A new US study reports that low concentrations of lutein and zeaxanthin in the central nervous system seem to be linked to reduced cognitive ability especially in patients with mild cognitive impairment.
The observational study measured the lutein and zeaxanthin concentrations in the retina (macular pigment optical density) – correlating with the concentrations of the carotenoids in the brain – and cognitive functions of 24 patients with mild cognitive impairment and 24 healthy participants, aged between 65 and 83 years (1). The study results showed that the patients with the lowest lutein and zeaxanthin levels had the most signi- ficant cognitive impairment (including reduced language ability and attention) while corresponding healthy participants showed less effected functions (reduced visual-spatial and constructional abilities).
The researchers commented that it is possible that the lutein and zeaxanthin status may be more strongly related to cognition when individuals are considered with established onset of cognitive decline. Thus, in- creased intakes of the carotenoids potentially should be part of a lifestyle intervention to both improve cent- ral neural function and reduce the probability of progression through the various stages of dementia. This conclusion, however, needs to be verified by a randomized controlled trial.
A growing body of empirical data suggests that lutein and zeaxanthin are directly related to many of the symptoms displayed by patients with mild cognitive impairment (2). Evidence indicates that these pigments also treat many aspects of the underlying pathology such as inflammation, oxidative stress and vascular damage, supporting their role in cognitive function and the possible delay of degenerative brain disease (3).