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  • From: Road's End Farm <organic87 AT frontiernet.net>
  • To: Market Farming <market-farming AT lists.ibiblio.org>
  • Subject: Re: [Market-farming] Now......golden rice
  • Date: Tue, 20 Sep 2011 14:33:32 -0400


On Sep 20, 2011, at 11:18 AM, Thamnophis wrote:

Wiki has some interesting info about Golden Rice that illustrates my point:


Thanks for finally producing something beyond your own statements, Thamnophis. However, note that the Wikipedia article is marked both "outdated" and "needs attention from an expert on the subject". While Wikipedia is often a good way of finding out enough about a subject to start doing research on it, the quality of its articles varies so widely that a Wikipedia article, even if not marked with warning language, doesn't work very well as a sole source of information.

I think the Golden Rice project may be well-intentioned. However, there are significant problems with it. For one thing, the vitamin may still not be present in large enough quantities, and is likely not to be properly absorbed if there's not a balanced diet otherwise. For another, it's hardly the only way of providing the vitamin.

(note: the article discusses a rice producing 33.3 micrograms of A per 100 g of rice; more than was being produced at the time the article was written. The newer Golden Rice 2 provides 37 micrograms; not enough to significantly change the situation.)


The goal is 33.3% micrograms/100g of rice.  Even if this goal is reached after a few years, it will be totally
ineffective in removing VAD.
 
Since the daily average requirement of vitamin A is 750 micrograms of vitamin A and 1 serving contains
30g of rice according to dry weight basis, vitamin  A rice would only provide 9.9 micrograms which is
1.32% of the required allowance.  Even taking the 100g figure of daily consumption of rice used in the
technology transfer paper would only provide 4.4% of the RDA.
 
In order to meet the full needs of 750 micrograms of vitamin A from rice, an adult would have to
consume 2 kg 272g of rice per day.  This implies that one family member would consume the entire
family ration of 10 kg.  from the PDS in 4 days to meet vitaminA needs through "Golden rice". [ . . . ]

vitamin A rice will also create deficiency in other micronutrients
and nutrients.  Raw milled rice has a low content of Fat (0.5g/100g).  Since fat is necessary for vitamin A
uptake, this will aggravate vitamin A deficiency.  It also has only 6.8g/100g of protein, which means less
carrier molecules.  It has only 0.7g/100g of iron, which plays a vital role in the conversion of Betacarotene
(precursor of vitamin A found in plant sources) to vitamin A.


The Food and Agricultural Organization (FAO) started a project in 1985 to deal with vitamin A deficiency using a combination of food fortification, food supplements and general improvements in diets by encouraging people to grow and eat a variety of green leafy vegetables. One main discovery is that the absorption of pro-vitamin A depends on the overall nutritional status, which in turn depends on the diversity of the food consumed.

"Predominant rice consumption" is most likely to be accompanied by other dietary deficiencies


From http://www.biotech-info.net/mirage_of_promise.html (BBC news):

golden rice sounded like a real answer to a genuine problem, especially since the biotech company responsible, Zeneca, said it would offer the seeds freely to farmers in poor countries.

The reality, though, appears a little more prosaic. For a start, the genes for beta-carotene are already present in conventional rice.

It is just that they do not work as well in the "natural" varieties as in the novel version.

Beyond that though, poorly-fed people are unlikely to be able to absorb beta-carotene even when they eat golden rice. To use it, they need a diverse diet, including green leafy vegetables.

But the sorts of vegetables people used to be able to find have declined in number as the green revolution of the 60s and 70s emphasised monocultures of new varieties.

Household consumption of vegetables in India has fallen by 12% in two decades.

The prospects for golden rice receded a little further in 2002, when scientists published the draft sequences of the rice genome. [. . .] 

That promised quicker results from conventional plant breeding, partly because it established where the beta-carotene "pathway" sat in the rice code.

A scientist from the biotech company Syngenta, which now includes Zeneca, said: "All the genes are present in rice. One could make a non-GM vitamin-A rice simply by studying those genes in a more focused way."


And it's hardly a matter of either, feed people golden rice or let them continue vitamin deficient. Here's another approach:

http://www.fao.org/docrep/V1610t/V1610t04.htm



-- Rivka; Finger Lakes NY, Zone 5 mostly
Fresh-market organic produce, small scale





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