Some people call it "vitamin of sight", and in fact it lutein is an important molecule for eye health. Her protective action it is based on the ability to filter the sun's rays.
Let's find out what it is, what yours are property and which benefits it is possible to derive from its assumption.
What is lutein
Lutein is a carotenoid. From a chemical point of view, therefore, it is related to molecules such as beta-carotene and vitamin A.
Together with zeaxanthin (another carotenoid) makes up the pigment present in the area of the retina where the observed image is formed (the macula). Compared to zeaxanthin, however, it is more concentrated in the more peripheral areas of the retina.
What is lutein for?
Lutein protects the eye from damage due to exposure to ultraviolet radiation and present in the sun's rays and to blue light.
Together with zeaxanthin it acts as a antioxidant, counteracting reactive oxygen species, and helps to reduce the formation of lipofuscin, a substance that accumulates can lead to the appearance of vision problems typically associated withaging.
Its main function, however, is to act as light filter that enters the eye.
Adequate intake of lutein and zeaxanthin promotes good vision and protects against two major causes of vision loss: age-related macular degeneration and cataracts.
Where is lutein
The human body is unable to synthesize lutein; for this it must be taken with food.
Among the foods richest in this carotenoid are included green leafy vegetables (such as kale, spinach, lettuce, Brussels sprouts and broccoli) whose lutein content can vary between 15 and 47% about, but not only.
The share of lutein is in fact equal to 54% in kiwifruit and 60% in corn, and an excellent source is also found among foods of animal origin: egg yolk, with a content equal to that of kiwi.
Other possible sources of lutein are:
- the watermelon;
- the winter melon;
- the Orange juice;
- la mela “Red Delicious”;
- spring onions;
- the celery;
- the pumpkin;
- the green pepper;
- green beans;
- the peas.
Contraindications to the use of lutein
Lutein can also be taken in the form of Dietary Supplements; however, it is necessary to remember that:
- its absorption is better when taken with a meal rich in grassi;
- the simultaneous assumption of beta-carotene can reduce the absorption of lutein;
- the simultaneous assumption of Vitamin E it can reduce the absorption and effectiveness of the latter;
- its absorption can be reduced in case of cystic fibrosis.
As for possible contraindications, some data suggest that elevated blood levels of lutein are associated with a slightly increased risk of skin cancer in high-risk people who have a history of skin cancer.
In general, according to the European Food Safety Authority (Efsa) the safe lutein dose is 1 mg per kg of body weight per day, except for smokers, who should not exceed 10 mg per day.
Also, taking high doses of lutein can lead to yellowing of the skin. The problem is reversible, but to avoid it at the root it is good not to exceed a dosage of 14 mg per day for periods longer than 2-5 months.
For a safe intake from all these points of view, the recommendation is to limit the intake of lutein in the form of supplements to no more than 6 mg per day.