The POLA study (June 1995 through July 1997) is a population-based study on cataract and age-related macular degeneration (AMD) and their risk factors in 2584 residents of Séte (South of France), aged 60--95 years. Classification of AMD was performed on 50 degrees fundus photographs, according to an international classification. The presence of cardiovascular disease and its risk factors was determined by interviewer-based questionnaire, clinical examination (anthropometry, blood pressure) and fasting plasma measurements. Using a logistic model adjusted for age and gender, late AMD was not significantly associated with a history of cardiovascular disease, diabetes, use of hypocholesterolemic drugs, hypertension, blood pressure or plasma lipids. Obese subjects (body mass index greater than 30 kg/m( 2)) had a 2.29-fold (95% confidence interval (CI): 1.00--5.23) and 1.54-fold (CI: 1.05--2.26) increased risk of late AMD and pigmentary abnormalities in comparison with lean subjects. Finally, the risk of soft drusen was decreased in those subjects with a history of cardiovascular disease (odds-ratio (OR) = 0.72, CI: 0.54--0.97), and increased with increasing levels of HDL-cholesterol (OR = 1.52, CI: 1.14--2.02). None of these results were modified by further adjustments for smoking, educational level and plasma alpha-tocopherol. These results need to be confirmed by other studies, which ideally should be longitudinal and prospective.

These results are strongly suggestive of a protective role of the xanthophylls, in particular zeaxanthin, for the protection against ARM and cataract.

The effects of spirulina and its chromophore phycocyanin, both without bound Se or selenium-enriched, were studied on plasma cholesterol, early atherosclerosis, cardiac production of superoxide anions, and NAD(P)H oxidase expression in hamsters. Forty hamsters were divided into 5 groups of 8 and fed an atherogenic diet for 12 weeks. They received by gavage either 7.14 mL/(kg day) phycocyanin (PC), Se-rich phycocyanin (SePC), spirulina (SP) or Se-rich spirulina (SeSP) in water, or water as control. SeSP and SePC supplied 0.4 microg of Se per 100 g body weight. Plasma cholesterol and non-HDL cholesterol concentrations were lower in group consuming SePC. HDL-cholesterol was never affected. SePC significantly increased plasma antioxidant capacity by 42% compared with controls. A sparing effect in liver glutathione peroxidase (87% on average) and superoxide dismutase (56% on average) activity was observed for all the groups compared to controls. Aortic fatty streak area was significantly reduced in the experimental groups, especially by PC (82%) and SePC (85%). Cardiac production of superoxide anion significantly decreased by approximately 46-76% in the four experimental groups and especially in SePC group (76%). The expression of p22phox subunit of NAD(P)H oxidase decreased by 34% after consumption of SePC. The results indicate that chronic consumption of Se-rich spirulina phycocyanin powerfully prevents the development of atherosclerosis. The underlying mechanism is related mainly to inhibiting pro-oxidant factors and at a lesser extent improving the serum lipid profile.

Arrhythmias following cardiac stress are a key predictor of death in healthy population. Carbon monoxide (CO) is a ubiquitous pollutant promoting oxidative stress and associated with hospitalization for cardiovascular disease and cardiac mortality. We investigated the effect of chronic CO exposure on the occurrence of arrhythmic events after a cardiac stress test and the possible involvement of related oxidative stress. Wistar rats exposed chronically (4 weeks) to sustained urban CO pollution presented more arrhythmic events than controls during recovery after cardiac challenge with isoprenaline in vivo. Sudden death occurred in 22% of CO-exposed rats versus 0% for controls. Malondialdehyde (MDA), an end-product of lipid peroxidation, was increased in left ventricular tissue of CO-exposed rats. Cardiomyocytes isolated from CO-exposed rats showed higher reactive oxygen species (ROS) production (measured with MitoSox Red dye), higher diastolic Ca(2+) resulting from SR calcium leak and an higher occurrence of irregular Ca(2+) transients (measured with Indo-1) in comparison to control cells after a high pacing sequence. Acute treatment with a ROS scavenger (N-acetylcysteine, 20 mmol/L, 1 h) prevented this sequence of alterations and decreased the number of arrhythmic cells following high pacing. Chronic CO exposure promotes oxidative stress that alters Ca(2+) homeostasis (through RYR2 and SERCA defects) and thereby mediates the triggering of ventricular arrhythmia after cardiac stress that can lead to sudden death.

Use of the vitE-PS membrane during a short period improves erythrocyte antioxidant defense mechanisms and seems to lead to a reduction in EPO requirements in HD patients.