Lutein and Zeaxanthin Influence Brain Function in Older Adults: A Randomized Controlled Trial

J Int Neuropsychol Soc. 2018 Jan;24(1):77-90. doi: 10.1017/S1355617717000534. Epub 2017 Jul 11.

Abstract

Objectives: The present study constitutes the first randomized controlled trial to investigate the relation of lutein (L) and zeaxanthin (Z) to brain function using functional magnetic resonance imaging (fMRI). It was hypothesized that L and Z supplementation in older adults would enhance neural efficiency (i.e., reduce activation) and cognitive performance on a verbal learning task relative to placebo.

Methods: A total of 44 community-dwelling older adults (mean age=72 years) were randomly assigned to receive either placebo or L+Z supplementation (12 mg/daily) for 1 year. Neurocognitive performance was assessed at baseline and post-intervention on an fMRI-adapted task involving learning and recalling word pairs. Imaging contrasts of blood-oxygen-level-dependent (BOLD) signal were created by subtracting active control trials from learning and recall trials. A flexible factorial model was employed to investigate the expected group (placebo vs. supplement) by time (baseline vs. post-intervention) interaction in pre-specified regions-of-interest.

Results: L and Z appeared to buffer cognitive decline on the verbal learning task (Cohen's d=.84). Significant interactions during learning were observed in left dorsolateral prefrontal cortex and anterior cingulate cortex (p < .05, family-wise-error corrected). However, these effects were in the direction of increased rather than decreased BOLD signal. Although the omnibus interaction was not significant during recall, within-group contrasts revealed significant increases in left prefrontal activation in the supplement group only.

Conclusions: L and Z supplementation appears to benefit neurocognitive function by enhancing cerebral perfusion, even if consumed for a discrete period of time in late life. (JINS, 2018, 24, 77-90).

Keywords: Aging; Carotenoids; Cognition; Diet; Food; Magnetic resonance imaging.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / drug effects
  • Aging / physiology*
  • Cognitive Dysfunction / diagnostic imaging
  • Cognitive Dysfunction / physiopathology*
  • Cognitive Dysfunction / prevention & control*
  • Dietary Supplements*
  • Female
  • Gyrus Cinguli / diagnostic imaging
  • Gyrus Cinguli / drug effects
  • Gyrus Cinguli / physiology*
  • Humans
  • Independent Living
  • Lutein / administration & dosage
  • Lutein / pharmacology*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Prefrontal Cortex / diagnostic imaging
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / physiology*
  • Verbal Learning / drug effects
  • Verbal Learning / physiology*
  • Zeaxanthins / administration & dosage
  • Zeaxanthins / pharmacology*

Substances

  • Zeaxanthins
  • Lutein