美国瘦肉精为什么在欧盟和世界上大部分国家禁止？请看

In April of this year, the European Food Safety Authority (EFSA) concluded that the metabolic fate of ractopamine hydrochloride is similar in pigs, cattle, laboratory animals, and humans. Their Panel on Additives and Products or Substances used in Animal Feed found from an acute study in dogs that tachycardia and peripheral vasodilatation occurred. Their report specified that NOAELS (no observable adverse effect levels) derived from pharmacological repeated dose studies should not be regarded as a meaningful basis for establishing an acceptable daily intake (ADI) because of the observed down regulation of lung beta-adrengergic receptors. They explained that when evaluating hypothetical risks for consumers, data from acute pharmacological studies would better reflect the consumer situation after intake of a single meal containing ractopamine residues.

According to this panel, significant subpopulations which may be at higher risk for adverse events after beta-adrenergic stimulation require particular consideration when estimating the safety factor. Attempts to derive an ADI so far have not sufficiently taken into account these population subsets at higher risk. The panel concludes that 5 mg, the lowest administered dose, cannot be considered a no-effect dose. Human study cannot be taken as a basis to derive an ADI as previously purposed, and no MRL could be established. The Committee for Medical Products for Veterinary Use concurred with this conclusion. This is in conflict with the Codex Joint Expert Committee on Food Additives which says ractopamine is a safe treatment for all concerned.

Others studying ractopamine have concluded that it may be more toxic after its first pass through the liver because metabolites have their own individual profiles. Ractopamine has not yet been studied after passage through animal livers in the form in which it would be present in the tissues of animals fed with it.

Paylean label says it's not for human use

There may be no clearing period required before turning ractopamine fed animals into dinner, but the Paylean label suggests significant hazards for humans using the substance. It clearly warns that individuals with cardiovascular disease should use special caution to avoid exposure. Persons mixing and handling Paylean are advised to use protective clothing, impervious gloves, protective eyewear, and NIOSH approved dust masks, as well as to wash themselves thoroughly immediately after handling Paylean.

Other countries say no to ractopamine

Only 24 counties support the use of ractopamine. It is banned in 160 countries including the EU, China and Tiawan, where punishment for its use includes fines and imprisonment. Imported meat is tested and turned away if traces of ractopamine are discovered.

U.S. based Smithfield Foods, the largest slaughter plant in the world, supplies pork to China. A recent industry article announcing a large Chinese order from Smithfield explains how that order will be filled. Since Smithfield has full control over their swine production, they will stop feeding Paylean for three weeks until the pigs test clear. This is an industry admission that fully three weeks of clearance time is needed to export meat that will pass the standards of China for being ractopamine free, a conclusion that is inconsistent with the stance of Codex.

Even the U.S. may be wising up

Smithfield subsidiary, John Morrell has just announced contracts with several large swine farms to supply them with pork that is free of both Paylean and antibiotics. Until this announcement, only small niche slaughtering plants have been interested in processing Paylean and antibiotic free hogs.

Use of ractopamine is cruelty to animals

Animals pay a great price for the chance to boost their producer's bottom lines. One of the swine producers contracting his Paylean free hogs to Morrell says that Paylean has the effect on pigs that steroids have on body builders. It makes pigs walk like arthritic old men, and act just as crotchety. Pigs on Paylean become emotional, mean and stubborn, and have to be beaten to get them loaded for market and into the chutes for processing.

Chris Birky of Birky Farms says Paylean makes animals extremely agitated and miserable. They become aggressive toward each other, and the people raising them. They lose their ability to cope with stress and can turn purple, shake and even fall down dead of heart attacks during any stressful event. At the same time, their bodies are flooded with stress related hormones that can end up in tissues.