Age-related
cataracts are the leading cause of low vision and blindness throughout the
world. Up to 30% of people over the age of 50 will develop them. By
age 75, about 70% will have cataracts. Surgery to remove cataracts has
become almost routine.
Cataracts develop when proteins build up
in the lens of the eye making it cloudy. It happens with age and is
primarily due to
oxidative damage. Age-related cataracts are the result
of a lifetime of molecular damage to the lens proteins by free radicals.
Can
your diet make a difference? Studies to date haven't been
conclusive. Animal studies have found that wheat grass
reverses cataract damage. Human studies have found only a
non-significant or modest association between fruit and vegetable intake and
cataract risk.
But
the most recent study from Spanish researchers is more promising. An article published
online onBMC Ophthalmology , finds a significant
relationship between high intakes of fruits and vegetables and lowered risk of
cataracts. In addition, taking in more vitamins C and E is also
associated with fewer cataracts.
High Intake of Fruits and Vegetables Lowers Cataract Risk
The
researchers analyzed data from the Spanish segment of the European Eye study
(EUREYE) collected between February 2000 and November 2001. The subjects
included 599 adults age 65 or older. Participants completed a food frequency
questionnaire to assess how many fruits and vegetables they typically
ate. The researchers also measured blood plasma levels of vitamin C,
alpha-tocopherol (vitamin E), and various carotenoids. Of the participants, 50%
ate five or more servings of fruits and/or vegetables a day. That number
is high compared to what Americans eat. The researchers noted that the
general population of Spain eats a Mediterranean
diet rich in fruits and vegetables, especially citrus
fruit. The researchers showed that the more combined fruits and vegetables
the participants ate, the lower their cataract risk. The same was true of
vitamin C.
Vitamins C and E Associated With Lower Cataract Risk
As
vitamin C intake increased above 107 mg per day, the risk of developing
cataracts significantly decreased. One orange has about 70 mg of vitamin
C. And the more vitamin C people ate – up to a point - the lower the
risk.
Compared
to those eating the least fruits and vegetables a day (between 13 mg to
83 mg), those eating up to 107 mg lowered their risk by 38%. Those
eating up to 143 mg per day lowered their risk by 51%. However, those
eating up to 408 mg every day didn't see much more improvement. They
lowered their risk by 54%. The researchers noted this was consistent with
other research finding human eye tissues become saturated at intakes of vitamin
C between 200 and 300 mg per day.
Vitamin
E intake above 8 mg per day showed a protective association against developing
cataract. An ounce of sunflower seeds contains about 10 mg of vitamin
E. But there was no evidence that more vitamin E contributed to additional
decreases in risk.
The
researchers also measured the effects of other dietary antioxidants including lutein,
zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene, and lycopene. But
none of those antioxidants were associated with cataract risk. The
researchers admitted this result was
not consistent with other epidemiological studies and
called for more research.
Until
then we know that high daily intakes of combined fruit and vegetables, as well
as vitamins C and E are associated with a significantly decreased risk of
cataract.
What
does this mean for you?
Foods To Protect Against Cataracts
The
researchers observed that high intakes of fruit alone did not significantly
lower cataract risk. But vegetables alone did make a significant
difference.
To
keep your eyes healthy, eat vegetables rich in vitamins C or E. Broccoli
is high in both of those vitamins.
Vegetables
high in vitamin C include kale, bell peppers, Brussels sprouts, cauliflower,
tomatoes, and snow peas. Foods high in vitamin E include spinach,
avocados, sunflower seeds, squash, and pumpkin.
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