Lutein is a color pigment known as a carotenoid and the same classification is shared by compounds such as beta carotene (provitamin A), lycopene, astaxanthin, and others. The chemical is of particular importance for eye health (it is even regarded as the “eye vitamin”) because of its function as an antioxidant and a molecule with the capability of filtering sunlight so that it does not damage the human eye. Together with another carotenoid pigment (zeaxanthin), lutein bio-accumulates in the macula of the eye’s retina and acts to protect the eyes from the blue wavelength of sunlight exposure and the resultant oxidative stress. Both lutein and zeaxanthin share equal importance for eye health. Many foods contain lutein including plants such as kale, spinach, corn, broccoli, orange pepper (paprika), kiwi, squash, and oranges. However, eggs are the best source because the bioavailability of egg lutein is superior to the one found in plants. The body absorbs the lutein in eggs more efficiently and many studies have been conducted proving this fact. Heat processing of plants can increase the bioavailability of lutein (like many other carotenoids such as beta carotene), but this improvement is still lower compared with eggs. However, the difference is not so significant that a person should focus his/her attention on this issue. In general, consumption of plentiful amounts of vegetables and fruits (especially heat-treated) and eggs is the main dietary route for lutein intake. As a fat soluble nutrient (like vitamin A and the other carotenoids) lutein is best taken with food containing dietary fat and that is probably the reason for the superiority of the lutein in eggs. It also appears to be stored well in the bodily tissues as higher-than-usual blood levels are detected months after intake has been stopped.
Supplementation with lutein can significantly increase the user’s blood levels of this molecule and it has been proven that with higher supplemental intake there is a dose-dependent increase in blood lutein levels and as a result an increase in the levels of this vital pigment in the eye structures. So taking a dietary supplement can be a sure way to reap the benefits of higher lutein levels. These are mostly related to diseases and conditions affecting the eyes such as age-related macular degeneration (ARMD - a degenerative eye disorder that is related to aging and affects around 5% of people above 65 years of age), cataracts, and various inherited vision disorders. ARMD is reported to be reduced in people who consume more lutein-rich foods and supplements and studies also find that supplementing lutein for 12 months can actually decrease the symptoms of people suffering from the disease. The combination of lutein with the other macular pigment – zeaxanthin – has been tested for a synergistic effect with promising results. The proven accumulation of these two pigments in the macula of the eye after supplemental intake is the proposed reason for the improved symptoms of ARMD and better eye protection. Another eye condition – cataracts (clouding of the lens in the eye which leads to a decrease in vision) – is also improved with supplementing lutein three times weekly for up to 2 years. This trial found improved vision of elderly patients with cataracts. Taking lutein may also reduce eye strain, especially when combined with other eye-healthy nutrients.
Other conditions unrelated to the eyes have also been reported to be improved by higher lutein intakes or blood levels of the nutrient, probably due to its proven antioxidant effects. There are associations between higher blood lutein levels and a reduced risk of developing breast cancer as well as developing high blood pressure during pregnancy. On the other hand, lower blood levels are linked with a greater risk of lung cancer. Also, it appears that older women can improvetheir speaking, memory and overall mental function by taking 12 mg of lutein plus omega 3 fatty acids for 4 months. Lutein supplementation is absolutely safe when taken in the recommended doses and intake of up to 15 mg per day for two years has not resulted in any unfavorable effects. Effective doses for a couple of eye conditions have been proposed by human clinical investigations. In order to decrease the risk of developing ARMD and cataracts people need to take between 6 mg and 12 mg per day with the higher dose being more effective. Regarding individuals who are already diagnosed with ARMD, a dose of 10 mg of supplemental lutein appears to be effective for symptom reduction.