To Your Health
November, 2013 (Vol. 07, Issue 11)
Help Preserve Your Eyesight With B Vitamins
By James P. Meschino, DC, MS
A study published in the July 2013 issue of the American Journal of Clinical Nutrition adds to the evidence suggesting certain B vitamins may be important in the prevention of age-related macular degeneration (AMD), which is the leading cause of vision loss in people over 55 years of age in the U.S. and Canada. Previous studies have shown that taking certain antioxidant vitamins and minerals as supplements (vitamin E, vitamin C, beta-carotene, selenium and zinc), at specific dosages, can slow the progression of AMD.
What the Latest Study Says
In the latest study, known as the Blue Mountain Eye Study, serum folate (B-vitamin folic acid), vitamin B12 and homocysteine status were determined from blood samples drawn in 1997-1999 from cohort members ages 55 and older. AMD was assessed in 1,760 survivors from retinal photographs taken in 2002-2004 and 2007-2009. Total intakes of folic acid and vitamin B12 were assessed using a food-frequency questionnaire.
Results showed that higher blood levels of homocysteine were associated with a significant increased risk of developing AMD, whereas higher levels of vitamin B12 were strongly associated with decreased risk of developing AMD. Homocysteine is a toxic end-product of metabolism known to damage blood vessels and increase the risk of cardiovascular disease. Studies continue to show that high blood levels of homocysteine also contribute to damage seen in AMD.
People with folate or vitamin B12 deficiency at the beginning of the study (baseline) were approximately twice as likely to develop AMD during the 10-year study period.
What is important is that homocysteine levels are reduced via supplementation with, and dietary intake of, vitamin B12 and folic acid. These B vitamins recycle homocysteine back to the nontoxic and highly useful amino acid known as methionine. This explains why high levels of serum homocysteine, and low levels of vitamin B12 and folic acid, are so strongly linked to the development of AMD, as confirmed in the Blue Mountain Eye Study.
How You Can Prevent AMD
It is thought that AMD is a highly preventable disease, thus requiring attention to various lifestyle behaviors. Extrapolating from what we know from experimental, observational and clinical studies, the following practices appear to be the best proactive strategies to prevent the development of AMD:
- Don't smoke
- Protect your eyes from UV light
- Prevent the onset of type 2 diabetes by maintaining your ideal weight, performing endurance and strength-training exercises regularly, and keeping your blood sugar levels within an ideal range (talk to your doctor to for more info)
- Eat a diet rich in brightly colored vegetables and fruit (dark green, yellow, orange, blue, purple, red).
- Keep your cholesterol level low by also consuming foods low in total cholesterol, saturated fat and trans fats.
- Take a high-potency multivitamin/mineral each day that contains the following dosages of antioxidants and B vitamins:
- Vitamin C: 1,000 mg
- Vitamin E: 400 IU
- Selenium: 200 mcg
- Zinc: 15 mg
- Beta-carotene: 15,000 IU
- Lutein powder: 6 mg
- B-50 complex, including 400 mcg folic acid, 50 mcg vitamin B12 and 50 mg vitamin B6 (which also lowers homocysteine)
If you're already suffering from advanced macular degeneration, higher dosages of certain vitamins, minerals and phytonutrients are required to slow the progression of the disease. These therapeutic dosages are available by taking my online nutrition / lifestyle / anti-aging assessment at www.naturalhealthtest.com. Talk to your doctor for additional information and before taking any vitamin or supplement for the first time, particularly if you are taking medication, other supplements and/or have a pre-exiting health condition.
James Meschino, DC, MS, practices in Toronto, Ontario, Canada and is the author of four nutrition books, including The Meschino Optimal Living Program and Break the Weight Loss Barrier.