A large number of studies demonstrate the beneficial effects of lutein on eye health. Lutein is a carotenoid with proven anti-inflammatory properties. In particular, it is known for its ability to help prevent and slow down the progression of age-related macular degenerationone of the main causes of blindness and serious visual problems in the elderly population. Lutein, in fact, is present in the human body in high quantities precisely in the macula, the central part of the retina, which due to its high concentration of photoreceptor cells is responsible for visual acuity and central vision. In addition, lutein is also present in the human lens, where it has a protective action against age-related eye diseases such as cataracts.
Properties of lutein
Although about 850 types of carotenoids have been discovered and characterised in nature, very few of them are present in human tissue. Of these, lutein and its stereoisomers, zeaxanthin and meso-zeaxanthin, are the only carotenoids present in the retina.Â
Lutein and its stereoisomers belong to the carotenoid class, called xanthophylls, which contain oxygen and are less hydrophobic than the carotene class, which is purely hydrocarbon and more hydrophobic.
Lutein has been shown to exert an extremely powerful antioxidant action, quenching singlet oxygen and eliminating free radicals. According to several studies, lutein is also able to reduce the production of reactive oxygen species (ROS).
In addition, lutein has another protective effect, exerted particularly at the ocular level, which consists in its ability to filter blue light, thus reducing phototoxic damage to retinal photoreceptors.
How to get lutein from the diet
Carotenoids are mostly synthesised in plants and microorganisms, but not in humans and other mammals. For this reason they must be taken via thepower supply. Green leafy vegetables such as cabbage, spinach, broccoli, peas and lettuce, as well as egg yolk, are the most common sources of xanthophylls, including lutein and zeaxanthin. Other sources are spelt, durum wheat and maize-related foods.
Sufficient dietary intake of carotenoids has beneficial effects on various systemic diseases and in eye diseases due to their action in protecting the retina from light damage. Lutein can be retained in the human retina for an extended period of time and when supplemented with diet, the concentration of serum lutein and the level of retinal lutein increase.
Benefits of lutein in eye diseases
Many clinical studies have confirmed the antioxidant action and anti-inflammatory properties of lutein in the eye, suggesting its beneficial effects on the prevention and improvement of eye diseases such as age-related macular degeneration, diabetic retinopathy, myopia and cataracts. More importantly, lutein is safe, with minimal side effects when taken long-term.
Due to its eye-protective properties and safety profile, lutein is often considered by many researchers as a potential therapeutic alternative or supplement for various eye diseases. To date, most research has focused on studying the effects of lutein on macular degeneration and diabetic retinopathy, as these are the most common causes of visual impairment in the ageing population and because oxidative damage and inflammation are involved in their pathological processes, against which lutein has its beneficial effects.
Most clinical studies have provided promising results, supporting the efficacy of lutein in delaying the development and progression of these conditions. For example, among patients with type 2 diabetes, a retrospective study showed that lutein and zeaxanthin supplementation can improve retinal thickness and function, demonstrating that a higher plasma lutein level is associated with a lower risk of development or progression of diabetic retinopathy.
Other studies have pointed to a possible role of lutein in alleviating the outcomes of other eye diseases, including retinopathy of the premature, myopia and cataracts. Regarding the latter, in particular, one study showed that subjects taking lutein had a 50% reduced risk of developing cataracts.
Further clinical studies will be necessary to fully evaluate the protective role of lutein, to better define the optimal doses according to the type of patient, and to understand whether lutein, from a simple supplement, can in future be considered as a genuine pharmacological aid in the treatment of eye diseases.
Bibliography:
Dr. Carmelo Chines
Direttore responsabile
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