Dietary Carotenoids, Smoking, & Age-Related Macular Degeneration

In an earlier EduFacts ("Multivitamin Use and Cataracts: Reviewing the Data") some data from the Nutrition and Eye Disease Study (1) was reported which suggested that regular multivitamin use could provide some modulation of the smoking risk factor for cataract development. Presumably this is caused by antioxidants in the multivitamin formula which provide added defense against the oxidative damage to the lens caused by smoking. Interestingly, data from Eye Disease Case Control Study (2) suggest that high intake of the carotenoids lutein and zeaxanthin may modulate some of the risk of AMD associated with smoking. Seddon, Adjani (2) and co-authors reported on 356 cases diagnosed with advanced AMD and 520 age and sex-matched controls.

Methods:

Dietary intake of specific food items was determined through use of a semi-quantitative diet questionnaire (including the use of supplements). The quantity of specific nutrients contained in food items was determined using U.S. Department of Agriculture sources. As one part of their analysis, patients in the lowest quintile of dietary intake of lutein/zeaxanthin (L/Z) and who had never smoked were used as the "reference" group (Odd's Ratio = 1).


Results:
 

Past smoking doubled the risk of AMD and current smoking tripled the risk among patients with low intake of lutein/zeaxanthin. Among patients in the upper fifth percentile of lutein/zeaxanthin intake, risk of AMD was reduced by 43% among those who had never smoked. However, past smokers and even current smokers with high L/Z intake continued to show reduced risk of AMD (16% reduction among past smokers and 38% reduction among current smokers) relative to non-smokers with low L/Z intake.

References

  1. Mares-Perlman JA Klein BEK, et al. Relationship between lens opacities and vitamin and mineral supplement use. Ophthalmology 1994;101:315-325.
  2. Seddon JM, Ajani UA, Sperduto RD et al. Dietary Carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. JAMA 1994; 272: 1413-1420.