The neuropharmacological and clinical effects of lutein: a systematic review.

Objectives: Neurodegenerative diseases are defined by specific protein accumulation and anatomic vulnerability leading to neuronal loss. Some studies have shown that lutein may have an effect on neurodegenerative diseases. As most of the neurodegenerative diseases don't have certain cure and therapies focus on symptom control, Lutein may be a complementary treatment. Due to controversies in studies investigating lutein effect on neurodegenerative diseases, we decided to perform a systematic review on these studies.

Methods: A systematic search was carried out in the available databases. We used all MeSH terms and relevant keywords. Studies that reported relationship between lutein and any neurodegenerative disease were included.

Results: We found 278 studies. After removing duplicates, screening by titles and abstracts and excluding irrelevant papers, 17 articles were included in this study. Fourteen studies investigated Alzheimer's disease, 2 studies Parkinson's disease and 1 study Amyotrophic lateral sclerosis. 1/17 study found that high serum levels of lutein at baseline were associated with a lower risk of AD mortality and lutein effect on lipid profile have been investigated in 2/17 studies. Also, 1/17 study has been shown that high intake of lutein may reduce the risk of ALS progression.

Conclusions: 4/17 studies confirm that lutein can improve cognitive function. 8/17 studies demonstrate a reduction in the progression of AD, and 2/17 studies indicate an improvement in lipid profiles. However, some studies did not find any significant associations. Additionally, there is a limited number of studies investigating the effects of lutein on other neurodegenerative diseases.