Lutein and Zeaxanthin Improve Cognition

Recent studies have shown that lutein and zeaxanthin, well known for protecting the eyes, also boost factors involved in brain function and cognitive performance.

The effects of these plant-based nutrients have been shown in young people and older adults—even those with early cognitive impairment.^1-5

What most people don’t realize is there is a connection between the eyes and brain.

When doctors examine the retina and optic nerve, they are looking at brain cells.

That’s why it makes sense that the nutrients lutein and zeaxanthin nourish the brain as well as the eyes.⁴

Levels of lutein and zeaxanthin in the retina correlate with their levels in brain tissue.^4,6,7

Multiple studies reveal that people with higher macular levels (central portion of the retina) of lutein and zeaxanthin have better brain function and cognitive performance than those with lower levels.^6,8-12

Lutein and zeaxanthin are demonstrating beneficial impacts on brain processing speeds, visual memory, cognitive flexibility, and improved brain blood flow.

Enhanced Brain Function

Neurological function relies on the ability of the brain to accurately process signals and carry out processing tasks.

Brain function can be measured by functional MRI (fMRI) scans, which reveal which brain areas are active during specific cognitive tasks.

A 2017 study using fMRI showed that people with higher macular lutein and zeaxanthin levels had greater neural efficiency on a test of learning and memory.⁹

A 2019 follow-up study showed that those improvements in brain efficiency occurred specifically in areas associated with:¹²

• Visual-spatial perception (Where is the object I’m looking at?),
• Processing (What is that object?),
• Decision making (Should I approach or avoid the object?),
• Motor coordination (Grasp the object or run away from it).

These findings suggest that the brains of people with higher lutein and zeaxanthin are better at distinguishing important signals from unimportant or irrelevant background “noise.”

This was further supported by a study of auditory signaling, which showed that people with higher levels of these plant pigments (lutein and zeaxanthin) could detect true sound signals more efficiently than those with lower levels.¹⁰

Brain Function Improvements

Two recent studies conducted at the University of Georgia demonstrate that brain function is improved by daily supplementation with 10 mg of lutein and 2 mg of zeaxanthin.^1,5

In the first study, healthy older adults (with a mean age of 72) were randomly assigned to receive supplements containing lutein and zeaxanthin or a placebo. Over the course of a year, the ability to learn and recall word pairs deteriorated in the placebo group, but not in supplemented participants.

Functional MRI scans taken during the task showed this benefit was produced by enhanced brain blood flow in the lutein and zeaxanthin supplemented group.¹

The second study measured brain cell activation in people receiving a placebo or 10 mg/day of lutein and 2 mg/day of zeaxanthin.⁵

At baseline, subjects with lower macular pigment levels had lower-powered visual signals from their brain cells, compared to those with higher levels of lutein and zeaxanthin.⁵

After a year of supplementation, visual signal power was significantly improved, providing subjects’ brains with a stronger signal-to-noise ratio.⁵

Improved Cognitive Performance

Cognitive performance refers to more advanced tasks involving memory, reasoning, and thinking, and it is measured by tests of cognition.

Higher macular lutein and zeaxanthin levels have been associated with improvement in:^6,8,11

• Overall cognition,
• Verbal learning and fluency,
• Recall,
• Processing and perceptual speed,
• Memory,
• Executive function (Information sorting, prioritizing, and taking action).

Two additional studies from the University of Georgia show that supplementing with lutein and zeaxanthin can support better cognitive functioning in both young and old populations.^2,3

In a group of healthy young adults (ages 18-30), subjects received daily doses of 10 mg lutein and 2 mg zeaxanthin or a placebo. Macular pigment measurements and cognitive testing were performed at the start and then every four months for a year.³

Supplementation increased macular levels of the pigments significantly, and this increase resulted in substantial improvements in:³

• Spatial memory (Where did I leave that book?),
• Reasoning ability (Where might I have left the book?), and
• Complex attention (Why am I reading the book anyway?).

Using the same study design and dosages, the second trial evaluated lutein and zeaxanthin supplementation in older adults (with a mean age of 73).²

Macular levels of lutein and zeaxanthin increased significantly in supplemented subjects, and this change was accompanied by improvements in complex attention and cognitive flexibility (the ability to hold conflicting facts in one’s mind at the same time, which is crucial in making complicated decisions).²

Men in the study also showed improvement in composite memory (verbal and visual memory) when supplemented.

Summary

Lutein and zeaxanthin are carotenoid pigments that have long been known to help improve retinal health and preserve vision.

New studies have now shown that people who supplement with 10 mg/day of lutein and 2 mg/day of zeaxanthin see significant improvements in brain function, including enhanced brain blood flow and neural efficiency.

That translates into improved cognitive performance in tasks related to thinking, learning, discerning, and judging—all elements of youthful brain behavior.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.

References

1. Lindbergh CA, Renzi-Hammond LM, Hammond BR, et al. Lutein and Zeaxanthin Influence Brain Function in Older Adults: A Randomized Controlled Trial. J Int Neuropsychol Soc. 2018 Jan;24(1):77-90.
2. Hammond BR, Jr., Miller LS, Bello MO, et al. Effects of Lutein/Zeaxanthin Supplementation on the Cognitive Function of Community Dwelling Older Adults: A Randomized, Double-Masked, Placebo-Controlled Trial. Front Aging Neurosci. 2017;9:254.
3. Renzi-Hammond LM, Bovier ER, Fletcher LM, et al. Effects of a Lutein and Zeaxanthin Intervention on Cognitive Function: A Randomized, Double-Masked, Placebo-Controlled Trial of Younger Healthy Adults. Nutrients. 2017 Nov 14;9(11).
4. Power R, Coen RF, Beatty S, et al. Supplemental Retinal Carotenoids Enhance Memory in Healthy Individuals with Low Levels of Macular Pigment in A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. J Alzheimers Dis. 2018;61(3):947-61.
5. Ceravolo SA, Hammond BR, Oliver W, et al. Dietary Carotenoids Lutein and Zeaxanthin Change Brain Activation in Older Adult Participants: A Randomized, Double-Masked, Placebo-Controlled Trial. Mol Nutr Food Res. 2019 Apr 5:e1801051.
6. Vishwanathan R, Iannaccone A, Scott TM, et al. Macular pigment optical density is related to cognitive function in older people. Age Ageing. 2014 Mar;43(2):271-5.
7. Vishwanathan R, Schalch W, Johnson EJ. Macular pigment carotenoids in the retina and occipital cortex are related in humans. Nutr Neurosci. 2016;19(3):95-101.
8. Feeney J, O’Leary N, Moran R, et al. Plasma Lutein and Zeaxanthin Are Associated With Better Cognitive Function Across Multiple Domains in a Large Population-Based Sample of Older Adults: Findings from The Irish Longitudinal Study on Aging. J Gerontol A Biol Sci Med Sci. 2017 Oct 1;72(10):1431-6.
9. Lindbergh CA, Mewborn CM, Hammond BR, et al. Relationship of Lutein and Zeaxanthin Levels to Neurocognitive Functioning: An fMRI Study of Older Adults. J Int Neuropsychol Soc. 2017 Jan;23(1):11-22.
10. Wong JC, Kaplan HS, Hammond BR. Lutein and zeaxanthin status and auditory thresholds in a sample of young healthy adults. Nutr Neurosci. 2017 Jan;20(1):1-7.
11. Ajana S, Weber D, Helmer C, et al. Plasma Concentrations of Lutein and Zeaxanthin, Macular Pigment Optical Density, and Their Associations With Cognitive Performances Among Older Adults. Invest Ophthalmol Vis Sci. 2018 Apr 1;59(5):1828-35.
12. Mewborn CM, Lindbergh CA, Robinson TL, et al. Lutein and Zeaxanthin Are Positively Associated with Visual-Spatial Functioning in Older Adults: An fMRI Study. Nutrients. 2018 Apr 7;10(4).