Glare disability, photostress recovery, and chromatic contrast: relation to macular pigment and serum lutein and zeaxanthin.

PURPOSE: A large body of research has linked macular lutein and zeaxanthin to reduced risk of degenerative eye disease. The earliest published hypothesis for the role of the pigments was not based on chronic protection but immediate function. Recent data on macular pigment (MP) have shown that screening the foveal cones from short-wave light does, in fact, result in improvements in photostress recovery (PR), glare disability (GD), and chromatic contrast (CC). This study examined those relations on a larger sample. METHODS: A total of 150 young healthy subjects were assessed. Plasma samples were obtained from 100 subjects for HPLC quantification of serum xanthophylls. MP density was measured using customized heterochromatic flicker photometery. GD, PR, and CC were measured in Maxwellian view using a broadband xenon light source. GD was measured by increasing the intensity of an annulus until it veiled a central target. PR was measured as the time necessary to regain sight of a central target after a 5-second exposure to an intense bleaching light. CC was measured as the amount of light necessary in a 460-nm background to lose sight of a central target. RESULTS: MP density was significantly related to serum lutein and zeaxanthin combined (r = 0.31, P = 0.002), GD (r = 0.24, P = 0.0015), PR (r = -0.18, P = 0.01), and CC (r = 0.46, P = 0.00005). CONCLUSIONS: These results confirm earlier reports of a significant relation between variation in macular pigment optical density and immediate effects on visual function. As with many species, intraocular yellow filters in humans appear to improve many aspects of the visual stimulus. (ClinicalTrials.gov number, NCT00909090.).

The effect of synthetic genistein on menopause symptom management in healthy postmenopausal women: a multi-center, randomized, placebo-controlled study.

OBJECTIVE: To evaluate the efficacy of synthetic genistein for reducing the frequency and severity of hot flushes. STUDY DESIGN: A 12 week randomized double-blind, placebo-controlled study in which 84 postmenopausal women received placebo or a single 30 mg dose of synthetic genistein. Outcome measures primary: percentage change in the number of daily hot flushes from pre-treatment to week 12. Secondary: duration and severity of daily hot flushes, Greene Climacteric Scale score, serum follicle stimulating hormone (FSH), 17ß-estradiol and endometrial thickness. RESULTS: Genistein supplemented subjects completing at least 4 weeks on trial (n=40) demonstrated a 51% reduction (9.4-4.7/day) in the number of hot flushes by week 12 compared to a 27% reduction in the placebo group (9.9-7.1/day) (p=0.026). Subjects in the genistein group also reported significantly fewer hot flushes per day (p=0.010) and a decrease in total duration of hot flushes per day (p=0.009) at week 12 versus placebo. Subjects on genistein (n=32) completing 12 weeks on trial demonstrated a 51% reduction (9.7-4.7/day) in the number of hot flushes by week 12 (p=0.049) compared to 30% reduction in the placebo group (9.8-7.0/day) and had fewer hot flushes per day and a decrease in total duration of hot flushes per day at week 12 compared to placebo (p=0.020 and p=0.017, respectively). There were no differences between groups in Greene Climacteric Scale, FSH, 17ß-estradiol, endometrial thickness or adverse events. CONCLUSIONS: The current study provides the first evidence that a single daily dose of 30 mg of synthetic genistein reduces hot flush frequency and duration.

Acute EGCG supplementation reverses endothelial dysfunction in patients with coronary artery disease.

BACKGROUND: Epidemiological studies demonstrate an inverse relation between dietary flavonoid intake and cardiovascular risk. Recent studies with flavonoid-containing beverages suggest that the benefits of these nutrients may relate, in part, to improved endothelial function. OBJECTIVE: We hypothesized that dietary supplementation with epigallocatechin gallate (EGCG), a major catechin in tea, would improve endothelial function in humans. DESIGN: We examined the effects of EGCG on endothelial function in a double blind, placebo-controlled, crossover design study. We measured brachial artery flow-mediated dilation by vascular ultrasound at six time points: prior to treatment with EGCG or placebo, two hours after an initial dose of EGCG (300 mg) or placebo, and after two weeks of treatment with EGCG (150 mg twice daily) or placebo. The order of treatments (EGCG or placebo) was randomized and there was a one-week washout period between treatments. RESULTS: A total of 42 subjects completed the study, and brachial artery flow-mediated dilation improved from 7.1 +/- 4.1 to 8.6 +/- 4.7% two hours after the first dose of 300 mg of EGCG (P = 0.01), but was similar to baseline (7.8 +/- 4.2%, P = 0.12) after two weeks of treatment with the final measurements made approximately 14 hours after the last dose. Placebo treatment had no significant effect, and there were no changes in reactive hyperemia or the response to sublingual nitroglycerin. The changes in vascular function paralleled plasma EGCG concentrations, which increased from 2.6 +/- 10.9 to 92.8 +/- 78.7 ng/ml after acute EGCG (P < 0.001), but were unchanged from baseline after two weeks of treatment (3.4 +/- 13.1 ng/ml). CONCLUSION: EGCG acutely improves endothelial function in humans with coronary artery disease, and may account for a portion of the beneficial effects of flavonoid-rich food on endothelial function.