Huge Study Validates Natural Approach to Prevent BlindnessJuly 2016
By William Faloon
Loss of eyesight was once an inevitable consequence of aging.
Modern medicine has virtually eliminated the blinding impact of cataracts.
Macular degeneration is today’s leading cause of vision loss.1 The challenge up until now is that macular degeneration is still viewed as being incurable.2
In 1985, Life Extension® introduced a carotenoid complex called xanthophylls. The three yellow pigments that make up xanthophylls are zeaxanthin, lutein, and meso-zeaxanthin.
What makes these carotenoids unique is that they provide structural densityfor the macula and protect it from UV light and oxidation.3-7
Previous studies looking at dietary intake of xanthophyll-rich foods have found protective effects against macular degeneration.8-11 It was not clear, however, if these carotenoids could slow the worsening of macular degeneration after it occurs.
This concern has been clarified in a study published by the American Medical Association involving over 102,000 people who were followed for an average of 25 years.12 Intense and frequent monitoring of food intake enabled the researchers to develop predicted plasma carotenoid scores.
The findings showed that men and women with the highest lutein/zeaxanthin scores had a striking 41% lower risk of advanced macular degeneration that often causes blindness. The researchers also discovered that alpha-carotene reduced the progression of macular degeneration towards blindness.12
The thoroughness of this long-term study provides fresh insight into how macular degeneration can be markedly delayed even after it is diagnosed.
This editorial describes how incidence of this blinding disease may soon dramatically decline.
The first article in this month’s issue will enlighten you to brand new findings showing how typical vision loss that occurs with aging can be partially restored!
Scurvy was an epidemic disease when access to vitamin C-containing foods was limited. Simple measures like eating lemons or limes during times of food scarcity eliminated scurvy.
We may be moving towards a similar era when blindness-caused macular degeneration may no longer be a prevalent health issue. Here are three major controllable causes of macular degeneration:
- Cigarette smoking
- Exposure to ultraviolet solar rays
- Deficiency of lutein, zeaxanthin, and meso-zeaxanthin.
The prevalence for smoking has been declining, use of UV-blocking sunglasses is widespread, and intake of nutrients like lutein/zeaxanthin from spinach or supplements has increased.13-15
Younger people thus have the opportunity to potentially avoid the sight-robbing impact of macular degeneration as they grow older.
The Problem with Baby Boomers
I’m 61 years old. In my youth, I never wore sunglasses. Even if I did, most sunglasses did not shield against oxidizing UV rays. Failure to wear protective sunglasses in youth was common in those who are over age 50 now. We didn’t know back then how damaging solar rays were to our eyes.
Increased consumption of cooked spinach can provide a good deal of lutein/zeaxanthin.16,17 To obtain higher doses of these carotenoids, low-cost supplements are readily available.
So what this means is that with proper education, younger people will wear UV-blocking sunglasses, avoid cigarettes, eat healthier and/or take the proper supplements. This will not only slash their risk of macular degeneration, but also delay cataract formation.
Most of us did not have this vision-protecting knowledge in our youth. As a result, many of us are in early stages of developing macular degeneration.
Fortunately, a large human study shows that it is not too late to initiate protective steps before advanced blinding macular degeneration manifests.
Findings from the Latest Human Study
A number of human studies reveal that those ingesting lutein and zeaxanthin have lower rates of macular degeneration.22-25 Some of these studies show improvement in vision in those who take the higher amounts of these carotenoids found in certain dietary supplements.26-29
The question doctors have been asking is whether these carotenoids can prevent worsening of macular degeneration after it occurs. This and other questions about macular degeneration and carotenoids motivated researchers to perform an analysis of over 102,000 people aged 50 years or older.12
The study period lasted over 20 years and adjusted for confounding factors like cigarette smoking and eating patterns. The focus was to meticulously assess blood levels of carotenoids based on exhaustive and frequent food questionnaires. This well-designed study was published in the Journal of the American Medical Association-Ophthalmology.12
The results showed that those with the highest intake of lutein/zeaxanthin had a marked 41% lower risk of progressing to advanced macular degeneration.12
This kind of advanced eye disease is referred to as “neovascular” or “wet” macular degeneration. What happens in these advanced cases is that new blood vessels abnormally grow into the damaged macula. These new blood vessels may then bleed and leak fluid, causing the macula to bulge or lift up from its normally flat position, thus distorting or destroying central vision. Under these circumstances, vision loss may be rapid and severe.1
In this huge human study, those who consumed the most spinach had the highest lutein/zeaxanthin score and the lowest rate of advanced macular degeneration. The authors also found a 31% lower risk of progression in those who consumed the most alpha-carotene.12
The conclusion of the study was:
“Higher intakes of bioavailable carotenoids, particularly lutein/zeaxanthin and a -carotene, are associated with reduced risk of advanced AMD [age-related macular degeneration].”12
Even Greater Benefits Possible
In determining this 41% reduction in advanced macular degeneration, the researchers adjusted their data to reflect smoking and other factors so that they could pinpoint that it was the lutein/zeaxanthin and alpha-carotene that was conferring the protection.
What’s remarkable is that high intake of these carotenoids also protected former smokers.12 The incidence of macular degeneration in former smokers is up to three-fold higher than non-smokers.30,31 This study showed that past smokers with the highest lutein/zeaxanthin scores also had sharply lower risk of advanced macular degeneration.12
This does not mean that anyone should continue smoking. It does corroborate published data showing the importance making sure to ingest enough lutein/zeaxanthin in your diet and/or supplement program. The value of wearing sunglasses that provide full-spectrum protection should not be overlooked.
While the 41% reduction in developing advanced macular degeneration is a spectacular finding, compelling evidence exists to show an even greater defense against blindness is possible when an additional protective measure is taken.
A Missing Link in Maintaining Macular Density
Over the past 25 years, researchers discovered that people who regularly ate spinach, collard greens, and certain other vegetables had lower rates of age-related macular degeneration.32
Compared to those with the lowest carotenoid intake, people with the highest carotenoid intake have a 43% reduction in their macular degeneration risk. Those who regularly ate spinach have an even greater reduction in macular degeneration incidence.32
When investigating what constituents of these vegetables protected the macula, lutein and zeaxanthin stood out as the most likely candidates. This was supported by research that involved testing the blood of people who contracted macular degeneration. Those with the highest plasma levels of lutein/zeaxanthin had the lowest rates of macular degeneration.24
Another reason scientists were so certain of their discovery is that in humans stricken with macular degeneration, the lutein/zeaxanthin content of their macula is severely depleted.33
If all people had to do was consume adequate lutein/zeaxanthin, then macular degeneration would theoretically disappear as a prevalent age-related disorder. Regrettably, macular degeneration still occurs even in some of those who regularly eat spinach.
Overlooked in the prevention of this blinding disorder is a compound naturally produced in younger retinas called meso-zeaxanthin, which is needed to maintain macular density.34
Meso-zeaxanthin is not found in the normal diet.34 It has been available for ten years in a dietary supplement used by Life Extension® supporters, but has not caught on with the general public.
In youth, the lutein people consume in their diet readily converts to meso-zeaxanthin in the macula.34 As we age, this conversion process is disrupted, thus making it critical to orally ingest meso-zeaxanthin.
To fully appreciate the importance of this, please know the macular pigment is made up of the following three carotenoids:
- Lutein 50%
- Zeaxanthin 25%
- Meso-zeaxanthin 25%
Macular degeneration is characterized by a reduction in the density of the macular pigment.35 When taken as a supplement,meso-zeaxanthin is absorbed into the blood stream and effectively increases macular pigment levels. 7
People with macular degeneration have been shown to have 30% less meso-zeaxanthin in their macula compared to healthy eyes.36 One reason for this deficiency of meso-zeaxanthin is lack of ingested lutein. Another explanation for the missing meso-zeaxanthin observed in macular degeneration is inability to adequately convert lutein to meso-zeaxanthin.
Meso-Zeaxanthin Deficiency Confirmed in Macular Degeneration
An autopsy study on donated eyes was done to measure levels of lutein, zeaxanthin, and meso-zeaxanthin in the retina of those with and without macular degeneration.
As expected, levels of all three carotenoids (lutein, zeaxanthin, and meso-zeaxanthin) were reduced in those with macular degeneration compared to control subjects.
The most significant finding, however, was the sharp decrease in meso-zeaxanthin in relation to zeaxanthin in the macula of macular degeneration subjects.40
This postmortem study helped confirm other studies indicating the importance of all three carotenoids (lutein, zeaxanthin and meso-zeaxanthin) in maintaining the structural integrity of the macula.40,41
Macular Degeneration-Induced Blindness: A Preventable Disease
The macula is the portion of the retina used to see details such as fine lines or the shape of an object. It is needed for both near and far vision.
The macular pigment is composed exclusively of lutein, zeaxanthin, and meso-zeaxanthin.42 These three carotenoids protect the macula and the photoreceptor cells beneath.43
Those who wear protective sunglasses, don’t smoke, and have a high intake of lutein/zeaxanthin (from either diet or dietary supplements) will likely enjoy a considerably lower incidence of macular degeneration.
The addition of alpha-carotene might afford additional protection based on the latest study published by the American Medical Association.
As I was concluding this editorial, an in-depth review of the chemistry and mechanisms of eye protection afforded by xanthophylls was being published.
I end here with a quote from this new scientific review on the prevention of eye disease:
“The macular pigment carotenoids, lutein, zeaxanthin, and meso-zeaxanthin are widely recommended as dietary supplements for the prevention of visual loss from age-related macular degeneration and other ocular diseases, but the basic and clinical science supporting such recommendations is underappreciated by clinicians and vision scientists”44
For longer life,
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- Moeller SM, Parekh N, Tinker L, et al. Associations between intermediate age-related macular degeneration and lutein and zeaxanthin in the Carotenoids in Age-related Eye Disease Study (CAREDS): ancillary study of the Women’s Health Initiative. Arch Ophthalmol. 2006;124(8):1151-62.
- Krinsky NI, Landrum JT, Bone RA. Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye. Annu Rev Nutr. 2003;23:171-201.
- Wu J, Cho E, Willett WC, et al. Intakes of lutein, zeaxanthin, and other carotenoids and age-related macular degeneration during 2 decades of prospective follow-up. JAMA Ophthalmol. 2015;133(12):1415-24.
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- Maddock JE, O’Riordan DL, Lee T, et al. Use of sunglasses in public outdoor recreation settings in Honolulu, Hawaii. Optom Vis Sci. 2009;86(2):165-6.
- Yang Z, Zhang Z, Penniston KL, et al. Serum carotenoid concentrations in postmenopausal women from the United States with and without osteoporosis. Int J Vitam Nutr Res. 2008;78(3):105-11.
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- Haddad S, Chen CA, Santangelo SL, et al. The genetics of age-related macular degeneration: a review of progress to date. Surv Ophthalmol. 2006;51(4):316-63.
- Bok D. Evidence for an inflammatory process in age-related macular degeneration gains new support. Proc Natl Acad Sci U S A. 2005;102(20):7053-4.
- Whitmore SS, Mullins RF. Transcriptome changes in age-related macular degeneration. BMC Med. 2012;10:21.
- Abdel-Aal el SM, Akhtar H, Zaheer K, et al. Dietary sources of lutein and zeaxanthin carotenoids and their role in eye health. Nutrients. 2013;5(4):1169-85.
- Mares-Perlman JA, Fisher AI, Klein R, et al. Lutein and zeaxanthin in the diet and serum and their relation to age-related maculopathy in the third national health and nutrition examination survey. Am J Epidemiol. 2001;153(5):424-32.
- Gale CR, Hall NF, Phillips DI, et al. Lutein and zeaxanthin status and risk of age-related macular degeneration. Invest Ophthalmol Vis Sci. 2003;44(6):2461-5.
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- Huang YM, Dou HL, Huang FF, et al. Effect of supplemental lutein and zeaxanthin on serum, macular pigmentation, and visual performance in patients with early age-related macular degeneration. Biomed Res Int. 2015;2015:564738.
- Kvansakul J, Rodriguez-Carmona M, Edgar DF, et al. Supplementation with the carotenoids lutein or zeaxanthin improves human visual performance. Ophthalmic Physiol Opt. 2006;26(4):362-71.
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