Tuesday, 12 February 2013

Nick Ferrari wrong about ragwort on This Morning

I blogged a few days ago about the stories now circulating that somehow ragwort was contaminating the horse meat that has got into burgers and other supposed beef products on sale in the UK.

I have tracked down the source of this story. It comes from a statement made by Nick Ferrari on ITV's This Morning programme last Friday.

He said, in the context of problems from horse meat contamination of meat products,  that horses got a liver complaint from ragwort. It was the repeated by people on twitter as posing a risk to human health, which was the context in which the remark was made.

It simply isn't true that there is a risk. It is one of a long list of  ragwort myths which are circulated frequently. It is almost understandable, because they are repeated so often, that people believe them to be true.

The first question really is "why horses?",  any grazing animal might be a cause. Ragwort poisoning is rare.
Despite all the stuff that has been made up about it. Animals won't eat it unless it is in hay, this is because of their basic biology. Animals always instinctively avoid common poisons and these chemicals are in 3% of the world's plants.

This is a statement  Dr Peter Cheeke of Animal Sciences Department Oregon State University, a leading researcher into Ragwort. It is in the context of sheep but it applies equally to other meats.

The PA [ pyrrolizidine alkaloids] are not accumulated in the tissues; it is the damage that is cumulative. The damage is confined to the liver, which in an animal with ragwort toxicity would be shrunken and fibrotic. The carcass would likely be condemned because of the liver damage. In sheep which had consumed ragwort but did not show obvious liver damage, there would be no residues of PA in the meat. The PA are metabolized in the liver, and excreted as conjugates in the urine. Small amounts of pyrrole bound to DNA in the liver would not be measurable. Thus in my judgement there is no concern whatsoever about possible human toxicity from consumption of meat from sheep which had consumed ragwort.

So we can see that it  just it isn't true.

Always these two sites will give proper information.

Ragwort Facts
Ragwort Myths and Facts

Ragwort Hysteria latest entries

Friday, 8 February 2013

Horse Meat Hoax

Today's entry is a little piece of hysteria that is being circulated on Twitter and may have been in the media, although I have, as yet, been unable to pin down precisely where.

Most of the scary stuff you will see about ragwort has been made up.

As I regularly blog there are a whole host of hoaxes and misunderstandings about ragwort and this tweet from Twitter exemplifies the latest manifestation of an old one.

Outrageous, BBC unaware health risks. Ragwort, bute, Trichinella worm. Could have been eating for years!

This is someone who seems to be trying to interest the BBC in repeating the hoax.

Ragwort does not pose a risk of an size at all to meat.  The horse meat scandal is one thing but all the science indicates that there is no risk to humans from ragwort. Firstly grazing animals have evolved to avoid eating poisons, secondly the possibility of the meat being a problem has been looked at by experts and it has found not to be a risk. Basically, the stuff goes out of an animal's system very quickly, and any  that remains is bound up
For the technical details see this briefing on ragwort and meat

Ragwort Hysteria latest entries

Wednesday, 6 February 2013

World Horse Welfare poor ragwort information

This is a few years old, this story, but I have just discovered this piece of poor information distributed by a horse charity. Unfortunately the horse charities have a poor record of accuracy. A while ago the British Horse Society were criticised after  their inaccurate stories led to one  of their leaflets being banned and a lot of inaccurate adverts stopped after action by the Advertising Standards Authority.

This time it is a letter published by World Horse Welfare.

It makes a number of questionable statements:-

I AM writing in response to Katie Campling’s article on ragwort “Get rid of this killer weed” (Examiner August 16).
The article stated that ragwort is “not thought to be dangerous to humans”, but World Horse Welfare would like to urge people to take extreme caution when handling it. Humans can absorb the poison through their skin, so ragwort should NEVER be handled without gloves..... 

However, people who have properly studied the plant have a different view. This article by Dutch Ragwort expert Esther Hegt and Dr Pieter Pelser a world leading authority on ragwort with a PhD on the plant  comes to a different conclusion.

Through our research about the sources of the reports on the danger of touching ragwort, we conclude that there is no substantial evidence that there is a health risk for people. The amount of pyrrolizidine alkaloids that might be absorbed through the skin is very low and there is no proof that these alkaloids are being changed into a toxic form.
Then the letter goes on:-

Ragwort is a hooligan plant which spreads incredibly quickly; once it flowers about 200,000 seeds per plant are open to the elements and this year World Horse Welfare field officers have answered record numbers relating to it.
Aside from the rather emotive and unscientific use of the word "hooligan" the facts seem at odds with these claims. Ragwort seeds have been studied and the overwhelming majority fall within a few metres of the parent plant. See Ragwort Seed dispersal for more details. So It does not spread "incredibly quickly"
It is also untrue that a plant usually produces 200,000 seeds per plant. This is a highly unlikely and exceptional figure in fact half that figure is a high figure as we would see from the studies here in this article on Ragwort Seed production.

As for them receiving record calls could that be because people like this charity are publishing exaggerated information which is generating hysteria?

We do know of course that lots of the panic about ragwort appears to be totally made up.
Ragwort Hysteria latest entries