Nutritionists are advertising rice bran as one of the newest weapons in the arsenal against high cholesterol, poor digestion, poor nutrition and other age-related problems. The claims are all true, but one fact kept more or less hidden is rice bran's toxicity.

Rice bran is residue from the milling process, which delivers polished white and brown rice to tables around the world, particularly Asia. The leftover part, which is rice's shell, or coating, and which was in the near past discarded as useless, contains nearly all the vitamins the human body needs, as well as antioxidants, which help cells reverse some very negative aging processes like cancer. The absent vitamins, D and C, are generally added after processing to round out rice bran's "whole food" profile.

And whole food it is, containing not only vitamins and antioxidants but some rarer ingredients like CoQ10, an enzyme used by some health enthusiasts to prevent cancer, improve heart function and strengthen the immune system. This former reject of the rice finishing process also contains omega fatty acids, also found in fish and walnuts, which cut "bad" cholesterol risk, and ferulic acid, another powerful but little-known antioxidant recently tested for its role in preventing cancer. 

Since unmilled rice, and rice bran, is prone to spoilage due to its oil content, the bran has to be stabilized, or heat-treated (with or without chemicals). This process prevents future spoiling but if improperly done can dilute or remove some of the nutrients in rice bran. It can also make the bran somewhat insoluble, so its use in liquid food supplements is questionable.

At worst, some of these stabilizing processes, whose techniques and chemicals are kept secret under patent laws, may render the bran not only nutritionally useless but outright dangerous. Most reputable rice bran manufacturers use safe and nutritionally sound stabilization processes without toxic chemicals, but in Asia (where most rice is grown) corners may be cut in the interests of production. This "quick and dirty" manufacturing philosophy, as witnessed with toxic toys from China, may result in some off-brands that are actually harmful to your health.

A greater problem, though, are the levels of arsenic in rice bran, a problem only recently diagnosed. According to Andrew Meharg of Aberdeen University, the levels are so high that most brands would be illegal in China, the only country in the world to establish food-arsenic limits within the last decade. Meharg and colleagues are now asking both the U.S. and the European Union to either add or update their standards. The U.S. has none. The UK last evaluated standards in 1959.  

In the meantime, the problem persists, affected not only by "background" levels of arsenic in soil and water dating from an era when the substance was widely-used as an insecticide and rodenticide, but by the fact that deep wells in Asia - notably Bangladesh - are high in natural arsenic from igneous rock formations. Arsenic in water also occurs naturally in Argentina, Chile, China and Southeast Asia, India, Mexico, Thailand, Australia and the U.S. You can view the maps of global fluoride and arsenic contamination of water. 

A few years ago, rice bran was considered waste except in Japan, where it was used for pickling, cooking fish, and dish washing. More recently, this byproduct of rice processing has found its way not only onto health food store and supermarket shelves, but into food aid programs to nations like Malawi, Guatemala, Nicaragua and El Salvador.

Most of this rice bran, according to Meharg, contains almost six times as much arsenic (3.3 mg/kg) as polished white rice (0.56 mg/kg). The Chinese limit is 0.15 milligrams per kilogram (mg/kg).

Arsenic causes cancers of the lung, bladder, kidneys and skin. It may lead to, or exacerbate, high blood pressure, heart disease and diabetes. It may have long-term reproductive effects. In the fetal or childhood stage, it can lead to lower IQs (pdf), impaired memory, learning delays and long-term neurological or mental health problems.

Researchers are cautioning the public that not all rice bran products are equally high in arsenic. Rice milled in Asia using the dry process may contain less arsenic than wet-milling. China may have the best standards, but not necessarily the best rice in terms of arsenic levels. Moreover, buying American rice, or rice bran, is no guarantee of lowered arsenic levels. In fact, a previous study found that U. S. rice had more arsenic than rice grown in some parts of Bangladesh, although rice grown in California is lower in arsenic than rice grown in places like Louisiana, Texas, Mississippi and Missouri, where former cotton fields treated with arsenic now yield rice.

For consumers struggling with choice, rice bran oil may be an excellent substitute, containing all the vitamins and antioxidants of rice bran, presumably without the concomitant levels of arsenic. According to a study published in the American Journal of Clinical Nutrition, rice bran oil was responsible for lowering LDL cholesterol by 7%, and so far no one has come forward to report significant levels of toxic chemicals.  

Established standards in the Western world for arsenic in food might help protect consumers, though most toxicologists recognize that there is no "safe" limit for arsenic. Still, Western consumers are presumably well enough educated to make their own risk/reward choices. In developing countries, where literacy is limited and rice bran donations represent a hedge against starvation, rice bran may be a charitable instinct whose benefits are largely overridden by its inherent dangers, and NutraCea's global food program may be more hype than hope.

I'm not advocating that the 40 million metric tons of rice bran produced worldwide every year go to waste, but I do think it would be better used as a biofuel feedstock than for rescuing starving children. That way, some of the land now used to grow biofuel feedstocks could be converted back to food production, leading to a win/win situation for both the environment and the world's poor.