Thursday, May 30, 2013

Omega-3 Fats Lower the Risk of Macular Degeneration

Reposted from Life Extension
http://blog.lef.org/2013/05/omega-3-fats-lower-risk-of-macular.html

By Michael A. Smith, MD
Age-related macular degeneration is the number one cause of blindness in the Unites States for people over 60.

In fact, as many as 11 million people in the United States have some form of age-related macular degeneration. This number is expected to double to nearly 22 million by 2050.1
 And not to state the obvious here, but this can have devastating and life-altering consequences.

That’s why it’s refreshing to see that something as simple as fish oil may be able to help reduce your risk.

What is Age-Related Macular Degeneration?

The macula or macula lutea (from Latin macula, "spot" + lutea, "yellow") is a highly pigmented yellow spot near the center of the retina of the human eye, providing the clearest, most distinct vision needed in reading, driving, seeing fine detail, and recognizing facial features.

Age-related macular degeneration (AMD) is a devastating condition characterized by the deterioration of the macula in which central vision becomes severely impaired. There are two forms of macular degeneration: atrophic (dry) and neovascular (wet). Both forms of the disease may affect both eyes simultaneously.

Age-related declines in retinal carotenoid antioxidants, coupled with photo damage induced by harmful ultraviolet (UV) rays, give rise to this debilitating condition. The progression and severity of macular degeneration, as with all age-related diseases, are exacerbated by factors such as oxidative stress, inflammation, high blood sugar, and poor vascular health.

What are the Risks for Age-Related Macular Degeneration?

At the top of the list of risk factors is low carotenoid intake. Low levels oflutein, zeaxanthin, and meso-zeaxanthin are linked to AMD. All three are carotenoids present in the retina and positively affect central vision and the pigment density in the macula.2

Lutein and zeaxanthin help to prevent AMD by supporting the macular density, resulting in less retinal tearing or degeneration. The therapeutic effect of lutein and zeaxanthin in AMD is significant, according to the Lutein Antioxidant Supplementation Trial (LAST), which showed improvement in several symptoms accompanying AMD.3
 The next risk factor is a high fat diet. Higher intake of specific types of fat, rather than total fat, may be associated with a greater risk of advanced AMD. A French study found that high total fat, saturated fat, and monounsaturated fat intake were all associated with an increased risk of developing AMD.4
 Eating red meat 10 or more times per week appears to increase risk for developing early AMD, while eating chicken more than 3.5 times per week may confer protection against the disease.5
 Lastly, high blood pressure appears to increase your risk. A study of 5,875 Latino men and women identified a pronounced risk for wet AMD if diastolic blood pressure was high, or if individuals had uncontrolled diastolic hypertension.6
 Besides replacing carotenoids, eating less fat and maintaining healthy blood pressure, let’s take a look at how omega-3 fats can help reduce your risk.

Omega-3 Fats Reduce Age-Related Macular Degeneration Risk

An article published in The Journal of Nutrition reports an association between high omega-3 levels and a reduced risk of age-related macular degeneration in older men and women.7
 The investigation included 963 participants, aged 73 and older. Blood samples collected between 1999 and 2001 were analyzed for plasma alpha-linolenic acid and the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA).

The subjects underwent initial eye examinations during 2006–2008 and were followed for an average of 31 months. Having a higher level of total omega-3 fatty acids was associated with a decreased adjusted risk of late macular degeneration in this age group in comparison with lower omega-3 levels.7

So there you have it — a really simple strategy for reducing your risk of age-related macular degeneration: Eat more fish and supplement daily with omega-3 fats. Think you can swing it?

References:

  1. http://www.brightfocus.org/macular/about/understanding/facts.html
  2. Surv Ophthalmol. 2005 Mar-Apr;50(2):183-93. Review.
  3. Optometry. 2004 Apr;75(4):216-30.
  4. Eur J Clin Nutr. 2007 Nov;61(11):1341-4. Epub 2007 Feb 14.
  5. Am J Epidemiol. 2009 Apr 1;169(7):867-76.
  6. Am J Ophthalmol. 2008Feb;145(2):308-16. doi: 10.1016/j.ajo.2007.10.007.
  7. J Nutr. April 2013 143: 505-511; first published online February 13, 2013. doi:10.3945/jn.112.171033
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