alpha-carotene and Hypercholesterolemia

Previous animal studies suggested that Chlorella, a unicellular green alga, has a preventive role in maintaining serum cholesterol levels against excess dietary cholesterol intake. This study aimed to conduct a pioneering investigation to clarify this issue in healthy subjects by adopting a dietary cholesterol challenge, which has not been used previously in similar studies of Chlorella in hypercholesterolemia.. In this double blind, randomized, placebo-controlled study, 34 participants ingested 510 mg of dietary cholesterol from three eggs concomitantly with a usual dose of Chlorella (5 g/d) or a matched placebo for 4 weeks.. The dietary cholesterol challenge induced consistently higher concentrations of serum total cholesterol (TC, P < 0.001), LDL-C (P = 0.004), and HDL-C (P = 0.010) compared with baseline values, suggesting that the challenge was reliable. Thus, we observed a preventive action of Chlorella in maintaining serum TC versus placebo levels (3.5 % versus 9.8 %, respectively; P = 0.037) and LDL-C versus placebo levels (1.7 % versus 14.3 %, respectively; P = 0.012) against excessive dietary cholesterol intake and in augmenting HDL-C versus placebo levels (8.3 % versus 3.8 %, respectively). Furthermore, serum α-carotene showed the best separation between the placebo and Chlorella groups (R(2)X and R(2)Y > 0.5; Q(2) > 0.4).. The results suggest that a fully replicated dietary cholesterol challenge may be useful in assessing the effectiveness of dietary supplements in maintaining the serum lipid profiles of adults whose habitual diets are high in cholesterol.. WHO International Clinical Trials Registry Platform ( KCT0000258 ).

Topics: Body Mass Index; Carotenoids; Chlorella; Cholesterol, Dietary; Cholesterol, HDL; Cholesterol, LDL; Diet; Double-Blind Method; Female; Humans; Hypercholesterolemia; Lipids; Male; Treatment Outcome; Triglycerides; Young Adult

Spreads enriched with plant sterol and stanol esters have been shown to possess similar cholesterol-lowering properties; however, their comparative capacity to alter circulating levels of other fat-soluble compounds has not been fully assessed. To compare actions of sterol and stanol ester consumption on serum fat-soluble vitamin and carotenoid concentrations, 15 hypercholesterolemic subjects were fed each of 3 fixed foods treatment diets over 21 days using a randomized crossover controlled design. Diets contained either (1) margarine (M), (2) margarine with sterol esters (MSE; 1.92 g/d), or (3) margarine with stanol esters (MSA; 1.76 g/d). No significant differences were found in initial or final serum fat-soluble vitamin and carotenoid concentrations among the 3 phases. Serum retinol and alpha- and gamma-tocopherol concentrations at baseline and endpoint and percentage changes relative to baseline for MSE and MSA were not significantly different from those of the M diet. After adjusting for total cholesterol reduction, no changes for alpha- and gamma-tocopherol were found. Serum vitamins D and K, lycopene, and lutein concentrations and percentage changes did not differ across diets. Serum concentrations at baseline and endpoint and percentage changes for alpha- and beta-cryptoxanthin and alpha- and gamma-carotene were not different among the diets, nor did serum alpha- and gamma-carotene concentrations to total cholesterol ratios differ. Serum lutein, beta-cryptoxanthin, and alpha-carotene concentrations increased over time. In conclusion, our results show no effect of consumption of esterified plant sterols or stanols on serum fat-soluble vitamin or carotenoid concentrations compared with a control diet.

Topics: Adult; alpha-Tocopherol; beta Carotene; Carotenoids; Cross-Over Studies; Cryptoxanthins; Diet; Double-Blind Method; gamma-Tocopherol; Humans; Hypercholesterolemia; Lutein; Male; Margarine; Middle Aged; Patient Compliance; Phytosterols; Placebos; Sitosterols; Solubility; Vitamin A; Vitamin K; Vitamins; Xanthophylls

To investigate the effects of low-fat stanol ester margarines on concentrations of serum carotenoids.. A randomized parallel double-blind study design consisting of a 4-week run-in (high-fat diet) and an 8-week experimental (low-fat, low-cholesterol diet) period. During the experimental diet period subjects consumed low-fat wood stanol ester (WSEM), vegetable oil stanol ester (VOSEM) or control (no stanol esters) margarine daily. The daily mean total stanol intake was 2.31 and 2.16 g in the WSEM and VOSEM groups, respectively.. Outpatient clinical trial with free-living subjects.. Altogether, 60 hypercholesterolaemic subjects were selected for the study out of 91 originally screened. The study was completed by 55 subjects.. Serum alpha- and beta-carotene and lycopene determined by the HPLC.. Serum alpha-carotene concentration did not change significantly in either of the experimental groups, whereas beta-carotene concentration decreased significantly in the WSEM and VOSEM groups (P<0.01), and the change differed significantly (P<0.05 and P <0.01, respectively) from that of the control group. Decrease in alpha+beta-carotene concentration was significantly greater (P <0.05) in both experimental groups than in the control group. However, the change in alpha-, beta- or alpha+beta-carotene/total cholesterol ratio did not differ significantly among the groups. No significant changes were found in serum lycopene or lycopene/total cholesterol ratio in both experimental groups.. Low-fat stanol ester margarines appeared to have little effect on serum concentrations of alpha-, beta- or alpha + beta-carotene, or lycopene.. Grant to the University of Kuopio by Raisio Benecol Ltd, Raisio, Finland.

Topics: Adult; Anticholesteremic Agents; beta Carotene; Carotenoids; Cholesterol; Dietary Fats; Double-Blind Method; Esters; Female; Humans; Hypercholesterolemia; Lycopene; Male; Margarine; Phytosterols