For example, obesity is becoming a serious health issue worldwide, as people consume too much calorie-dense food, yet these same people can be deficient in specific nutrients from eating too little of the nutrient-rich foods. Reports based on current research can assure us one day that a particular nutrient is the best thing for us, then link it to a health problem the next day. When taking supplements, knowing how much to take is important. Most nutrients will cause certain health problems if deficient, but can be toxic at higher levels.
In this country, the conditions causing the most frequent problems with vision and eye health are cataracts, macular degeneration, glaucoma, and dry eyes. In addition, several systemic diseases have associated effects on the eye, such as diabetes, hypertension, thyroid disease and most arthritic diseases. It used to be easy to think of these conditions as an inevitable part of aging, but they are now starting to show up in younger people also. Recent research is suggesting that long term, low-grade inflammation is responsible for many of the eye diseases. Our ability to control the inflammation and avoid these eye diseases is largely related to what we eat over our entire lifetime, not just as adults.
Over the past several years, I have read many reports and attended lectures on our diet as it relates to the health of our eyes. Here are some of the main points that I have filtered out of all of that information. If you are changing your diet - always be careful of potential allergies and sensitivities to the new foods.
The omega 3 essential fatty acids DHA and EPA are natural anti-inflammatory agents. Both omega 6 and omega 3 essential fatty acids are required in our diets, but they must be present in the proper balance. The best ratio of omega 6 to omega 3 is no higher than 4:1. Unfortunately, the ratio is closer to 20:1 in our modern diet, because of grain fed beef and pork, and the widespread use of processed vegetable oils high in omega 6, such as corn, safflower, sunflower and soybean oils. Omega 6 fatty acids are pro-inflammatory. We need them to help heal injuries and fight off disease-causing microorganisms, but too much can lead to chronic inflammatory conditions, including macular degeneration and dry eyes. Too much can also cancel out the anti-inflammatory benefits of omega 3.
The best sources of omega 3 fatty acids are cold water fish such as salmon, herring, sardines, tuna and mackerel. Supplements are also widely available. One of the best is natural cod liver oil, which contains vitamins A and D in addition to the omega 3. If using a supplement, aim for one containing at least 1000 mg of combined DHA and EPA per day. Supplements from other sources are also available for those allergic to fish. Decreasing the intake of omega 6, by avoiding cookies, pastries, and fried and processed foods also helps to bring the ratio closer to 4:1.
Fruits and vegetables, in general, are very good sources of many antioxidants important to the eyes, such as vitamins C and E, and beta-carotene. Antioxidants protect our cells and molecules from the damaging free radicals which form as a natural by-product of the cells’ use of oxygen. The recommended 5 to 10 servings a day supply an abundance of vitamins and other phytonutrients with antioxidant properties to help prevent macular degeneration and cataracts. They are also a good source of fibre, which can help regulate blood sugar and decrease the risk of developing Type 2 diabetes, with its associated eye problems. (When counting your servings, don’t count potatoes as a vegetable but, rather, in the same category as rice and pasta.)
Lutein and zeaxanthin are the two main phytonutrients found in the macula of the eye, which is the part of the retina responsible for our sharpest central vision. They act as a filter, protecting the macula from damaging blue light, and also have antioxidant properties. Research has shown that macular degeneration is more prevalent in people with lower amounts of these macular pigments. Another study very recently has suggested that increased intake of lutein can improve visual function in young people who spend many hours in front of a computer daily. It is thought to improve the eye’s ability to see in low contrast situations. Computers, cell phones, tablets, and anything with a lit screen give off blue light – and may accelerate the aging process in our eyes. Increasing the amount of lutein and zeaxanthin in our diets significantly increases their density in our retinas. Both are found in dark green vegetables such as spinach, kale, broccoli and turnip greens, as well as yellow foods such as egg yolks, corn and oranges. One of the best sources of zeaxanthin is orange bell peppers. If taking a supplement, 10 - 15 mg daily of lutein or preferably a combination of lutein and zeaxanthin is recommended. (The Vision Institute of Canada has an excellent reference on nutrition and the eye. Go to Vision Institute , click on “About Us” and then “Nutrition and Vision”.)
Substituting these foods for other high fat, less nutritious foods can improve your diet in a number of ways. All are good sources of fibre, which helps control blood sugar levels, decreasing the risk of diabetes.
Unless you are allergic, nuts and seeds are also a good source of vitamin E and zinc, two of the more important nutrients for eye health, plus antioxidants and omega 3 fatty acids. Walnuts, in particular, are known to decrease the risk of macular degeneration as well as the risk of heart attack. Choose nuts that haven’t had extra salt and oil added to them.
Beans are a good source of protein, besides being high in antioxidants. Regular consumption of beans helps to reduce the risk of many health problems including diabetes, high cholesterol, cancer, hypertension, and obesity. The beans that are darkest in colour have the highest levels of antioxidants. Black and red beans are especially good.
Grains that go through the refining process lose most of their fibre, B vitamins, minerals, vitamin E and other phytonutrients. Eating oatmeal or other whole grain cereals for breakfast, and substituting whole wheat bread and pasta for the refined varieties, are easy ways to improve your nutrition.
Smoking is one of the absolute worst things you can do to your eyes. Smokers have 2 - 3 times the risk of developing cataracts and 6 times the risk of macular degeneration.
Regular exercise improves the circulation to the eyes, transporting those nutrients to where they are needed. It also helps to improve insulin sensitivity, reducing the risk of developing diabetes. Something as simple as walking regularly can help to reduce your risk of developing age-related eye diseases.