In a previous blog I discussed how eating leafy green vegetables, many types of fruits, and foods containing omega-3 fatty acids can improve your vision health. I would now like to tell you why.
Before I do so, let me tell you about an excellent book that explains all of this in a very understandable way, and also provides you with recipes that can help you along the way. The book, entitled: "Eyefoods. A food plan for healthy eyes" is written by two Canadian Optometrists, Drs Laurie Capogna and Barbara Pelletier, and can be purchased on-line via the CNIB webstore at the following link:
I would like to look at each of the three recommended food categories separately.
Leafy Green Vegetables:
Studies have shown that people who eat a diet rich in leafy green vegetables have a lower risk of developing age-related macular degeneration (AMD), the number one cause of vision loss in Canada. The main reason for this is that these leafy greens contain the pigments lutein and zeaxanthin, as well as other useful nutrients. Both lutein and zeaxanthin are present in the healthy retina and are believed to play a role in the prevention of AMD. In fact, both are currently under investigation as supplements in a large study being conducted in the United States, called the AREDS-2 trial. More information on this study can be obtained at the following link: http://www.areds2.org/
Now that we've discussed the technical side of these veggies, what in fact are leafy green vegetables? I must admit that I had not heard of some of these till just a few years ago. Eyefoods lists the following vegetables in this category: kale, spinach, dandelion greens, romaine lettuce, leaf lettuce, arugula, Swiss chard, rapini and collard greens. The book also lists creative ways that these leafy greens can be incorporated into meals to overcome objections from people averse to eating them.
The main reason that fruits are great for your vision health has to do with the fact that they contain antioxidants (vitamins and minerals that prevent damage to the eye through oxidation). Foremost amongst these are Vitamin C, Vitamin E, selenium and carotenoids. The latter are a group of over 600 naturally occurring pigments and include lutein and zeaxanthin which I have already discussed as being good for prevention of AMD. So these important pigments can be obtained in both leafy greens and fruits.
Eating fruit that contains high levels of antioxidants such as berries, kiwi and citrus fruits has been shown to decrease the risk of developing AMD and research has shown that Vitamin C can reduce the risk of developing cataracts.
Many fruits also contain zinc, a mineral regarded as essential for the eye.
Omega-3 Fatty Acids:
We hear a lot about omega-3 fatty acids (omega-3's) these days. This is good because these fatty acids can lower the risk of AMD and are also therapeutic for people with dry eye syndrome. In fact a recent study showed that people who eat fish containing omega-3's at least twice a week could lower their risk of developing AMD by about 50% compared with people who didn't eat fish. Animal studies have also shown that omega-3's may protect the eye against diabetic retinopathy.
What we don't know is whether taking supplements containing omega-3's will have the same effect, nor how much one should be taking. To help answer this question, omega-3 fatty acids are also being investigated as a supplement in the AREDS-2 trial I mentioned before. The best sources of omega-3's are oily fish, nuts and flax seed oil. Salmon and trout head the list of fish high in omega-3's but other fish also have significant amounts. The concentration of omega-3's in tuna is about one seventh to one tenth that of Atlantic salmon.
The good news about all of this is that the foods that are good for your ocular health are also good for your general health, so by taking care of your eyes, you can also take care of your body. The other good news is that the book by Drs Capogna and Pelletier has some delicious recipes containing all of this healthy food, so that a diet that is good for the eyes can also be good for the taste buds. Wishing you happy and healthy eating, and bon appétit!