Lutein and zeaxanthin in the eye

Of the more than 600 plant pigments called carotenoids found in nature, only two carotenoids, zeaxanthin and lutein, selectively accumulate 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 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.
• 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.

Consuming adequate amounts of lutein and especially zeaxanthin through food can be particularly difficult, as it requires many servings a day of certain fruits and vegetables. (Note: Zeaxanthin is 10 to 20 times less common than lutein in the average diet.)

The other option is to take concentrated supplemental lutein as well as zeaxanthin from standardised marigold flower extract. Ensure the eye 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 of dosing, it would make good sense to look for a formula with both concentrated lutein and zeaxanthin to protect eyes from the damaging effects of blue lights and UV rays and help keep age-related macular degeneration and cataract at bay.

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.