In the latest study, Dr Menon’s team compared arsenic absorption across different types of rice, with different contamination rates, and while using different cooking methods.
They found white and parboiled rice, which are most commonly eaten in the West and across Asia, absorb more arsenic than brown rice when cooked with contaminated water.
Dr Menon said that finding and rolling out better ways to reduce arsenic-contamination in rice is critical, given the health ramifications. For instance in Bangladesh, it emerged in the late 1990s that thousands of wells were contaminated after millions of people became sick.
Acute arsenic poisoning has dramatic and immediate effects, including vomiting, abdominal pain, diarrhoea and – in extreme cases – muscle cramping and death.
But numerous studies have also linked long-term exposure to various cancers, cardiovascular disease and diabetes. According to the WHO, early childhood exposure can also have a negative impact on cognitive development, and increased deaths in young adults.
There are some strategies to reduce the risk. In Bangladesh – where people consume an average of 170kg of rice annually – authorities now paint wells red or green, after testing them for arsenic.
But the problem persists, and researchers are now focusing on strategies to reduce the amount of arsenic that rice absorbs.
Also working in Bangladesh, Dr Menon’s team found that draining and rinsing rice (like you would with pasta or noodles) once cooked reduces exposure compared to parboiled rice.
Meanwhile, Prof Meharg’s research has found that dehusking rice before you parboil and dry it, rather than afterwards, reduces inorganic arsenic levels. But he said this has “not been widely taken forward” so far.
“The realisation that there is a massive problem was some 30 years ago and nothing has been done to date,” he warned.
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