Lutein is a type of pigment called a carotenoid, which is responsible for the yellow, orange, and red colors found in many plants. Since the human body cannot produce it, lutein must be obtained through diet. It functions as an important antioxidant and is highly concentrated in the retina of the eye, specifically in the macula, where it helps protect sensitive eye tissues. This nutrient is found in foods such as leafy green vegetables like kale and spinach, as well as in egg yolks, peas, and yellow-orange fruits and vegetables.
Signs of Excessive Lutein Intake
Consuming very high amounts of lutein from supplements can lead to a harmless condition called carotenodermia, which causes a yellowish discoloration of the skin. The yellowing is most apparent on the palms of the hands and soles of the feet, as the body stores excess carotenoids in the skin’s outer layers. This reversible condition is the most common sign of excessive intake, and skin color returns to normal once the nutrient intake is reduced. Some individuals might also experience mild digestive issues from high-dose supplements.
Potential Health Complications
While high lutein intake from diet is not associated with adverse effects, very high-dose supplementation has been linked to the development of crystals in the retina in rare cases. This has been observed in a few case studies where individuals took high doses of lutein for an extended period.
The formation of these crystals is a very rare event. The mechanism is not fully understood but is thought to be related to an oversaturation of the macular pigments. It is important to distinguish these rare occurrences from the safe profile of lutein when consumed at recommended levels.
Recommended Dosage and Safety Levels
Health authorities have not established an official Tolerable Upper Intake Level (UL) for lutein. However, scientific research provides guidance, showing that supplemental doses for adults of up to 20 milligrams per day are considered safe. The concern regarding excessive intake is almost exclusively related to high-dose dietary supplements, as the amount of lutein from a balanced diet is not linked to overdose symptoms.
Interactions with Medications and Nutrients
High doses of lutein supplements can interfere with the body’s absorption of other nutrients. As a carotenoid, it competes for absorption with other compounds in the same family, such as beta-carotene. This competition can reduce the body’s ability to absorb and utilize beta-carotene.
Additionally, because lutein is a fat-soluble nutrient, its absorption can be influenced by certain medications. Drugs designed to block dietary fat absorption, for instance, could also reduce the amount of lutein the body can absorb from food or supplements.