At the top of Wednesday’s CBS Early Show, co-host Harry Smith cast doubt on talk show host and major Obama supporter, Oprah Winfrey: "And call it the ‘Oprah Effect.’ She speaks, people listen. But is her show actually leading her audience astray?" Oddly, no mention was made of Winfrey’s very public endorsement Barack Obama in the 2008 campaign.

Later, co-host Julie Chen also teased the upcoming segment with similar declarations: "Still ahead in this half hour, it is no secret that Oprah is a great sales person, but just because she's selling, the question is should you be buying?...Well up next, the Oprah Winfrey seal of approval. Is it all that it's cracked up to be? We're going to look at the pros and the cons of Oprah's power." During the latter tease from Chen and briefly in the report that followed, footage of Oprah speaking at an Obama rally was shown, but not discussed.

The report, by correspondent Michelle Miller, featured Syracuse University pop culture professor Robert Thompson, who explained: "She has managed to put the Oprah seal of approval, which is a really powerful seal of approval, on some things that I think most people would call real crackpot ideas." Miller cited Newsweek magazine’s reporting on the topic and quoted senior editor Weston Kosova: "Some of the advice she gives on the show, especially with regard to health matters and medicine, is not good advice. Sometimes the advice that guests give on the show could actually hurt you."

The report mainly focused on some of the highly questionable medical advice doled out by guests on Oprah’s show, as opposed to the talk show host’s political advice. Miller pointed out one example: "Jenny McCarthy's theory that vaccines cause autism." However, McCarthy appeared on the Early Show recently pushing the same theory and CBS has done numerous stories investigating a supposed link between vaccinations and autism.

Miller concluded the report: "But even Oprah believes her’s should not be the last word." Strange that disclaimer did not appear at the end of CBS stories on Oprah’s endorsement of Obama.

Here is the full transcript of the segment:

7:00AM TEASE:

HARRY SMITH: And call it the ‘Oprah Effect.’ She speaks, people listen. But is her show actually leading her audience astray?

WESTON KOSOVA: Sometimes the advice that guests give on the show could actually hurt you.

SMITH: A new take on Winfrey's wisdom.

7:15AM TEASE:

SMITH: Then, she's a talk show diva, not a doctor. Why viewers should think twice before taking Oprah's advice.

7:30AM TEASE:

JULIE CHEN: Still ahead in this half hour, it is no secret that Oprah is a great sales person, but just because she's selling, the question is should you be buying? We're going to take you inside what's being called the ‘Oprah Effect.’

7:37AM TEASE:

CHEN: Well up next, the Oprah Winfrey seal of approval [Footage of Oprah at Obama rally]. Is it all that it's cracked up to be? We're going to look at the pros and the cons of Oprah's power.

7:40AM SEGMENT:

JULIE CHEN: Call it the ‘Oprah Effect.’ If the talk show queen likes something, millions of loyal fans line up to follow her advice. But as CBS News correspondent Michelle Miller tells us, a new report is questioning whether Oprah is really helping or hurting.

MICHELLE MILLER: It seems everything Oprah favors turns to gold.

OPRAH WINFREY: Woo!

MILLER: More than 40 million viewers tune in each week to get a dose of advice on everything from fashion and beauty to cutting-edge medicine.

ROBERT THOMPSON [PROFESSOR, SYRACUSE UNIVERSITY]: She has managed to put the Oprah seal of approval, which is a really powerful seal of approval, on some things that I think most people would call real crackpot ideas.

MILLER: The fact that it's not just doctors, but celebrities, dispensing some of that information, has caught the attention of Newsweek magazine.

WESTON KOSOVA [SENIOR EDITOR, NEWSWEEK]: Some of the advice she gives on the show, especially with regard to health matters and medicine, is not good advice. Sometimes the advice that guests give on the show could actually hurt you.

MILLER: One example cited by Newsweek, Jenny McCarthy's theory that vaccines cause autism. Another, the unconventional routine actress Suzanne Summers uses to stay young.

SUZANNE SOMERS: I take about 40 supplements.

MILLER: Oprah seemed to embrace Somers' use of hormone replacement therapy, but critics say that show may have lost balance by not aggressively citing the potential dangers of HRT.

CYNTHIA PEARSON [EXEC. DIRECTOR, NATIONAL WOMEN’S HEALTH NETWORK]: Women were left by Oprah in a state not really knowing all the information that they needed to make a safe and effective choice.

MILLER: Oprah's response to CBS News, ‘I trust the viewers. And I know that they are smart and discerning enough to seek out medical opinions to determine what may be best for them.’

PEARSON: She does a wonderful job of conveying information that's important to people and touching on issues that really speak to them.

MILLER: But even Oprah believes her’s should not be the last word. Michelle Miller, CBS News, New York.

—Kyle Drennen is a news analyst at the Media Research Center.