Abstract
Purpose: :
Studies investigating the relationship between macular pigment optical density (MPOD) and adiposity have consistently shown an inverse relationship between these variables. This study was designed to investigate changes in MPOD, and serum concentrations of lutein (L) and zeaxanthin (Z), in response to weight loss.
Methods: :
We recruited 104 subjects into this randomised-controlled study. MPOD was measured by customised heterochromatic flicker photometry (HFP) using the Macular DensitometerTM. Adiposity was assessed by dual energy x-ray absorbtiometry (DEXA). Weight loss was encouraged and supported by providing a customised dietary plan and exercise programme to subjects in the intervention group of the study.
Results: :
There was a statistically significant weight loss in the intervention group over the study period. Mean ± SD weight (kg) for the intervention group (n=14) at baseline and 12 months was 95.6 ± 18.2kg and 90.6 ± 17.1kg, respectively (p = 0.002). There was no significant weight change seen in the control group (n=17) over the study period (p > 0.05). There was no statistically significant correlation between MPOD and weight change in either the intervention group or the control group over the 12 month study period (r = 0.029, p = 0.563, and r = 0.057, p = 0.372, respectively).
Conclusions: :
From the data currently available, the weight loss intervention has resulted in a statistically significant weight reduction. However, the data do not show any statistically significant correlation with change in MPOD for the intervention group. Also, when the data were analysed after including only subjects who lost weight, we found no statistical significance. However, it is important to note that these results are only based on 31 of 104 subjects enrolled in this study. Further analysis will include more subjects as well as data on dietary L and Z, serum concentrations of L and Z, and body fat, which will allow us to control for these important known and confounding variables on MPOD.
Keywords: macular pigment • antioxidants • age-related macular degeneration