Dietary dilemmas

After a member of the Retinal Detachment support group on Facebook gave us all the heads up that the question of whether certain foods or nutritional supplements could improve eyesight was going to be explored on the BBC2 programme ‘Trust me, I’m a Doctor’, I decided I’d better dust off the TV and  tune in.  As the haunted fish tank is something which no longer features in my life, I completely forgot.  But – hurrah for iPlayer – I managed to catch up with it a couple of weeks later.

The programme mentioned the three carotenoids which are important for eye health: lutein, zeaxanthin, and meso-zeaxanthin.  These are pigments found in plants, which protect our eyes from damaging blue or UV light.  Lutein and zeaxanthin are found in green leafy vegetables such as kale and spinach, brightly coloured peppers, sweetcorn, broccoli, and a number of other fruits and vegetables (check out ‘Good Eye Food’ for a more complete list).  Meso-zeaxanthin can’t be found in plants but it’s believed that it’s made in our bodies from lutein.

The programme went on to refer to recent research undertaken by Professor John Nolan at the Waterford Institute of Technology in Ireland, which suggests that increasing the levels of these three carotenoids in our diets can improve our eyesight.  The programme makers put this to the test by conducting an experiment in which ten volunteers drank a green smoothie every day for five weeks.  The recipe had been designed so that it contained high levels of lutein and zeaxanthin, in order to find out whether it was possible to improve the eyesight of the volunteers through diet.  The presenter, Michael Moseley (by the way, he really *did* qualify as a doctor… I checked), also took part in the experiment, but he took supplements containing lutein, zeaxanthin, and meso-zeaxanthin every day for twelve weeks.  Now, I’m not even going to start discussing the results because these experiments are clearly flawed.  The sample size of ten volunteers for an experiment such as this is miniscule.  Not only that, but the viewer was given no information about the other variables or whether they had even been considered.  For example: were the volunteers all of the same age; did they have any medical conditions; what was their eyesight like to start with; what was the rest of their diet like… etc.  The timespan of five weeks also seems extremely short.  Not only that, but the programme didn’t compare like for like.  Results of ten volunteers over five weeks were directly compared to results of one (!) volunteer over twelve weeks.  Making the claim, “Research suggests that it’s cheaper and more effective to take supplements” based on these experiments is dodgy to say the least.

Upon reading a couple of articles associated with the programme, I discovered that the Waterford Institute of Technology had carried out a year-long study of approximately 100 volunteers who all took the same supplements.  “I don’t get it!”, I complained to my sister, in annoyance.  “Why have they done this pseudo-scientific experiment when an actual proper researcher has carried out the work to obtain far more convincing data?  Why didn’t they just discuss the real research?”  “It’s telly, isn’t it?”, observed my sister with the wisdom of one who’s watched a fair amount of trash over the years.  “They’ve just dumbed it all down to reach a wider audience.”

As I was a little frustrated by all this TV malarkey, I went off to look up some information about the research undertaken by the Waterford Institute of Technology.  I learned that Professor Nolan is Principal Investigator of the Macular Pigment Research Group, the mission of which is to “study the role of nutrition for optimising visual function and prevention of blindness, cognitive function and prevention of Alzheimer’s disease”.  In conducting trials for their research, they recruited volunteers with normal eyesight and volunteers who had been diagnosed with early-stage age-related macular degeneration (AMD) in one eye.  Their website specifically states that people with diabetes or who have had laser eye surgery were not suitable.

After further reading around the subject, I was still no closer to an answer as to whether or not supplements containing lutein, zeaxanthin, and meso-zeaxanthin would help me, as an RD patient.  So, I turned to my eye buddies, posting a question on the RD support group site asking whether anyone had specifically been recommended to take nutritional supplements by their ophthalmologist.  Unusually, there was a fairly resounding silence.  Only one person said that she had been recommended a supplement containing lutein by an ophthalmologist.  Someone else said that her retinal surgeon had told her that lutein may be helpful but that it couldn’t be known for certain.  Another person made the sensible comment that even supplements can be harmful so it’s best to seek medical advice to ensure the benefits outweigh the risks.  So I guess that’s one more question for the ophthalmologist at my next appointment…

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2 thoughts on “Dietary dilemmas

  1. Steve Rockey

    It’s very frustrating knowing what to do for the best regarding supplements etc. Often you get one set of advice only for it to be contradicted by something else. I’d say if it’s reasonably affordable give it a go as you have nothing to lose.

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    1. ejb117 Post author

      I’m going to ask an ophthalmologist at some point. I think one of my eye buddies was right in saying it’s best to seek proper medical advice first. 🙂

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