Salt named as major culprit in onset of cataract

The website said a new Australian study recently published in the American Journal of Epidemiology found a relationship between a high-salt diet and posterior subcapsular cataracts. It reported that people with high salt diets ran twice the risk of developing the most visually disabling form of the disease. The study found no association between dietary salt and nuclear or cortical cataracts. Some 2,783 people aged 49 to 97, with a median age of 65, took part in the study, of whom 160 had posterior subcapsular cataracts, 350 had nuclear cataracts and 650 had cortical cataracts. They were put into five groups according to their salt intake. Researchers asked participants to fill out food frequency questionnaires to assess their salt intake. The highest quintile consumed 3,200 mg (slightly more than one and a quarter teaspoons) of salt a day, while the lowest intake was 1,300 mg (just over half a teaspoon). These results were compared with the recommended daily intake of 2,400mg (slightly more than one teaspoon). People in the top quintile had known risks for cataracts - the highest median age, the highest incidence of diabetes, the highest incidence of hypertension and were most likely to have used steroids. However, the researchers said their finding indicated that even after taking these factors into account, excessive salt seemed to make it harder for the body to maintain the low levels of intracellular sodium required to maintain lens transparency.