Table 2.
Studies investigating antioxidant rich supplements on cataract incidence.
| Author | Sample Size (n), Age (years) | Nutrients Examined | Key Findings |
|---|---|---|---|
| Multi-Vitamins | |||
| Mares-Perlman, 2000 [85] | n = 3089 | Supplementary Multivitamin, Vitamin C, Vitamin E | The 5-year risk for any CAT was 60% lower for multivitamins or any supplement use containing Vitamin C or E for more than 10 years. 10-year multivitamin use lowered the risk for NUC and CX but not for PSC (OR 0.6, 95% CI 0.4–0.9; OR 0.4, 95% CI 0.2–0.8; and OR, 0.9 95% CI 0.5–1.9; respectively). |
| Kuzniarz, 2001 [11] | n = 2873, 49–97 years | Supplementary Vitamin A, Thiamine, Riboflavin, Niacin, Pyridoxine, Folate, Vitamin B12 | Use of multivitamin supplements was associated with reduced prevalence of NUC, OR 0.6, 95% CI 0.4–1.0, P =0.05. For both NUC and CX, longer duration of multivitamin use was associated with reduced prevalence (NUC, trend P = 0.02; CX, trend P = 0.03). Use of thiamin supplements was associated with reduced prevalence of NUC (OR 0.6, 95% CI 0.4–1.0, P = 0.03, dose trend P = 0.03) and CX (OR 0.7, 95% CI 0.5–0.9, P = 0.01, dose trend P = 0.02). Riboflavin (OR 0.8, 95% CI 0.6–1.0, P = 0.05) and niacin (OR 0.7, 95% CI 0.6–1.0, P = 0.04) supplements exerted a weaker protective influence on CX. Vitamin A supplements were protective against NUC (OR 0.4, 95% CI 0.2–0.8, P = 0.01, dose trend P = 0.01). Folate (OR 0.4, 95% CI 0.2–0.9, P = 0.03) appeared protective for NUC, whereas both folate (NUC 0.6, 95% CI 0.3–0.9, P = 0.01, dose trend P = 0.04) and Vitamin B12 supplements (OR 0.7, 95% CI 0.5–1.0, P = 0.03, dose trend P = 0.02) were strongly protective against CX. |
| Age-Related Eye Disease Study Research Group, 2006 [86] | n = 4590, - | Supplementary CentrumTM Multivitamin (Vitamin A, E, C, B1, B2, B12, B6, D, Folic acid, Niacinamide, Biotin, Pantothenic acid, Calcium, Phosphorus, Iodine, Iron, Magnesium, Copper Zinc) | CentrumTM use is associated with a reduction in any lens opacity progression (OR 0.84, 95% CI 0.72–0.98, P = 0.025). Also protective for nuclear opacity events (OR 0.75, 95% CI 0.61–0.91, P = 0.004). |
| Zheng Selin, 2013 [83] | n = 31120, 45–79 years |
Supplemental Vitamin C, Vitamin E, Low dose multivitamins |
The multivariable- adjusted HR for Vitamin C supplements only was 1.21 (95% CI 1.04–1.41) in compared to non-users. The HR for long-term Vitamin C users (≥10 years before baseline) was 1.36 (95% CI 1.02–1.81). The HR for Vitamin E use only was 1.59 (95% CI 1.12–2.26). Use of multivitamins only or multiple supplements in addition to Vitamin C or E was not associated with cataract risk. |
| Single Vitamins | |||
| Christen, 2004 [87] | n = 39876, ≥ 45 years | Supplementary Beta-carotene (50mg.d-1, alternate days) | 129 CAT in the beta-carotene group and 133 in the placebo group (RR 0.95, 95% CI 0.75–1.21). For cataract extraction, there were 94 cases in the beta-carotene group and 89 cases in the placebo group (RR 1.04, 95% CI 0.78–1.39). |
| Christen, 2008 [88] | n = 39876, ≥ 45 years | Supplementary Vitamin E (600 IU.d-1, alternate days) | No significant difference between the Vitamin E and placebo groups in the incidence of CAT (RR 0.96; 95% CI 0.88–1.04). No significant effects of Vitamin E on the incidence of NUC (RR 0.94; 95% CI 0.87–1.02), CX (RR 0.93; 95% CI 0.81–1.06), or PSC (RR 1.00; 95% CI 0.86–1.16). |
| Christen, 2015 [89] | n = 35533, ≥50 years | Supplementary Selenium (200 μg.d-1 from L-selenomethionine), Vitamin E (400 IU.d-1 of all rac-α-tocopheryl acetate) | 185 CAT in the selenium group and 204 in placebo (HR 0.91; 95 % CI 0.75–1.11; P = 0.37). For Vitamin E, there were 197 cases in the Vitamin E group and 192 in placebo (HR 1.02; 95 % CI 0.84–1.25; P = 0.81) |
| Christen,2010 [90] | n = 11545, ≥50 years | Supplementary Vitamin E (400 IU.d-1, alternate days) Vitamin C (500 mg.d-1 alternate days) | 579 CAT in the Vitamin E treated group and 595 in the Vitamin E placebo group (HR 0.99; 95% CI 0.88–1.11). For Vitamin C, there were 593 cataracts in the treated group and 581 in the placebo group (HR 1.02; 95% CI 0.91–1.14). |
| Christen,2002 [91] | n = 22071 | Supplementary Beta-carotene (50 mg.d-1, alternate days) | No difference between the beta-carotene and placebo groups in the overall incidence of CAT (998 cases vs 1017 cases; RR 1.00; 95% CI 0.91–1.09) or CAT extraction (584 vs 593; RR 1.00; 95% CI 0.89–1.12). |
| Ferringo, 2005 [92] | n = 1020 | Supplementary Vitamin A, Vitamin C, Vitamin E, Beta-carotene | High Vitamin C levels were associated with a protective effect on NUC (OR 0.54; 95% CI 0.30, 0.97) and PSC (OR: 0.37; 95% CI: 0.15–0.93). High Vitamin E levels were associated with increased prevalence of CX (OR 1.99; 95% CI 1.02–3.90), PSC (OR 3.27; 95% CI 1.34–7.96) and of any CAT (OR 1.86; 95% CI 1.08–3.18). |
| Rautiainen, 2009 [15] | n = 24593, 49–83 years | Supplementary Vitamin C | HR of Vitamin C supplement users compared with that for nonusers was 1.25 (95% CI 1.05, 1.50). The HR for the duration of 10 y of use before baseline was 1.46 (95% CI 0.93, 2.31). The HR for the use of multivitamins containing Vitamin C was 1.09 (95% CI 0.94, 1.25). Among women aged 65 y, Vitamin C supplement use increased the risk of CAT by 38% (95% CI 12%, 69%). |
| The REACT Group,2002 [84] | n = 297 | Supplementary Vitamin E (200 mg all-rac alpha-tocopherol acetate), Vitamin C (250 mg ascorbic acid), and b-carotene (6 mg) | After two years of treatment, there was a small positive treatment effect in U.S. patients (p = 0.0001); after three years a positive effect (p = 0.048) in both the U.S. and the U.K. groups. The positive effect in the U.S. group was even greater after three years: (IPO = 0.389 (Vitamin) vs. IPO = 2.517 (placebo); p = 0.0001). |