"While I don't want to say mad cow is a good thing" for the vegetarian movement, he added, "there is a lot of evidence that we are creating an unhealthy beef industry to support our meat consumption."

On Tuesday, U.S. officials said a cow in Washington state had preliminarily tested positive for the same brain-wasting disease that ravaged farms in Europe in the mid-1990s, prompting the mass slaughter of cows.

Vegetarian practices increased dramatically in the United Kingdom after mad cow disease hit Europe, said Liz O'Neill, a spokeswoman for The Vegetarian Society of the United Kingdom, which boasts singer Paul McCartney as a patron.

Americans tend to be more accepting of meat industry practices such as the use of hormones to boost growth and show a greater confidence in the safety of the commercial food supply than Europeans, experts have said.

Even so, the discovery of mad cow disease at home may turn normally meat-loving Americans into veggie and tofu fans instead, according to Madden and others in the San Francisco Bay Area, known as a bastion of healthy, ecological and alternative lifestyles that range from yoga to recycling to veganism.

"People are very concerned about the mercury levels in fish, what happens if they eat meat, all the antibiotics that go into chicken," said Annie Somerville, executive chef at the popular Greens Restaurant in San Francisco. "More people are turning to alternatives to meat."

CONSCIOUSNESS RAISING

Steven Lande, general manager of Roxanne's, a restaurant specializing in raw, vegan and organic foods in Larkspur, about 20 miles north of San Francisco, agreed.

"This adds to the questions already being asked about what food people are putting into their bodies, what they are taking out of the ground and what they are putting into the ground," Lande added.

The discovery of mad cow disease could also raise consciousness about the entire food cycle and its impact on the environment, said Steven Burbank, owner of Urban Forage, which offers raw foods, juices and other organic items.

"A lot of people think they need to eat meat to survive, and it's just simply not true," he said. "There is a certain self-discipline that it takes to not eat packaged foods. It's also about not eating things in packages and generating trash."

If the health benefits of vegetarianism were not enough incentive to forego meat, the TV video of so-called "downer," sick or injured, cattle who can barely walk might be, others said.

"Image after image of these crippled animals promote empathy and shock people into rejecting" inhumane treatment of cattle, said Bruce Friedrich, director of vegan outreach at People for the Ethical Treatment of Animals. "Something like mad cow disease really puts this front and center."

While Al Petri, owner of Alfred's Steakhouse in downtown San Francisco said it was too early to tell whether his business would be hurt by the mad cow scare, at least one resident said he had already made up his mind.

"I'm going to try to completely cut out red meat from my diet," said Geoff Brown. "This hits closer to home. You never know what kind of stuff is on our shelves."