Archive for May, 2012

Fluoride & the Brain: Déjà Vu

May 30, 2012

The alternative health community is at it again, once more spreading fear and misinformation regarding the effects of water fluoridation and the use of dental fluoride. In a post title “Fluoride Lowers Your IQ | A Debated Truth?“, Mike Barret of Natural Society cites a 2010 study titled “Serum Fluoride Level and Children’s Intelligence Quotient in Two Villages in China” to argue that the “great deal of controversy revolving around the addition of fluoride in many communities’ drinking water” is based on demonstrable health concerns. I’ve dealt with Natural Society before and once again the current study being cited does not actually support the claim being made. Citing studies done on the health dangers of high levels of naturally occurring fluoride in groundwater, exposure to industrial pollution, and occupational fluoride exposure as evidence against the controlled use of dental fluoride and water fluoridation programs is a common tactic among anti-fluoridationists. I have long maintained that whenever possible, one should read the original study. The study cited by Barret involved 512 children from two villages, Wamiao and Xinhuai, in China. The authors of the study describe the villages,

Wamiao and Xinhuai are located 64 km apart in Sihong County. Wamiao village, in northeast Sihong County, about 32 km northeast of Sihong, is a severe endemic fluorosis area. The mean fluoride level in Wamaio drinking water was 2.47 ± 0.79 mg/L (range 0.57–4.50 mg/L), and the prevalence of dental fluorosis and defected dental fluorosis was 88.56% and 38.98%, respectively. Xinhuai village, in the southwest part of Sihong county, about 32 km southwest of Sihong, is a non endemic fluorosis area. The mean level of fluoride in Xinhuai drinking water was 0.36±0.15 mg/L (range 0.18-0.76 mg/L), and the prevalence of dental fluorosis was 4.48%, with no cases of defected dental fluorosis identified (Xiang et al. 2004, National Standard of P.R. China 1997).

In the study children in Wamiao were found to have lower IQ scores[1] and higher serum fluoride levels than children in Xinhuai. In Xinhua 27.59% scored in the >110 range indicating “high intelligence”, 51.72% of children scored in the 90-109 or “normal range”, and another 6.2% in the <79 range, this is compared to only 8.11% of children from Wamiao scoring in the >110 range, 47.30% in the 90-109 range, and 15.31% in the <79 range. The authors came to the conclusion that the difference in fluoride exposure is responsible for the differing IQ scores after accounting for various factors. Take notice of the levels of fluoride reported for each village. Wamiao, where lower IQ scores were reported, had levels that ranged from 0.57–4.50 mg/L which on the high end exceeds the current Environmental Protection Agency’s enforceable guideline (4.0 mg/L) for fluoride in groundwater and is double the secondary guideline (2.0 mg/L) meant to protect children. However the village of Xinhuai, where IQ scores were higher, had levels of 0.18-0.76 mg/L which is actually quite close to the Department of Health and Human Service’s current standard (0.7 mg/L) for community water fluoridation and is below both the EPA’s enforceable and secondary guidelines. Both the DHHS and EPA’s guidelines are evidence-based, in general reflecting the current scientific literature and consensus, and they are amicable to review and revision. This is a great example of science in action. Rather than providing evidence that community water fluoridation is dangerous, this study actually is in line with the current guidelines and regulations. There is always room for more science, but continuing to the repeat the same canards over and over while crying “SHILL” & “CONSPIRACY!” at any dissent is not advancing science.

Further Reading:
Fluoride & Brain Damage

Fluoride & Heart Disease?

Fluoride & the Brain: Strike 3, You’re Out!
Fluoride & the Brain: The China Studies
Community Water Fluoridation: Guidelines and Recommendations
Your community’s fluoridation level can be seen at My Water’s Fluoride

[1] I will not delve into the issues surrounding IQ testing at this moment but I will direct my readers here for a introduction to the controversy

Animal Genes & Rothamstead Wheat Trial

May 2, 2012

An issue in relation to genetic engineering of crops often brought up by other vegans and vegetarians is, “What about inserting animal genes into plants, doesn’t that make them no longer vegan/vegetarian?” The short answer is, no, absolutely not, and as pointed out before, the fear of consuming “animal genes” in plants is only theoretical because there are no such products on the market. But in light of the irrational stances taken by groups such as the Vegan Society and the International Vegetarian Union I feel this issue could use further exploration.

Courtesy of the National Human Genome Research Institute

To begin we must understand what genes are. Genes are small segments of DNA, consisting of the four chemical bases adenine, cytosine, guanine, and thymine. Genes code for specific proteins that perform a variety of functions. Genes are like the blueprints for life. The relationship between genes and proteins is explained by long-time vegetarian and Professor of Microbiology & Molecular Genetics, Dr. Emanuel Goldman,

Think of these four individual chemicals in DNA as an alphabet consisting of four letters. Protein is made when these letters are “read” by cellular machinery as a series of “triplets”–that is, different sets of three letters in sequence which designate one or another of 20 amino acids in the intended protein. The arrangement of those four letters in groups of three at a time constitutes the entire dictionary of words of the language; a gene is a collection of those words in sequence, much like this article is a collection of words in sequence. Just as this article can be reprinted in another publication, a sequence of DNA containing a gene from one source can be cut out by molecular “scissors” (which are enzymes) and pasted by molecular “glue” (which are other enzymes) into the DNA of another source. This is what recombinant DNA and genetic engineering accomplishes. When the information of a gene in DNA from an animal is copied and placed in the DNA of bacteria, often those bacteria will be able to produce the animal protein. Similarly, when a foreign gene is inserted into the DNA of a plant, that plant may produce the foreign protein, which is the case in some genetically engineered crops.

You see, the genetic language of life is common to all living beings, we all share a common ancestor and significant amounts of our genetic code, there is no special category of “animal genes” and “plant genes”. A gene is a gene is a gene. Furthermore, genes can not suffer, they are not sentient. They are simply bits of DNA. Karl Haro von Mogel gives us further insight using what is likely the most iconic example of transgenic crops,

The fish-tomato example is rather ironic, as this meme began when scientists were experimenting with using the “antifreeze protein” from a species of fish to see if they could keep tomatoes from freezing (They were never commercialized). But as it turns out, a similar antifreeze protein in cod evolved out of noncoding DNA– going from useless sequences (sometimes haphazardly referred to as ‘junk DNA’) into a functional and essential gene. If you put this antifreeze gene in a tomato, is it even a fish gene? Or a junk gene? What if it once was a viral gene that got into fish, and eventually became what it was before a genetic engineer stuck it in a fruit, is it still a viral gene?
It’s an antifreeze gene… that evolved in fish. And you would essentially still be eating a tomato.

nucleotide sequences in wheat

In his book, Pandora’s Picnic Basket, Alan McHughen explores this issue even further,

      No doubt, some vegetarians will decide that a single pig gene in a soya burger is sufficient to prohibit consumption. Other–perhaps even vegans–will decide, like the rabbi, that the single pig gene lacks the ‘essence’ of the animal and so the burger is therefor suitable for consumption.
    Even here, though, drawing a line is difficult. Consider what happens if scientists wanted to improve the nutrient balance of legumes. We might use a gene from a Brazil nut, producing a protein rich in cysteine and methionine, amino acids which are deficient in soya bean and other legumes. We have to reject this gene, though, because the resulting protein is allergenic. As an alternative, we find a more suitable, non-allergenic protein from a tomato gene, although this gene provides a protein not quite as rich in the two amino acids. Our soya bean with the modified tomato gene would seem perfect for vegetarian consumption, having better nutritional balance, not being allergenic, and lacking animal genes or products. It would seem acceptable to vegetarians. We later discover the modified tomato protein is identical to a pig protein. Is it still suitable for vegetarian consumers? If not, at what point does it or did it become prohibited?
    Lets throw in another question. We just discussed a genetically modified tomato gene. Now assume we find a natural unmodified tomato gene is identical to a pig gene. If ordinary tomatoes (and, in all likelihood, other fruits and vegetables) are suddenly blacklisted because they share a gene with a pig, what do people then eat? If ordinary fruits and vegetables sharing pig genes are not prohibited, there’d be no scientific basis to prohibit GM plants carrying a gene similar or identical to those in pigs.

It is interesting that McHughen explores this line of reasoning because it is actually quite relevant to a recent controversy that has reared its ugly head. In the town of Harpenden the worlds oldest agricultural research center, Rothamsted Research, is conducting a trial of a new genetically engineered wheat that repels aphids and will drastically reduce wheat farmers’ need for pesticides. Unfortunately, a group calling themselves Take The Flour Back have been spreading misinformation and fear about this trial and have even threatened to destroy it on May 27th 2012 in a public “decontamination”. Ive written previously about the specific claims Take The Flour Back make in their propaganda video and in the end the video is little but distortions, falsehoods, and tired myths. A central scare tactic of the Take The Flour Back campaign is that this wheat has been modified to contain “an artificial gene ‘most similar to a cow’” and they have even whipped up a little graphic (seen above) to really bring it home. The problem is this is a gross oversimplification of the project to the point of misrepresentation. Rothamsted Research explains the the modification as,

Chemically synthesised gene sequences that had been codon-optimised for wheat encoding plastid-targeted enzymes (E)-β-farnesene synthase and farnesyl diphosphate synthase were assembled by GenScript Inc. NJ, USA and introduced into plant cells on complete binary plasmids by biolistic transformation. Genes encoding (E)-β-farnesene synthase and farnesyl diphosphate synthase both possessed a wheat chloroplast transit sequence from the small subunit of RubisCo, previously validated to correctly target the proteins to wheat plastids (Primavesi et al 2008). The nucleotide sequences of these genes are synthetic and chimaeric and not found naturally. However, the enzyme encoded by the EBFS cassette is similar to that found in peppermint (Mentha × piperita) and the enzyme encoded by the FPPS cassette has most similarity to that from cow (Bos taurus) but is generally ubiquitous and occurs in most organisms. Both plasmids carry right and left T-DNA border sequences, origins of replication and bacterial selectable marker genes necessary for maintenance in E.coli and Agrobacterium.

Put in more lay terms for the public record

       The organisms to be released are wheat plants that have been genetically modified to test a novel resistance to aphids, a major pest of cereals. The genetically modified plants were made by inserting new DNA into the wheat genome using a micro-particle delivery system.
      The new genes added encode enzymes that lead to the production of a volatile chemical that is naturally produced by aphids and many other plants. This chemical, (E)-β–farnesene (EBF) is known to repel aphids and to attract their natural enemies such as parasitoids and predators to the plant.
      The two new genes are synthetic i.e. they were not taken from another organism but chemically synthesized to function like wheat genes. The proteins they encode are common in nature and the particular forms used here are similar to those found in peppermint and cow.
     The plants also contain two selectable marker genes which both originate in bacteria. The bar gene gives the plant resistance to glufosinate herbicides and was used in the selection of transgenic plants. The nptI gene confers resistance to the antibiotic kanamycin and was used in the gene cloning steps. Glufosinate will not be used to control weeds on the trial site and this antibiotic resistance gene is not considered harmful in the context of this trial.

This wheat trial is a publicly funded project that is under strict regulations and has undergone plenty of safety evaluation, the level of fear and distrust displayed by Take The Flour Back is unwarranted and the continued promotion of misinformation in order to drum up more fear is highly irresponsible. Even more irresponsible and unethical is the intended destruction of valuable scientific research. The scientists at Rothamsted Research are not taking the threats of “decontamination” lightly and have issued a letter to Take The Flour Back appealing to their consciences in addition to a petition calling for the defense of science. I urge all my readers to watch the video below, read the appeal letter, and sign the petition. Tell anti-GM activists to back-off and leave the Rothamsted wheat trial alone.

Further reading:
Rothamstead Research Application: part A & part B
ACRE’s advice for Rothamsted Research’s GM wheat
What do you want to know about GE wheat? by Karl Haro von Mogel
You’re eating viral DNA? by Karl Haro von Mogel
Animal DNA in My Tomato??? on Beyond the Rows
Objection to genetic engineering statement in “THE WORLD-WIDE MILLENNIUM PLEDGE.” by Dr. Emanuel Goldman
Veggie Tales: Eating plants with animal genes does not make you a carnivore. by Ronald Bailey
Q&A: Plant scientists answer your questions



Follow

Get every new post delivered to your Inbox.

Join 265 other followers