This is the VOA SpecialEnglish AGRICULTURE REPORT.
Too much metal in the soil is considered pollution. Yet toolittle metal in a person’s diet can cause health problems. AnAmerican scientist says the answer to both problems may be plantsthat take up large amounts of metal in their tissues.
David Salt is an expert on plants at Purdue University in WestLafayette, Indiana. He is working with plants that store largeamounts of metals.
In recent years, scientists have shown interest in using suchplants to clean up harmful waste materials. Professor Salt says suchplants also could be used to improve people’s diets or even tocreate foods that fight cancer.
Humans need a number of metals in their diets, including iron andzinc. These metals are needed in very small amounts, however. Thatis why they are called micronutrients. The lack of micronutrients isblamed for health problems in many developing countries. Childrenand pregnant women are mostly affected.
Recently, Mister Salt announced that he has identified and copiedthe genes from a kind of plant that stores metals in its tissues.The Proceedings of the National Academy of Sciences published hisfindings.
Mister Salt says his study suggests it may be possible to developplants that contain minerals needed for good health.
For example, the metal selenium is a strong anti-cancer agent.Some wild plants store selenium naturally. Mister Salt says foods tofight cancer might be created if genes from these plants could bemoved into crop plants.
A plant called locoweed stores selenium. Locoweed is common inthe western United States. Mister Salt says it may be possible tocreate cancer-fighting foods from locoweed. He and scientists from acompany called NuCycle Therapies have copied the gene that causeslocoweed to take up selenium from the soil.
Many people take pills to add important minerals or vitamins totheir diet. However, Mister Salt notes that most selenium productssold in health food stores are of little use. That is because thehuman body can only take in and use selenium if it is in the rightchemical form.
The scientist says his team would like to develop a vegetablecrop high in selenium. He wants to create an anti-cancer product inthe foods we already eat.
This VOA Special English AGRICULTURE REPORT was written by GeorgeGrow.