Purpose:
The three carotenoids lutein (L), zeaxanthin (Z), and meso-zeaxanthin (meso-Z), which account for the "yellow spot" at the macula and referred to as macular pigment (MP), are believed to play a role in visual function and protect against age-related macular degeneration (AMD), via their optical and/or antioxidant properties. This study was undertaken to investigate determinants of MP in a large randomly selected sample from the Republic of Ireland.
Methods:
4,593 participants were recruited into the health assessment component of The Irish Longitudinal Study on Ageing (TILDA). MP optical density (MPOD) was measured using customized heterochromatic flicker photometry (cHFP) in 4,373 participants. Socio-demographic and self-reported health data was obtained using computer assisted personal interview (CAPI) and a wide array of objective health measures were also obtained during the health assessment.
Results:
Mean (SD) MPOD for the study group was 0.203 (0.156) with a range of 0 to 1.01. MPOD was higher for participants with secondary education [mean (SD) = 0.205 (0.148)] than for those with only primary education or no education [mean (SD) = 0.183 (0.113); p <.001]. MPOD was also higher for those with tertiary education [mean (SD) = 0.232 (0.231)] compared with primary/no education or secondary education (p < .001 for both comparisons).
Conclusions:
We report a relative lack of MP amongst those participants of a population-based study who did not have secondary or third level education. Given the emerging evidence that MP is important for visual performance and comfort, and given the putative protection that this pigment confers against AMD (especially important in the context of increased risk of AMD in this social group), public health measures aimed at improving diet for this at-risk population need to be considered.
Keywords: macular pigment • carotenoids/carotenoid binding proteins