Archive for the ‘Vitamin & Nutrition Corner’ Category

Vitamin & Nutrition Corner: Are carrots really good for your eyes?

Friday, September 24th, 2010

We all have heard that eating carrots is good for the eyes, but is this really true? Can carrots make your eyes healthier? Can carrots make your vision better?

Yes, yes, and no.

Carrots’ claim to fame is beta-carotene, which the body converts to Vitamin A. Click here to see my earlier blog post on Vitamin A, but in summary Vitamin A is essential for your retina to function properly. It combines with proteins in your retinal cells that are responsible for absorbing light, especially during night vision. A lack of Vitamin A would result in diminished or delayed visual ability to adapt during low light conditions, aka night blindness.

But, Vitamin A also serves as an antioxidant within the retina to reduce chemical stress and it was part of the National Eye Institute’s formula of vitamins used in its landmark study on Macular Degeneration. That anti-oxidant property also plays an important role in regulating the tear-film or moisture layer on the front surface of the eyes.

However, Vitamin A won’t reduce a person’s near-sightedness or far-sightedness. Unfortunately, eating a bag of carrots every morning won’t spell the end to glasses and contact lenses but it can make yours healthier. And in the end, healthy eyes are the goal in order to maintain your vision for the long haul.

Here’s a video from Bill Nye The Science Guy regarding the same question:

Tags: carrots, vitamin A
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Vitamin & Nutrition Corner: Omega-3 Fatty Acids

Tuesday, May 11th, 2010

Omega-3 Fatty Acids

Fatty acids are a group of nutrients that are extremely important in the function of cells, muscles, nerves and organs. They also influence blood pressure and other cardiovascular functions through their ability to interact with hormone controls. An “essential” fatty acid is one that our bodies can’t make naturally and must be obtained by consuming food. Two such categories of “essential” fatty acids are Omega-3 and Omega-6.

Omega-3 fatty acids are found in high proportions within the cell membranes in the retina and they play an important role in regenerating pigments within the retinal cells responsible for vision. A deficiency of Omega-3′s could lead to decreased visual performance in certain situations. Omega-3′s have also been identified as an important factor in Age-related Macular Degeneration (AMD), which is a leading cause of permanent blindness in America. Two recent articles, highlighting studies in Australia, showed that higher consumption of Omega-3 fatty acids were correlated with significantly lower risk for AMD.

Omega-3 fatty acids have also demonstrated significant anti-inflammatory properties in the treatment of Dry Eye Syndrome. A 2005 study at Brigham and Women’s Hopsital of Boston showed that increased consumption of omega-3 significantly reduced symptoms associated with Dry Eye Syndrome. The study also showed that patients who consumed tuna 5-6 times a week had almost a 70% reduction in Foods Containing Omega 3 And Fatty Acids 250x300 Vitamin & Nutrition Corner: Omega 3 Fatty Acids symptoms compared to those who only consumed tuna once a week.

With respect to general health, Omega-3′s have been found to lower triglycerides and the American Diabetes Association now recommends diabetics increase their fatty acid intake by consuming 3 oz. of fish 2 to 3 times a week.

In general, the American diet shows a significant deficiency in Omega-3 fatty acids. However, there are some easy ways to change that. One of the greatest sources is the consumption of cold water fish. Salmon, tuna, herring, mackerel, and halibut show the greatest levels of omega-3 fatty acids, while other types of fish have much lower amounts. Fish oil supplements have recently become popular and may serve as an alternative to consuming fish. Flax seed may even be a better source of certain Omega-3′s, and may be found through Flax seed oil supplements. In a future post, I will touch on how Omega-6 fatty acid and its ratio to Omega-3 is also important in maintaining ocular health.

How Much Omega-3 fatty acids?

1-2 grams per day
or 4-5 servings of fish per week, depending on the type of fish

Where to get Omega-3 fatty acids?

Cold water fish: salmon, herring, mackerel, tuna, halibut
Fish oil supplements
Flax seed oil supplements

What are the Benefits of Omega-3 fatty acids?

Reduced triglycerides

Possible reduction of blood pressure or other cardiovascular disease risks

Lowered risk for ischemic stroke

Lowered risks for Age-related Macular Degeneration

Improvement of Dry Eye Syndrome

Possible improvement of retinal function in vision

Tags: Dry Eye, macular degeneration, omega-3
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Vitamin & Nutrition Corner: Vitamin E

Monday, April 5th, 2010

Vitamin E: Integral Antioxidant

Vitamin E is another essential nutrient due to its effects on both your ocular and overall health. Vitamin E is a fat-soluble vitamin that helps protect your cells and Vitamin A against oxidation. Vitamin E is also essential to your circulatory system, assists in the formation of red blood cells, and allows for better use of Vitamin K in the clotting process.

One study has suggested that patients taking Vitamin E supplements had a slower progression of cataracts. This is believed to be the result of Vitamin E’s anti-oxidant protection of the intraocular lens against free radical damage. Free radicals are circulating chemicals that cause damage to all body tissues and lead to cataracts.

Within the retina, Vitamin E is found in high concentrations within the photoreceptors, which are the cells that absorb light and vision. And it’s Vitamin E’s antioxidant properties that again come into play by protecting these very important cells from the damaging stress of aging. Vitamin E was also a component in the supplement treatment of Macular Degeneration in the landmark Age Related Eye Disease Study (AREDS).

In most developed countries, a true deficiency of Vitamin E is pretty rare. In conditions, such as Crohn’s, where fat metabolism is disrupted Vitamin E may be markedly deficient. But most Americans have a diet containing a fair amount of Vitamin E with the moderate need for supplements or dietary additions in order to obtain the vitamin’s full benefit.

It should be noted that Vitamin E is a fat-soluble vitamin, which means that excess intake could have harmful effects. Excess use may increase risk for hemorrhagic events (stroke) and may demonstrate muscle weakness, headaches, fatigue, and decreased thyroid function. If you are taking blood thinning agents, Vitamin E should be discussed with your primary care physician before taking larger amounts.

How Much Vitamin E:

30 IU (International units)

Where to get Vitamin E:

Vegetable oils
Leafy green vegetables
Egg yolks
Almonds, sunflower seeds, peanuts
Vitamin supplements

Benefits of Vitamin E

Reduced progression of cataracts
Anti-oxidant protection of retina
Reduced progression of Macular Degeneration in combination with other anti-oxidants
Improved circulatory system function, red blood cell formation, and clotting function.

Tags: vitamin E
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Vitamin & Nutrition Corner: Lutein

Sunday, February 21st, 2010

Lutein: A Vital Antioxidant for Eye Health

After speaking last month about Vitamin A’s antioxidant protection in Macular Degeneration, Lutein is a great follow-up. Lutein is a type of carotenoid, which is a natural pigment in vegetables and fruits. Just like beta-carotene and Vitamin A, Lutein serves as a powerful antioxidant within your eyes and protects against the free-radical damage of aging and the sun. In fact, Lutein has become a star within eye care’s discussion of nutrition in the management of Macular Degeneration.

The macula area of the retina is responsible for your fine, central vision. And it’s interesting that of the 600 naturally occurring types of carotenoids, only two are found concentrated in the macula area of your retina: Lutein and Zeaxanthin. Intake of Lutein has been shown to increase the density of pigment cells within the macula, thus protecting vision in patients with Macular Degeneration.

Should you still be interested in Lutein if you don’t have Macular Degeneration? Yes! Think blue light. The high energy wavelengths of blue light, within the visible spectrum of light, can cause oxidative damage to your cells. Lutein acts as a natural filter of blue wavelengths of light (not to be confused with ultraviolet or UV light). Some studies say Lutein may be able to filter up to 90% of these harmful light rays, but keep in mind that 73% of all statistics are made up. But the point is Lutein can help protect the macula area of your retina, and thus protect fine central vision whether or not you have Macular Degeneration.

Last month, I made special note of the side effects of vitamin overdose. But Lutein is water-soluble. Unlike Vitamin A, which is fat-soluble, excess Lutein will be excreted in urine and not build up in your tissues. Excessive intake is not an issue with Lutein. The recommended daily dose of Lutein is 6-20 mg. Spinach is the greatest natural source of Lutein, and a large serving may constitute up to 15-20mg of Lutein.

How much Lutein:

The recommended dose is between 6-20 mg per day.

Where to get Lutein:

Leafy green vegetables such as spinach, kale, and leafy lettuce
spinach, eggs, corn
Synthetic vitamin supplements

Benefits of Lutein:

Filtering of blue light to protect macula area of retina against oxidative damage from visible light
Protect the macula in patients with Macular Degeneration
Increase the pigment density in the macula and possibly improve vision
May help fight certain types of cataracts
May promote favorable results on the thickening of artery walls in atherosclerosis
Possibly improve skin hydration

Tags: blue light, Lutein, macular degeneration
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Vitamin & Nutrition Corner: Vitamin A

Tuesday, February 2nd, 2010

An essential component to ocular health: Vitamin A

If you ever walk by the vitamin and supplements aisle of the grocery store, you’ll notice dozens of brands specifically promoting eye health. Which of these vitamins are important to eye health? How much should you take? What happens if you get too little or too much of these vitamins? These are all great questions that I hope to answer with the ‘Vitamin & Nutrition Corner.’

First up is Vitamin A, which is a pivotal nutrient for eye health. Vitamin A is important in the function of both the exterior and interior portions of the eye.

For example, Vitamin A plays a large role in regulating the make up of your tear or moisture film on the surface of your eye. Vitamin A is also an antioxidant which reduces oxidative stress on the surface of your eye from environmental conditions and aging. As a result, a deficiency of vitamin A may lead to dry, irritated eyes.

Vitamin A is also essential for your retina to function properly. It combines with proteins in your retinal cells that are responsible for absorbing light, especially during night vision. A lack of Vitamin A would result in diminished or delayed visual ability to adapt during low light conditions, aka night blindness. Vitamin A also serves as an antioxidant within the retina to reduce chemical stress and it was part of the National Eye Institute’s formula of vitamins used in its landmark study on Macular Degeneration. vitamin a 300x198 Vitamin & Nutrition Corner: Vitamin A

No discussion of Vitamin A is complete without talking about Beta-carotene, which is a precursor that is metabolized by your body into vitamin A. Beta-carotene is found in plants with orange pigments: carrots, apricots, canteloupe, chili peppers, and sweet potatoes.

When we discuss vitamins, it’s important to note that excessive intake of any vitamin can actually be toxic to your body. Taking megadoses of vitamins should be avoided until it’s discussed in detail with your primary care physician. Getting more than 6000 IU of Vitamin A on a daily basis is considered excessive. Since Vitamin A competes with Vitamin D’s role in bone health, excessive Vitamin A may lead to osteoporosis. Excessive Vitamin A may also cause fatigue, joint soreness, upset stomach, and irritability. Smokers should avoid Beta-carotene as it may increase the risk of lung cancer with tobacco use. Smokers should take vitamin supplements that substitute Lutein in place of Vitamin A.

Yet, consuming proper amounts of Vitamin A or beta-carotene is an important means of keeping your eyes and your body in great health.

How much Vitamin A:

The recommended dose is between 1200-5000 IU.

Where to get Vitamin A:

Beef and chicken liver are HUGE sources of vitamin A
Milk, margarine, and eggs
Via Beta-carotene consumption from fresh carrots, canteloupe, etc.
Synthetic vitamin supplements

Benefits of Vitamin A:

Decreased ocular dryness
Better antioxidant protection of the eyes against environmental and aging stress
Proper retinal function during night vision
Promotion of better macular health in patients with Macular Degeneration
Improved bone and teeth development
Better skin function, especially during wound healing
Improves resistance to respiratory infections
Promotes proper testicular and ovarian function

Tags: antioxidant, beta-carotene, Dry Eye, macular degeneration, night vision, vitamin A, vitamins
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