You don't need to be a doctor. You don't even need to play a doctor on TV. These days, if you want to give medical advice to the population at large, it's enough to merely be on television.

The problem of celebrities dispensing dangerous nonsense about medical science is nothing new, but it recently reached a new level with the publication of Jenny McCarthy's Louder than Words: A Mother's Journey in Healing Autism.

For those who choose not to wallow in American pop culture, McCarthy entered public life in 1993 by posing nude for the airbrush artists at Playboy Magazine. From this beginning, she parlayed her talent into a successful career as an actress, appearing in several movies and television shows. In a testament to the class mobility that is possible in American society, McCarthy has climbed from actress to well-regarded author, publishing books on such topics as pregnancy, motherhood and giving birth.

But it was in her 2007 book Louder than Words that she began to publish her medical research, writing "let's just say a child is born with an allergy to honey, and after a mom gives birth, the doctors rub honey all over this child's body for the next eighteen months. Some bad shit is gonna happen."

This is just an example of the colorful logic used by McCarthy in her book to link childhood vaccinations with autism, and by implication to recommend to the general public that it not vaccinate children against often fatal diseases. It is bad enough that this irresponsible advice was printed by Dutton, an imprint of major U.S. publisher Penguin Group. Unfortunately, the salaciousness of a former nude model fighting frankenscience was also too much for the likes of Oprah Winfrey and Larry King to ignore. Both of these titans of the tube have invited McCarthy onto their television programs and allowed her to deliver her weighted opinion to the biggest audience the anti-vaccination movement has ever garnered.

This is not the only time that the two talk show hosts have been the conduits of nonsense. Both have repeatedly allowed television actress Suzanne Somers to use their programs to promote her books, which advise the public to forgo chemotherapy as a cancer treatment and to use bioidentical hormones for menopause.

Being on television is not the only easy road to a de facto medical degree. One can also apparently achieve medical know-how by playing the electric guitar. To be fair, rock n' roll personality Billy Corgan was sure to remind us that he wasn't an actual doctor before declaring in a recent blog post that he "for one will not be taking the (H1N1) vaccine. I do not trust those who make the vaccines, or the apperatus (sic) behind it all to push it on us thru (sic) fear." His denouncement of fear mongering is followed soon after with "the state will have the power to come into your home and incarcerate you for being unwilling to comply with a vaccination order. Didn't you hear? Soon, you won't even have the choice to live OR die as you wish!"

It's no secret that fame and success can inflate an ego, and so it is no surprise that our beloved celebrities might feel qualified to frighten us away from proven medical science. But do people really listen to this malarkey?

Polling this year by The Associated Press shows roughly one-third of Americans are not confident of the safety or efficacy of the swine flu vaccine. [1] [2] [3] Herbal supplement sales are doing fine even as the economy declines. [4] Yet at the same time, childhood immunization rates are at record highs. [5] More to the point, even as fear of the swine flu vaccine floods the mediascape, there is enough of a demand to to make available supplies of the vaccine inadequate.

Clearly, this tide of medical paranoia among celebrities is not driving public opinion as a whole, but we do not know the untold stories of individuals who have made poor decisions based on the perceived authority of their favorite celebrity. It happens all the time. Humphrey Bogart is probably responsible for more cancer deaths than Suzanne Somers could ever hope to be. In the history of rock 'n' roll, more young people have been influenced to take a shot than to avoid one. Celebrities do influence behavior, but at what rate and to what effect, it is difficult to gauge.

Self-appointed celebrity medical authorities bring these weird ideas out from the dark corners of American society. The anti-vaccination movement used to be the stuff of late-night radio. Most were not aware that their friends or neighbors might harbor a conspiratorial disapproval of immunizing children against the mumps. Today, this is not the case. Vaccination denial has moved aboveground, where it must answer for itself. Because celebrities have tried to validate it, this dangerous concept will have to endure the meat grinder of public debate.

Whether celebrity endorsement gives alternative medicine new life, or whether it gives it a chance to be debunked, it is hard to say. There is certainly no shortage of celebrities who want to practice medicine without a license, and one can only hope that it results in greater awareness of the argumentum ad celebrity fallacy.