The responses of subjects taking a 20 mg/day lutein diacetate supplement were compared with that for a 20 mg/day crystalline lutein or a placebo. Ten subjects, assigned to each of three groups, lutein diacetate (group 1), lutein (group 2), and a placebo (group 3), were supplemented for 24 weeks. Groups 1 and 2 consumed a dose equivalent to 20 mg per day of free lutein. Serum samples, collected at baseline, and at weeks 6, 12, 18, and 24 were analyzed by HPLC. Macular Pigment Optical Density (MPOD) was obtained by heterochromatic flicker photometry at baseline and weeks 6, 12, 18 and 24.
Results: The average serum lutein concentrations for weeks 6 to 24 expressed as a ratio to the baseline value (±S.D.) were 5.52 ± 2.88 for group 1, 4.43 ± 1.61 for group 2, and 1.03 ± 0.25 for group 3. The median rate of macular pigment increase (milli-absorbance units/week) for groups 1, 2, and 3 were 2.35, 1.55, and 0.19 mAU/wk, respectively. P-values for these serum and MPOD increases are both highly significant when compared to placebo. The average serum response was about 25% higher for group 1 compared with group 2 and, the median MPOD response was 52% higher for group 1 than group 2. P-values calculated for the differences in these increases were, p = 0.066, marginally significant, for serum, and p = 0.09 approaching significance, for MPOD.