Lead is one of the most toxic metals known to man - and it's everywhere in our environment. It tends to settle in our bones, and it has already been blamed as a possible cause of various chronic disorders, usually associated with ageing, such as hypertension and cognitive decline.
But researchers are now linking high lead levels to cataracts, still the major cause of blindness in the world. A research team from the Brigham and Women's Hospital in Boston has made the connection after studying the health records of 795 males who participated in an ageing study.
They checked the participants' bone-lead levels and the development of cataracts. They found that 122 of the men were developing cataracts - and they were also the ones who had nearly three times greater lead concentrations in their bones than participants with healthier eyes.
And the risk increased to over three times when the researchers also included other known factors, such as cigarette smoking, diabetes and lead levels in the blood.
Few in the cataract group were taking supplements such as vitamins C, E and carotenoids, which might have offset some of the symptoms of lead toxicity.
And this probably is the key that you can use to help protect yourself. Although government agencies have finally recognized the dangers of lead in the environment, and especially by reducing levels in petrol and car emissions, most homes have unacceptably high levels of lead pollution, particularly from paint and the piping around the walls. It's reckoned that up to 80 per cent of homes in the United States that were built before 1980 have high levels of lead in the environment.
So the least we can do is to keep on taking the supplements.
(Source: Journal of the American Medical Association,2004; 292: 2750-4).