Here are some reference notes on this subject.
Lutein is well-known for its vision-enhancing properties. Research also suggests it has neuroprotective qualities, improving memory and boosting intelligence.
There’s an inverse association between lutein levels in the eyes and age-related macular degeneration (AMD), the primary cause of blindness in the elderly, as well as cataracts,
Lutein has also been shown to prevent cell death caused by retinal detachment when administered in a timely manner, and can help improve night vision.
Lutein may help prevent neurodegenerative diseases by preventing DNA damage, the depletion of BDNF and the degradation of a synaptic vesicle protein involved in Alzheimer’s and Parkinson’s. It’s also been shown to help maintain the integrity of your brain’s white matter
Your body cannot manufacture lutein, so you need to get it from your diet. Lutein is a carotenoid found in egg yolks, avocados, cruciferous vegetables and dark, leafy greens, especially kale and spinach.
Lutein — a carotenoid found in egg yolks, avocados, cruciferous vegetables and dark, leafy greens — is well-known for its vision-enhancing properties.1 Research also suggests it has neuroprotective qualities, 2 improving memory 3 and boosting intelligence. 4 As reported in the Senior Resource Guide:5
“Lutein belongs in the subclass of xanthophylls, which have polar molecular structures that possess unique membrane properties, such as fluidity, communication between brain cells, ion exchange, diffusion of oxygen, membrane stability, and the prevention of oxidation and inflammation.
Like other xanthophylls, lutein accumulates in neural tissue. In fact, lutein accounts for most of the carotenoid accumulation in the human brain, and this high concentration of lutein in the brain may indicate its neuroprotective value.
Lutein accumulates in the brain and embeds in cell membranes. There, lutein protects the neuronal structure and function of brain cells. While lutein is distributed in the gray matter of the brain, researchers have detected its presence in the temporal cortex, the prefrontal cortex, and the hippocampus. Lutein accumulates in the brain over a person’s lifespan and may therefore provide lifelong benefits to brain health.”
Your body cannot manufacture lutein, so you need to get it from your diet. Unfortunately, many do not get enough lutein simply because they don’t eat enough vegetables and/or eggs.
How Lutein Protects Your Vision
As its name implies, lutein is found in high concentrations in your macula lutea,6 the small central part of your retina responsible for detailed central vision. It’s also found in your macular pigment (it’s responsible for the yellow hue of the macula) and the lens of your eye.
Epidemiological research has found an inverse association between lutein and zeaxanthin levels in the eyes and age-related macular degeneration (AMD), the primary cause of blindness in the elderly, and cataracts.
As explained in the 2013 paper, “The Role of Lutein in Eye-Related Disease,” lutein and zeaxanthin (another carotenoid present in high concentration in the eyes) help prevent age-related eye degeneration by ameliorating the damage caused by blue light and oxygen free radicals. Blue light is responsible for a majority of the damage to the eye, and lutein selectively absorbs blue light.
According to this paper, “Dietary concentrations between 6 and 20 mg per day of lutein have been associated with a reduced risk of ocular disorders such as cataracts and age-related macular degeneration.”
A more recent scientific review, published in 2019 in PLOS ONE, found people who took 10 mg or 20 mg of lutein per day had greater macular pigment optical density (MPOD), and better visual acuity and contrast sensitivity than those who did not supplement.
Macular pigment, the yellow pigmented area found in the center of your retina, acts as “internal sunglasses,” protecting your macula from harmful blue light. The denser your macular pigment, the lower your risk of developing AMD. Greater MPOD is also associated with better visual performance overall.
According to the authors of the 2019 PLOS ONE review, “The available evidence suggests that dietary lutein may be beneficial to AMD patients and the higher dose could make MPOD increase in a shorter time.” Lutein has also been shown to prevent cell death caused by retinal detachment, when administered in a timely manner, and can help improve night vision.
Lutein’s Role in Brain Health and Cognition
More recent research has also found lutein plays an important role in brain health, and may even help prevent neurodegenerative diseases. As noted in the 2012 paper, “Neuroprotective Effects of Lutein in the Retina,” lutein benefits your brain and cognition by preventing:
DNA damage
Depletion of brain-derived neurotrophic factor (BDNF), which is important for brain health
Degradation of synaptophysin, a synaptic vesicle protein involved in neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease
Lutein and zeaxanthin have also been shown to help maintain the integrity of your brain’s white matter,18 and this too can lower your risk of age-related decline.
Lutein Benefits Both the Old and the Young
In one 2017 study, which involved 60 adults between the ages of 25 and 45, those with higher levels of lutein in middle-age had more youthful neural responses than those with lower levels.
Carotenoid status was assessed by measuring MPOD, which is also highly correlated with the lutein status in your brain. Most studies have focused on the effects of diet after cognitive decline has already set in.
Of the 600 carotenoids found in nature, only these two are deposited in high quantities in the retina (macula) of the eye … Many studies have shown that lutein and zeaxanthin reduce the risk of chronic eye diseases, including AMD and cataracts … Beyond reducing the risk of eye disease, separate studies have shown that lutein and zeaxanthin improve visual performance in AMD patients, cataract patients and people in good health.”
As an added benefit, those with higher levels of lutein in middle-age have been found to have more youthful neural responses than those with lower levels, which suggests a lutein-rich diet may also keep you cognitively sharp.19 Lutein and zeaxanthin are primarily found in organic pastured egg yolks and green leafy vegetables, with kale and spinach topping the list of lutein- and zeaxanthin-rich foods.
You’ll also find it in orange- and yellow-colored fruits and vegetables. Adding dark blue or purplish, almost black-colored berries like black currants and bilberries to your diet is another wise strategy, as they contain high amounts of antioxidant anthocyanins. Research suggests bilberry, in particular, may be effective for preventing cataracts and AMD.20
Astaxanthin Works Double Duty for Your Eyes and Your Brain
Astaxanthin is another notable nutrient that has emerged as the best carotenoid for eye health and the prevention of blindness. Research shows it easily crosses into the tissues of your eye and exerts its effects safely and with more potency than any of the other carotenoids, without adverse reactions.
Specifically, astaxanthin has been shown to ameliorate or prevent light-induced damage, photoreceptor cell damage, ganglion cell damage and damage to the neurons of the inner retinal layers. Astaxanthin provides protective benefits against a number of eye-related problems, including:
Age-related macular degeneration
Glaucoma
Cataracts
Inflammatory eye diseases such as iritis, keratitis, retinitis and scleritis
Cystoid macular edema
Retinal arterial occlusion
Diabetic retinopathy
Venous occlusion
Astaxanthin also helps maintain appropriate eye pressure, energy levels and visual acuity. Krill oil is a great source of astaxanthin that comes with the added benefit of omega-3 fats, which are also protective of healthy vision. People with the highest intake of animal-based omega-3 fats have a 60 percent lower risk of advanced macular degeneration compared to those who consume the least.
For higher doses of astaxanthin, a supplement works well. If you decide to give astaxanthin a try, I recommend starting with 4 milligrams (mg) per day and working your way up to about 8 mg per day — or more if you’re suffering from chronic inflammation. Taking your astaxanthin supplement with a small amount of healthy fat, such as grass fed butter, coconut oil, MCT oil or eggs, will optimize its absorption.
As with lutein, astaxanthin works double duty, also protecting your brain. Researchers found that supplementing with astaxanthin-rich (microalgae) extract led to improvements in cognitive function in older individuals who complained of age-related forgetfulness. Another study found it may help prevent neurodegeneration associated with oxidative stress, as well as make a potent natural “brain food.”