Dietary intakes, scores and serum lutein and zeaxanthin levels in selected adult Australian population

Objectives: Age-related macular degeneration (AMD) is one of the leading causes of blindness in Australia and globally. Many studies have reported dietary and non-dietary risk associated factors to AMD, but few studies have focused on the dietary intakes and relative bioavailability of serum lutein (L) and zeaxanthin (Z). This study aimed to assess the dietary intakes, scores and serum L and Z levels in a selected Australian Adult population. Methods: A cross-sectional study involving 33 healthy adults aged 19–29 and 30–52 years was carried out. Background demographic information on all participants was obtained using an online self-administered questionnaire while diet intakes were obtained using the USDA’s 24 hours recall questionnaire, the Victorian Cancer Council (Australia) food frequency questionnaire. Serum L and Z levels were determined using HPLC. Dietary intakes, scores against serum L, Z, and L + Z were established using descriptive statistics, Pearson’s correlation, and multiple regression. Results: Mean serum concentration of L + Z were higher in older vs younger adults (49.0 ± 10.0 μg/dL vs 43.0 ± 14.0 μg/dL) whereas dietary intakes were lower (15.7 μg/100 g vs 18.7 μg/100 g). Percentage (%) dietary scores were slightly higher among the older age group (43.0% vs 41.3%). Among women vs men, women had higher scores, dietary intakes of L + Z (19.3 μg/100 g vs 15.0 μg/100 g) and % dietary scores (43.9% vs 40.1%). There was no observed gender difference in serum L + Z levels (46.0 ± 12.0 μg/dL). Serum L + Z levels correlated more with the ethnic group of African descent (P = 0.357, P < 0.022) and duration of residency (>10 years) (P = 0.348, P = 0.025). About 59% of participants had L/Z ratio of either 3 : 1 or 4 : 1. Multivariate regression identified percentage dietary scores, ethnicity, age as major predictors of serum L + Z concentrations (R2 = 0.837). Conclusions: Established age-specific reference range for dietary intakes and serum L + Z levels is required to determine populations at risk of AMD. Women are making better food choices than men. This was apparent in dietary intakes, scores. Ethnicity and longer residency status in Australia correlated with serum L + Z concentrations.