Diet substance may have killed elk
Friday, March 26, 2004 Posted: 9:57 AM EST (1457 GMT)
CHEYENNE, Wyoming (AP) -- A substance found in some weight-loss diet supplements -- and in a type of lichen -- may have fatally poisoned more than 300 elk in Wyoming in recent weeks, scientists say.
Scientists theorize the substance, usnic acid, may have caused the animals to weaken and collapse -- too helpless to eat, drink or escape predators. The chemical was extracted from tumbleweed shield lichen, which grows on the ground in many northern states.
Captive elk fed it developed the same fatal illness; usnic acid poisoning also has been documented in livestock, though cattle tend to recover.
Scientists say they cannot yet confirm their suspicion. For example, it is not clear why the poisoning didn't affect the animals' livers -- as it might in humans. Instead, the elk muscles appeared pale and sickly.
"That's one of the reasons we don't want to chalk this up to usnic acid at this point," said Walt Cook, a wildlife veterinarian at Wyoming's state veterinary lab in Laramie. "Either the usnic acid is affecting the elk differently or it's not usnic acid at all. There may well be other compounds in there that may be the toxic compounds."
Cook said it will take a few more months to confirm a cause.
Usnic acid has anti-bacterial properties and lichen containing it have several uses in traditional medicine, including as a poultice. Put into pills, it can promote weight loss by boosting metabolism.
Side effects from the substance have occurred, however. In January, the Food and Drug Administration said more study is needed of three diet drugs, including usnic acid.
In 2001, the FDA asked Syntrax Innovations to stop selling Lipokinetix, a diet drug containing usnic acid, saying it was to blame for a number of serious liver injuries in some people who used the drug more than two weeks.
Usnic acid is still readily available over the Internet.
"As we learn of the information and evaluate the science behind it, we'll proceed accordingly," said Kimberly Rawlings, an FDA spokeswoman.
Friday, March 26, 2004 Posted: 9:57 AM EST (1457 GMT)
CHEYENNE, Wyoming (AP) -- A substance found in some weight-loss diet supplements -- and in a type of lichen -- may have fatally poisoned more than 300 elk in Wyoming in recent weeks, scientists say.
Scientists theorize the substance, usnic acid, may have caused the animals to weaken and collapse -- too helpless to eat, drink or escape predators. The chemical was extracted from tumbleweed shield lichen, which grows on the ground in many northern states.
Captive elk fed it developed the same fatal illness; usnic acid poisoning also has been documented in livestock, though cattle tend to recover.
Scientists say they cannot yet confirm their suspicion. For example, it is not clear why the poisoning didn't affect the animals' livers -- as it might in humans. Instead, the elk muscles appeared pale and sickly.
"That's one of the reasons we don't want to chalk this up to usnic acid at this point," said Walt Cook, a wildlife veterinarian at Wyoming's state veterinary lab in Laramie. "Either the usnic acid is affecting the elk differently or it's not usnic acid at all. There may well be other compounds in there that may be the toxic compounds."
Cook said it will take a few more months to confirm a cause.
Usnic acid has anti-bacterial properties and lichen containing it have several uses in traditional medicine, including as a poultice. Put into pills, it can promote weight loss by boosting metabolism.
Side effects from the substance have occurred, however. In January, the Food and Drug Administration said more study is needed of three diet drugs, including usnic acid.
In 2001, the FDA asked Syntrax Innovations to stop selling Lipokinetix, a diet drug containing usnic acid, saying it was to blame for a number of serious liver injuries in some people who used the drug more than two weeks.
Usnic acid is still readily available over the Internet.
"As we learn of the information and evaluate the science behind it, we'll proceed accordingly," said Kimberly Rawlings, an FDA spokeswoman.