Skip to comments.Omega-3 fatty acids appear to impact AMD progression
Posted on 06/18/2009 3:01:23 PM PDT by decimon
BOSTON (June 18, 2009) - Omega-3 fatty acids found in fatty fish such as tuna and salmon may protect against progression of age-related macular degeneration (AMD), but the benefits appear to depend on the stage of disease and whether certain supplements are taken, report researchers at the Laboratory for Nutrition and Vision Research (LNVR), Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University.
The researchers calculated intakes of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from dietary questionnaires administered to 2,924 men and women, aged 55 to 80 years, participating in an eight-year supplement trial, the Age-Related Eye Disease Study (AREDS) of the National Eye Institute (NEI). The AREDS trial results suggest taking supplements of antioxidants plus zinc prevents progression of late-stage AMD. AREDS study participants were randomly allocated to receive either a placebo or supplements containing the antioxidants vitamins C and E and beta carotene, the minerals zinc and copper, or a combination of both.
"In our study, we observed participants with early stages of AMD in the placebo group benefited from higher intake of DHA, but it appears that the high-dose supplements of the antioxidants and/or the minerals somehow interfered with the benefits of DHA against early AMD progression," says senior author Allen Taylor, PhD, director of the LNVR at the USDA HNRCA. Taylor is also a professor at the Friedman School of Nutrition Science and Policy at Tufts and Tufts University School of Medicine (TUSM).
The antioxidant supplements did not seem to interfere with the protective effects of DHA and EPA against progression to advanced stages of AMD. Participants who consumed higher amounts of DHA and EPA appeared to have lower risk of progression to both wet and dry forms of advanced AMD. The results are published on-line ahead of print in the British Journal of Ophthalmology.
"Data from the present study also shows the supplements and omega-3 fatty acids collaborate with low-dietary glycemic index (dGI) diets against progression to advanced AMD," says corresponding author Chung-Jung Chiu, DDS, PhD, a scientist in the LNVR and an assistant professor at TUSM. "Our previous research suggests a low-GI diet may prevent AMD from progressing to the advanced stage. We hypothesize that the rapid rise of blood glucose initiated by high-GI foods results in cellular damage that retinal cells cannot handle, thus damaging eye tissues."
dGI is a scale used to determine how quickly carbohydrates are broken down into blood sugar, also known as blood glucose. Foods such as sweetened drinks, sodas and white bread are high-GI because they trigger a sharp rise and fall of blood sugar. Low-GI foods, such as whole grain versions of pasta and bread, have a milder effect on blood sugar response. Earlier data published by Taylor and Chiu suggests that daily substitution of five slices of whole grain bread for white bread out of a total intake of 250 g of carbohydrate might cut out almost 8% of advanced AMD over five years. This is readily achievable with little diet behavior modification.
Eating two to three servings of fatty fish such as salmon, tuna, mackerel, shellfish, and herring every week would achieve the recommended daily intake of DHA and EPA. However, the majority of AREDS participants and Americans eat a much lower level than recommended. "If changing dietary habits is not easy, supplementation is an option," says Chiu.
The authors stress it is still premature to conclude dietary recommendations for people with AMD and more studies are warranted. "Taken together, these data indicate that consuming a diet with higher levels of omega-3 fatty acids, antioxidants and low-GI foods may delay compromised vision due to AMD," says Taylor. "The present study adds the possibility that the timing of a dietary intervention as well as the combination of nutrients recommended may be important."
AMD is a progressive disease that attacks central vision, resulting in a gradual loss of eyesight and, in some cases, blindness. The NEI reports that AMD is the most common causes of non-remediable vision loss in Americans over 60.
The study was awarded The Association for Research in Vision and Ophthalmology (ARVO)-American Foundation for Eye Research (AFER)/Merck Innovative Ophthalmology Research Award at the ARVO 2009 Annual Conference in May. The award is given to researchers under 45 to encourage research leading to improved quality of life for patients.
The authors received funding for this study from the following: United States Department of Agriculture (USDA), the National Institutes of Health, the Johnson & Johnson Focused Giving Program, the American Health Assistance Foundation and the Ross Aging Initiative.
About Tufts University School of Nutrition
The Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University is the only independent school of nutrition in the United States. The school's eight degree programs which focus on questions relating to famine, hunger, poverty, and communications, are renowned for the application of scientific research to national and international policy. For two decades, the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University has studied the relationship between good nutrition and good health in aging populations. Tufts research scientists work with federal agencies to establish the USDA Dietary Guidelines, the Dietary Reference Intakes, and other significant public policies.
If you are a member of the media interested in learning more about this topic, or speaking with a faculty member at the Friedman School of Nutrition Science and Policy at Tufts University, or another Tufts health sciences researcher, please contact Andrea Grossman at 617-636-3728 or Christine Fennelly at 617-636-3707.
I'm not surprised....
Is that the most Intel-igent reply you could muster? ;-)
I immediately thought that this was another of Intel’s nefarious plots to end competition.
I’m worried. I use an AMD quad core....
Don't fry your fish on it and you should be okay.
Well, I suppose I could drag it closer to topic by pointing out that AMD and Intel are a big part of the reason why it has become immeasurably easier for teen boys to go blind....
"Age-related macular degeneration (AMD) is one of the leading causes of blindness in adults, a growing problem as the population ages. Now a team of researchers at the University of Kentucky has raised hope for early detection and preventive treatment."
You can leave the tuna off the list. It has so very little that it isn't worth the risks of eating such a garbage-laden fish. Wild caught Sockeye Salmon is the way to go.
I eat a couple of tablespoons of ground flax seed each day.
It is very comparable to fish oil.
Cook it well to kill off the tapeworms.
If you’re that worried about tapeworms, go with grass fed beef; it actually beats the salmon, but costs five times as much.
Eye injections. Sounds like a fun thing.
Can I just eat some grass? Smoke some grass?
The flora in your intestines convert the flax oil to EPA/DHA, but they only convert a small portion of the oil.
Maybe that is the reason your head is so big, ya think?
(sorry I couldn’t help myself, I have been serious all day)
Maybe. I’ll have to have it examined.
I've experimented on my self with them all, even though I was naturally prejudice against old fashioned Cod Liver Oil , it turned out I could really feel the difference.
Not to mention it's the cheapest.
Like Epsom Salts , sometimes the old fashioned health cures beat all.
The health professionals will rarely admit it because it cuts into their bottom line.
Yep! I'm discovering the joys of food-grade diatomaceous earth.
Kills every type of insect without chemicals [or having the insects build up a resistance], kills internal parasites and supplies the body with silica.
Pretty neat stuff, IMHO.
From my own research, the only issue with Cod Liver Oil is its Vitamin A content. Some people are more sensitive to high doses than others, but it is probably not an issue for most people. You are right, it is much cheaper than other types of fish oil or krill oil.
I'm not a mega dose fan.
I don't think any of us need to take as much as would cause Vit. A problems.
With Cod Liver Oil, a little goes a long way, and "that's a good thing"'.
I was naturally prejudice against old fashioned Cod Liver Oil , it turned out I could really feel the difference.
I’m curious, how does it make you feel better - joints, well being, or can you tell a difference in your vision when you take it?
There is AMD in my family (very elderly father) and take flaxseed oil and lutien, but they don’t effect how I feel that I can tell. Then again I have been taking it regularly for a long time...
And, yes, I can see real good, it's almost embarrassing.
Less pain, yes, almost none.
It's all good, to use a term the youngsters are fond of.
One other thing, I like to swim, I think it helps me there as well, in that I can stretch better in my strokes, and faster too!
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