Get this: Research shows there are two compounds that may possible do double duty protecting our cognitive functioning while keeping our vision sharp. This twosome are lutein and zeaxanthin, key nutrients that have substantial evidence-based science indicating the role they play in keeping two very important organs – the eyes and the brain - healthy and working their best.
What are lutein and zeaxanthin
Lutein and zeaxanthin are members of xanthophyll carotenoids which are part of more than 600 naturally occurring pigments found in nature that are the sources of the red, yellow, and orange colors of many plants. The human body cannot make them on its own and less than 20 of the over 600 carotenoids are found in the human body. Together, lutein and zeaxanthin have impressive antioxidant potential for eye health and now promising potential for cognitive or brain health.
Their role in eye health
It’s been known for many years that lutein and zeaxanthin are important for helping to lower the risk of age-related macular degeneration (AMD). AMD is a chronic eye disease affecting more than 15 million American adults that gradually destroys the macula. The macula is a small region in the retina – a light sensitive tissue lining the back of the eye – that’s responsible for clear central vision. It leads to an irreversible vision loss in the center of the field of vision but without affecting peripheral vision. The center field of view will appear blurry, distorted or dark and is like placing your fist at the bridge of your nose creating a blind spot, making it difficult to read, drive, do any close-up work or recognize faces. AMD is the number one cause of severe vision loss and legal blindness of people over the age of 60 in the U.S.
Out of all the carotenoids present in the body, only lutein and zeaxanthin are found in the retina and in high concentrations in the macula of the retina. This is important as lutein and zeaxanthin filter harmful high-energy blue wavelengths of light and act as antioxidants in the eye, helping to protect and maintain healthy cells from environmental and light-induced oxidative damage caused by smoking, pollutants and sun exposure.
Two research studies over the years have provided convincing evidence of the vital role lutein and zeaxanthin play in helping to prevent or slow the progression of AMD. The first study occurred back in the 1990’s which was a large, randomized clinical trial conducted by the National Institutes of Health’s National Eye Institute. This study oversaw the Age-Related Eye Disease Study (AREDS). Then a second study was completed in 2013 (AREDS2) that confirmed the role of supplements in preventing advanced AMD. The study used a formulation of high-dose antioxidants that showed a 25% reduction risk of developing advanced AMD and a 19% lower risk of central vision loss of people with intermediate or advanced disease. The two nutrients that stood out from the others were lutein and zeaxanthin. Both AREDS and AREDS2 studies used supplementation of lutein at 10 mg a day and supplementation of zeaxanthin of 2 mg a day. Currently, there is no recommended daily intake for lutein or zeaxanthin. However, to lower the risk of AMD, research has shown it takes at least 6 mg of lutein each day but the average adult takes in less than 2 mg of lutein a day.
Their role in brain health
In recent years, it appears that lutein and zeaxanthin may now be useful in maintaining cognitive function in the elderly. Data from various studies have supported the importance of lutein and zeaxanthin in brain health. Like the eye, lutein is the predominant carotenoid in the brain and is absorbed by the brain more than any other carotenoid.
Years of oxidative stress and inflammation can make the brain vulnerable to decreases in cognitive functioning. What may help are dietary antioxidants and anti-inflammatory agents that delay oxidative damage to the brain. Lutein and zeaxanthin function as both an antioxidant and anti-inflammatory agents in order to maintain proper brain functioning.
Data from a double-blind, placebo-controlled study provided valuable information, particularly on lutein’s role in brain health. The study used healthy older women and results showed those who received 12 mg of lutein along with 800 mg of DHA per day were found to have improved verbal fluency, memory scores and a higher learning rate after 4 months. This study helped to support the role carotenoids like lutein and zeaxanthin along with DHA working together synergistically, can improve brain health.
Research has also confirmed that the amount of carotenoids like lutein and zeaxanthin in the brain are related to the amount of these same carotenoids found in the macula of the retina of the eye. Therefore, the more lutein and zeaxanthin concentrations found in the macula, this most likely reflects higher lutein and zeaxanthin concentrations in the brain which could mean higher cognitive functioning.
Nutrition’s role in eye and brain health
At this time it is encouraged for people to consume more carotenoid-rich foods that contain lutein and zeaxanthin to maintain and possibly prevent developing AMD or decreased cognitive functioning. If it is difficult for a person to eat foods rich in lutein and zeaxanthin, then a supplement containing both is recommended.
Here are some ideas to help increase food intake of lutein and zeaxanthin:
· The dark green leafy vegetables can be eaten raw if preferred.
· Try to consume at least a couple of the above foods daily
· Don’t like the taste? Blend them with other foods in a smoothie
· Discuss with your physician or optometrist on nutritional supplements containing lutein or zeaxanthin
None of us want to develop AMD or have decreased cognitive function as we age. The good news is we can take nutritional preventative measures that can help prevent or at least delay any progression taking place. Remember the words lutein and zeaxanthin – they may just be the key to clearer thinking and eyesight in the future.