Plant stanol and sterol esters and macular pigment optical density

Although the carotenoid levels and compositions of most tissues largely reflect those of the serum, the human retina differs. In particular, the macular pigment in the fovea consists of just three carotenoids: lutein, zeaxanthin, and meso-zeaxanthin. Plant sterols and stanols are well known for their serum low-density lipoprotein (LDL)-cholesterol-lowering effect. Since LDL-cholesterol is the main transporter of lutein and zeaxanthin through the circulation, functional foods enriched with plant sterol or stanol esters may lower their serum concentrations and as a result decrease the macular pigment optical density. This may increase the risk of age-related macular degeneration, since several studies have shown that low intake of these carotenoids and/or low carotenoid blood levels increase the risk of this degenerative disease.