An investigation of the effects of lutein and zeaxanthin supplementation on inflammatory markers, oxidative stress and age-related macular degeneration risk

Age-related macular degeneration is the leading cause of blindness. Numerous risk factors have been proposed, and many are common to both AMD and CVD. Similar processes in the pathogenesis of these diseases pave been proposed, i~cluding oxidative stress and inflammation. Antioxidants associated with CVD risk, oxidative stress and inflammation may be involved in AMD prevention, particularly the macular carotenoids. Different study designs were used including a cross-sectional study, an 8week intervention study comparing carotenoid-rich foods, an 8-week randomised double-blind placebo-controlled intervention study, and a casecontrol study. In the cross-sectional study, smokers had higher ICAM-1 levels, and lower antioxidant levels. MPD was inversely associated with age. In the intervention studies, no difference in change in MPD between groups was· observed, and no difference in change in inflammatory and/or oxidative stress markers was noted. In the case-control study, 8MI and smoking were shown to be risk factors for AMD. Ch91esterol was higher in AMD cases than controls. A higher proportion of sUbjects with IHD history had a history of hypercholesterolaemia, and a higher proportion were AMD cases than those with no IHD history. These findings suggest smokers may have increased risk of AMD and CVD through reduced antioxidant status and increased endothelial activation. The lack of association between lutein, zeaxanthin, and MPD, and. the nonsignificant difference in change in MPD, oxidative stress markers, and inflammatory markers between groups in both intervention studies is adverse to previous research. The case-control study confirmed that 8MI, and smoking are risk factors for AMD. The finding that a higher proportion of subjects with IHD history were AMD cases gives support to these diseases having common causal mechanisms. Until therapies for AMD and CVD are established, prevention through modification of risk factors may be most beneficial in reducing disease risk.EThOS - Electronic Theses Online ServiceGBUnited Kingdo