Eye Health Update
Our eyes have no protection from damaging light rays, including the blue light that emits from our computer and cell phone screens. We wear sunglasses outside, and there are glasses and screens that purport to reduce the fatigue of blue light on the eyes. But we can add to our eyes' protection by providing them with the nutrients that keep them healthy. In these studies, researchers looked at the effects of antioxidants, carotenoids and more on eye health.
Zinc Slowed AMD
Many nutrients help slow vision loss in the early stages of age-related macular degeneration (AMD), where sight declines in the center field of vision. This study measured zinc in the diets of 547 people with late-stage, wet AMD, a more serious version of the condition, where new, weak blood vessels form under the macula, leak fluids, and make the macula bulge or lift.
Those who got less than 8.1 mg of zinc per day were more likely to have sub-macular fluid and greater central-macular thickness. Doctors said the zinc finding is promising for those with later stages of AMD, particularly the wet variety.
Reference: Clinical & Experimental Ophthalmology; 2019, ceo. 13644
Lutein, zeaxanthin during pregnancy boost vision in offspring at age three
The dark green and orange-colored fruits and vegetables contain the carotenoids lutein and zeaxanthin, and mothers’ higher levels during pregnancy meant better eyesight in their offspring. In this study, doctors measured lutein and zeaxanthin levels during pregnancy, and at delivery, then followed up with the children at age three.
Kids whose mothers had higher levels of either lutein or zeaxanthin during pregnancy were 37 to 38 percent less likely to have poor visual acuity at age three compared to kids whose mothers had lower levels of these two carotenoids.
The results remained significant even after doctors adjusted for whether mothers breastfed their babies, or differences in the children’s diets of fruits and vegetables.
Reference: Nutrients; Vol. 12, No. 2, 10.3390/nu12020274
CoQ10 improves retinal health
People can lose vision from several conditions affecting the retina of the eye, including loss of blood flow to the optic nerve. In this study, doctors gave 48 people with one of several retinal blood vessel diseases 100 mg of CoQ10 per day, then followed up for an average of 43 months.
Using a standard measurement, called the Visual Field Index (VFI), doctors ranked annual changes in the percentage of the field of vision available to participants, with a score of 100 percent representing a perfect age-adjusted visual field.
Overall, all participants who took CoQ10 improved in measurements of VFI at least 9.3 percent per year, and as much as 22 percent per year, depending on the blood vessel disease affecting the retina. VFI scores decreased when one participant discontinued CoQ10, and increased after resuming CoQ10.
Reference: Nutrients; Vol. 12, No. 3, 10.3390/nu12030723
Vitamins, minerals, carotenoids and omega-3s beneficial
In age-related macular degeneration (AMD) people gradually develop blind spots in the center field of vision. In this study, doctors analyzed findings from two large clinical trials that photographed the interior surfaces of 14,135 eyes annually for over 10 years.
Doctors periodically measured the diets of study participants and found several nutrients appeared to significantly decrease chances of progressing to late-stage AMD. These included vitamins A and B6, beta-carotene, copper, lutein/zeaxanthin, magnesium, the omega-3 fatty acid DHA, and alcohol.
The nutrients slowed progress in two areas: late-stage AMD, where cells in the retina deteriorate and die; and drusen, pinhead-sized protein/fat deposits under the retina that can distort vision if too many develop or become too large.
Doctors said certain vitamins, minerals, carotenoids, and fatty acids appear to slow the progression from early to late-stage AMD, and fortifying the diet with these readily available natural nutrients may be an effective preventative.
Reference: Ophthalmology, 2020, S0161-6420(20)30836-8
The macula of the eye contains the colorful pigmented carotenoids lutein and zeaxanthin that absorb damaging blue light, protecting vision. In this study, 16 Japanese men and women, aged 26 to 57, took 29 mg of lutein, 4 mg of zeaxanthin, vitamins C, E, copper, and zinc, per day. Beginning at eight weeks and continuing through the end of the study at 16 weeks, the concentration, or density, of macular pigment increased. Those with a body-mass index score less than 25 improved more than those with higher BMI scores. Levels of the protective carotenoids in the skin also began increasing by week four, and continued to increase through 16 weeks.
Reference: Scientific Reports; 2020, Vol. 10, No. 10262
Carotenoids protect the eye, boost cognition
The deep yellow and orange pigments, in the macula of the eye, called carotenoids, protect the eyes from damaging blue light. Now, new research suggests important links to cognition for these essential nutrients.
In this study, 59 healthy adults took a placebo or 10.86 mg of lutein, 2.27 mg of zeaxanthin, plus meso-zeaxanthin; or double these carotenoid amounts, per day. After six months, macular pigment density measured at the eye retina had significantly increased in both carotenoid groups.
Doctors also measured cognitive factors and, in the carotenoid groups, found significant increases in a protein that promotes the growth and survival of nerve cells (neurons), known as brain-derived neurotrophic factor, or BDNF. At the same time, levels decreased for an inflammatory factor, interleukin-1-beta (Il-1β) that can lower BDNF levels.
In tests of cognition, while the placebo group did not change, both carotenoid groups saw improved scores in verbal memory, sustained attention, and physical and mental reaction times.
Discussing the findings, doctors said the changes in BDNF and Il-1β over the course of the study suggest regularly consuming macular carotenoids interrupts the inflammatory cascade that can lower BDNF levels, helping to preserve vision and cognition.
Reference: Physiology & Behavior; 2019, 112650; Published Online
Vitamin D levels low in uveitis
Non-infectious uveitis (NIU) is the inflammation of the uvea, the pigmented layer between the inner retina and outer layer of the eye; a serious, sight-threatening condition that, when active, must be treated immediately. In this study, doctors measured vitamin D levels in 74 people with active NIU, in 77 with inactive NIU, and in a healthy non-participating, local population.
The group with active NIU had the lowest levels of vitamin D: 46 nanomoles per liter of blood (nmol/L). Those with inactive NIU had 64 nmol/L of vitamin D, and local non-participants had 62 nmol/L. Taking vitamin D supplements and getting sunshine both decreased NIU activity.
Reference: Ophthalmology; 2019, S0161-6420, Published Online
Remember, always follow bottle or doctor directions when taking supplements. There can be too much of a good thing. For example, excess zinc can impair immunity rather than support it.
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BetsyHealth Note: This article is for informational purposes only. It is not intended to diagnose, treat, prevent, or cure any disease. Consult your healthcare provider before taking a supplement, especially if you have a medical condition, including being pregnant or nursing, or take prescription or over-the-counter medications. For example, many supplements in this article also thin blood.
Article copyright 2021 by Natural Insights for Well Being. All rights reserved. Used with permission.