Purpose: To investigate the relationship between percentage of body fat and macular pigment (MP) optical density.
Methods: One hundred healthy subjects of ages between 22 and 60 years volunteered to participate in this study. MP optical density was measured psychophysically, serum lutein and zeaxanthin were quantified by HPLC, and dietary intake of lutein and zeaxanthin was assessed using a validated food frequency questionnaire. Body fat was measured by dual energy x-ray absorptiometry (DEXA); body mass index (BMI) was also calculated for each subject. Clinical and personal details were recorded, with particular attention directed toward putative risk factors for AMD.
Results: There was a significant inverse relationship between the percentage of body fat and MP optical density in males (r=-0.392, P <0.01), and after correcting for age and dietary lutein and zeaxanthin, this inverse relationship remained significant (r=-0.290, P <0.05). The relationship between MP optical density and percentage of body fat in females was inverse, but not significant (r=-0.197, P=0.149). A significant and inverse relationship between serum zeaxanthin and percentage of body fat was observed for females only (r=-0.354, P <0.01). Dietary intake of fat was inversely related to serum lutein and zeaxanthin, and significantly so for lutein (r=-0.256, P <0.05). However, dietary fat was unrelated to MP optical density (r=0.041, P=0.688).
Conclusions: A relative lack of MP is associated with adiposity in men, and may underlie the association between body fat and risk for AMD progression in males. Further, the processes governing accumulation and/or stabilization of lutein and zeaxanthin in fat tissue appear to differ for males and females.