Location, condition of land affect arsenic levels in rice

In recent months there has been an increasing number of headlines about arsenic in foods. First, apple juice was implicated, and more recently, brown rice syrup was found to be high in arsenic.

Because brown rice syrup is often used in baby foods and natural food products in place of other sweeteners like high-fructose corn syrup, it is of particular concern. Since overconsumption of arsenic leads to health problems, brown rice syrup is under increased scrutiny, and many people are wondering whether they should worry about eating rice.

QUESTION: Does rice contain significant amounts of arsenic?

ANSWER: Concerns about arsenic in rice have been around for quite a while. In fact, China even has a legal limit for the amount of arsenic permitted in rice.

The arsenic content of rice varies depending on the amount of arsenic contained in the water and soil. As a general rule, California-grown rice has lower levels of arsenic than rice from Southern states. Also, because arsenic accumulates mostly in the outer layer of the rice grain, white rice contains less arsenic than whole-grain brown rice.

Rice from other countries varies greatly in arsenic content and can be low or high depending on where the rice is grown. Rice grown in some parts of South and Southeast Asian countries has very high arsenic levels. Since rice is consumed as a starch staple in these areas, some researchers consider the high arsenic content of the rice to constitute a “health emergency.”

Q: What are the main sources of arsenic?

A: Seafood and grains generally contribute most of the dietary arsenic. In some locations, however, water is the major arsenic source, especially well water.

Q: How does arsenic affect the body?

A: Based on animal studies, the body may actually require trace amounts of arsenic. When arsenic is completely absent from animal diets, growth and reproduction are impaired.

Because there is plenty of arsenic naturally present in foods and water, getting enough arsenic is not an issue. In the United States the average dietary intake of arsenic by people ranges from 12 to 40 micrograms per day. Based on animal studies, researchers have estimated that humans require 12 to 25 micrograms per day. At present, however, there is no official recommendation for arsenic intake as a nutrient.

There is, of course, concern for the toxic effects of excess arsenic intake.

Arsenic in foods is present in two general forms, inorganic and organic. Inorganic arsenic is considered to be the more toxic form.

When arsenic is consumed in normal amounts, it is handled by the liver and rapidly excreted from the body in urine. However, the body has a limited capacity to handle arsenic, so excess arsenic on a continuing basis becomes toxic.

Arsenic toxicity symptoms include skin problems, nerve damage, increased cancer risk and other potential problems. Thus, avoiding excessive arsenic in drinking water and food is important for long-term health.

Currently, arsenic is a hot food toxin topic. The reality, however, is that many other toxins are naturally present in most of the foods we eat. For a normal, healthy person, these toxins are readily detoxified and excreted from the body. They do not cause problems unless the intake exceeds the body’s capacity to handle the toxin. Consuming a wide variety of foods helps to reduce the odds of getting too much of a toxin that might be high in any one food.

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Joannie Dobbs, Ph.D., C.N.S., and Alan Titchenal, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dobbs also works with University Health Services.