Nutrition plays a key role in the overall health of a person with no exception to the eye.
Antioxidants are effective against oxidants and found in Vitamin A, C and E, especially carotenoids found in vegetable sources which get converted to vitamin A, are most effective for better eye health and vision.
Lutein and zeaxanthin are two types of carotenoids, which are yellow and red coloured pigments found in vegetables and other plants. Lutein, if present in high concentration appears orange-red. They display important functions in the body like guard the body from damaging effects of free radicals, which play a role in the prevention of many diseases.
A cataract is the major cause of blindness due to deficiency of carotenoids in diet or infections. Other visual impairments are glaucoma, age-related macular degeneration (AMD).
Food sources of Lutein and Zeaxanthin
It is important to derive them from diets as they cannot be produced by the body.
Vegetables - kale, red peppers, lettuce, spinach, broccoli, peas
Orange and yellow coloured fruits eg oranges, mangoes.
Egg yolk * better bioavailability due to the presence of fat in it.
Cereals- durum wheat, corn
Dietary supplements containing lutein and zeaxanthin should be encouraged in the elderly and individuals at high risk of clinical conditions. This can help enhance the intake regularly.
Absorption and Metabolism
After ingestion, lutein gets absorbed by the mucosal cells of the small bowel and then bound to chylomicrons ,which get secreted into lymphatic system and reaches the liver, where it gets incorporated into lipoproteins and gets distributed to the peripheral tissues, specifically the retina of the eyes, where it is demonstrated to be in highest concentrations. Also, being fat-soluble, the content of lipids mediates its absorption by forming micelles. Furthermore, deficiency of iron, zinc as well as protein may affect the absorption rate. Also, smoking and alcohol decrease the absorption rate.
Other health benefits
Lutein may help protect against heart problems such as atherosclerosis (buildup of fatty deposits in arteries), the leading cause of heart attacks.
Lutein and zeaxanthin also prevent or reduce the generation of free radicals in our body. These antioxidants may help protect your skin.
Some studies observed that supplements containing lutein and zeaxanthin helped increase the optical density of the eyes and believed to protect against macular degeneration due to ageing.
Hence, lutein and zeaxanthin, both are very potent antioxidants and may retard the onset of both cataract and AMD (Age-Related Macular Degeneration) in people above 40 years. Many favourable studies support its positive health role, particularly in eye health. Further studies may better elucidate the possible role in human health.
References
- Buscemi et al (2018).The Effect of Lutein on Eye and Extra-Eye health.www.mdpi.com
- Sayed et al (2013).Dietary Sources of Lutein and Zeaxanthin Carotenoids and Their Role in Eye Health. Nutrients.
