Multivitamin Use Lowers Cataract Risk in Male Physicians

Nutrients and Risk of Cataract

A recent meta-analysis of 6 high quality prospective studies involving 42,000 participants reported that higher consumption of lutein and zeaxanthin was associated with a 25% reduced risk of nuclear cataract (1).  The study’s authors also observed a dose-response relationship: For every 300 mcg (0.3 mg) of additional lutein intake daily, the risk of nuclear cataract declined by 3%.  These findings echo the results of AREDS2 (2), where participants with the poorest intake of dietary lutein and zeaxanthin were 32% less likely to progress to a level of cataract requiring surgery.  The average US intake of lutein and zeaxanthin at 2 mg daily is considerably below the 6 mg daily that has been linked to cataract risk reduction.

Thus it appears that adequate intake of these carotenoids may be protective of developing cataract, particularly nuclear cataract the most common type and the most common type associated with aging. 

In addition to lutein and zeaxanthin, a relationship between daily multivitamin supplementation and cataract formation has also been observed. Now, the final results for cataract and AMD from the multivitamin component of the Physicians’ Health Study II (PHS II) have been reported. They indicate that long-term daily ‘multi’ use (with only trace levels of lutein and zeaxanthin) modestly and significantly reduces the risk of cataract.

Study Design

The PHS II was a randomized, double blind, placebo controlled, factorial trial evaluating a daily multivitamin, alternate day vitamin E, and daily vitamin C in the prevention of cancer and CVD among 14, 461 male physicians aged 50 and older. Cataract and AMD were pre-specified secondary end points of PHS II.

A total of 11,497 participants did not report cataract at baseline and were included in this analysis. Of these, 5,736 men were in multi group and 5761 were in the placebo group. A total of 14,233 men did not report AMD at baseline, with 7,111 assigned to the multi group and 7,122 to placebo.

The main outcome measures were incident cataract and visually significant AMD with BCVA 20/30 or worse.

Results

During an average 11.2 years of treatment and follow-up, a total of 1,817 cataract cases and 281 cases of visually significant AMD were confirmed.

Overall, there was a significant 9% lower risk of cataract in the multi group compared with placebo. The risk of nuclear cataract was 13% lower in the multi group.  Multi- vitamin use had no significant effect on visually significant AMD.

References

1. Le Ma et al. A dose-response meta-analysis of dietary lutein and zeaxanthin intake in relation to risk of age-related cataract. Graefes Arch Clin Exp Ophthalmol Oct 23, 2013. [Epub ahead of print]
2. AREDS2 Research Group. Lutein/zeaxanthin for the treatment of age-related cataract: AREDS2 randomized trial report no. 4. JAMA Ophthalmol 131:843-50, 2013.
3. Christen WG et al. A multivitamin supplement and cataract and age-related macular degeneration in a randomized trial of male physicians. Ophthalmol  Nov 20, 2013. [Epub ahead of print]