Abstract
Purpose: :
Lutein, a phytochemical and a principle component of the human macular pigment, is obtained exclusively from dietary sources. Levels of lutein in the retina have been shown to be photoprotective of the retina and correlated to a reduced risk of advanced AMD. Numerous commercial supplements are now marketed to provide individuals whose intake of this carotenoid may be otherwise inadequate a robust and bioavailable source of lutein. The bioavailability of a commercial product (Four Leaf Japan, Ltd.) was investigated for the purpose of demonstrating its suitability as a supplement.
Methods: :
In accordance with the requirements of the FIU IRB thirty volunteers were recruited to participate as research subjects. The subjects were divided into two groups, a placebo group of 10 subjects and an experimental group of 20 subjects and the study was conducted as a double-blind, placebo controlled investigation. All subjects were provided supplement (~9 mg/d) or placebo (0 mg, identical in appearance to the supplement) for a period of 30 days. Serum samples were obtained on days 0, 15, and 30 and were analyzed for lutein levels. Cholesterol, triglycerides, and C-reactive protein were measured on days 0 and 30.
Results: :
The concentrations of lutein were measured by HPLC and quantified relative to an internal standard. Serum lutein levels for the placebo group on days 0.15, and 30 were 0.21±0.1, 0.22±0.1, 0.19±0.09 µg/ml. Lutein serum concentrations for the experimental group were 0.15±0.05, 0.57±0.27, 0.72±0.37 µg/ml. Lutein serum responses have been compared to the serum cholesterol, triglyceride, and C-reactive protein levels.
Conclusions: :
The baseline serum lutein levels of both groups were identical (p = 0.121 ) and the lutein concentration of the placebo group remained unchanged throughout the study. The serum response of the experimental group was robust and statistically significant (p < 10-5) on both day 15 and day 30.
Keywords: macular pigment • carotenoids/carotenoid binding proteins • nutritional factors