Welcome to Zinc Information



Proper Eye Nutrition

Introduction-

For example, half a fresh carrot a day will give you the recommended daily allowance of vitamin A, which is very well known for being good for your eyes. There are many other examples of everyday food stuffs that are also beneficial for you and easily obtainable in any supermarket.

The recommended daily allowance:

In Europe the daily allowance for certain vitamins is measured in International Units [IU] and the vitamins extracted from either animal or plant sources vary. In the U.S, the recommended daily allowance- [RDA in its shortened version] for vitamins that are essential to healthy eyes is measured in Retinol Equivalents -RE. This daily allotment of vitamins is different for men and women; in the U.S.A the RDA for women is 800 RE a day and for men it is 1000 RE a day. To compare between the European and the American measurements, one American RE is equivalent to 3.3 European units that come from animal sources and one American RE is equivalent to 10 IU for plant products. Some vitamins, such as vitamin C, aren’t measured in RE units, but in milligrams per serving.

The role of antioxidants

Antioxidants are useful in preventing muscular degeneration and eye diseases. Vitamins C, A and E are all antioxidant vitamins important to eye-care. They are also beneficial in preventing cataracts or reducing cataract deterioration, as the antioxidants play a vital role in reducing the levels of protein buildup in the eyes that lead to cataract development. They are found either in meat products and various vegetables. Meat and vegetables hold the optimum amount of vitamins when they are fresh and as a general rule, the consumption of alcohol reduces the body’s effectiveness in absorbing these nutrients.

1. Vitamin A:

Vitamin A is found in meat, especially in the richly blooded internal organs, such as the liver or in dairy products that are rich in natural fats. Chicken liver, for example, contains over six thousand RE units in a 100g serving. This is six times a man’s recommended daily allowance and even a small portion of that serving would be greatly beneficial to maintaining the health of your eyes. Beef liver contains even more RE units if vitamin A- atleast 10,500 in a 100g serving. Vitamin A deficiency is the prevalent source of blindness in developed countries, where malnutrition and famine are a constant reality. Even in developed countries lack of proper nutrients in your food can lead to vitamin A deficiencies; leading to the development of cataracts or night blindness. Ongoing malnutrition or just bad eating habits can deteriorate simple night blindness to full onset of blindness if left untreated and if the diet isn’t corrected to include vitamin A-rich foods. Furthermore, cigarettes and alcohol both reduce the body’s ability to absorb nutrients and these unhealthy habits deplete the body’s ability to hold on to already digested vitamin A-rich foods.

2. Carotenoids:

A second, powerful antioxidant is carotenoid. Certain types of carotenoids are more beneficial for the eyes than others. Certain carotenoids, such as beta-carotene, which one of the most commonly found carotenoid types, also help the body break down vitamin A in the food. Lutein and Zeaxanthin are closely related carotenoids found most frequently in green, leafy vegetables such as spinach, and studies have shown that both these types are advantageous in preventing cataracts and muscular denegation. They are also found in yellow vegetables such as corn. The body doesn’t produce either of these carotenoids, so it’s doubly important to include green vegetables in your diet.

The best values of carotenoid-rich food sources are in fresh, uncooked vegetables. Cooking reduces the vitamin values and so every healthy diet should include a daily dose of fresh salad and fruits. If fresh produce isn’t available the frozen packets can substitute, as the freezing process reduces the vitamin content only marginally as long as the vegetables themselves were frozen still very fresh. Canned produce is never recommended, as canned goods are invariably suffused with chemicals and preservatives, deteriorating the vitamin value greatly.

Carrots, for example, are bright orange in color because they contain carotenoid, which is an antioxidant found in brightly colored fruits and dark green, leafy vegetables. Carrots contain almost three thousand RE units per 100g. and a single, average-sized, fresh carrot contains over 2000 RE. Carotenoid colors the vegetables red, yellow or orange and has been found to reduce the risk of all sorts of eye diseases. Carotenoid-nutrient foods are easily distinguishable because of this characteristic that provides pigment and allows for easy absorption in the body. A single medium sized mango contains 800 RE, a single sweet potato [also called yams] contain 2,660 RE units, a red bell pepper contains about 500 RE and a cantaloupe contains 320 RE for every 100g serving.

3. Vitamin C:

Vitamin C is found in citrus fruits, such as oranges and lemons, also in tropical fruits [pineapples, papaya, etc’], berries, every kind of pepper [red, yellow and green], potatoes and green, leafy vegetables. An important supplement that accompanies vitamin C is the group of bioflavonoids that appear in all the same fruits and vegetables. Bioflavonoids are chemical compounds that give certain foods their color and help the body absorb vitamin C. Though they are not vitamins themselves, they act as antioxidants in the body. Buckwheat is a good source for this compound, as are grapes, plums, cherries and the pith of citrus fruits. Bilberry is also an excellent source of bioflavonoids, but they are seldom seen in the U.S

Vitamin C should be consumed in produce as fresh as possible, as heat and light reduces it potency. Vitamin C-rich foods should be kept in a cool, dark place and even orange juice is better stored in an solid, enclosed container rather than a translucent container such as clear glass. The RDA [recommended daily allowance] for vitamin C is sixty milligrams for both women and men. One single orange contains 70 mg, one mango contains 57 mg, grapefruits contains 90 mg, one cup of raspberries contains 31 mg and one cup of strawberries contains over 85 mg of vitamin C. Green vegetables contain slightly less per weight- one cup of chopped broccoli contains 82 mg and one cup of chopped green peppers contains 133 mg.

Like Lutein and Zeaxanthin, the human body doesn’t produce vitamin C naturally and foods rich with this vitamin are vital to general good health and certainly eyesight. In fact, vitamin C isn’t stored for very long in the body’s reserves and daily doses are required. Like other antioxidants, this vitamin reduces the risks of various eye ailments, especially cataracts and muscular erosion. It is especially important for people aged 50+, as the body retains less vitamin C as the years progress, leading to the onset of age-related diseases.

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Vitamin E for eye-health-

The best and most obvious source of vitamin E is in nuts and this vitamin is another preventive measure against muscular degeneration and the development of cataracts. Almost all nut types contain great amounts of this vitamin. It is the important third vitamin for eye health after vitamins A and C. The recommended daily allowance in the U.S for vitamin E is 8 mg for women and 10 mg for men. Sunflower seeds are the richest in vitamin E and half a cup of sunflower seeds contains 36 mg of vitamin- which is four and a half times the daily allowance for women. Peanuts are also good for you and half a cup contains 7 mg, while the same amount of blanched or untreated almonds contains 17 mg and in hazelnuts its 16 mg.

Minerals-

Minerals are inorganic substances, which mean that they are not formed by living matter and contain no carbon. We require very tiny amounts of minerals in our diet and minerals in general comprise only four percent of our body’s weight. Minerals have several functions in the body;- they are cofactors in various metabolic reactions, they are electrically charged elements in the body that make movement of cell membranes and muscles possible and they comprise part of the balance between enzymes, hormones, vitamins and other factors that are the result of our diet. Selenium- Some minerals help the body absorb vitamins that are necessary for eye-health, such selenium, which helps with the absorption of vitamin E. Selenium is required to break down fats and other body chemicals and it also helps he body make its own antioxidants. It is found in yeast, whole-grain cereals, Brazil nuts, all seafood that comes from the sea and not freshwater, egg yolks, whole milk and fresh garlic. The estimated daily recommendation for selenium is about 5 mg to 20 mg for adults and this trace amount of mineral should already be present in your normal diet. There is definitely no need to take any supplements in this case.

Zinc- Zinc has a whole array of functions in the body to do with general good health. Zinc deficiencies are quite common and can lead to a plethora of physiological problems. It is vital for the development of certain white cells in the immune system, it helps gastrointestinal function and it encourages healthy skin and growth during childhood and adolescence. In the case of eyesight and eye-health, zinc is important in the development of certain eye tissues that enable vision in dim light, and subsequently lack of zinc in your diet will encourage night blindness. This mineral helps your body absorb the all-important vitamin A and reduces the number of free radicals in your system, protecting against muscular degeneration. The recommended daily allowance for both men and women is 15 mg and it can be found in red meat, liver, poultry, various whole-wheat grains, oysters and nuts. “Junk food” is virtually lacking in zinc and fast-food hamburgers don’t come close to filling the RDA for this mineral.

The role of fatty acids in your diet-

Fat is certainly a controversial issue in the field of nutrition today, though the importance of some level of fat and cholesterol in the body for maintaining good health is undisputed. Fat is the most concentrated source of dietary energy at our disposal and it certainly makes food taste better. Its function is to store energy, standing as reserve for times when we cannot eat regularly, it enables the body to absorb and utilize vitamins, such as vitamins A, E,D and K [which are all fat-soluble] and it provides linoleic acid, which is known as an essential fatty acid. Fatty acids have been proven to be indelibly linked to visual development in infants, and deficiencies can to impaired vision. It adults it can lead to retinal damage and even blindness. Linoleic acid is a component of fat found in corn oil and other vegetable oils and though it is vital to the body’s functioning, only a small amount is required for good health. Unlike butter, which has a very high percentage of saturated fats, corn oil is composed mainly of polyunsaturated fats and this is a far healthier alternative in any diet. Ideally, it shouldn’t exceed two percent of person’s daily calories, which can be obtained from a single tablespoon of soybean, corn or any other vegetable oil.

Omega-3 EFA:

Essential Fatty Acids [EFAs] are divided into two categories- the first is omega-3 EFA and the second is omega-6 EFA. Both make up polyunsaturated fats in the body, and both are necessary to good health. The first type, omega-3, is an alpha-linoleic acid [LNA for short] and it helps the body convert prostaglandins, which moderate the pressure inside the eye. In the August 2001 ‘Archives of Ophthalmology’ a published article came out claiming that a link had been found between omega-3 and it ability to prevent the deterioration of severe muscular degeneration.

Omega-6 EFA:

Omega-6 is a linoleic acid [LA for short] and studies have shown that while most Americans don’t consume enough omega-3 in their diet, they certainly do consume enough omega-6. Like omega-3, this acid plays a part in maintaining and regulating the eyes internal pressure and thus reducing muscular problems and the development of problems related to high intraocular pressure. However, unlike the more beneficial omega-3, this acid has been found to increase the potential for eye problems if it is too present in your daily diet. You should be consuming about equal amounts of each and current studies have shown that most Americans should cut down on omega-6 rich foods.

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Summary-

As you can see, there are many different factors that go into good eye care and balancing a healthy diet that will not only protect the body from various ailments, but also especially the eyes. This is particularly important as we age and the eyes begin to retain higher levels of protein in them, clouding vision and inducing cataracts. However, so many easily accessible foods contain all that we need to stay healthy and maintain good eyesight that sustaining health should be no problem. Vitamin A reduces the risk of night blindness, dry eye syndrome, blindness, the development of cataracts and muscular degeneration. Vitamin C and bioflavonoids also protect against cataracts and other age-related diseases and carotenoids are generally beneficial to the eyes, while also helping the body to break down and absorb vitamin A. And so the recommended diet for good eye health should always include brightly colored vegetables and fruits, such as carrots and sweet red peppers, citrus fruits like oranges, green leafy vegetables such as parsley, broccoli or spinach and various nuts and seafood, especially cold-water fish from the sea or oysters.

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