Consumption or carotenoid lutein contained in green leafy and cruciferous vegetables, may slow orprevent the decline of cognitive function in older adults.
Lutein
β,ε-carotene-3,3′-diol
One of 600 known naturally occurring carotenoids.
Lutein is synthesized only by plants.
Found in high quantities in green leafy vegetables such as spinach, kale and yellow carrots.
Lutein is obtained directly or indirectly, from plants.
Is found in egg yolks and animal fats.
Colors yolks, and causes the yellow color of chicken skin and fat, and is used in chicken feed for this purpose.
The human retina accumulates lutein and zeaxanthin.
Zeaxanthin predominates at the macula lutea while lutein predominates elsewhere in the retina.
It may serve as a photoprotectant for the retina from the damaging effects of free radicals produced by blue light.
It is isomeric with zeaxanthin, differing only in the placement of one double bond.
Has primarily been used as a natural colorant due to its orange-red color.
Lutein absorbs blue light and therefore appears yellow at low concentrations and orange-red at high concentrations.
Lutein is also anti angiogenic inhibiting vascular endothelial growth factor (VEGF).
Lutein is not used as a colorant in other foods due to its limited stability.
Concentrates in the macula, a small area of the retina responsible for three-dimensional vision.
The hypothesis it helps keep the eyes safe from oxidative stress and the high-energy photons of blue light.
A direct relationship exists between lutein intake and pigmentation in the eye.
Studies show that an increase in macula pigmentation decreases the risk for eye diseases such as age-related macular degeneration (AMD).
A randomized clinical trial to demonstrated a benefit for lutein in macular degeneration.
Epidemiological evidence suggests a relationship between low plasma concentrations of lutein and zeaxanthin, and an increased risk of developing age-related macular degeneration (AMD).
Some studies suggest supplemental lutein and/or zeaxanthin help protect against AMD.
Epidemiological evidence suggests increasing lutein and zeaxanthin intake lowers the risk of cataract development.
Consumption of more than 2.4 mg of lutein/zeaxanthin daily from foods and supplements is significantly correlated with reduced incidence of nuclear lens opacities, but not cortical or subcapsular cataract.
There is evidence for improvement in visual performance and decrease in glare in patients taking 10 mg lutein and 2 mg zeaxanthin per day for 12 months.
A natural part of human diet when fruits and vegetables are consumed.
For individuals lacking sufficient lutein intake, lutein-fortified foods are available.
Norecommended daily allowance currently exists for lutein, but positive effects have been seen at dietary intake levels of 6–10 mg/day.
The only definitive side effect of excess lutein consumption is bronzing of the skin.
The safe level for lutein, is 20 mg/day.
Neither the U.S. Food and Drug Administration nor the European Food Safety Authority consider lutein an essential nutrient or have acted to set a tolerable upper intake level.
The lutein market is segmented into pharmaceutical, dietary supplement, and food.