Toxins in plant-derived foods can be reduced

Even whilst grains, vegetables and other plant-derived foods are processed well, not all of them come out as toxin-free, since contaminates can be absorbed from the soil and accumulate in plants. The heavy metal cadmium (Cd) is one of the most common toxins found in plant-derived foods, and it can accumulate in the human body for decades. There are new ways to reduce the amount of Cd found in the food we eat, according to a review published online in the Cell Press journal Trends in Plant Science.

"Cadmium is virtually everywhere in the environment, and it is taken up into the human body and bioaccumulates for decades in the kidney," says first author Dr Stephan Clemens, of the department of plant physiology at the University of Bayreuth, in Germany. Cd exposure may lead to kidney dysfunction, osteoporosis, cancer, cardiovascular disease, and other serious health conditions.Because there is no safe level of cadmium exposure, there is an urgent need for lowering its intake.

“We need to further develop molecular understanding of the mechanisms that lead to plant Cd uptake for the reduction of Cd levels in food. Fortunately, our knowledge is growing,” says Dr Clemens who, along with colleagues investigated how Cd accumulates in certain plants. Data they gathered will be used in determining how to develop low Cd accumulating plants.

"Through excellent basic rice molecular biology and genetics research, we have in the past couple of years learned a lot about why one rice plant accumulates” more Cd in the grain than another rice plant even when they are grown on the same field, he explains. “This knowledge can now be used for targeted and efficient breeding to develop cultivars that retain their favourable characteristics but transport less Cd to the grain."

Cd accumulation in wheat and potato should also be studied, according to Dr Clemens.  As far as the researchers can tell, breeding crops for low Cd accumulation is not common practice but is doable since certain varieties of plants have varied Cd uptake. Moreover, the genes that can be used as markers to select specific varieties to breed have already been identified. Dr Clemens also points out that it is better to eliminate cadmium from the environment although it is a long process.