More evidence suggests that eating oily fish might protect the eyes

Age related macular degeneration (AMD) is the most common cause of blindness in people over the age of 50 in the UK.  The condition is one that I have written about many times previously.  The exact causes of AMD are unknown although free radical damage, where unstable oxygen molecules damage the eye cells, is strongly implicated.  Tobacco smoke and sun exposure can increase the level of free radicals in the body and both are a risk for AMD.  High blood pressure and diabetes are also risk factors as these conditions can limit blood flow to the eyes.  There is no cure for AMD, but certain treatments may prevent or delay serious vision loss.   Please read my previous posts for nutrition related ideas for keeping eyes healthy.

Antioxidants such as vitamin C, E, carotenes, zinc, lutein and zeaxanthin have all been implicated in keeping eyes healthy and slowing the progression of AMD.  There has also been evidence to suggest that fish oil might be helpful in prevention of the condition

A recently published study (1) has concluded that the “data support a protective effect of fish/shellfish intake against advanced AMD”.  The study researchers wanted to determine the relationship between fish and shellfish consumption and AMD status.  Over 2500 people aged between 65 and 84 were included in the study.  A specific food frequency questionnaire was used to estimate weekly fish/shellfish consumption for each participant and AMD status was determined from photographic analysis.  The scientists then investigated the links between weekly fish/shellfish intake and risk of AMD.

15% of the participants were found to have early- or intermediate-stage AMD, while just under 3% were in the advanced stage of the disease (1).  Overall, there was no clear relationship between participants’ reported fish intake and the risk of AMD.  However, there was a connection between higher intake of omega-3-rich fish and the risk of advanced AMD, those with advanced AMD were significantly less likely to consume fish/shellfish high in omega-3 fatty acids.  Individuals who ate one or more servings of oily fish (e.g. salmon, trout, mackerel and sardines) each week were 60% less likely to have advanced AMD than those who averaged less than a serving per week.  This statistic took into account known risk factors for AMD such as sex, race and smoking habits.

The results (1) are interesting but do not prove that eating oily fish cuts the risk of developing the advanced stages of AMD.  However, the study results do add to previous evidence that fish eaters tend to have lower rates of AMD than people who infrequently eat fish.  The results also add to the increasing evidence that omega 3 fatty acids, found in oily fish, may be important for eye health and prevention of AMD and AMD disease progression.  More research is certainly necessary before any firm conclusions or recommendations can be made.

Long chain omega 3 fatty acids from oily fish do seem to be particularly important for health and including oily fish as a regular part of the weekly diet would seem sensible.  Sadly many people in the UK do not regularly consume oily fish.  On average, adults in the UK are eating 1/3 of a portion of oily fish per week, with 70% of adults eating no oily fish at all.   The Government advises that individuals aim to eat at least two portions of fish every week, one of which should be oily (2).  It is not yet recommended that omega 3 supplements be taken specifically for protection against AMD, however if you do not regularly eat oily fish you may wish to talk to your doctor about the possibility of taking a fish oil supplement.  Vegetarians and vegans can take a flaxseed oil supplement (which provides short chain omega 3 fatty acids) or look into buying EPA/DHA supplements produced from algae, these supplements are becoming increasingly available.

For more information about AMD please visit Macular Disease Society website.  The Macular Disease Society aims to build confidence and independence for those with central vision impairment.  They are the only UK charity dedicated to helping people with macular degeneration and offer information, a helpline, counselling and emotional support among other resources.

(1)Bonnielin K. Swenor KB et al.  2010.  The Impact of Fish and Shellfish Consumption on Age-Related Macular Degeneration.  Opthalmology.  E-Pub.  doi:10.1016/j.ophtha.2010.03.058 

(2) British Nutrition Foundation.  http://www.britishnutrition.org.uk/home.asp?siteId=43&sectionId=593&subSectionId=322&parentSection=299&which=1

Written by Ani Kowal

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