Lutein is a carotenoid pigment that occurs naturally in many fruits and vegetables, including a handful of plants that perform double duty as a culinary or medicinal herb. Specifically, lutein is a xanthophyll carotenoid because it exists as a yellow-orange pigment. The concentration of lutein is why your macula lutea, the spot close to the retina that permits your eyes to focus while driving, reading or sewing, appears yellow. Lutein also helps protect your eyes from damage from the sun's ultraviolet rays and oxidative stress. It is available as a dietary supplement, but you can also get lutein from your diet by eating plenty of fresh vegetables and herbs.
Research
Lutein might play a role in preventing various eye disorders, including age-related macular degeneration. The September 2007 issue of "Archives of Ophthalmology" included the results of a six-year study led by John Paul SanGiovanni of the National Eye Institute in Maryland, which followed the diet and lifestyle habits of study participants 60 to 80 years of age. The research group found that dietary lutein reduces the risk of blindness due to macular degeneration in this population. According to a paper published in the Aug. 26, 2010 issue of "Current Medical Research and Opinion," lutein might also decrease the risk of developing cataracts.
African Marigold
African marigold is not the same as some garden plants you might be familiar with that are also called marigolds, namely French marigold and pot marigold. The former is in the same family as African marigold, but is actually Tagetes patula, while the latter belongs to the Calendula genus and is botanically known as Calendula officinalis. African marigold, or Tagetes erecta, is the herb that supplies the food industry with lutein for use as a coloring agent. It is added to poultry feed to make chicken skin appear golden yellow and to enhance the color of egg yolks.
Kale
Kale is a member of the Brassica group of plants, also known as the cabbage family. This dark green, leafy plant has a wide global distribution and is featured in the cuisines of Africa, Europe and Asia. In the southern United States, kale is often combined with mustard or collard greens. According to the American Macular Degeneration Foundation, a half-cup serving of cooked kale provides about 15,798 mcg of lutein, compared with 1 cup of raw kale, which provides approximately 39,550 mcg of lutein.
Safety Considerations
No known adverse side effects are associated with dietary or supplemental lutein, but high doses of carotenoids might produce a condition called carotenodermia, in which the skin turns orange. Also, Sandra Desorgher, co-director of the World Community Autism Program, advocates a lutein-free diet in the management of autism-spectrum disorders based on the theory that the immune system responds to lutein as an invading pathogen. However, little scientific evidence supports the effectiveness of a lutein-free diet for autism at this time.
References
- "Archives of Ophthalmology"; "The Relationship of Dietary Carotenoid and Vitamin A, E and C intake with Age-related Macular Degeneration in a Case-control Study: AREDS Report No. 22"; J.P. SanGiovanni et al.; 2007
- "Current Medical Research and Opinion"; "Dietary Supplementation: Effects on Visual Performance and Occurrence of AMD and Cataracts"; F.M. Barker; 2010
- General Standard for Food Additives: Lutein from Tagetes erecta (161b(i))
- American Macular Degeneration Foundation: Lutein
- World Community Autism Program: The Lutein Free Diet -- A Treatment Option for Autism
