPT). The LRC-CPPT was a multicenter placebo-controlled trial of cholestyramine resin and CHD with a follow-up period of 13 years. Serum carotenoids were measured at baseline. The placebo group of the LRC-CPPT, which consisted of 1899 men aged 40 to 59 years with type II-a hyperlipidemia and without known preexisting CHD, cancer, or other major illnesses. Nonfatal myocardial infarctions and deaths attributable to CHD ascertained from hospital records, autopsy reports, and death certificates and reviewed by a panel of cardiologists. After adjustment for known CHD risk factors including smoking, serum carotenoids were inversely related to CHD events. Men in the highest quartile of serum carotenoids had an adjusted relative risk (RR) of 0.64 (95% confidence interval [CI], 0.44 to 0.92) compared with the lowest quartile. For men who never smoked, this RR was 0.28 (95% CI, 0.11 to 0.73). The LRC-CPPT participants with higher serum carotenoid levels had a decreased risk of incident CHD. This finding was stronger among men who never smoked.

• 3. Serum carotenoids in relation to risk factors for development of atherosclerosis.

  Xiao, X. et al. (2012). Serum carotenoids in relation to risk factors for development of atherosclerosis. Clinical biochemistry. ;45(16-17):1357-1361.

  To explore associations between serum carotenoids and risk factors for development of atherosclerosis. The studied 40 early atherosclerosis patients without clinical cardiovascular events and comparable healthy controls aged 45-68 years. Intima-media thickness (IMT) and arterial stiffness were simultaneously measured by carotid ultrasonography, and serum carotenoids and cytokines were determined by high-pressure liquid chromatograph (HPLC) and ELISA kits respectively. We evaluated the associations between serum carotenoids, early atherosclerosis and serum cytokines. Serum concentrations of lutein and zeaxanthin in early atherosclerosis patients were significantly lower than those of control subjects. PCA logistic analysis found that serum carotenoids were associated with decreased risk of atherosclerosis. In contrast, blood pressure, body mass index and serum triglyceride were positively related to the risk of atherosclerosis. Ridge regression analysis revealed that serum carotenoids were associated with inflammatory cytokines and apoE. More specifically, serum lutein was inversely associated with IL-6 (P<0.001) and positively associated IFN-γ (P=0.002). In contrast, zeaxanthin had a significant negative association with VCAM-1 (P=0.001) and apoE (P=0.022) .Lycopene was inversely associated with VCAM-1(P=0.011) and LDL (P=0.046). The results suggested that early atherosclerosis patients had lower serum concentrations of lutein and zeaxanthin than healthy subjects. Serum carotenoids were associated with reduced risk of atherosclerosis. The associations between serum carotenoids and inflammatory cytokines may help to explain the possible protective effects of carotenoids on atherosclerosis.

• 4. Carotenoids and Cardiovascular Risk

  Giordano,P. et al. (2012). Carotenoids and Cardiovascular Risk. Current Pharmaceutical Design. 18(34): 5577-5589.

  Fruits and vegetables (typically associated with the Mediterranean diet) are very rich in carotenoids, i.e. fat-soluble pigments really important in human life. Structurally, carotenoids consists of eleven (beta-carotene, zeaxanthin, lycopene) or ten (alpha-carotene, lutein) conjugated double bonds, responsible for their antioxidant capability in agreement with their substituents. Low-Density Lipoprotein (LDL) particles oxidation process is the one of the most important first steps of atherosclerotic disease and, consequentially, the first pathogenetical step of cerebro- and cardiovascular events like myocardial infarction and stroke, which are the first cause of death in industrialized countries. Reactive oxygen species (ROS) also seem to be the target of Carotenoids main action, by scavenging singlet oxygen (1O2) and free radicals. Literature data showed that ROS increase atherosclerotic individual burden. The carotenoids scavenging action could reduce atherosclerosis progression partly due to such a decrease in ROS concentrations. Many studied demonstrated such a reduction by analyzing the relationship between carotenoids and Intima-Media Thickness of common carotid artery wall (CCA-IMT), [a well established marker of atherosclerosis evolution] reduction. Aim of this review is to evaluate actual knowledge about the importance of carotenoids molecules in slowing down the starting and the progression of atherosclerotic plaque, and to consider their implementation in everyone's diet as a tool to obtain a sharp decrease of LDL oxidation and their possible effect on endothelial function.