Have you ever tried on yellow sunglasses designed to block the blue light that damages our eyes? The world suddenly takes on a yellow hue.
Their yellow hue is also responsible for one of the health benefits of lutein and zeaxanthin. These two yellow pigments found in a wide variety of plants protect our eyes’ retinas and macula from blue-light damage.
In other words, they do for our eyes what they do for leaves exposed to more sunlight than they can absorb. The pigments help protect the leaves from photo-oxidative damage.
And this research review article (Kusha et al.) looking at lutein, zeaxanthin, and eye health describes “… the role of these carotenoids as blockers of blue-light damage and quenchers of oxygen free radicals.”
How trustworthy are such claims?
According to this 2018 review (Buscemi et al.) of multiple studies, the benefits of lutein and zeaxanthin for eye health are well established:
“A large body of evidence shows that lutein has several beneficial effects, especially on eye health. In particular, lutein is known to improve or even prevent age-related macular disease…”
However, the same reviewers also observe that “… conflicting data had been reported concerning L [lutein] efficacy.”
So, the research results on additional benefits of lutein and zeaxanthin have been conflicting.
That said, it’s clear that our retinas and macula absorb more lutein and zeaxanthin than any other carotenoids. And the windows to our souls are also the windows to our brains.
From Cradle to Grave, Lutein and Zeaxanthin Help Us Think Clearly
What do infant’s brains do with the lycopene and zeaxanthin that comes their way?
This research review from Tufts University Adjunct Professor and research scientist Elizabeth Johnson, Ph.D., explored the roles they play in visual and cognitive health throughout our lives.
One study (Vishwanathan et al.) she reviewed examined infants’ brains. Lutein and zeaxanthin accounted for 59 and 16 percent of their total carotenoids, respectively.
She compared those figures to the dietary intake to the two pigments from the NHANES III (1988-1994) report.
For infants in the same age group as those in the first study, lutein accounted for only 12% percent of carotenoid intake.
Dr. Johnson’s take on the difference between dietary intake and actual brain concentration of the two pigments?
“This strongly suggests a preferential uptake of lutein into infant neural tissue.”
She also cites a third study (Johnson et al.) indicating this “preferential treatment” continues our entire lives.
Analyzing data collected over three years from 285 participants aged 98 or older, it found that lutein and zeaxanthin remained the brain’s preferred carotenoids – at 31 and 10 percent.
Beyond Macular Degeneration: Other Benefits of Lutein and Zeaxanthin
The two pigments may also protect us from:
- heart disease
- metabolic syndrome (associated with type 2 diabetes).
- mild cognitive impairment
- Alzheimer’s disease
and cognitive decline.
For example, in this study (Barnett et al.), researchers measured the lutein and zeaxanthin brain levels of 56 eight and nine-year-olds.
They then tested the children’s:
- overall academic achievement
- mathematics skills
- written language skills
The higher their pigment levels, the better the children performed even after accounting for other variables.
And this randomized, double-masked, placebo-controlled trial split 51 participants with an average age of 73.7 years into two groups.
One took a placebo, and the other, a supplement with 12mg of lutein and zeaxanthin. After one year, both groups took a cognitive functions test.
The results were startling!:
Complex Attention (Average Error Reduction)
- Supplement group +5
- Placebo group -1
Cognitive Flexibility (Average Score)
- Supplement group +14
- Placebo group +5
Executive Function (Average Improved Score)
- Supplement group +13.5
- Placebo group +6.5
Where to Get the Benefits of Lutein and Zeaxanthin
Take a walk through the eye-care section of any health food store, and you’ll find shelves full of products containing lutein and zeaxanthin. All will make various claims to:
- nourish your eyes
- promotes vision function
- protect your eyesight
However, only yesterday, I was championing the importance of getting our nutrients as Nature intended – from whole-food ingredients!
And a study I looked at a few days ago showed that those eating one serving of green leafy vegetables per day had the cognitive skills of someone ”… 11 years younger in age.”
So, it turns out are the best natural sources of these vision-empowering panaceas are…
Check out the lutein-zeaxanthin content in only ½ cup of three common leafy greens, according to Tufts University Antioxidant Research Lab:
- Kale, cooked: 10.3 mg
- Spinach cooked: 6.7 mg
- Spinach, raw: 4.5 mg
- Lettuce, raw, romaine: 1.1 mg
Compare those figures to those avocado and egg producers like to brag about:
- Avocado: 0.3 mg
- Egg, hard-boiled: 0.2mg
Personally, I have no trouble seeing the benefits of lutein and zeaxanthin – and seen through yellow sunglasses, my kale and spinach still look green.
I’ll keep eating greens every day and try to convince everyone else to do the same!