Dietary Carotenoids Lutein and Zeaxanthin Change Brain Activation in Older Adult Participants: A Randomized, Double-Masked, Placebo-Controlled Trial.
SCOPE
Steady-state visual evoked potentials (SSVEP) can be used to test the topological response of cortical neurons. Studies have shown that a lutein (L) preferentially accumulates within cortical tissue. L, zeaxanthin (Z), and their isomers can be measured directly in retina (macular pigment optical density, MPOD), and retinal L+Z correlate highly with L+Z levels in cortical visual processing areas. The purpose of this study was to determine the relation between MPOD and SSVEP signal power, cross-sectionally and after supplementation with L+Z.


METHODS AND RESULTS
SSVEP to three different driving frequencies of stimulation (5, 10, and 16.6 Hz) were obtained for community-dwelling older adults, at baseline and after 12 months of supplementation with either 12 mg L+Z or placebo. Power was quantified at the driving frequencies. Non-specific activation was quantified within the 10-15 Hz band. MPOD was measured psychophysically. Subjects with low MPOD had reduced power at 16.6 Hz and reduced non-specific activation, compared with subjects with high MPOD. Supplementation significantly improved signal power at 5 and 10 Hz.


CONCLUSION
Past research suggests that L+Z can improve visual memory, visual processing speeds, etc. One possible mechanism for that improvement may be improving signal-to-noise ratio throughout the vision system.
['Ceravolo|S Anna|SA|', 'Hammond|Billy R|BR|', 'Oliver|William|W|', 'Clementz|Brett|B|', 'Miller|L Stephen|LS|', 'Renzi-Hammond|Lisa M|LM|0000-0003-4334-8202']
D000368:Aged D000369:Aged, 80 and over D001921:Brain D003430:Cross-Sectional Studies D004569:Electroencephalography D005074:Evoked Potentials, Visual D005260:Female D006801:Humans D014975:Lutein D065348:Macular Pigment D008297:Male D010919:Placebos D059629:Signal-To-Noise Ratio D065146:Zeaxanthins
lutein zeaxanthin steady-state visual evoked potentials aging cognition