ngin - Norfolk Genetic Information Network
Date:  4 March 2001


Thanks to Mark Murray for this v. interesting article.
*  *  *
Bioengineered rice loses glow as vitamin A source
By Tina Hesman , Saint Louis Post-Dispatch - 4 March 2001 (search: rice)

* Golden Rice is years from market and, as a practical food source for the poor, may not meet nutritional goals.

When Swiss researchers announced last year that they had engineered rice grains to combat vitamin A deficiency, world health officials, biotech advocates and others hailed the development as a major advance in solving nutritional problems in the developing world.

Many in the biotechnology industry touted the rice - called Golden Rice for its color - as a savior for the beleaguered industry: a symbol of genetic engineering's promise.

But the rice may not be all it's puffed up to be.

The product, designed to make beta-carotene, is at least five years from market.  Moreover, some critics say that the amount of rice a person would have to eat to get the nutritional benefits promised is more than humanly practical.

Their estimates equate to a child having to eat 27 to 54 bowls of rice a day to get the recommended daily allowance of vitamin A. However, scientists involved in the project insist they can achieve some nutritional benefits with the equivalent of just two to four bowls a day.

Now, both sides in the debate over Golden Rice are playing a numbers game, with no clear winner yet.   But it's obvious from another set of numbers who's losing.

Consider these statistics provided by Gurdev S. Khush, the principal plant breeder at the International Rice Research Institute in the Philippines:

* About 400 million people are at risk of vitamin A deficiency, 124 million of them children.

* 1 million to 2 million children die every year because of a lack of vitamin A in their diets.

* About 500,000 children go blind as a result of vitamin A deficiency.

Many of the people at highest risk of developing a vitamin A deficiency live in Southeast Asia, where rice is a dietary staple. Normal rice grains don't contain vitamin A, or any of the chemicals, such as beta-carotene, that can be converted to vitamin A.

So when researchers led by Ingo Potrykus at the Swiss Federal Institute of Technology in Zurich came up with a way to get rice to produce beta-carotene in the edible parts, the innovation seemed like a potential nutritional boon for the developing world.

Companies that owned licenses on the technology used to create the yellow rice quickly offered up duty-free rights for humanitarian uses.  Monsanto Co. of Creve Coeur was one of the first agriculture biotechnology companies to get on board.

"This was an admirable project and a beautiful piece of science," said Gerard Barry, the head of rice genomics for Monsanto.  Five other companies also gave up their technology licenses to allow
humanitarian development of the rice.

Biotechnology industry representatives quickly seized on the companies' generosity and held Golden Rice up as a model for the way genetically modified crops could help feed the world. It was a badly needed positive message for an industry under fire, said Adrian Dubock, an executive at European biotech giant Syngenta Ltd.

"The biotech industry has come under exceedingly virulent attack," he said. "There was not a day that went by last year that there was not a huge wad of rubbish being published on the front page of the tabloid newspapers."

Amid the controversy about genetically engineered food, Golden Rice was a brilliant flash, something slick U.S. marketing firms could sell to a skeptical public in television and print ads, Dubock said.

But not everyone bought the soft-focus television images of mothers frolicking with their children while a smooth announcer discussed the potential benefits of Golden Rice and biotechnology.

"This whole project is actually based on what can only be characterized as intentional deception," said Greenpeace campaigner Von Hernandez in a prepared statement. "We recalculated their figures again and again. We just could not believe serious scientists and companies would do this."

Golden Rice won't be ready for widespread use in developing countries for another five or six years, rice breeder Khush said.

Researchers at the International Rice Research Institute have just planted Golden Rice seeds and are waiting for the plants to grow and flower, a process that will take about three months, Khush said.  Then, about two years of breeding experiments will be required. Environmental safety studies, nutritional studies and seed propagation will take two to three years more.

"We can't just start crossing and growing plants in the field without serious analysis to confirm that everything is fine," said Paola Lucca, one of the developers of the rice.

Activists are questioning the nutritional value of the rice as well.  By the most conservative estimates of nutritionists, a 4-year-old would have to eat nearly 4 pounds of Golden Rice, which would fill about 9 cups, to meet the entire recommended daily allowance of vitamin A. And
that's 4 pounds of uncooked rice.

Cooked, the rice would fill more than 27 bowls - well beyond the amount of rice any child could be expected to eat in a day.

A new report by the Food and Nutrition Board of the Institutes of Medicine, which is associated with the National Academies of Science, indicates that the situation could be even worse.

Previous nutritional calculations were based upon data that indicated that the body needs 6 micrograms of beta-carotene to produce 1 microgram of vitamin A. More recent studies suggest that it takes 12 micrograms or more of beta-carotene from food to make 1 microgram of vitamin A in the body.

Based on the new estimate, a 4-year-old would have to eat 54 bowls of Golden Rice to get all the vitamin A in the recommended daily allowance. Supporters of the technology say it's ridiculous to expect Golden Rice to supply all of a child's vitamin A needs. Having any vitamin A in the
diet is much better than none, they say.

The inventors of Golden Rice never intended it to be more than a dietary supplement, Lucca said. The developers aimed for a daily allowance of 100 micrograms of vitamin A, a level that should prevent night blindness, she said. A child could get that much vitamin A by eating two
to four bowls of Golden Rice each day.

But the nutrition board says that a 4-year-old needs at least 150 micrograms of vitamin A every day to prevent night blindness. That would require three to six bowls of Golden Rice.

But at that level of vitamin A in the diet, 50 percent of children would still suffer night blindness. The board said that in order to achieve complete alleviation of night blindness, children need at least 210 micrograms of vitamin A per day - four to eight bowls.

But the truth is, no one really knows exactly how much Golden Rice a 4-year-old would have to eat to keep from going blind, said Allison Yates, director of the Food and Nutrition Board.

That's because no one knows how much beta-carotene Golden Rice will yield to the body, Yates said. And a number of variables, including the fat content in a child's diet and whether the child has an infection, could influence how much beta-carotene the child could absorb.

"One would assume there's been lots of studies on this, but there's really just a handful," she said.

How Golden Rice adds up

The calculations used in this story for the amount of Golden Rice a 4-year-old would have to eat are based on some assumptions:

* The recommended daily allowance of vitamin A for children 4 to 6 years old is 500 micrograms.

* Golden Rice contains 1.6 micrograms of beta-carotene per gram of rice.

* The body needs 6 micrograms of beta-carotene to make 1 microgram of vitamin A.


* To get 500 micrograms of vitamin A, a child needs to consume 3,000 micrograms of beta-carotene.

* To get 3,000 micrograms of beta-carotene, a child needs to eat 1,875 grams (4 pounds) of Golden Rice.

* Considering that one cup of uncooked rice weighs about 7.1 ounces, 4 pounds would be equal to 9 cups of uncooked rice.


* When cooked, rice expands to about three times its volume. So 9 cups of uncooked rice would make 27 cups - each equivalent to about one bowl - of cooked rice.

Source: F. Jack Francis, University of Massachusetts; Paola Lucca, Swiss Federal Institute of Technology; Post-Dispatch research
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