Summary:
During the period 2007-2008, a case-control study was conducted to identify
risk factors for cataract and to assess the association between diet and risk
of cataract in the Mediterranean Greek population. 314 cases and 314
frequency-matched controls of both genders, aged 45 to 85 years, attending the
ophthalmology department of a major teaching hospital in Athens, Greece, were
included in the study.
Cases were medically diagnosed and classified. Controls were healthy
visitors without cataract. A detailed questionnaire, covering demographic,
socioeconomic, somatometric, lifestyle and medical history variables, provided
data on possible risk factors for cataract. All participants were also
interviewed using a semi-quantitative food-frequency questionnaire, covering
the average frequency of consumption of about 120 food items.
Analyses were conducted through multiple logistic regression. The analysis was
carried out taking cataract as a general outcome (all types of cataract
combined) and repeated by the specific type of cataract.
Statistically significant increased risk for cataract overall was found
for current smokers (OR=1.99, 95%CI:1.23-3.23 and p=0.01) and ex-smokers
(OR=1.64, 95%CI:1.02-2.70 and p=0.04), history of coronary heart disease
(OR=2.25, 95%CI:1.43-3.55 and p=0.001), family history of ophthalmologic
diseases (OR=1.51, 95%CI:1.03-2.20 and p=0.03) and higher sunlight exposure at
the beach (OR=2.26, 95%CI:1.37-3.72 and p=0.001) as well as at work (OR=2.03,
95%CI:1.32-3.12 and p=0.001). Use of measures protecting against sunlight at
the beach, i.e hat (OR=0.58, 95%CI: 0.39-0.85 and p=0.005) and vision repair
spectacles (OR=0.44, 95%CI:0.30-0.65 and p<0.001), were associated with reduced
risk. Results for cataract overall were also evident for the nuclear type and
in most circumstances for PSC type, but were only suggestive for the cortical
type of cataract.
Regarding the association between diet and cataract, we found
significant inverse associations of cataract with dietary consumption of fish
(OR=0.69, 95% CI:0.57-0.85 and p<0.001), vegetables (OR=0.47, 95% CI:0.38-0.59
and p<0.001), fruits (OR=0.53, 95% CI:0.39-0.72 and p<0.001), and potatoes
(OR=0.76, 95% CI:0.62-0.91 and p=0.004), while consumption of meat was
positively associated with cataract (OR=1.46, 95% CI:1.17-1.81 and p=0.001).
High intake of total fat (OR=2.00, 95% CI:1.42-2.81 and p<0.001) and
cholesterol (OR=1.65, 95% CI:1.27-2.15 and p<0.001) increased the risk of
cataract. There was a protective association between cataract risk and intake
of carbohydrates (OR=0.39, 95% CI:0.24-0.64 and p<0.001), carotene (OR=0.56,
95% CI:0.45-0.69 and p<0.001), vitamins C and E (OR=0.50, 95% CI:0.39-0.64 and
p<0.001 and OR=0.50, 95% CI:0.38-0.66 and p<0.001 respectively).
In conclusion, we identified certain possible risk factors for
age-related cataract. In a Mediterranean Greek population we found that
smoking, use of cortisone drops, cardiovascular heart disease and sunlight
exposure increase the risk for cataract, while use of hat and vision repair
spectacles act protectively.
We, also, identified an association between the risk of cataract and
several food groups and nutrients. Diets rich in fruits, vegetables, fish,
pulses and starchy foods may protect against cataract. In addition, high intake
of vitamins C and E and carotene with reduction of intake in total fat and
cholesterol may be beneficial. Dietary advice along these lines may provide
adequate public health guidelines for the delay of age-related cataract.
