ID 1684 -
Zeaksantyna
PL: Zeaksantyna
EN: Zeaxanthin
Pdf: zeaxanthin
Oświadczenie (2)
- oko zdrowia i wizji
- wymagane plamki pigmentu w oczy dla zachowania zdrowych oczu funkcji
- pomaga zachować elastyczność i przepuszczalność naczyń włosowatych siatkówki i wspiera dobre krążenie krwi w oczy
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claim is zeaxanthin. Zeaxanthin is a dietary carotenoid that can be measured in foods by standard methods. This opinion applies to the (3R, 3'R) stereoisomer of zeaxanthin.
The Panel considers that the food constituent, zeaxanthin, which is the subject of the health claim is sufficiently characterised.
2. Znaczenie oświadczenia dla zdrowia człowieka
The claimed effects are “eye health and vision”, “helps to preserve elasticity and permeability of capillaries of retina and supports good blood circulation in eyes” and “required for macular pigmentation in the eyes for maintaining healthy eye functions”. The Panel assumes that the target population is the general population. In the context of the proposed wordings, the Panel assumes that the claimed effects refer to maintenance of normal vision.
The Panel considers that maintenance of normal vision is a beneficial physiological effect.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka - Utrzymanie prawidłowego wzroku
A total of 123 references were provided to substantiate the claimed effect. Nine of these were textbook references, three were statements by authoritative bodies and one reference was an abstract. A further 22 references were narrative reviews. These publications establish that zeaxanthin is a component of the macular pigment in the eye. 78 of the references provided were not pertinent to the claimed effect as they did not address either the food constituent (zeaxanthin alone) that is the subject of the health claim or relevant functional outcomes. A total of 10 references were considered to be pertinent to the claim, of which seven were human studies, two were conducted in animals and one was an in vitro study.
One of the human studies (Kvansakul et al., 2006) was an intervention study in 24 subjects who were given either zeaxanthin or a combination of zeaxanthin and lutein or placebo for six months followed by doubled supplementation for a further six months. There was no effect of zeaxanthin supplementation on high mesopic acuity thresholds and there was no correlation between this measurement and macular pigment optical density.
The other six studies in humans were epidemiological in design. Delcourt et al. (2006) reported on data from 899 subjects in the POLA Study cohort in France. After multivariate adjustment, the highest quintile of plasma zeaxanthin was significantly associated with decreased risk of age-related macular degeneration (ARMD) and nuclear cataract. Subjects with high concentrations of zeaxanthin
(>0.09 µM) compared with subjects with low concentrations (<0.04 M) had a 93 % reduced risk of ARMD and a 75 % decreased risk of nuclear cataract. Gale et al. (2003) also found that the risk of ARMD was significantly associated with plasma zeaxanthin concentrations in 380 men and women, aged 66-75 years in the UK. People whose plasma zeaxanthin was in the lowest third compared with those in the highest third had an odds ratio of 2.0 (95 % CI: 1.0-4.1) for risk of ARMD. Mares- Perlman et al. (1995), however, found no associations between plasma zeaxanthin and risk of ARMD in 167 cases and controls in the US. Mares-Perlman et al. (2001) also did not find any relationship between dietary (8,596 participants) or plasma zeaxanthin (8,229 participants) and risk of ARMD in the third National Health and Nutrition Examination Survery (NHANES) in the US or any relationship between dietary zeaxanthin and risk of ARMD in a cross-sectional study of 1,968 US participants, aged 43-86 years (Mares-Perlman et al., 1996). Similarly, Moeller et al. (2006) found no relationship between estimates of dietary zeaxanthin consumption and risk of ARMD among 1,787 women, aged 50-79 years in the CAREDS cohort in the US. The Panel notes that the findings from these epidemiological studies are inconsistent as four out of the six, including the two largest studies, did not observe a relationship between dietary or plasma zeaxanthin and risk of ARMD. Moreover, the two studies which found a relationship between zeaxanthin and risk of ARMD were cross- sectional in design and, therefore, it cannot be assumed that low plasma zeaxanthin preceded the development of the disease.
The two animal studies cited used quail as the animal model. Thomson et al. (2002a) found that zeaxanthin supplementation increased retinal zeaxanthin in these birds and that the number of dying photoreceptors after light exposure was negatively associated with retinal concentrations of zeaxanthin but positively associated with the sum of alpha-tocopherol and zeaxanthin concentrations. Birds fed on a carotenoid depleted diet for six months did not have lower carotenoid retinal concentrations than those birds fed a commercial turkey diet. Thomson et al. (2002b) reported that retinal zeaxanthin concentrations, but not serum zeaxanthin concentrations, were negatively correlated with the number of apoptotic rods and cones in light-damaged eyes of quail. The Panel notes that these two studies provide evidence that zeaxanthin might be able to protect photoreceptors in quail eyes but that retinal zeaxanthin concentration appears to be resistant to dietary depletion of zeaxanthin and is not correlated with plasma zeaxanthin concentration.
The in vitro study of Sundelin and Nilsson (2001) found significantly decreased lipofuscin formation in rabbit and calf retinal pigment epithelial cells exposed to normobaric hyperoxia (40 %) after the addition and uptake of zeaxanthin. The Panel notes that the data from this in vitro model under the artificial condition of hyperoxia cannot predict in vivo effects of zeaxanthin in human retinal tissue.
In weighing the evidence, the Panel noted that the only pertinent intervention study in humans did not indicate a benefit of zeaxanthin supplementation on a functional measure of vision. The epidemiological evidence was strongly in favour of no relationship between dietary or plasma zeaxanthin and risk of ARMD. The Panel considers that the evidence provided in the animal studies does not predict an effect of zeaxanthin consumption on vision in humans.
The Panel concludes that a cause and effect relation has not been established between the consumption of zeaxanthin and maintenance of normal vision.
Warunki i możliwe ograniczenia stosowania oświadczenia
1-3 mg/day, if taken together with lutein.