In Vision Part I we talked about the role a special antioxidant, carnosine, plays in improving cataracts – the number one cause of vision problems in people over-age 60. Here in part II, I want to tell you about another amazing substance that helps prevent another vision problem associated with aging – ARMD, or age-related macular degeneration.
Over 9 million Americans over the age of 40 already have symptoms of ARMD which, next to cataracts, is the second highest vision stealer. Yet, ARMD can be prevented if you pay a little closer attention to your greater nutritional needs as you get older. One of these nutritional needs is getting optimal amounts of docosohexanoic acid (DHA), an Omega-3 fatty acid.
Along with EPA, another Omega-3 fatty acid, DHA has been all over the news in the last few years for its incredible protective heart benefits and its significant role in the early development of the neurological system of the human fetus. DHA has also been shown to be protective against colon cancer, stroke and allergies, as well as boosting the immune system in general. Lately, I’ve also been telling my patients about DHA’s incredible role in protecting vision as well. Here’s why.
DHA Fatty Acids and Your Vision
There are a few organs in your body that are comprised of a high percentage of DHA containing fat. These include your brain and your eyes. Because of their high fat content, these organs are more susceptible to free radical damage and have an ongoing need for optimal levels of antioxidants. Many antioxidants like beta carotene, vitamin D3 and vitamin E are very beneficial to eye health as they are fat-soluble and are better absorbed into the fatty tissue of the eye. In fact, the retina of the eye has a very high percentage of DHA-containing fat and this is why DHA levels must be kept optimal to protect against free radical damage to those tissues.
Research cited in the Archives of Ophthalmology as far back as 2000 had shown that even moderate level consumption of DHA-rich fatty fish, like salmon, mackerel, etc, offered increased protection against age-related macular degeneration. More current research has shown even greater benefit of DHA in both protecting vision and improving it. Here’s how:
1. Protects photoreceptors: The photoreceptors (cones and rods) of your retina are responsible for seeing color and bright light (cones) and being able to see in low light (rods). DHA works with the antioxidants lutein and zeaxanthin that ensure proper development and function of these structures. Photoreceptors contain the highest amount of DHA in your body and levels must be kept optimal.
2. Maintains retinal health: DHA helps to maintain the strength of the epithelial cells (surface layer) of the retina and function of the photoreceptors. This surface layer of cells is called the RPE (retinal pigment epithelium).
3. Creates retinal antioxidant: DHA is the precursor to a neuro/retina protective molecule called neuroprotectin D-1. This molecule acts as an antioxidant in both brain tissue and retinal eye tissue, providing anti-inflammatory benefits as well as protecting the RPE cells from free radical damage and death. It has been noted in research that damage of these retinal pigment epithelial cells is what leads to macular degeneration and loss of vision.
How Much DHA Do You Need To Protect Vision?
My patients are amazed when I tell them that eating a good size portion of fatty fish like salmon, mackerel, trout, tuna (canned okay), even once a week can cut their risk of developing retinal damage and vision problems by a whopping 42%! You can do the math for the benefit you would receive if you ate this type of fish 2 or 3 times a week – you could get over 100% protection from developing ARMD as you age. That’s quite a payback from eating a little more fish every week.
However, cooking heats may destroy some of raw fish’s DHA value and that’s why I also recommend my patients take an algae-based DHA supplement in addition to a healthy diet. Be sure to get about 900-1000 mg DHA a day. You have to read the label on the back of the supplement to see how much actual DHA is offered in the supplement you choose. A label that states “1200 mg” may not actually have that much DHA in it, as Omega-3 fats are divided between EPA and DHA. Also, if you choose canned tuna, make it water packed as the oil packed varieties will leach the Omega-3 out of the fish and most of it will wind up in the garbage can.
What Else Can You Do to Protect Your Vision?
In addition to ensuring that you get enough DHA in your diet through your food and/or supplement, there are several other substances I recommend to my patients that augment the effects of DHA. These are bilberry, lutein/zeaxanthin, vitamin E, beta carotene, quercetin and bromelain (natural anti-inflammatories) and carnosine.
Maintain a good amount of monounsaturated fats (from olive oil and nuts) in your diet as well as Omega-3 fats (flax seed, olive oil, walnut oil, etc). Too low fat diets are not great for either your eyes or your brain since their very composition depends on a certain amount of fat in your diet – just remember to make them healthy fats and not too many saturated fats. Also remember to wear sunglasses in bright sun and protective eye cover while working or using sprays.
Your eyes are your primary method of getting information from your environment. Protect them from age-related vision changes by using protective measures now to preserve healthy vision.
Mark Rosenberg, M.D.
DHA Vision and Retinal Health, http://www.visionvitality.com/content/DHA-_The_Omega-3_for_Eye_Health.htm
photo credit: thismamacooks