Main content

    Health Information

    Macular Degeneration (Holistic)

    Macular Degeneration (Holistic)

    About This Condition

    Keep your vision in good condition by taking care to prevent macular degeneration, a leading cause of blindness later in life. According to research or other evidence, the following self-care steps may be helpful.
    • Load up on lutein

      Supply the eyes with this healthy antioxidant by taking 10 mg per day and eating plenty of green leafy vegetables

    • Seek support from a multi

      Protect your sight by taking a daily multivitamin containing beta-carotene, vitamin C, vitamin E, zinc, copper, manganese, selenium, and riboflavin

    • Block those rays

      Wear glasses that block ultraviolet rays to prevent eye damage that can contribute to macular degeneration

    • Go for the ginkgo

      Get help for early stage macular degeneration by taking 120 to 160 mg a day of a standardized Ginkgo biloba herbal extract

    • Say good-bye to smoking

      Kick this unhealthy habit that has been linked to increased risk

    About

    About This Condition

    Macular degeneration is the degeneration of the macula retinae, also called the macula lutea, an oval disc on the retina in the back of the eye. 

    Degeneration of the macula retinae is the leading cause of blindness in elderly Americans.1

    Symptoms

    Macular degeneration is typically painless and includes symptoms of dark or blurry areas in the center of vision, seeing distortions of straight lines, and difficulty doing activities that require sharp vision (e.g., driving and reading). Peripheral (side) vision may remain clear.

    Healthy Lifestyle Tips

    Smoking has been linked to macular degeneration. Quitting smoking may reduce the risk of developing macular degeneration.

    Eating Right

    The right diet is the key to managing many diseases and to improving general quality of life. For this condition, scientific research has found benefit in the following healthy eating tips.

    Recommendation Why
    Feast on fish
    People who eat fish more than once per week have half the risk of developing age-related macular degeneration compared with people who eat less fish.

    According to preliminary research, people who eat fish more than once per week have half the risk of developing age-related macular degeneration compared with people who eat fish less than once per month.2

    Choose good fats
    In a preliminary study, high intake of saturated fat and cholesterol was associated with an increased risk of developing macular degeneration, so look for lean meats and low-fat dairy, and cook with unsaturated fats, such as olive oil.

    In a preliminary study, high intake of saturated fat and cholesterol was associated with an increased risk of developing macular degeneration.3

    Stay tuned about alcohol
    Beer drinking has been linked to increased macular degeneration risk, while wine drinking has been linked to a decreased risk, these reports are too preliminary to be conclusive.

    Total alcohol consumption has not been linked to macular degeneration in most studies.4 , 5 However, one research group has linked beer consumption to macular degeneration,6 , 7 and in one of two trials, wine drinkers were found to have a significantly lower risk of macular degeneration compared with people not drinking wine.8 , 9 Most doctors consider these reports too preliminary to suggest either avoiding beer or increasing wine consumption.

    Supplements

    What Are Star Ratings?

    Our proprietary "Star-Rating" system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by some in the medical community, and whether studies have found them to be effective for other people.

    For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

    3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.

    2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.

    1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

    Supplement Why
    2 Stars
    Acetyl-L-Carnitine, Coenzyme Q10, and Fish Oil
    Follow label directions
    Learn More

    In a double-blind study, supplementation with a proprietary blend of acetyl-L-carnitine , omega-3 fatty acids from fish oil , and coenzyme Q10 for 12 months resulted in an improvement in both visual function and in objective findings on eye examination (a decrease in the drusen-covered area on the retina).10

    2 Stars
    Ginkgo
    120 to 240 mg daily of a standardized herbal extract
    Learn More

    Ginkgo (Ginkgo biloba) may help treat early-stage macular degeneration, according to small, preliminary clinical trials.11 Many healthcare professionals recommend 120 to 240 mg of standardized extract (24% ginkgo flavone glycosides and 6% terpene lactones) in capsules or tablets per day.

    2 Stars
    Lutein and Zeaxanthin
    6 to 10 mg daily
    Learn More

    Lutein and zeaxanthin are antioxidants in the carotenoid family. These carotenoids, found in high concentrations in spinach, collard greens, and kale, have an affinity for the part of the retina where macular degeneration occurs. Once there, they protect the retina from damage caused by sunlight.12

    Harvard researchers reported that people eating the most lutein and zeaxanthin-an average of 5.8 mg per day-had a 57% decreased risk of macular degeneration, compared with people eating the least.13 While spinach and kale eaters have a lower risk of macular degeneration, blood levels of lutein did not correlate with risk of macular degeneration in one trial.14 , 15 In a double-blind study of people with macular degeneration, supplementation with lutein (10 mg per day) for one year significantly improved vision, compared with a placebo.16 Lutein was beneficial for people with both early and advanced stages of the disease. Lutein and zeaxanthin can be taken as supplements; 6 mg per day of lutein may be a useful amount.

    2 Stars
    Melatonin
    Take under medical supervision: 3 mg daily at bedtime
    Learn More

    In a preliminary trial, supplementation with melatonin (3 mg per day at bedtime for at least three months) resulted in an improvement in the abnormalities observed on eye examination in the majority of cases.17 Melatonin is believed to work by regulating eye pigmentation (and, consequently, the amount of light reaching the retina) and by functioning as an antioxidant.

    2 Stars
    Multivitamin
    Follow label directions
    Learn More

    In a blinded six-month study of people with macular degeneration, vision was the same or better in 88% people who took a nutritional supplement, compared with 59% of those who refused to take the supplement (a statistically significant difference). The supplement used in this study contained beta-carotene , vitamin C , vitamin E , zinc , copper , manganese , selenium , and riboflavin .18 People wishing to take all of these nutrients may supplement with a multivitamin-multimineral formula .

    2 Stars
    Vitamin B6, Vitamin B12, and Folic Acid
    2.5 mg folic acid, 50 mg vitamin B6, and 1 mg vitamin B12
    Learn More

    In a double-blind study of female health professionals who had cardiovascular disease or cardiovascular disease risk factors, daily supplementation with folic acid (2.5 mg), vitamin B6 (50 mg), and vitamin B12 (1 mg) for 7.3 years significantly decreased the incidence of age-related macular degeneration.19 

     

    2 Stars
    Zinc
    45 mg daily (with 1 to 2 mg of copper to protect against depletion)
    Learn More

    Two important enzymes in the retina that are needed for vision require zinc . In a double-blind trial, supplementation with 45 mg of zinc per day for one to two years significantly reduced the rate of visual loss in people with macular degeneration.20 However, in another double-blind trial, supplementation with the same amount of zinc did not prevent vision loss among people with a particular type of macular degeneration (the exudative form).21

    1 Star
    Beta-Carotene
    Refer to label instructions
    Learn More

    Caution: Synthetic beta-carotene has been linked to increased risk of lung cancer in smokers. Until more is known, smokers should avoid all beta-carotene supplements.

    Sunlight triggers oxidative damage in the eye, which in turn can cause macular degeneration.22 Animals given antioxidants -which protect against oxidative damage-have a lower risk of this vision problem.23 People with high blood levels of antioxidants also have a lower risk.24 Those with the highest levels (top 20th percentile) of the antioxidants selenium , vitamin C , and vitamin E may have a 70% lower risk of developing macular degeneration, compared with people with the lowest levels of these nutrients (bottom 20th percentile).25 People who eat fruits and vegetables high in beta-carotene , another antioxidant, are also at low risk.26 Some doctors recommend antioxidant supplements to reduce the risk of macular degeneration; reasonable adult levels include 200 mcg of selenium, 1,000 mg of vitamin C, 400 IU of vitamin E, and 25,000 IU of natural beta-carotene per day. However, a preliminary study found no association between age-related macular degeneration and intake of antioxidants, either from the diet, from supplements, or from both combined.27 Moreover, in a double-blind study of male cigarette smokers, supplementing with vitamin E (50 IU per day), synthetic beta-carotene (about 33,000 IU per day), or both did not reduce the incidence of age-related macular degeneration.28

    1 Star
    Bilberry
    Refer to label instructions
    Learn More

    Bilberry's active flavonoid compounds, anthocyanosides, act as antioxidants in the retina of the eye. Therefore, supplementing with bilberry would theoretically be of value for the prevention or treatment of early-stage macular degeneration.29 Bilberry has also been shown to strengthen capillaries and to reduce bleeding in the retina.30 A typical amount of bilberry used in studies was 480-600 mg per day of an extract standardized to contain 25% anthocyanosides, taken in capsules or tablets.

    1 Star
    Carotenoids
    Refer to label instructions
    Learn More

    Lutein and zeaxanthin are antioxidants in the carotenoid family. These carotenoids, found in high concentrations in spinach, collard greens, and kale, have an affinity for the part of the retina where macular degeneration occurs. Once there, they protect the retina from damage caused by sunlight.31

    Harvard researchers reported that people eating the most lutein and zeaxanthin-an average of 5.8 mg per day-had a 57% decreased risk of macular degeneration, compared with people eating the least.32 While spinach and kale eaters have a lower risk of macular degeneration, blood levels of lutein did not correlate with risk of macular degeneration in one trial.33 , 34 In a double-blind study of people with macular degeneration, supplementation with lutein (10 mg per day) for one year significantly improved vision, compared with a placebo.35 Lutein was beneficial for people with both early and advanced stages of the disease. Lutein and zeaxanthin can be taken as supplements; 6 mg per day of lutein may be a useful amount.

    1 Star
    Fish Oil
    Refer to label instructions
    Learn More
    An assessment of 3,654 Australians aged 49 years or older found an association between a diet high in omega-3 fatty acids from fish and a lower risk of age-related macular degeneration.36
    1 Star
    Goji Berry
    Refer to label instructions
    Learn More

    Goji berries are also a rich source of zeaxanthin, a carotenoid that when consumed becomes concentrated in the macular pigment of the eye and may help protect the retina.37 , 38 Both human and monkey studies have shown that consuming goji berries or extracts high in zeaxanthin raises blood levels of zeaxanthin,39 , 40 , 41 , 42 but only animal research has verified that goji berry consumption increases macular pigment, and no research has looked at whether goji berries provide protection from diseases of the retina.

    1 Star
    Selenium
    Refer to label instructions
    Learn More

    Sunlight triggers oxidative damage in the eye, which in turn can cause macular degeneration.43 Animals given antioxidants -which protect against oxidative damage-have a lower risk of this vision problem.44 People with high blood levels of antioxidants also have a lower risk.45 Those with the highest levels (top 20th percentile) of the antioxidants selenium , vitamin C , and vitamin E may have a 70% lower risk of developing macular degeneration, compared with people with the lowest levels of these nutrients (bottom 20th percentile).46 People who eat fruits and vegetables high in beta-carotene , another antioxidant, are also at low risk.47 Some doctors recommend antioxidant supplements to reduce the risk of macular degeneration; reasonable adult levels include 200 mcg of selenium, 1,000 mg of vitamin C, 400 IU of vitamin E, and 25,000 IU of natural beta-carotene per day. However, a preliminary study found no association between age-related macular degeneration and intake of antioxidants, either from the diet, from supplements, or from both combined.48 Moreover, in a double-blind study of male cigarette smokers, supplementing with vitamin E (50 IU per day), synthetic beta-carotene (about 33,000 IU per day), or both did not reduce the incidence of age-related macular degeneration.49

    1 Star
    Vitamin C
    Refer to label instructions
    Learn More

    Sunlight triggers oxidative damage in the eye, which in turn can cause macular degeneration.50 Because vitamin C functions as an antioxidant, it has the potential to protect against macular degeneration. However, in a double-blind trial, supplementing with 500 mg of vitamin C daily for eight years did not decrease the incidence of macular degeneration in healthy male physicians.51

    1 Star
    Vitamin E
    Refer to label instructions
    Learn More

    Sunlight triggers oxidative damage in the eye, which in turn can cause macular degeneration.52 Animals given antioxidants -which protect against oxidative damage-have a lower risk of this vision problem.53 People with high blood levels of antioxidants also have a lower risk.54 Those with the highest levels (top 20th percentile) of the antioxidants selenium , vitamin C , and vitamin E may have a 70% lower risk of developing macular degeneration, compared with people with the lowest levels of these nutrients (bottom 20th percentile).55 People who eat fruits and vegetables high in beta-carotene , another antioxidant, are also at low risk.56 Some doctors recommend antioxidant supplements to reduce the risk of macular degeneration; reasonable adult levels include 200 mcg of selenium, 1,000 mg of vitamin C, 400 IU of vitamin E, and 25,000 IU of natural beta-carotene per day. However, a preliminary study found no association between age-related macular degeneration and intake of antioxidants, either from the diet, from supplements, or from both combined.57 Moreover, in a double-blind study of male cigarette smokers, supplementing with vitamin E (50 IU per day), synthetic beta-carotene (about 33,000 IU per day), or both did not reduce the incidence of age-related macular degeneration.58 Another double-blind trial found that supplementing with 600 IU of vitamin E every other day did not reduce the incidence of age-related macular degeneration in healthy women.59

    References

    1. National Advisory Eye Council. Report of the Retinal and Choroidal Diseases Panel: Vision Research CA National Plan: 1983-1987. Bethesda, MD: US Dept of Health and Human Services, 1984. National Institutes of Health publication 83-2471.

    2. Smith W, Mitchell P, Leeder SR. Dietary fat and fish intake and age-related maculopathy. Arch Ophthalmol 2000;118:401-4.

    3. Mares-Perlman JA, Brady WE, Klein R, et al. Dietary fat and age-related maculopathy. Arch Ophthalmol 1995;113:743-8.

    4. Smith W, Mitchell P. Alcohol intake and age-related maculopathy. Am J Ophthalmol 1996;122:743-5.

    5. Ajani UA, Christen WG, Manson JE, et al. A prospective study of alcohol consumption and the risk of age-related macular degeneration. Ann Epidemiol 1999;9:172-7.

    6. Moss SE, Klein R, Klein BE, et al. Alcohol consumption and the 5-year incidence of age-related maculopathy: the Beaver Dam eye study. Ophthalmology 1998;105:789-94.

    7. Ritter LL, Klein R, Klein BE, et al. Alcohol use and age-related maculopathy in the Beaver Dam Eye Study. Am J Ophthalmol 1995;120:190-6.

    8. Obisesan TO, Hirsch R, Kosoko O, et al. Moderate wine consumption is associated with decreased odds of developing age-related macular degeneration in NHANES-1. J Am Geriatr Soc 1998;46:1-7.

    9. Ritter LL, Klein R, Klein BE, et al. Alcohol use and age-related maculopathy in the Beaver Dam Eye Study. Am J Ophthalmol 1995;120:190-6.

    10. Feher J, Kovacs B, Kovacs I, et al. Improvement of visual functions and fundus alterations in early age-related macular degeneration treated with a combination of acetyl-L-carnitine, n-3 fatty acids, and coenzyme Q10. Ophthalmologica2005;219:154-66.

    11. Lebuisson DA, Leroy L, Reigal G. Treatment of senile macular degeneration with Ginkgo biloba extract: a preliminary double-blind study versus placebo. In Rokan (Ginkgo biloba): Recent Results in Pharmacology and Clinic, Fünfgeld FW, ed. Berlin: Springer-Verlag, 1988, 231-6.

    12. Bone RA. Landrum JT. Distribution of macular pigment components, zeaxanthin and lutein, in human retina. Methods Enzymol 1992:213:360-6.

    13. Seddon JM, Ajani UA, Sperduto RD, et al. Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. JAMA 1994:272:1413-20.

    14. Blumenkranz MS, Russell SR, Robey MG, et al. Risk factors in age-related maculopathy complicated by choroidal neovascularization. Ophthalmology 1986:93:552-8.

    15. Mares-Perlman JA, Brady WE, Kleain R, et al. Serum antioxidants and age-related macular degeneration in a population-based case-control study. Arch Ophthalmol 1995;113:1518-23.

    16. Richer S, Stiles W, Statkute L, et al. Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Optometry 2004;75:216-30.

    17. Yi C, Pan X, Yan H, et al. Effects of melatonin in age-related macular degeneration. Ann N Y Acad Sci 2005;1057:384-92.

    18. Olson RJ. Supplemental dietary anoxidant vitamins and minerals in patients with macular degeneration. J Am Coll Nutr 1991;10:550.

    19. Christen WG, Glynn RJ, Chew EY, et al. 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 2009;169:335-41.

    20. Newsome DA, Swartz M, Leone NC, et al. Oral zinc in macular degeneration. Arch Ophthalmol 1988:106:192-8.

    21. Stur M, Tihl M, Reitner A, Meisinger V. Oral zinc and the second eye in age-related macular degeneration. Invest Ophtholmol 1966;37:1225-35.

    22. Young RW. Solar radiation and age-related macular degeneration. Surv Ophthalmol 1988:32:252-69.

    23. Katz ML, Parker KR, Handelman GJ, et al. Effects of antioxidant nutrient deficiency on the retina and retinal pigment epithelium of albino rats: a light and electron microscopic study. Exp Eye Res 1982;34:339-69.

    24. West S, Vitale S, Hallfrisch J, et al. Are anti-oxidants or supplements protective of age-related macular degeneration? Arch Ophthalmol 1994:112:222-7.

    25. Eye Disease Case-Control Study Group. Antioxidant status and neovascular age-related macular degeneration. Arch Ophthalmol 1993:111:104-9.

    26. Goldberg J, Flowerdew G, Smith E, et al. Factors associated with age-related macular degeneration. Am J Epidemiol 1988:128:700-10.

    27. Smith W, Mitchell P, Webb K, Leeder SR. Dietary antioxidants and age-related maculopathy: the Blue Mountains Eye Study. Ophthalmology 1999;106:761-7.

    28. Teikari JM, Laatikainen L, Virtamo J, et al. Six-year supplementation with alpha-tocopherol and beta-carotene and age-related maculopathy. Acta Ophthalmol Scand 1998;76:224-9.

    29. Scharrer A, Ober M. Anthocyanosides in the treatment of retinopathies. Klin Monatsbl Augenheikld Beih 1981;178:386-9.

    30. Mian E, Curri SB, Lietti A, Bombardelli E. Anthocyanosides and the walls of microvessels: Further aspects of the mechanism of action of their protective in syndromes due to abnormal capillary fragility. Minerva Med 1977;68:3565-81.

    31. Bone RA. Landrum JT. Distribution of macular pigment components, zeaxanthin and lutein, in human retina. Methods Enzymol 1992:213:360-6.

    32. Seddon JM, Ajani UA, Sperduto RD, et al. Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. JAMA 1994:272:1413-20.

    33. Blumenkranz MS, Russell SR, Robey MG, et al. Risk factors in age-related maculopathy complicated by choroidal neovascularization. Ophthalmology 1986:93:552-8.

    34. Mares-Perlman JA, Brady WE, Kleain R, et al. Serum antioxidants and age-related macular degeneration in a population-based case-control study. Arch Ophthalmol 1995;113:1518-23.

    35. Richer S, Stiles W, Statkute L, et al. Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Optometry 2004;75:216-30.

    36. Chua B, Flood V, Rochtchina E, Wang JJ, Smith W, Mitchell P. Dietary fatty acids and the 5-year incidence of age-related maculopathy. Arch Ophthalmol 2006;124:981-6.

    37. Peng Y, Ma C, Li Y, et al. Quantification of zeaxanthin dipalmitate and total carotenoids in lycium fruits (Fructus Lycii). Plant Foods Hum Nutr 2005;60:161-4.

    38. Zhou L, Leung I, Tso MO, Lam KW. The identification of dipalmityl zeaxanthin as the major carotenoid in Gou Qi Zi by high pressure liquid chromatography and mass spectrometry. J Ocul Pharmacol Ther 1999;15:557-65.

    39. Khachik F, Beecher GR, Smith JC Jr. Lutein, lycopene, and their oxidative metabolites in chemoprevention of cancer. J Cell Biochem Suppl 1995;22:236-46.

    40. Cheng CY, Chung WY, Szeto YT, Benzie IF. Fasting plasma zeaxanthin response to Fructus barbarum L. (wolfberry; Kei Tze) in a food-based human supplementation trial. Br J Nutr 2005;93:123-30.

    41. Benzie IF, Chung WY, Wang J, et al. Enhanced bioavailability of zeaxanthin in a milk-based formulation of wolfberry (Gou Qi Zi; Fructus barbarum L.). Br J Nutr 2006;96:154-60.

    42. Leung I, Tso M, Li W, Lam T. Absorption and tissue distribution of zeaxanthin and lutein in rhesus monkeys after taking Fructus lycii (Gou Qi Zi) extract. Invest Ophthalmol Vis Sci 2001;42:466-71.

    43. Young RW. Solar radiation and age-related macular degeneration. Surv Ophthalmol 1988:32:252-69.

    44. Katz ML, Parker KR, Handelman GJ, et al. Effects of antioxidant nutrient deficiency on the retina and retinal pigment epithelium of albino rats: a light and electron microscopic study. Exp Eye Res 1982;34:339-69.

    45. West S, Vitale S, Hallfrisch J, et al. Are anti-oxidants or supplements protective of age-related macular degeneration? Arch Ophthalmol 1994:112:222-7.

    46. Eye Disease Case-Control Study Group. Antioxidant status and neovascular age-related macular degeneration. Arch Ophthalmol 1993:111:104-9.

    47. Goldberg J, Flowerdew G, Smith E, et al. Factors associated with age-related macular degeneration. Am J Epidemiol 1988:128:700-10.

    48. Smith W, Mitchell P, Webb K, Leeder SR. Dietary antioxidants and age-related maculopathy: the Blue Mountains Eye Study. Ophthalmology 1999;106:761-7.

    49. Teikari JM, Laatikainen L, Virtamo J, et al. Six-year supplementation with alpha-tocopherol and beta-carotene and age-related maculopathy. Acta Ophthalmol Scand 1998;76:224-9.

    50. Young RW. Solar radiation and age-related macular degeneration. Surv Ophthalmol 1988:32:252-69.

    51. Christen WG, Glynn RJ, Sesso HD, et al. Vitamins E and C and medical record-confirmed age-related macular degeneration in a randomized trial of male physicians. Ophthalmology 2012;119:1642-9.

    52. Young RW. Solar radiation and age-related macular degeneration. Surv Ophthalmol 1988:32:252-69.

    53. Katz ML, Parker KR, Handelman GJ, et al. Effects of antioxidant nutrient deficiency on the retina and retinal pigment epithelium of albino rats: a light and electron microscopic study. Exp Eye Res 1982;34:339-69.

    54. West S, Vitale S, Hallfrisch J, et al. Are anti-oxidants or supplements protective of age-related macular degeneration? Arch Ophthalmol 1994:112:222-7.

    55. Eye Disease Case-Control Study Group. Antioxidant status and neovascular age-related macular degeneration. Arch Ophthalmol 1993:111:104-9.

    56. Goldberg J, Flowerdew G, Smith E, et al. Factors associated with age-related macular degeneration. Am J Epidemiol 1988:128:700-10.

    57. Smith W, Mitchell P, Webb K, Leeder SR. Dietary antioxidants and age-related maculopathy: the Blue Mountains Eye Study. Ophthalmology 1999;106:761-7.

    58. Teikari JM, Laatikainen L, Virtamo J, et al. Six-year supplementation with alpha-tocopherol and beta-carotene and age-related maculopathy. Acta Ophthalmol Scand 1998;76:224-9.

    59. Christen WG, Glynn RJ, Chew EY, Buring JE. Vitamin E and age-related macular degeneration in a randomized trial of women. Ophthalmology 2010;117:1163-8.

    This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

    Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.