Despite a substantial body of science supporting the eye health of lutein, a DRI (dietary reference intakes) for lutein is still many years away, say experts.
DRIs exist for vitamins, minerals, essential fatty acids and essential amino acids. Having a DRI would make lutein part of public nutrition policy, and could mean inclusion in large-scale publically-funded surveys such as the NHANES (National health and Nutrition Examination Survey).
The link between lutein and eye health was first reported in 1994 by Dr. Johanna Seddon and her co-workers at Harvard University, who found a link between the intake of carotenoid-rich food, particularly dark green leafy vegetables like spinach, and a significant reduction in AMD.
«Although the science around lutein is substantial, additional research needs to be carried out on broader population groups to further support the DRI process. This is an opportunity for industry and the scientific community to work together to evaluate the collection of data and build upon what has already been established».
A long and arduous process…
Dietary Reference Intakes (DRIs) are a set of four nutrient reference values for healthy populations. They include the Recommended Daily Allowance (RDA), Adequate Intake (AI), Estimated Average Requirement (EAR), and Tolerable Upper Intake Level (UL).
«Each of these reference values distinguishes between gender and different life stages. RDAs, AIs and ULs are dietary guidelines for individuals, whereas EARs provide guidelines for groups and populations. In addition, factors that might modify these guidelines, such as bioavailability of nutrients from different sources, nutrient-nutrien and nutrient-drug interactions, and intakes from food fortificants and supplements, are incorporated into the guidelines in much greater detail than previously».
OmniActive’s Doyle called the route for establishing DRIs for lutein as «a long and arduous process».
Lutein, zeaxanthin & and the macula
The macula is a yellow sport of about five millimeters diameter on the
retina. As we age, levels of the pigments in the macula decrease
naturally, thereby increasing the risk of AMD. The yellow color is due
to the content of the carotenoids lutein and zeaxanthin.