Not only did the researchers confirm reports that the carotenoid has stronger antioxidant activity than beta-carotene and lycopene, that lutein is safe at all the doses tested, but could protect against mutations and genetic damage.
These findings could open up new avenues of research for a micronutrient traditionally associated with eye health.
"In addition to providing additional proof of safety and efficacy of lutein, this paper may also stimulate additional research into the effects of lutein upon the human immune system," said Dick Roberts, Ph.D., senior manager of scientific affairs for Kemin Health, maker of FloraGLO branded lutein.
While Kemin Health have a long history of working with researchers to generate data supporting the efficacy and safety of purified lutein for use in dietary supplements and foods, the company was not involved in this new research.
Public awareness of lutein has never been higher in Europe, with a recent survey, from Frost and Sullivan and commissioned by Kemin, finding that awareness has doubled compared to last year, to 25.8 per cent and 16 per cent in Italy and France, respectively.
Germans showed the greatest awareness, of 33.3 per cent. The UK was the only country where it seemed to have slipped slightly, to 20 per cent (compared to 25.8 in 2005).
The new research, which was partly funded by Canadian natural products supplier, The Healing Arc, investigated the antioxidant activity, (anti-)mutagencity and (anti-)clastogenicity of lutein.
The researchers measured the antioxidant activity of the carotenoids, lutein, beta-carotene and lycopene using the photochemiluminescence (PCL) assay the beta-carotene-linoleic acid model system (beta-CLAMS).
For both measures it was found that lutein had a significantly higher antioxidant activity - PCL: lutein, 0.266 trolox equivalents, compared to 0.027 and 0.018 for beta-carotene and lycopene, respectively. Beta-CLAMS: 34.5 per cent for lutein, compared to 13.8 and 13.3 per cent for beta-carotene and lycopene, respectively.
The researchers also tested in vitro the mutagenicity/ anti-metagenicity at three doses - 334, 668, and 1335 micrograms of lutein per plate.
"Lutein was not only found to be non-mutagenic at all doses, but it showed an anti-mutagenic effect in a dose-dependent manner," wrote lead author Mingchen Wang from Zhengzhou University in China.
And similar results were observed in the chromosome damage test using Chinese hamster ovary cells.
"The protective effects of lutein on mutation and chromosomal damages induced by known mutagens and clastogenic compounds in this study suggest that lutein is not only safe, but can potentially help reduce risks of human chronic diseases," said Wang.
Roberts told NutraIngredients.com that the results of the new study were "similar to or advance the available evidence that free lutein purified from marigold oleoresin is safe and effective as an antioxidant for incorporation into products for supplementation of human nutritional needs."
Much of this information was previously known, said Roberts, and was employed in the determination of the GRAS (Generally Recognized As Safe) status as well as in the establishment of JECFA (Joint FAO/WHO Expert Committee on Food Additives) acceptable daily intake (ADI) level of 0 to 2 mg per kilogram of body weight obtained for lutein.
But the anti-mutagenicity and anti-clastogenicity results at such high doses of lutein appear to be new, said Roberts, who was able to quote three previous studies looking at anti-mutagencity, and one looking at both anti-mutagenicity and anti-clastogenicity.
"The anti-mutagenicity and anti-clastogenicity results obtained by Wang and associates in this recent publication may indicate that purified lutein has a potent effect upon reducing the direct damage to the genetic materials in cells of the human body caused by environmental exposure," Roberts told NutraIngredients.com.
"Although significantly more research is needed in this area, the findings published in this paper provide additional evidence that purified lutein may have many additional modes of efficacy in the human body than are currently attributed to it."
The article, "Antioxidant activity, mutagenicity/ anti-metagenicity, and clastogenicity/ anti-clastogenicity of lutein from marigold flowers" was published in the peer-reviewed journal Food and Chemical Toxicology (Vol. 44, pp. 1522-1529).