Vitamin C linked with reduced risk of cataracts

Whilst I believe that conventional medicine is less effective and more hazardous than its image suggests, I don’t shun it completely. For instance, a few months ago I saw a patients who told me that in his late 40s had developed cataracts (cloudiness in the lenses of the eyes) which had been removed and replaced with synthetic lenses by an ophthalmic surgeon. Because of the procedure this man could see, and without it would probably be blind. I regard that as a medical success story.

However, because I have a strong interest in preventive medicine, my eyes are generally on the look out for ways we may preserve our health, including our eyesight. Recently, a study was published which looked at the relationship between vitamin C intake and cataract risk in more than 35,000 Japanese men and women over a five-year period. Cataracts that come on during the ageing process are thought to be at least in part related to damaged in the lens of the eye reeked by ‘free radicals’. Vitamin C quells free radicals and therefore might help to prevent or slow the development of cataracts.

This study found that individuals with the highest levels of vitamin C intake were at significantly reduced risk of cataract compared to those with the lowest levels. Risk reduction associated with higher levels of vitamin C intake were 35 and 41 per cent for women and men respectively.

Below, I have added an article which reviews other evidence which suggests specific nutrients may help to ward off cataracts. Eating a diet rich in fruit and vegetables, perhaps with supplementation of key nutrients too, would seem to me to be a reasonable insurance policy for those seeking to preserve their vision as they age.

References:

Yoshida M, et al. Prospective study showing that dietary vitamin C reduced the risk of age-related cataracts in a middle-aged Japanese population. Eur J Nutr 2007 Jan 30 [Epub ahead of print]

Preventing cataracts with nutritional therapy  25th August 2002

When I was at medical school I learnt that blue eyes are associated with an increased risk of succumbing to the blood disorder pernicious anaemia. For years, I have taken comfort from the belief that having brown eyes afforded me some degree of immunity from disease. This month, however, new research has linked brown eyes with a substantially increased risk of cataract (cloudiness in the lens of the eye). While I and other dark-eyed folk might feel somewhat aggrieved at this fact, it turns out that even those with eyes of lighter hue are at significant risk of developing cataracts: almost everyone over the age of 65 has some degree of cataract formation, and the incidence of this condition is set to treble in the next 50 years. Fortunately, research suggests that upping our intake of certain foods and nutrients has the capacity to dramatically reduce cataract risk. For those of us who are keen to preserve our eyesight as we age, there really does appear to be light at the end of the tunnel.

In health, the lens in the eye is composed of a transparent, jelly-like material that is rich in protein. Over time, the protein in the lens may become damaged, causing it to become cloudy. This process is similar to the change that is plain to see when an egg white is cooked: while a raw egg white is transparent, it becomes opaque when the protein within it is damaged during the cooking process. The damage to the lens that can ultimately lead to cataract formation is wreaked by destructive molecules known as free radicals. Quenching free radicals is believed to be a key to reducing cataract risk.

Free radicals are neutralised in the body by substances known as antioxidants. Some antioxidants are manufactured within the body, but many come directly from the food we eat. Research has found that consuming foods rich in antioxidants known as carotenoids may protect against cataract development. While beta-carotene is perhaps the best-known carotenoid, its less celebrated relatives lutein (pronounced loo-teen) and zeaxanthin (pronounced zee-ah-zanthin) are believed to have a special role to play in terms of combating free radical damage in the eye. One food that is rich in both lutein and zeaxanthin is spinach. In one study, spinach was the food most consistently associated with a reduced cataract risk. Other veggies rich in lutein and zeaxanthin include leeks, peas, and cos lettuce.

While the right diet certainly has a role to play in preserving the health of the eyes, there is also evidence that supplementation with antioxidants such as vitamins C and E can help too. One study published in Archives of Ophthalmology last year showed that individuals taking a multivitamin and mineral containing either or both of these nutrients for 10 years or more enjoyed a 60 per cent reduction in risk of cataract. Another study published in American Journal of Clinical Nutrition found that taking vitamin C supplements for at least a decade reduced the risk of cataract development by a very impressive 70 per cent. The evidence suggests that eating our greens along with additional supplementation with a multivitamin and mineral supplement and 250 ” 500 mg of vitamin C each day can be an effective strategy for keeping our eyes clear of cataracts in the long term.

2 Responses to Vitamin C linked with reduced risk of cataracts

  1. helen 17 June 2007 at 10:52 pm #

    Strangely enough Codex is wanting to stop the sale of thereputic amounts of this most effective vitamin & suggest that we only need 60mg of vitamin C a day. As I currently take 4000mg a day & have done so for many many years with the only side effect being improved health what would I know?
    Why is our health in the hands of such stupid people? Well my health currently is in my quite capable hands & it is the one thing I will not give over to any “authority” other than my own good sense. The right diet needs supplementation now no matter how healthy it is & who is to say what the right diet is the same idiots who are saying what it is now?? Lots of carbs no saturated natural fats very little protein…….riiiiiigghht!!

  2. the site company 12 December 2007 at 2:11 pm #

    i read that if you are a big comsumer of sugar then most of the vitamin c you ingest doesn’t get absored.. people read these things and start pumping their bodies with vitamins but whats the point when they are stuffing their faces with sugar?

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