Tuesday, November 20, 2012

A possible role for lutein and zeaxanthin in cognitive function in the elderly.

It is already well established by scientific research that increased lutein and zeaxanthin in the diet lowers the risk of cataracts and age related macular degeneration (AMD) two eye diseases that cause permanent vision loss. Catracts can be treated by removing the damaged lens of the eye and transplanting a new artificial lens but AMD has not treatment and the only way to fight it is through prevention.

Eating five servings of fruits and vegetables each day can provide about 5 to 6 mg of carotenoids, including lutein and zeaxanthin if you give some thought to your food choices and choose fruits and vegetables that are high in these nutrients.

The problem is that most people in North America do not eat five servings of fruits and vegetables each day. While the studies recommend that you consume 6 milligrams or more of lutein and zeaxanthin, the average intake of lutein and zeaxanthin is approximately 2 mg per day. For people who have trouble eating the recommend amount of lutein and zeaxanthin, vitamin supplements are available. Ask your eye doctor to recommend a trustworthy, clinically proven formulation.

New research suggests that lutein and zeaxanthin may be useful to us even beyond preventing eye diseases.

Lutein and zeaxanthin form macular pigment in the eye. They also accumulate in the human brain. Studies in animals have show that individuals with high levels of Lutein and zeaxanthin in the macula of the eye also had high concentrations of these nutrients in their brain tissue.  This means that macular pigment can be used as a biomarker of lutein and zeaxanthin in brain tissue.

It is no surprise, then, that studies have found a significant correlation between macular pigment density and general cognitive function in healthy elderly people.   For exampled one study followed different groups of elderly women for four months.  The group of women that used lutein supplementation (12 mg/day), alone or in combination with DHA (800 mg/day), showed that verbal fluency scores improved significantly in the DHA, lutein, and combined-treatment groups. Memory scores and rate of learning improved significantly in the combined-treatment group, who also showed a trend toward more efficient learning.