Increased breastfeeding frequency, duration protective against cataract
Parous women who are breastfeeding more children and have been doing so in the long-term appear to have a lower risk of developing cortical cataract, a study reports.
Researchers analysed data from 3,821 parous women at least 50 years of age in the Korea National Health and Nutrition Examination Survey 2010-2012. The women were grouped into four according to the number of breastfed children (0 to 1, 2, 3 and 4–12) and breastfeeding duration in months (0–16, 17–35, 36–60 and 61–324).
Of the women, 2,197 (57.5 percent) had age-related cataract. Logistic regression analysis showed that the risk of developing cortical cataract was significantly lower in women who breastfed 4–12 children than in those who breastfed no or one child (odds ratio [OR], 0.56; 95 percent CI, 0.35–0.89; p=0.010 for trend across quartiles).
Likewise, the risk was reduced in women who breastfed for 36–60 months (OR, 0.61; 0.42–0.90) or 61–324 months (OR, 0.53; 0.33–0.83) than in those who breastfed for 16 months or less (p=0.003 for trend across tertiles).
The population-attributable fractions of cortical cataract associated with number of children breastfed <3 and duration of breastfeeding <36 months were 9.4 percent and 10.7 percent, respectively.
Researchers postulated that some metabolic diseases are likely to mediate the protective role of breastfeeding on age-related cataract. Several pathways have been implicated in the reduced risks of metabolic diseases in women who breastfed relatively many children or for a long-term period. For example, fat accumulated during pregnancy could be used to produce energy of lactation, and changes in weight during lactation might help reduce the risk of metabolic diseases.
Additional prospective and longitudinal studies are required to clarify the mechanisms underlying breastfeeding-related cataract formation, they added.