Lutein and zeaxanthin

Lutein and zeaxanthin are natural yellow-pigmented nutrients belonging to the carotenoid family. Carotenoids are the red, yellow, and orange pigments found in yellow-orange fruits and vegetables, dark green, leafy vegetables, and corn.

Of the more than 600 plant pigments called carotenoids found in nature, only two carotenoids, zeaxanthin and lutein, selectively accumulates in the retina, macular, and lens.

Zeaxanthin is the dominant component in the centre of the macular, while lutein dominates at the outer edges. The eye is selective and preferentially places dietary zeaxanthin in the very centre of the macular, the most critical area for central vision, with the greatest need for protection.

Concentrated in the lenses and retina, these two carotenoids fulfil two essential functions:

• Shields the eyes from damaging ultraviolet (UV) light
  
  Acting as a filter to shield against harmful UV-blue light, both lutein and zeaxanthin help to reduce the risk of age-related macular degeneration (AMD) and cataract.
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• Act as antioxidants to protect the lenses, retina and macula against free radical damage due to exposure to sunrays, computer screens, and other harmful form of lights.

Both lutein and zeaxanthin absorb the very high-energy and most damaging portions of the light spectrum (ultraviolet blue). The absorption of the high-energy light spectrum is critical for the protection of the lens, retina, and macula portions of the eye. High-energy blue light also generates "free radicals" that cause damage to the tissues of the eye.

Like many other important nutrients, lutein and zeaxanthin are not manufactured in the body. The only way to consume it is by consuming food rich in these antioxidants or by supplementing with lutein and zeaxanthin. Unfortunately as we age, the concentration of lutein and zeaxanthin in the eyes decline. Increasing one's dietary intake of lutein and zeaxanthin increases the density in the macular.

Lutein and zeaxanthin offers protection against the two most common causes of vision loss: cataracts and age-related macular degeneration. In addition to its role in preventing cataracts, lutein and zeaxanthin may improve vision in people who already have cataracts.

For those taking eye supplements, ensure that the supplement contains at least 6mg, but preferably 10mg, of standardised lutein. Many lutein and zeaxanthin supplements contain only very small amounts of zeaxanthin - in the micrograms (mcg), whereas studies have found that zeaxanthin is beneficial only when their amounts are much higher, e.g. at least 5mg daily.

For convenience, it would make good sense to look for a two-in-one eye health formula with concentrated lutein and zeaxanthin to protect eyes from the damaging effects of blue lights and UV rays to keep age-related macular degeneration and cataract at bay whilst promoting sharper vision and healthier eyes.

References:

1. Johnson EJ, Hammond BR, Yeum KJ, et al. Relation among serum and tissue concentrations of lutein and zeaxanthin and macular pigment density. Am J Clin Nutr. 2000 Jun;71(6):1555-62.

2. Alves-Rodrigues A, Shao A. The science behind lutein. Toxicol Lett. 2004 Apr 15;150(1):57-83.

3. Olmedilla B, Granado F, Blanco I, Vaquero M. Lutein, but not alpha-tocopherol, supplementation improves visual function in patients with age-related cataracts: a 2-y double-blind, placebo-controlled pilot study. Nutrition. 2003 Jan;19(1):21-4.

This article is courtesy of Pahang Pharmacy. For more information, e-mail starhealth@thestar.com.my. The information provided is for educational purposes only and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.

-The Star/Asia News Network