Edible GM cottonseed

January 2020

In October 2019, the US Food and Drug Administration (FDA) gave the green light for GM cottonseed to be sold as food.

Cottonseed isn't a familiar food item. This is because cotton plants contain 'gossypol', a rather nasty toxin.

Gossypol is a highly reactive phenolic toxin present throughout the cotton plant which it protects from insect pests and microbial pathogens.

In animals, gossypol is known to damage heart tissue, red blood cells, the liver and thyroid function. It's best known for severe impairment of the male and female reproductive system and embryo development.

In the 1950s, China experienced a sharp drop in the birthrate in rural areas where people were consuming cottonseed oil which hadn't been purified of its gossypol content.

Gossypol readily binds to minerals and amino acids (building blocks of proteins), making them unavailable and compromising nutrition.

Cottonseed itself already has FDA approval for food use, providing it comes from a low-gossypol strain of the plant. Such conventionally-bred cottonseed hasn't been an agricultural success because, without its gossypol, the crop is susceptible to insect attack and disease.

The GM cotton contains a mechanism for RNA interference (RNAi) designed to act only in the seed where it blocks the first stage in the biochemical pathway for gossypol production [1]. It also contains an antibiotic resistance marker gene used in the development of the GM crop.

American regulators had no difficulty in approving the new GMO: it contains only 3% of conventional cottonseed gossypol levels; its RNAi content does not count as a food 'additive'; both DNA and RNA are 'generally recognised as safe' in any form in US law; no new protein is produced*; it's 'as safe as' and 'comparable' to human food from non-GM cottonseed.

*Note. The protein produced by the antibiotic resistance marker gene is considered an 'additive' and is obviously a protein but was approved for US food use in 1994.

Why would anyone want to eat cottonseed?

Like all seeds, cotton is packed with protein. Cotton is widely grown in areas where many people are poor and their diet is protein-deficient: edible cotton seed could become a staple part of their food supply. The high-protein meal left-over from oil extraction will feed into the processed and factory-baked food industries.

While conventional cottonseed can only be fed to mature cows in controlled amounts, GM cotton can be extended to feed the whole livestock industry, poultry, pigs, fish and shrimp.

For the farmer, GM edible cottonseed will create a dual-purpose crop, giving them added value for the same effort, inputs and land-use.

Why would you not want to eat GM cotton?

Despite the "strong evidence" suggesting natural RNAi molecules in plants "can survive digestion, enter the body and affect gene expression patterns" (Nawaz), no testing has been carried out to check for artificial RNAi interference with human, livestock or wildlife genes.

Note. The GM cotton's developers are well aware of RNAi mobility through living tissues. Their concern, however, was limited to the possibility that RNAi movement out of the GM seed would reduce gossypol levels elsewhere in the plant and create a crop susceptible to pests and disease.

Epigenetic effects of RNAi are recognised, but these have not been considered [2].

Besides gossypol, cotton has the capacity to produce at least fourteen other phenolic toxins. These are normally at low concentrations and are deemed to have little toxicological significance. The possibility of alternative toxin pathways kicking in to compensate for the loss of gossypol or as a stress response to the artificial gene interference, especially under conditions of environmental pressure, hasn't been considered. Gossypol, and presumably its cousins too, has a cumulative toxic effect, so low levels don't necessarily mean 'safe'.

Because phenolic toxins are damaging to microbial life, even small increases present in a staple food could profoundly alter the gut flora with negative consequences for health [3].

It's quite clear that it would not be possible to create this cotton by conventional breeding: it's highly unnatural. This, and the finding of unexplained significant differences in up to 20 components in crude compositional analyses of the GM cotton suggests its artificially disturbed genome is not performing in an equivalent way.

Note. The significant compositional differences were dismissed by comparing the GM cotton, not to its equivalent non-GM version, but to industry data derived from irrelevant historical total ranges.

GM low-gossypol cottonseed promises to be the first of many RNAi detoxified food crops, and is no doubt destined to incorporate GM 'Bt' insecticide and herbicide-tolerance too.


Given the rising, very real, concern about antibiotic resistance genes circulating in our environment, approving GM crops containing such genes might now be considered a crime against humanity [4].

Targeting the most vulnerable populations with an untested, novel staple food, which also conveniently supports the global commodity market, the processed food industry and the intensive rearing of livestock, raises ethical questions. Be prepared to give these people all the support you can.


[4] GM IN SEWAGE - December 2019

  • Muhammad Amjad Nawaz, et al., December 2018, Addressing concerns over the fate of DNA derived from genetically modified food in the human body: A review, Food and Chemical Toxicology 124
  • Let them eat GM cottonseed! GM Watch 15.10.19
  • Cotton with transformation event TAM66274 (TAM66274 cotton), Biotechnology Notification File No.000163 CFSAN Note to the File, US FDA, 18.09.19
  • Rial Christensen, Memorandum: Biotechnology Notification File No.000163 CFSAN Note to the File, 9.09.19
  • TAM-66294-5, International Service for the Acquisition of Agri-biotech Applications GM Approval database, 17.10.19
  • Sandra E. Morgan, Gossypol Toxicity in Livestock, Oklahoma Cooperative Extension Service VTMD-9116,
  • Shawna Williams interview with Keerti Rathore, The Long Road to Edible Cotton, The Scientist, 11.10.19
  • Ganesann Sunikuimar, et al., November 2006, Engineering cottonseed for use in human nutrition by tissue-specific reduction of toxic gossypol, PNAS
  • Dan Charles, Not Just For Cows Anymore: New Cottonseed Is Safe For People To Eat,, 17.10.18
  • Jack A. Heinemann, el al., 2013, A comparative evaluation of the regulation of GM crops or products containing dsRNA and suggested improvements to risk assessments, Environment International 55
  • Will Dunham, U.S. regulators allow genetically modified cotton as human food source, Reuters, 11.10.19
  • Ivana Cristina N. Gadelha, et al., May 2014, Gossypol Toxicity from Cottonseed Products, The Scientific World Journal

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