Arsenic and Rice
In May 2009, the UK Food Standards Agency published results from two studies: one on arsenic levels in rice drinks and one on cooking methods to reduce arsenic levels in rice.
Arsenic occurs naturally in a wide range of foods at low levels. The toxicity of the arsenic depends on the chemical form in which it is present. The organic form is less harmful than the inorganic form which is known to cause cancer. Most arsenic in the diet is present in the less harmful organic form.
Rice Drinks
The Food Standards Agency carried out a survey of inorganic arsenic in 60 samples of rice drinks. Arsenic was detected in all samples of rice drinks at low concentrations. An average concentration of 0.023 milligram/kilogram of total arsenic and 0.012 milligram/kilogram of inorganic arsenic was found.
They now recommend that toddlers and young children should not have rice drinks, often known as rice milk, as a replacement for cows’ milk, breast milk or infant formula.
Cooking Methods
Arsenic levels were examined in rice that had undergone various forms of cooking. Basmati, long-grain, polished (white) and wholegrain (brown), as well as parboiled rice, were investigated. The effect of rinse washing, low volume (2.5:1 water:rice) and high volume (6:1 water:rice) cooking, as well as steaming, were investigated.
Rinse washing was effective at removing about 10% of the total and inorganic arsenic from basmati rice, but was less effective for other rice types. While steaming reduced total and inorganic arsenic rice content, it did not do so consistently for all rice types.
Low volume water cooking did not remove arsenic. High volume water rice cooking did effectively remove both total and inorganic arsenic for the long-grain and basmati rice, by 35% and 45% for total and inorganic arsenic content, respectively, compared to uncooked (raw) rice.
References
http://www.food.gov.uk/news/newsarchive/2009/may/arsenicinriceresearch