I was just having a conversation with a friend who is soon to have his cataracts treated*. Given a diet high in sugars has all sorts of consequences, including AGE formation, I got to wondering if a high glycaemic increased the likelihood/speed of cataract formation. (Cateracts are where the lenses in your eyes become clouded/opaque, so you can’t see properly.) In essence, studies suggest the answer is partly no and partly yes and partly maybe.
Types of cataracts
How is this? First, we need to know there are different types of cataracts; the three main types are:
— Nuclear cataracts (affecting the centre of the lens)
— Cortical cataracts (affecting the adjacent peripheral area)
— Subcapsular opacities (those in the posterior outer aspect of lens tissue; ie, back edge)
Glycaemic Index (GI)
The GI is a way of measuring one food type against another in relation to its carbohydrate load and how quickly it’s absorbed into the blood stream. There’s a similar scale, GL (glycaemic load) which looks at the total likely to be absorbed. Put simply, the higher the GI or GL, the more simple sugars are hitting your bloodstream. Both indeces are tools, nothing more, but they are handy for studies.
Carbohydrates and AGEs
Secondly we need to know that sugars are implicated in ageing and malfunctioning of tissues; excess sugars bind to proteins in the wrong positions, twisting the proteins up. These are known as AGEs – advanced glycation end products. The more carbohydrates (especially simple carbs) one has in the diet over time, the worse this effect can be.
Carbohydrates and cataracts
Reasearchers from the Age-Related Eye Disease Study (which looked at 3,377 men and women, aged 60 to 80), conclude the glycemic index is associated with an increased risk of nuclear cataracts
The study results suggest:
— A positive relation between GI and nuclear opacities
— An insignificant relationship between carbohydrate intake and cortical opacities
— Foods with a higher GI may increase the damage to nuclear tissue of the lens by exposing the tissue to glucose for longer periods
— Dietary carbohydrates may be associated with cataractogenesis
Dr Taylor added, ‘Although the glycation mechanism has been linked to other age-related chronic diseases, such as diabetes, and coronary heart disease, specific mechanisms underlying the carbohydrate association with lens opacities remain to be clarified.’
You can see more of this report here.
While this is not conclusive, I think this is another good reason to cut down carbohydrates in your diet.
*Did you know they can put new lenses in that allow your brain to focus on far, middle and near distances now?! Amazing 🙂