| Research in recent years has shown that two | | | | zeaxanthin and acts as a transporter--may also |
| nutrients--lutein and zeaxanthin--often used in | | | | yield a better transport means for lutein and |
| nutritional supplements--work wonders in | | | | zeaxanthin and thus leading to a better |
| preventing age-related macular degeneration | | | | effectiveness of these nutrients in AMD. |
| (AMD). When consumed, these nutrients reach | | | | How Lutein and zeaxanthin play their role in AMD... |
| the eyes from the gut--passing through the | | | | Lutein and zeaxanthin are important constituents |
| bloodstream--and play an important role in | | | | of the macula region of retina--they help form the |
| protecting the eyes against AMD. But it has been | | | | fovea. So, it's apparent that maintaining an |
| a mystery how these nutrients work. Unveiling | | | | increased concentration of these nutrients in the |
| this mystery, a recent research has come up | | | | retina may protect the macula from degenerative |
| with new hope for the Nutritional Treatment of | | | | changes. These nutrients also protect the eyes |
| AMD. The study, entitled Xanthophylls are | | | | against AMD by working as antioxidants and thus |
| preferentially taken up compared with | | | | reducing oxidative stress. That apart, these |
| beta-carotene by retinal cells via a | | | | pigments also help protect the eyes against AMD |
| SRBI-dependent mechanism, has been published in | | | | by filtering blue light; blue light is known to be |
| the August 2008 issue of a professional journal, | | | | damaging for the macula. |
| Journal of Lipid Research. | | | | AMD: a silent enemy... |
| What the current study says... | | | | Age-related Macular Degeneration affects nearly |
| The current study has been carried out by US | | | | 10 millions people in the United States. It affects |
| researchers from the Ohio State University. | | | | the eyes slowly and silently, and gradually |
| Previous studies have shown that dietary | | | | removes the power to see sharp and clear |
| compounds lutein and zeaxanthin can protect the | | | | images of the objects around us, leading to |
| eyes against age-related macular degeneration. | | | | difficulties in performing various important |
| These two compounds belong to a class of | | | | day-to-day activities, such as driving, reading, and |
| carotenoids called xanthophylls (carotenoids are | | | | doing finer work (for example, threading a needle). |
| organic pigments which absorb light; they're | | | | According to the National Eye Institute, AMD |
| divided into two classes: Xanthophylls and | | | | affects the macula, the center part of the retina |
| carotenes). Xanthophylls have the property to | | | | (the light sensitive part at the back of the eyes) |
| absorb blue light; they get accumulated in the | | | | which is responsible for a detailed vision. It's a |
| macula area of retina and form a spot known as | | | | painless condition and a leading cause of vision loss |
| the fovea. This is why xanthophylls are also called | | | | in the US people aged 60 and more. |
| macular pigments, and it's believed that they have | | | | Nutritional Supplements: a boon in AMD... |
| an important role in vision. | | | | Public interest is quite high regarding the nutritional |
| Although the main carotenoid that we obtain from | | | | treatment of AMD, which is why new research is |
| diet is beta-carotene, its quantity in the retina is | | | | taking place all over the world to explore the |
| very small. About 80% of the carotenoid content | | | | nutritional treatment to tackle AMD. However, |
| in the retina is Lutein and zeaxanthin. The dietary | | | | here is what some previous studies say regarding |
| sources for these nutrients are carrots, squash, | | | | effectiveness of nutritional supplements in AMD: |
| peaches, papaya, broccoli, spinach, peas etc. Lutein | | | | - In a study, a nutritional supplement comprising of |
| and zeaxanthin, according to the current study, | | | | vitamins A, C and E, omega 3 fatty acids, taurine, |
| may have a definite mode of action through | | | | copper, zinc oxide, lutein and zeaxanthin, showed |
| which they reduce the risk of AMD in elderly | | | | substantial improvement in the best-corrected |
| individuals. | | | | visual acuity in 76.7% of the participants with dry |
| In order to solve the mystery of how lutein and | | | | AMD after 6 months of nutritional treatment with |
| zeaxanthin protect the eyes against AMD, the | | | | these supplements. The study was published last |
| researchers introduced these two nutrients, along | | | | year in the professional journal BMC |
| with beta-carotene (for comparison), into the | | | | Ophthalmology. |
| experimental cells of retina. The cells absorbed | | | | - Another study published last year in the |
| much more lutein and zeaxanthin compared to | | | | professional journal Archives of Ophthalmology, |
| beta-carotene, the researchers noted. They also | | | | suggested that consuming lutein and zeaxanthin in |
| found that lutein and zeaxanthin did bind with a | | | | higher amount can significantly reduce the risk of |
| protein, called SR B1 (scavenger receptor class B, | | | | AMD. |
| type 1), which acted as a transporter to carry | | | | - In the Age-Related Eye Disease Study (AREDS), |
| those nutrients from the bloodstream to retina. | | | | which included 4757 individuals, patients who |
| The same protein was also involved during the | | | | consumed a nutritional supplement comprising of |
| absorption of lutein and zeaxanthin in the gut (by | | | | vitamins C and E, beta carotene and high-dose of |
| the cells in the intestine), the researchers found in | | | | zinc, had a 28% reduced rate of progression |
| an earlier work. | | | | towards the "end-stage AMD". |
| What's different in this study? | | | | - Another study published in June 2008 in the |
| It appears from this study that though | | | | Archives of Ophthalmology, suggested that |
| beta-carotene is the major carotenoid we | | | | consuming high amount of omega 3 fatty acid in |
| consume through diet, its importance in AMD is | | | | the diet can significantly reduce the risk of late |
| far less, compared to Xanthophylls, such as lutein | | | | AMD. |
| and zeaxanthin. Lutein and zeaxanthin are the | | | | - High level of vitamin D in blood significantly |
| carotenoids, which substantially help reduce the | | | | reduces the risk of AMD, suggests a study |
| risk of AMD, and thus nutritional treatment using | | | | published last year in Archives of Ophthalmology. |
| these nutrients may yield impressive results, | | | | According to the study, vitamin D level in blood |
| compared to nutritional treatment only with | | | | was inversely associated with the risk of early |
| beta-carotene. That apart, further researches on | | | | AMD. |
| the protein (i.e. SRB1)--which binds with lutein and | | | | |