The Science of Eye Nutrition

Despite our poor economy of late, it seems the vitamin supplement business is booming. With all of our advancements in medicine and technology, it would appear that there is now a “perfect pill” for every conceivable nutritional problem we may have.  And as an eye doctor, it’s as though lately everywhere I look there are advertisements for eye vitamins of every kind. But is there a vitamin for every visual disorder or eye disease you may have or be at risk acquiring?

The short answer is no; there is not a magic pill for everything/anything.  We all know that’s essentially true.  So, why do we see such a flood of products out there and how are we to wade through the confusion?

This is a huge subject to cover here, but I’d like to take a brief walk through the basics of eye nutrition that have been shown to be beneficial to your eyes.

First, let’s take a step back and look at the larger picture of vitamin supplementation in general. Keep in mind that this is mega money making industry.  Worldwide, the vitamin supply industry in 2008, for example, grossed $68 billion dollars.  In the same year, the eye health ingredients market made $138 million in the USA! Is all of this regulated like our drug market?  No. The FDA (Food and Drug Administration) only regulates these products by having them state their potency and the ingredients.  And they must not contain pharmaceuticals or steroids. Unfortunately, the FDA is not responsible for ensuring that a nutritional supplement or ingredient is safe before it is marketed.  Only the manufacturer of that supplement is responsible.  The FDA only has to do something after it hits the market if an issue of safety arises.   Since these manufacturers are not held to the testing regulations of our pharmaceuticals, mislabeling and confusion are of concern.

This does not mean that everyone is out to get you, but “buyer beware” should always be on your mind. You may be thinking, if nutritional supplementation is all a money-making scheme, then why take anything at all? Ideally, of course, we should be getting everything we need in the foods we eat, right? But we don’t.  Life in 2012 can be full of stress, poor eating habits, lack of sleep, smoking and alcohol consumption, and environmental pollutants in the air, water, and food supply.  These all take their toll on us resulting in increased diseases and poor quality of life. My mom used to say that if they could make one vitamin pill that had everything in it to make up for our poor diets each day, it would be the size of a tennis ball!

By far, research has shown that a healthy lifestyle of exercise and non-smoking along with eating plenty of leafy vegetables high in the antioxidants, as well as foods rich in zinc and omega 3 fats can prevent many health conditions and slow the progress of diseases already acquired.  Unfortunately, about 80% of today’s Americans consume only five servings of fruits and vegetables each day, while the recommended amount is around twelve servings

What does this mean for our eyes?
 
Many studies have proven a direct link between what we eat or don’t eat and the incidence of ocular diseases like macular degeneration and dry eyes.

Diets rich in green leafy vegetables, red, orange and yellow vegetables and fruit, nuts, and cold-water fatty fish have been shown to either prevent or slow the progression of these eye diseases. For your eye health specifically, the advantages of good nutrition seem to work best when you make it a lifelong choice instead of starting to take supplements as a response to a disease.   So, prevention is the key for the most part.

We have been told that our whole-body health has been shown to benefit hugely by eating a healthful diet with antioxidants to bump up what our modern lifestyles seem to lack.  But we don’t seem to be doing well at that so let’s try to get these into our system with some combination of diet and supplementation.

So, what is an antioxidant?  Antioxidants are nutrients (vitamins and minerals) and enzymes that counteract the damaging, but normal effects of oxidation in animal tissue.  Fighting oxidation is a good thing. The antioxidants that specifically help your eyes are; vitamin A, vitamin C, vitamin E, zinc, three carotenoids: lutein, zeaxanthin and meso-zeaxanthin,  and the essential fatty acids DHA and EPA or the omega-3’s as they are called.

Vitamin A is somewhat debatable as an antioxidant but is found in foods of animal origin like egg yolks, liver, fish oil, whole milk, and butter. In green, yellow and orange vegetables it’s in the form of β-carotene.  Once you eat a carrot, it goes to your liver and changes into vitamin A and has protective properties for your eyes. So, yes carrots are good for you, but not really any better than all the other green, yellow and orange veggies.  Vitamin C can be found in our fruits and vegetables.  Vitamin E is in nuts, some cereals, vegetable oils, and sweet potatoes.  Zinc is in red meat, oysters, and poultry.  Lutein, zeaxanthin, and meso-zeaxanthin (Carotenoids) are found naturally in green leafy vegetables.  Omega-3’s or the essential fatty acids DHA and EPA are found naturally in tuna, salmon, sardines, ground flaxseed and walnuts as well as in fish oil supplements.

So, how does all this help our eyes regarding eye disease?

Studies have shown that our macular pigment, (in the area where we get macular degeneration), and our retinal photoreceptors can be damaged by oxidative radicals.  Antioxidants in our diets fight these radicals and protect our eyes.  As prevention for macular degeneration or for those at risk due to family history, the antioxidants lutein and zeaxanthin, zinc and the omega-3’s may preserve the integrity of the macula.  If you already have macular degeneration, increased doses of lutein, zeaxanthin and omega 3’s have been shown to slow the progression to worsening degeneration, again by protecting the macula.

The omega 3’s have shown in study after study to help those with dry eyes, meibomian gland dysfunction
and blepharitis
conditions. They are often prescribed to patients one to three months in advance of having LASIK
surgery to be sure the eyes are well lubricated with a healthy tear film prior to the procedure.

Recent clinical trials show that omega 3’s, lutein and vitamin A palmitate can slow further vision loss in some forms of Retinitis Pigmentosa.  There was no prevention, cure or reversal, but a slowing of progression of the disease.

That’s pretty amazing stuff for eye vitamin supplements. It’s not all hype and profit.  When applied to your diet and lifestyle, these nutrients, weather is taken in your diet or via supplements, can make a big impact on your eye health both preventatively and as a treatment in many cases.

The saying, “Everything in moderation” is really true.

It may seem like I’m telling you to load up on all of these nutraceuticals; the more the better, what’s the harm?  No, as in everything, too much is not a good thing.

For example, high doses of vitamin A can affect liver function, as well as have other adverse systemic effects.   In its β-carotene form, it has also shown some negative effects on those who smoke or who have recently quit smoking.  You must consult with your doctor regarding all of these supplements, just like they are drugs.  Mega doses of vitamin E can increase the effects of pharmaceutical blood thinners.  When zinc is taken as a supplement, it’s best to combine it with copper. High doses of zinc alone have been shown to affect the absorption of other nutrients; including the drug tetracycline.

How do you get these supplements?  There are many products and formulations out there, at your local drug stores to the big supermarket chains.  Read those labels.  Many multivitamins include reasonable doses of these key eye nutrients. You need to sit down with your doctor to be sure you are getting the correct dosages.  Those of you at high risk for macular degeneration or with dry macular degeneration, for example, need higher doses of some of these nutrients now, not later. Then you can select from foods, pills, gel-caps, tablets, even powders to be put into shakes.  It’s not too hard to incorporate two servings of tuna per week into your lifestyle.  Nor is it too difficult to pile on the lettuce and veggies, even as in-between snacks instead of grabbing those empty sugary goodies. Diabetes and obesity appear to be in epidemic proportions, especially in our children, and we actually have choices we can make today that will make a difference.

This review is meant only to guide you to have an informative conversation with your eye doctor about your specific eye health needs.  These supplements need to be considered drugs, as they can be potent to your eye health as well as interacting with your other systemic medications. Everyone is different, and your eye doctor can tailor the vision supplements to fit your eyes right now and for your future eye health.

Let’s talk…