The risks of 'pharm' rice

December 2011

Different types of rice. Photo from Wikimedia Commons
Scientists in China have developed GM rice which could be used to produce an important human blood protein in the foreseeable future.

The protein is ‘human serum albumin’ (HSA), a major constituent of blood. It has wide, life-saving, clinical applications in treating, for example, burns and blood loss, and is necessary for the cell cultures used to produce vaccines and pharmaceuticals.



Currently, HSA is derived from donated human blood: the global market demand is 500 tons per year and supplies are limited. This shortage is exacerbated by concerns over viral or prion contamination of blood sources. In China, the high price and shortage of HSA has even led to fake albumen appearing on the market.

With a potential yield of, a whopping, 2.75 grams per kilogram of brown rice (over 10% of the soluble protein contained in the rice), transgenic rice would provide a substantial supply of HSA. The novel albumen is formed in the grain only and seems to be chemically and immunologically equivalent to natural HSA.

Because rice is highly self-pollinating and the pollen short-lived, the authors consider that established containment protocols for growing and transporting the GM crop will largely diminish environmental impacts.

'Pharm' crops are not new. Between 1991 and 2011, 101 such GM experimental crops reached the stage of open field trials in the USA. Food and feed plant varieties were used for 77 of these, 21 of which involved GM rice. Advocates of open-field plant pharmaceutical production have not been obliged to report comprehensive ecological studies following their trials, and environmental management is mostly withheld as a trade secret. In cases where environmental impact studies have been reported, the safety requirements employed appeared to be very primitive and in most cases ineffective.

Transgenic pharmaceuticals produced in fields will impact on wildlife, farm animals, the soil and water.
Despite the author' opinion on the feasibility of containment, the lessons of the global contamination caused by a small-scale open plot of experimental herbicide-tolerant rice in America and several gene escapes in China, indicate that GM rice is particularly problematic to control. Contamination of the human food chain due to seed spillage, admixing of grains during storage and transport, pollination and horizontal gene transfer (especially if the plant-pathogen Agrobacterium is used as a transfection agent) are all very real risks. Professor Joe Cummins comments:
“The use of primary food and feed crops such as maize and rice in open fields is pure folly”. 
He is adamant that pharm crops must only be grown greenhouses which are pollen-, seed-, insect- and rodent-proof, and also, if viruses are used in the process, virus-proof. Dependence on the plants' intrinsically limited pollen spread is totally insufficient.

Besides the dangers to the environment there are dangers to humans from transgenic HSA.

So far the safety profile of the novel albumen seems good. However, as Prof Cummins has pointed out, HSA can form derivatives (Advanced Glycosylation End-products, AGEs) which can be toxic: they can accumulate causing alterations in proteins and tissue damage, they can change cell responses and can cause DNA mutations.

If transgenic HSA inadvertently became a regular feature of our diet, the potential for chronic disease, cancer and foetal damage is inescapable.

OUR COMMENT

An added concern here is that HSA will be seen as a very safe first attempt at persuading regulators to allow pharm crops to be grown in open fields. Like the first GMO to hit the grocery shelves, the FlavSavr tomato, which sailed through the regulatory process because it didn't actually contain any novel protein but still became the bench-mark for all subsequent safety evaluations, HSA might well become the Trojan Horse which smuggles drugs onto your dinner plate.

NOW is the time to demand full physical containment of all pharm crops, and a ban on the import of food and feed from countries which don't implement these measures.


SOURCES
  • Prof. Joe Cummins, Pharm Crops Ignoring Health & Environment, Institute of Science in Society Report 9.11.11
  • Lauren Gravitz, rice seed yields blood protein, Nature online, 31.10.11
  • Yang He, et al., 2011, Large-Scale production of functional human serum albumin from transgenic rice seeds, PNAS
  • Belinda Martineau, First Fruit, 2001, ISBN 0-07-140027-3

No comments:

Post a Comment

Thanks for your comment. All comments are moderated before they are published.