Rice is one of the most popular foods on the planet — by some estimates, it supplies over one-fifth of all calories consumed by humans. Recently, however, dangers associated with rice have caught the attention of journalists and the public. Rice, as it turns out, is particularly susceptible to contamination by the metals arsenic and cadmium, both of which can have detrimental effects in humans — including an increased risk of heart disease, cancer, Type 2 diabetes, and bone fractures. But rice also carries some well-established health benefits, leaving many people unsure whether they should consume the grain.
The benefits of brown rice, in particular, have been touted for people with diabetes. A 2010 post on the New York Tiimes blog Well notes that brown rice has a lower glycemic index than white rice, and that its bran (the outer layer, which is removed in white rice) is rich in beneficial nutrients like magnesium, potassium, and fiber. That year, a study published in the journal JAMA Internal Medicine found that Americans who ate at least two servings of brown rice each week had a 10% lower risk of developing Type 2 diabetes, compared with those who ate it less than once a month. Other studies have found that consuming white rice, on the other hand, is associated with an increased risk of developing Type 2 diabetes.
Just last month, another study found that eating any variety of rice was associated with a healthier diet. Researchers at the Baylor School of Medicine in Texas found that frequent rice-eaters had higher levels of magnesium, folate, iron, potassium, and fiber in their diets. They also consumed significantly less saturated and total fat than infrequent rice-eaters, and more servings of fruit, vegetables, meat, and beans.
But, alas, only two days later, the health-conscious public was faced with an opposing consideration when Well posted another piece about rice, this time highlighting the problem of heavy-metal contamination. These metals, primarily arsenic and cadmium but also mercury and tungsten, accumulate in the husk and bran of the plant, making white rice far less likely to contain them at high levels. The problem doesn’t lie primarily in soil contamination, since soil naturally contains varying levels of these elements. Rather, rice — like many plants — has biological mechanisms to absorb and transport necessary nutrients, and these heavy metals are chemically similar in structure to other elements: arsenic to silicon, and cadmium to manganese. Cadmium contamination is primarily a concern in Asia, while arsenic levels in rice are a growing concern in the United States — the US Food and Drug Administration (FDA) is considering whether a maximum level of arsenic in rice should be established. In the United States, rice grown in the floodplain of the southern Mississippi River tends to contain the highest levels of arsenic.
Were you familiar with the risks and benefits associated with white and brown rice before reading this post? If so, have you tried to consume more white or brown rice as a result, or neither? Could you see yourself cutting rice out of your diet entirely, possibly replacing it with another grain? Would you support efforts to breed new varieties of rice — possibly using genetic engineering — that are less prone to heavy-metal contamination? Leave a comment below!