The pigments in the macula of the eye are predominantly composed of three carotenoids: lutein, zeaxanthin, and meso-zeaxanthin.
Researchers report that these pigments, called xanthophylls, act as both filters and antioxidants and how they protect the eye from the onset of macular degeneration. Evidence suggests that increased levels of macular pigment are related to a decreased risk of age-related macular degeneration. Previous studies reveal that oral supplementation with lutein and zeaxanthin can increase the levels of macular pigments in the retina and plasma.
Macular xanthophylls, described above, are made of the same compounds that cause egg yolks to be yellow too. Eating eggs (preferably organic from free-range chickens) can actually help decrease your chances of developing the potentially blinding macular degeneration.
An egg a day can protect people over age 60 from developing macular degeneration. A study published in the Journal of Nutrition the levels of powerful antioxidants lutein and zeaxanthin in participants’ blood increased between 26 and 38% if they ate one egg per day.
The single egg did not contribute to participants’ cholesterol levels.
A new study examined how walnuts can increase the plasma antioxidant capacity of healthy adults. Study authors did not find any measurable increases, but they believe that further study is warranted.
They did find that levels of important compounds, the fatty acid linoleic acid and pyridoxal phosphate (vitamin B6), did increase over the course of the 19 week study, and these nutrients have been helpful in preventing eye disease.
Source: Nutrition Journal
Omega-3 Fatty Acids
A meta analysis study about the relationship between omega-3 fatty acids, consumption of fish and their effect on the age-related macular degeneration risk identified 274 abstracts, and 9 other studies.
Researchers quantitatively determined that high consumption of omega-3 fatty acids in the diet was connected with 38% lower risk of advanced macular degeneration. Consumptoin of fish at least 2 times a week was tied to lower risk of both early and late AMD.
Source: Archives of Ophthalmology. 2008;126(6):826-833.
A later study of over 38,000 women over a 10 year period (from dietary questionnaires) supports this finding: that consumption of omega-3 fatty acids decreases the likelihood of developing macular degeneration: that the the regular intake of omega-3 fatty acids DHA and EPA, which are most commonly found in fish, can help reduce macular degeneration risk by up to 45%.
Published: Archives of Ophthalmology, 2009
Still another study has determined that eating fatty fish more than once a month is connected to 60 percent lower risk of developing AMD.
A key finding in this study was the positive effect of fatty fish consumption (white fish intake was not significantly associated with AMD). Fatty fish included in this study were both fatty “blue” fish (fresh tuna, canned tuna without oil, mackerel, sardine, salmon) and fatty fish canned in oil (tuna, sardine, anchovy).
This population-based study from southern France reviewed nutritional data from a dietician-administered food-frequency questionnaire to assess the associations of dietary fat with the risk of AMD. AMD was classified from retinal photographs using the international classification and included neovascular age-related macular degeneration, geographic atrophy, soft indistinct drusen, and soft distinct drusen associated with pigmentary abnormalities.
Results of dietary fat analysis showed that high total, saturated, and monounsaturated fat intake were linked to increased risk for AMD, while total polyunsaturated fatty acid was not significantly associated with AMD. Review of fish intake showed that total and white fish intake was not significantly associated with AMD, but intake of fatty fish more than once a month was associated with a 60% reduction in AMD.
Source: Dietary fat and the risk of age-related maculopathy: the POLANUT Study.
Eur J Clin Nutr. 2007 Feb 14; Inserm, Research Unit U593 for Epidemiology, Public Health and Development, Bordeaux, France, Universite Victor Segalen Bordeaux 2, Bordeaux, France.
Fish in US Government Diet Guidelines
The US government’s Dietary Guidelines have put a lot more fish on the recommended table.
They recommend that we eat 8 ounces a week (2 4-ounce servings). Women who are pregnant or breast-feeding should have 12 ounces.
The real benefit of increasing our fish and shellfish intake is in the omega-3 fatty acids that are abundant in seafood. As research has shown, omega-3’s are key to helping us fight the potentially blinding disease macular degeneration.
Mercury in larger fish is a concern, especially for women in their child-bearing years. It is recommended that women who are pregnant or may become pregnant steer clear of tilefish, shark, swordfish and king mackerel (also known as golden bass). Different sources vary on the safety of tuna; some sources say it is safe to eat a maximum of 6 ounces of canned tuna per week.
Even more important are the cartenoids lutein and zeaxanthin, which are primarily obtained from dark green leafy vegetables. Research shows that risk of AMD was significantly lower in those who increased the cartenoids in their diet – up to 43%. So, eat your spinach and your kale and your collards and consider supplementing your diet further to really protect yourself from macular degeneration.
Research shows that the amino acid taurine has the ability to prevent, treat and stabilize retinal changes in some cases. Eggs and fish are good sources of taurine, but you can also take it in supplement form.
An important note: taurine should be taken on an empty stomach.
Antioxidants and Omega-3
Antioxidant and omega-3 supplements continue to be a simple, low-cost, effective therapy for AMD.
A study designed to measure changes in visual function in subjects with atrophic (dry) age-related macular degeneration (AMD) found that three-quarters of the subjects receiving a nutritional supplement demonstrated stabilization or improvement of visual acuity at 6 months.
Many research studies have indication that nutrition can play an important role in slowing the onset or limiting the AMD effects. The Taurine, Omega-3 Fatty Acids, Zinc, Antioxidant, Lutein (TOZAL) study tried to identify the possible benefits of a supplement formulated to limit AMD risk.
Researchers in this clinical study evaluted the vision of 37 patients average age 76 years, and gave them a nutritional supplement specifically designed to combat AMD. The product included natural beta-carotene, vitamins A and E, zinc, and copper. Results were compared to subjects in other tests who had received placebos. 76.7% of subjects receiving the nutritional supplement demonstrated stabilization or improvement of visual acuity at 6 months. This was a very small study not using its own controls, but some correlation is still suggested.
SOURCE: TOZAL Study: An open case control study of an oral antioxidant and omega-3 supplement for dry AMD, Cangemi, BMC Ophthalmology 2007, 7:3doi:10.1186/1471-2415-7-3.
Not only lutein, zeaxanthin, taurine and omega-3 fatty acids, but lycopene, vitamins A and E, zinc, copper, betacarotene, selenium, as well as gingko biloba for circulation, bilberry and glutathione may be helpful for macular degeneration.
Limiting Refined Carbohydrates
Limiting refined carbohydrates in one’s diet may slow the progression of age-related macular degeneration, according to a recent study a research center supported by the U.S. Department of Agriculture.
The study supports findings that suggest men and women over the age of 55 who consume diets of higher-than-average Dietary Glycemic Index foods have an increased risk of AMD.
The Dietary Glycemic Index indicates the speed at which carbohydrates are metabolized into glucose. Foods that are high on the glycemic index are associated with a faster rise (and subsequent fall) in blood sugar levels than those that are low on the glycemic index.
In the study, investigators analyzed dietary questionnaires of 4,757 non-diabetic men and women participating in the Age-Related Eye Disease Study (AREDS) – a nationwide eight-year study of men and women from 55 to 80 years of age, experiencing varying stages of macular degeneration.
The study examined participants’ carbohydrate intake over a one year period to calculate the average dietary glycemic index level of foods eaten by the participants.
The researchers concluded that the those who have the largest amount of refined carbohydrates in their diet were 17% more likely to develop macular degeneration than the group that consumed the least amount of refined carbohydrates.
Refined carbohydrates refer to foods with their high-fiber components – the bran and the germ – removed. Examples include: white rice, bread and pasta, sugary cereals.
Unrefined carbohydrates contain the whole grain, including the bran and the germ, and are therefore higher in fiber such as whole-grain rice, breads, wheat, oatmeal, and pasta.
The conclusion is that it is wise to limit refined carbohydrates in your diet, especially if you are elderly and/or have other risk factors for development of macular degeneration. Doing so could reduce the lower the incidence of advanced macular degeneration cases by 8% over a five year period.
Source: Chiu CJ, Milton RC, Klein R, et al. Dietary carbohydrate and the progression of age-related macular degeneration: A prospective study from the Age-Related Eye Disease Study. American Journal of Clinical Nutrition. 2007;86(4):1210-8.
Scientists at the Laboratory for Nutrition and Vision Research have substantiated that the regular consumption of specific “protective nutrients” in conjunction with a low-glycemic-index, or “slow carb,” diet protected study participants from age-related macular degeneration.
Scientists have long known that our diets influence our risk of age-related macular degeneration (AMD). High glycemic-index diets have now been identified as a risk factor for AMD by researchers from the University of Sydney and the University of Melbourne in Australia, and the National University of Singapore.
The glycemic index (GI) is a measure of the effects of carbohydrates on blood glucose levels. Carbohydrates that break down rapidly during digestion releasing glucose rapidly into the bloodstream have a high GI; carbohydrates that break down slowly, releasing glucose gradually into the bloodstream, have a low GI.
Scientists examined the association between the dietary glycemic index and the incidence of AMD in the Blue Mountain Eye Study population.
During 1992–1994, 3654 people aged 49 years or older attended baseline examinations. Of these, 2335 patients were reexamined after 5 years and 1952 were examined again after 10 years. At each examination, lens photography was performed and food-frequency questionnaires were administered. An Australian database was used to calculate the mean glycemic index.
Over 10 years, 208 of 1810 participants developed early AMD. After adjusting for age, smoking, and other risk factors, a higher mean dietary glycemic index was associated with an increased risk of early AMD.
Conversely, a greater consumption of predominantly lower glycemic index foods was associated with a reduced risk of incident early AMD. No relation was observed with late AMD.
Researchers concluded that a high-glycemic-index diet is a risk factor for early AMD, but they also noted that low glycemic-index foods such as oatmeal may protect against early AMD.
Learn more about the glycemic index and use a free GI database to find the GI index of your favorite carbohydrates at this University of Sydney Glycemic Index web site
SOURCE: Kaushik, et al, Dietary glycemic index and the risk of age-related macular degeneration, American Journal of Clinical Nutrition, Vol. 88, No. 4, 1104-1110, October 2008.
Limit Red Meat
A new study indicates that a red-meat heavy diet may increase the risk of developing age-related macular degeneration.
In a study of more than 6,700 people aged 58 to 69, researchers assessed relationships between consumption of red meat and chicken and AMD by looking at food frequency questionnaires. The researchers took digital photographs of the patients’ maculas and evaluated them for the presence of macular degeneratoin. In the study group, neary 1700 patients had early AMD, and 77 had advanced AMD.
It was discovered that participants who ate 10 or more portions of red meat each week were nearly 50 percent more likely to experience deterioration of the retina. Participants who consumed chicken at least three times a week reduced the risk by more than 50 percent.
Source: “Red Meat and Chicken Consumption and Its Association With Age-related Macular Degeneration”, Chong, et al, American Journal of Epidemiology 2009 169(7):867-876.
Researchers: University of Melbourne in AustraliaAdd: Eggs | Walnuts | Omega-3 | Fatty Fish | Other Nutrients Limit: Refined Carbohydrates | Red Meat