Nutrition and Age Related Macular Degeneration

Nutrition and Age Related Macular

Fats/Fatty Acids

Nutritional fats and fatty acids are a significant source of energy and an essential part of the human diet. Fatty acids are, in fact, central components of fat molecules. DHA and EPA are two of the most important fatty acids that are found in fleshy fish and other aquatic animals and help in the prevention of macular degeneration. Similar to carbohydrates, essential fatty acids are also important for the maintenance of eye health. They are known for supporting the cardiovascular, immune, nervous and reproductive systems of human beings. Their intake is also important because they are helpful in the development of vision and facilitate the functioning of retina. If an individual's DHA/EPA levels are low, he/she has a higher risk of dry eye syndrome. The lack of DHA/EPA in the human body can also causes diseases like AMD and diabetic retinopathy ("Diet, Nutrition and," 2009).

It is not a secret that a human body is not capable of creating all the essential fatty acids it needs. Therefore, it becomes essential for us to get the essential fatty acids through the intake of appropriate diet and/or nutritional supplements. Scientists recommend that an individual must consume 500 mg/day of essential fatty acids. Cooked Halibut, Mackarel, Salmon, Scallops, Snapper, Trout and Tuna are the best sources of DHA and EPA. Oil-canned Anchovy is also another important source of essential fatty acids i.e. DHA and EPA ("Diet, Nutrition and," 2009).

DHA performs a vital role in the functioning of the retina. It is evident from the fact that if premature born children are not provided DHA supplements, they could have a dawdling development of optical sharpness as compared to the children who are supplemented with this essential fatty acid. When experiments were conducted on rat retina, it was found out that DHA helps in the prevention of reparations of oxidative stress, a key aspect of aging. A different experiment on monkeys demonstrated that nutritional utilisation in the retina of animals gets better that are given omega-3 fatty acids. Simultaneously, it also lessens the harmful effects of oxidative damage. Therefore, the people should be encouraged to make fatty fish a regular part of their diet or they should begin to take omega-3 nutritional supplements. The standard of prophylactic cure with omega-3 fatty acids must be initiated in an early age so that the development of degenerative diseases like ARMD could be prevented. This is exceedingly necessary as ARMD is one of those disabling diseases that could condense life expectancy and relentlessly diminish quality-of-life for older people (Bryhn, 2006).

As already discussed, age-related macular degeneration is a universal disease that leads to permanent blindness. The number of older people who have got this hindering disease will rise, as more citizens are reaching high age. However, high ingestion of omega-3 fatty acids can put a stop to the development of macular degeneration. It has been observed that regular intake of fish (1-3 fish meals for every month) prevented the growth of ARMD. A high intake of fish has demonstrated a thirty-five percent lower risk of macular degeneration as compared to people who only infrequently consume fish meals (Bryhn, 2006).

A weekly intake of fish rich in omega-3 fatty acids possibly will decrease the hazard of developing age-related macular degeneration. The nutritional intakes of 2,258 Australians were followed by the researchers of University of Sydney for 5 years. They found out that people who consumed fish three times a week reduced their risk of ARMD by 70%. On the other hand, people consumed about one fish portion every week reduced their risk of early AMD development by 40%. Researchers have concluded that diets short of omega-3 fatty acids may perhaps lead to unusual metabolism in the retina upsetting cell restoration ("Food in the News," 2006, p. 78).

The reason why scientists believe that the omega-3 fat DHA is good for eyes is because the retina is made of DHA structurally. Moreover, it is not only important in supporting the structure of the retina but also protects the eye against inflammation. The question is whether omega-3 fats slow down or prevent macular degeneration? When the central part of the retina known as macula dries up, it becomes impossible for the people to see the particulars finely and distinguish faces. According to Chew, "people who ate fish at least twice a week had almost a 50% reduction in the risk of advanced macular degeneration compared to people who never ate fish" (as qtd. In Liebman, 2007). DHA also protects the eye from retinopathy. It is a condition retina is affected by the growth of abnormal blood in it. According to the researchers, if an individual just makes a 2% change in his/her diet; he/she may have a 50% less chance of having an eye disease in the future (Liebman, 2007).

In order to function properly, the rods and cones of the macula require a definite amount of omega-3. Omega-6 fatty acids are not required by the human beings, on the other hand. However, large quantities of common vegetable oils that are mostly consumed by people contain omega-6 fatty acids that is the cause of increasing risk of macular degeneration. Therefore, it is very necessary to reduce the consumption of omega-6 and avoid packaged foods containing vegetable oil. The oils that should be used are olive and canola oil containing omega-6 fatty acids. On the other hand, fish oil and flaxseed oil must be consumed for omega-3 fatty acids (Mogk & Mogk, 2004).

Micronutrients

All through their lives, human beings require micronutrients (vitamins and minerals) in small quantities. They are important for performing a whole range of physiological functions. However, human beings are not capable of producing them. Therefore, certain foods and supplements are required to be consumed for getting these micronutrients. More than fifty essential nutrients including vitamins and minerals are known for their significance for the human body. There has been a very active research that is going on regarding nutrition and the eye. The obtained information is useful because it recommends vitamin and mineral sources and supplements that can help in the prevention of eye diseases like age-related macular degeneration (Brown, Bron, Harding & Dewar, 1998).

Vitamins

Vitamin A

The Vitamin A has been known for its importance in several body functions. However, it is particularly recognized for its importance in vision (Mather, 1999). It is particularly important in the formation of the photoreceptor pigments of the retina (Brown, Bron, Harding & Dewar, 1998). A person with a lack of Vitamin A can have a defective night vision (Brown, Bron, Harding & Dewar, 1998) or become permanently blind (Mather, 1999). The health of the ocular surface is also maintained by Vitamin A and in case of its deficiency, keratomalacia may occur (Brown, Bron, Harding & Dewar, 1998).

Lutein and zeaxanthin are related to Vitamin A and are the members of the carotenoid family of antioxidants. Lutein is significantly known for preventing age-related macular degeneration. Fruits and vegetables that are red, yellow, orange and green are pigmented by carotenoids such as lutein. Lutein and zeaxanthin are highly assessed as significant nutrients due to the fact that they are fundamental in the protection of the retina against free radical destruction that causes ARDM. Both these nutrients are extremely essential. Therefore, they must be taken as a supplement too because only food cannot provide enough of them (Mather, 1999).

Lutein and zeaxanthin are found together in spinach, kale, collards, green peas, broccoli, parsley, green beans, eggs, tangerines, Swiss chard, oranges, turnip greens, romaine lettuce and corn. These nutrients are deposited in the macula, retina and lens through diet and supplementation. Macular pigment optical density (MPOD) calculates the amount of lutein and zeaxanthin in the macula. Both these nutrients help in the protection and maintenance of healthy cells by acting as antioxidants. They also help in the filtration of cells-damaging high-energy blue wavelengths of light by functioning as an internal pair of sunglasses. Research demonstrates that taking lutein and zeaxanthin supplements can increase MPOD levels in the eye at a significant rate. It becomes possible for the individuals with higher MPOD levels to tolerate the intensity of glaring light. Such individuals can also recover from glare in a short time. Higher levels of MPOD also help the individuals to have an increased visual range and visual performance. They percept objects more clearly and respond to varying environmental conditions more quickly. The individuals with higher MPOD are also able to notice bits and pieces unmistakably even in faint light. Doctors recommend 10mg of lutein supplementation a day and 2mg of zeaxanthin supplementation a day ("Diet, Nutrition and," 2009).

To cut a long story short, an addition of extra amounts of lutein and zeaxanthin in one's diet can decrease the risk of ARMD. The early stage of the disease, age-related maculopathy, can also be benefitted by the supplementation of lutein and zeaxanthin. Thus, the deposition of lutein and zeaxanthin as a layer (macular pigment) gives the eye a built-in protection. This is the reason why people with a higher density of macular pigment have a reduced risk of macular degeneration in their old age ("Macular Degeneration Could Be," 2004, p. 13). It is, therefore, necessary to eat fresh or frozen vegetables for ingesting lutein (Mogk & Mogk, 2004).

Vitamin B

The supplemental use of folic acid and B. vitamins can help in the prevention of age related macular degeneration. This was proved when women were treated with Vitamin B supplements and followed for 7.3 years and it was concluded that they had a 35 -- 40% decreased risk of macular degeneration (Christen, Glynn, Chew, Albert & Manson, 2009).

According to the scientists, there is a direct connection between homocysteine (an amino acid) level in the blood and the threat of ARMD. However, the treatment with folic acid and B. vitamins demonstrated that they have the potential to lower the homocysteine levels in an individual's blood. When homocysteine levels are high, it causes dysfunctioning of the blood vessel lining. However, when treated with vitamin B6, vitamin B12 and folic acid, the homocysteine levels are reduced resulting in the reversal of the blood vessel dysfunction. Not only does the homocysteine level are lowered, B vitamins and folic acid were also found to improve the functioning of blood vessels in the eye (Christen, Glynn, Chew, Albert & Manson, 2009).

The unprocessed foods are rich in Vitamin B Meat products contain Vitamin B in an adequate quantity. Other than that, whole grains, molasses, bananas, potatoes, beans, chilli peppers and lentils also contain Vitamin B It is, therefore, really important to include Vitamin B rich foods in the diet to prevent age-related macular degeneration.

Vitamin E

Vitamin E is also a member of the antioxidant family. Nuts, fortified cereals and sweet potatoes are the excellent sources of Vitamin E This vitamin is particularly beneficial for the eyes as it helps in the promotion of cell membranes and repairmen of DNA. It also is known for its significance in the functioning of the immune system. According to the research and concluded evidence, Vitamin E could prove to be beneficial in the prevention of age-related macular degeneration by twenty five percent and visual acuity loss by nineteen percent. 22.5 IU of Vitamin E a day has been recommended as a daily dose. However, as far as the eye health is concerned, doctors suggest 400 IU a day. Therefore, it is important to intake almond, hazelnuts, peanuts, sunflower seeds, creamy/chunky peanut butter and cereal that are all rich in Vitamin E ("Diet, Nutrition and," 2009). However, Vitamin E supplementation is also necessary.

Vitamin C

Vitamin C (ascorbic acid) is a water-soluble nutrient. It is highly valued because of its excellent antioxidant properties. As it is significantly known for its capability of neutralizing free radicals and minimizing oxidative damage, Vitamin C is recommended for the prevention age-related macular degeneration. A daily dosage of 500 mg of Vitamin C daily can reduce the rate of development of macular degeneration ("Vitamin C," 2012). Vitamin sC works to counterbalance or deactivate the potentially cell-damaging molecules called 'free radicals' that cause harm to the lens and macular of the eyes.

Citrus fruits (oranges, lemons), berries, strawberries, guava, kiwi, sweet peppers/red peppers, Brussels sprouts, tomatoes, cantaloupe, broccoli, parsley, and dark leafy greens contain the highest quantities of Vitamin C If one wants to maximize the benefits of vitamin C benefits, he/she must make sure that he/she takes vitamin C several times a day for the maintenance of adequate serum levels as this water-soluble vitamin rapidly excretes ("Vitamin C," 2012).

Minerals

Zinc

Zinc is an important mineral that plays a pivotal role in the metabolism of the retina and eyes' lens. It is a vital component of a number of enzymes. Therefore, it is really important for the many metabolic activities of the body. Zinc ions are a main constituent of superoxide dismutase (enzyme). This enzyme plays a chief role in the foraging of superoxide radicals. The concentration of zinc in the retina and choroid is on the whole one of the maximum levels in the body, Therefore, it is not an untold secret that zinc is especially important for the eye. There is an association of zinc with vitamin A and together they are responsible for the generation of the visual pigments of the retina. Even in the presence of adequate vitamin A in the body, the lack or absence of zinc can cause night blindness. Similar to anti-oxidant vitamins, this essential mineral plays an anti-oxidant role ("Diet, Nutrition and," 2009).

When elderly individuals who have early retinal macular degeneration were supplemented with zinc, it was found out that their visual acuity was maintained in a very good way as compared to those who were not given zinc supplements. Studies have demonstrated that zinc plays a specific role in the maintenance of retinal health. In the same way, this anti-oxidant mineral is important in the maintenance of the health of the lens of the eye ("Diet, Nutrition and," 2009).