New study extends lutein’s ‘functional evidence’ for eye health benefits
Results from a one year study indicated that 10 mg per day of lutein (Cognis/BASF) indicated that supplementation with the carotenoid significantly reduced levels of sC5b-9, a marker of systemic inflammation, compared to placebo.
“This study is the first to show that an increased dietary intake of lutein reduces the plasma level of sC5b-9,” wrote scientists from the University Eye Clinic Maastricht in The Netherlands and the University of Manchester in England.
“Due to the important role of the complement system as a mediator of inflammation and its role in the pathogenesis of AMD, lutein supplementation can be considered as a potential prevention and treatment for AMD.”
The study, published in Acta Ophthalmology, adds to an ever growing body of science supporting the vital role of the carotenoids lutein and zeaxanthin for eye health. These compounds are the only carotenoids capable of filtering the harmful blue light than can damage cells in the eye, the rods and the cones.
A thin macular pigment can allow the blue light through and destroy the cells. Maintaining high levels of both carotenoids, and therefore the macular pigment, is a valid approach to maintaining eye health and reducing the risk of diseases, like AMD.
The link between lutein and eye health was first reported in 1994 by Dr Johanna Seddon and her co-workers at Harvard University, who found a link between the intake of carotenoid-rich food, particularly dark green leafy vegetables like spinach, and a significant reduction in AMD (JAMA, Vol. 272, pp. 1413-1420).
Research dollars have flowed into research (both public and private) exploring lutein and zeaxanthin for eye health, with many positive studies boosting the lutein/zeaxanthin market, worth approximately $145 million globally. In the US it is estimated to be between $90 and 100 million.
The researchers recruited 70 people with early stage AMD and randomly assigned to them to receive either 10 mg per day of lutein or placebo for one year.
Results indicated that sC5b-9 levels decreased by 1.1 ng/ml per month in the lutein group, which produced an annual decrease from 60.3 ng/ml at baseline to 46.3 ng/ml at the end of the study period. On the other hand, sC5b-9 levels increased monthly in the placebo group, said the researchers.
“In the current study, we investigated the soluble factor sC5b-9, which is the final product of the three complement activation pathways (the classic pathway, the alternative pathway and the lectin pathway), also known as MAC,” explained the researchers.
“The relative contribution of the three pathways to sC5b-9 in plasma is not yet known in AMD patients nor is it clear from our data whether lutein has a differential effect on the three activation pathways mentioned. To date, we have circumstantial evidence that lutein may affect release of CFD from adipocytes, thereby controlling the alternative pathway. Whether lutein has an effect on the classical or lectin pathway necessitates further study.”
Source: Acta Ophthalmology
Volume 93, Number 2, Pages 141-145, doi: 10.1111/aos.12535
“Lutein supplementation leads to decreased soluble complement membrane attack complex sC5b-9 plasma levels”
Authors: Tian Y, Kijlstra A, van der Veen RL, Makridaki M, Murray IJ, Berendschot TT.