Daily Archives: June 16, 2013

Lead contamination in rice studies could not be replicated

Independent laboratories have not been able to confirm the levels of lead contamination in imported rice reported recently (April 2013) by various news agencies like BBC,CBS, Science Daily.  Some of the highest levels were found in baby food, reported the scientists, at the 245th National Meeting & Exposition of the American Chemical Society. Since FDA and independent laboratories have not been able to confirm these findings yet, scientists led by Dr. Tongesayi’s team, which is with Monmouth University in N.J., have delayed publishing their findings. To read more about “Study Linking Rice to Elevated Lead Levels Withdrawn” in FoodProductDesign.com, you may click here, and “Study of lead levels in Rice under Scrutiny” in BBC News Science & Environment.

Lead has been recognized as a poison for thousands of years, but the profound impact that chronic exposure to even low levels of lead can have on developing children only became widely recognized in the United States in the 1970s.

A rice field in Korea

A rice field in Korea

The Lead Contamination in Rice Study

The US imports 7% of its rice and 65% of this rice is from China, Taiwan, India, Italy, Bhutan, Israel, Czech Republic. Dr Tsanangurayi Tongesayi of Monmouth University in New Jersey, US, and his team tested for heavy metal contamination in rice, especially lead, from local food stores in New Jersey. They were concerned by the higher lead levels and speculated that daily lead exposure was higher. These levels were two to twelve times higher than what FDA finds a health concern. They concluded these levels could potentially cause harm to health. To read the full BBC News reported article you may click here.

Children would be most at risk in groups that ate more rice than any other grain. Asians and Latinos are rice preferring societies. Other societies drink rice milk to substitute for milk (lactose or casein) intolerance and rice cakes to substitute for wheat (gluten) or oat intolerance.

An active area of research is why different people react differently to similar levels of lead exposure. This variability is the reason why the Centers for Disease Control (CDC) always refers to a child as having an “elevated” blood lead level – i.e., a level above which symptoms are frequently seen in children – as opposed to calling a child “lead poisoned”. There is clear evidence even very low levels of lead are harmful to children’s health. In addition, studies suggest individuals who suffer from chronic lead poisoning during early childhood are more likely to behave violently and engage in criminal behavior later in life. Hilary A. Godwin, Ph.D. Professor, UCLA Department of Environmental Health Sciences, article summarizes our understanding of the effects of lead exposure on children’s health, and explains why the focus of the pediatric and environmental health communities has shifted toward prevention of lead poisoning.

An important take-home message from all of these studies of the effects of lead poisoning is that it is better to prevent lead poisoning from happening in the first place than to treat lead poisoning after it has occurred, an approach often referred to as “primary prevention of lead poisoning”. Possible known sources of lead exposure are lead house paint, and contaminated soil.

Diet to lower absorption of lead

Diets rich in nutrients, such as iron, calcium, and zinc, and low in fat have been shown to reduce the amount of lead that children (and adults) absorb into their bodies for a given exposure. There is an interesting relationship between zinc and protein — people who do not include a sufficient amount of protein in their diets do not have sufficient amounts of zinc in their body. The body can get zinc from protein-rich foods such as nuts, pecans, pumpkin seeds, and sunflower seeds. The best sources of zinc include milk, yeast, peanuts, potato, whole wheat bread, cheese, beans, yogurt, brown rice, wholegrain cereals, etc. You may read more about such a zinc rich diet by clicking here for this Newsmax Feb 2011 article.

Interestingly, the 1999 Nobel Prize in Medicine was for discovering that humans need protein to absorb minerals like zinc. Which means a healthy diet must include protein and minerals like zinc.

Ironically, rice plants may come naturally fortified with zinc. One might speculate: could rice naturally fortified with zinc prevent detrimental effects of lead exposure through lead contaminated rice? Rice plants grown in zinc deficient soils suffer from “Khaira” disease, or zinc deficiency. You may read more about the Khaira zinc deficiency disease of rice in India by clicking here, for a 1985 journal article by scientists Chatterjee and Mandal, in the Department of Agricultural Chemistry and Soil Science, Kalyani, India. Total dietary intakes of zinc of the people from Japan, Indonesia and China, where rice is the primary cereal grain, was higher than the recommended dietary allowance of daily zinc intake from foods by the American standard diet (15 mg/person). You may click here to read more about the zinc levels of rice in these three countries. Needless to add, perhaps, this natural level of zinc in rice can protect upto a certain threshold of lead contamination in rice, and has been developed by ancient societies that consume rice over the millennia.

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