Currently it is Save Your Vision Month in America, a campaign run by the American Optometric Association (1). The role that diet plays in preserving our eyesight is highly important and certainly worth a loud mention. In August last year I wrote about cataracts and age related macular degeneration (AMD) and mentioned how diet, particularly omega 3 fatty acids from oily fish and antioxidants from vegetables and fruits, was important in preventing these conditions and preserving good eyesight. In the UK Age-related Macular Degeneration (AMD) is the leading cause of blindness, with 45% of those registered as blind suffering from the disease. For more info on AMD please read my previous blog post.
Very recently a paper was published (2) suggesting that B vitamins, particularly folic acid, vitamin B6 (also known as pyridoxine hydrochloride) and vitamin B12 (cyanocobalamin) may be particularly important for good eye health. The study was conducted since previous research had indicated the links between homocysteine concentrations in the blood and the risk of age related macular degeneration (AMD).
I have previously written about homocysteine. Most people are aware that high levels of homocysteine in the blood have been linked to an increased risk of heart problems. Recently high homocystein levels have also been linked to poor bone health and other health problems. To recap from my past blog posts: Homocysteine is produced when the amino acid (the building blocks of protein) methionine is broken down in the body. Normal levels of homocysteine are important to help build and maintain body tissues, however elevated concentrations in the blood can be harmful and have been associated with an increased risk of many disorders. At normal levels homocystein can be converted in the body into a harmless substance called cystanthionine. The conversion of homocysteine into this harmless substance depends upon various B vitamins (B6, B12 and folic acid). Having good levels of these B vitamins appears to be a very good way of preventing high homocysteine levels and low levels of B vitamins have been associated with raised homocysteine levels.
The researchers of the eye health study (2) wanted to examine the incidence of AMD in a trial of combined folic acid, vitamin B6 and vitamin B12 therapy. The trial was well designed and involved over 5000 women aged 40 or older with no diagnosis of AMD at the start of the trial. These women received either a daily placebo supplement or a supplement containing 2.5mg folic acid, 50 mg vitamin B6, and 1g vitamin B12. After around 7 years of treatment and follow-up it was found that the women receiving the supplement had a significantly reduced risk of AMD. The women taking the multi-B vitamin supplement were around 35% less likely to develop AMD than those taking the placebo.
The research seems to support the idea that taking a multiple B vitamin supplements is useful for sight preservation. It is not entirely clear whether the B vitamins worked to protect eyesight simply via lowering homocysteine levels. These vitamins may have also been working via exerting antioxidant effects or by improving blood vessel function. Further studies would be necessary to evaluate these ideas and strengthen data before strong recommendation for B vitamin supplementation can occur.
In the diet the B vitamins may be found in the following sources (vegetarians and vegans may wish to consider a multiple B vitamin supplement):
Vitamin B6 – Mainly found in meat, fish and eggs
Vitamin B12 – liver, meat, eggs, milk, yeast extract
Folic acid – liver, orange juice, green vegetables, nuts
Continuing with the theme of eye health. Scientists at the University of Liverpool (3) have recently announced that the degeneration of sight caused by AMD could be reduced by up to 20% through dietary changes alone, specifically through the increase of vegetables, fruits and nuts in the diet. Professor Ian Grierson, Head of Ophthalmology at the University of Liverpool, has produced a comprehensive cooking guide called ‘Fruit for Vision’, designed to add fruit and vegetables into everyday meals. The recipes were formulated in order to help AMD sufferers slow down the degeneration process by increasing micronutrient, vitamin and antioxidant intake in the diet. Non-sufferers can also use the book to add fruit, nuts and vegetables into each meal to protect against the disease.
Professor Grierson said (3): “Poor eating habits have a huge impact on health in general and the health of your eyes is no exception. Eye problems such as AMD, cataract and even glaucoma can all be affected by what we eat. But a relatively minor change in diet – adding a little more fruit into our meals – can make a profound difference and can keep eye diseases like AMD at bay for up to 20% longer. There are of course other risk factors related to AMD such as age, light exposure, smoking and being overweight. But if we can improve the kind of food that we eat, we could dramatically reduce the number of people who may suffer from eye diseases in the future.”
Fruit for Vision is published by Indigo Creative Marketing and the Macular Disease Society. It provides easy recipes that incorporate fruit and nuts in to the diet. The recipes suggest minor additions to what we already eat, rather than major dietary changes.
Over in America, the AOA has also released information (4) in order to highlight the importance that diet and nutrition play in eye health. The AOA highlights six nutrients important for eyesight:
Lutein, Zeaxanthin, Essential fatty acids, Vitamins C, Vitamin E, Zinc
In their press release the AOA mention the following food sources of these specific nutrients:
Lutein and zeaxanthin: Colorful fruits and vegetables such as broccoli, spinach, kale, corn, green beans, peas, oranges and tangerines
Essential fatty acids: Oily fish like trout, salmon, sardines, or herring, nuts and seeds, whole grain foods, chicken and eggs
Vitamin C: Fruits and vegetables, including oranges, grapefruit, strawberries, papaya, green peppers and tomatoes
Vitamin E: Vegetable oils, such as safflower or corn oil, almonds, pecans, sweet potatoes, and sunflower seeds
Zinc: Lean red meat, poultry, liver, shellfish, milk, baked beans, and whole grains
(1)American Optometric Association (AOA)
(2)William G. Christen, ScD et al. 2009. Folic Acid, Pyridoxine, and Cyanocobalamin Combination Treatment and Age-Related Macular Degeneration in Women. The Women’s Antioxidant and Folic Acid Cardiovascular Study. Arch Intern Med.169(4):335-341.
(3)University of Liverpool – press release
(4) Open Your Eyes To Healthy Eating Habits – press release by the AOA
Written by Ani Kowal
Related posts:
- New evidence points toward the importance of B vitamins for bone health
- Folate might impact cholesterol levels
- More evidence points toward the importance of vitamin B12 to protect against Alzheimer’s disease
- Dietary advice for the prevention of age related cataracts
- A diet high in B vitamins might be linked to a lower risk of heart disease and stroke
Great article!