Abstract
Purpose: :
Lutein and zeaxanthin, which form the macular pigment, are lipid-soluble micronutrients. Their metabolism is therefore strongly interlinked with lipid metabolism. A few recent studies have suggested that dietary intake of omega 3 fatty acids may favour the retinal accumulation of lutein and zeaxanthin and thus increase the density of macular pigment.
Methods: :
The PIMAVOSA study bears on 108 healthy volunteers born in the Southwest of France, aged 20 to 60 years. Macular pigment density (MPD) was measured using the two-wavelength autofluorescence method with a modified scanning laser ophthalmoscope (HRA, Heidelberg Engineering Inc, Heidelberg, Germany). It was estimated as average optical density within a circle centred on the fovea, at different eccentricities (0.5, 1, 2 and 6 degrees). Plasma measurements were performed from fasting blood sample collected on the day of the eye examination. Plasma fatty acids were measured by gas chromatography, after extraction of plasma lipids with the method of Lepage&Roy.
Results: :
MPD within 0.5 degree was significantly correlated with plasma omega 3 fatty acids (r=0.19, p=0.05). The association was similar with long-chain omega 3 fatty acids (r=0.19, p=0.05), while there was no association with the precursor alpha-linolenic acid (r=-0.04, p=0.68). Associations of long-chain omega 3 fatty acids with MPD were similar at different eccentricities (r=0.20 and p=0.04 within 1 degree, r=0.19 and p=0.05 within 2 degrees, r=0.21 and p=0.03 within 6 degrees). There were no significant associations with other types of fatty acids (saturated, monounsaturated, omega 6 polyunsaturated).
Conclusions: :
Our results suggest that macular pigment density is associated with status in long-chain omega 3 fatty acids status. Further studies are needed to confirm this finding, and identify the underlying mechanisms.
Keywords: macular pigment • nutritional factors • imaging/image analysis: clinical