Here are 4 of the biggest quacks plaguing America with false claims about science

It may be easy to draw a caricature of a "quack” as a cross between the ShamWow pitchman and an alchemist, but they’re really not so easy to spot. Modern-day quacks often cherry-pick science and use what suits them as semantic backdrop to fool unsuspecting consumers. Quacks may dazzle people with fanciful research studies or scare them with intimidating warnings before trying to peddle products that make unreasonable promises. And those who use these alternative, unproven products may forego treatments that would be more likely to help them.

In short, quackery is dangerous. It promotes fear, devalues legitimate science and can destroy lives. Here are the four biggest quacks giving dubious health advice in the media and some samples of their detrimental advice.

1. Dr. Joseph Mercola. Mercola is not a strict medical doctor, but an osteopath who practiced in suburban Chicago (according to Chicago magazine, he gave up his practice in 2006 to focus on Internet marketing). Mercola has also written several books on health that have become bestsellers.

Mercola operates one of the Internet's largest and most trafficked health and consumer information sites. With an estimated 15.5 million unique monthly visitors, Merola.com dwarfs even ConsumerReports.org and HealthCentral.com. The site vigorously promotes and sells dietary supplements, many of which bear Dr. Mercola’s name.

A typical article on Mercola’s site touts the wonders of yet another miracle cure or supplement. Some recent articles include "13 Amazing Health Benefits of Himalayan Crystal Salt" and "Your Flu Shot Contains a Dangerous Neurotoxin." His site has also touted Vitamin D as "The Silver Bullet for Cancer."

Many of Mercola’s musings clash — sometimes bitterly — with conventional medical wisdom. Mercola advises against immunization, water fluoridation, mammography, and the routine administration of vitamin K shots for newborns.

The medical community says Mercola is dangerous, and that he steers patients away from proven medical treatments in favor of unproven therapies and supplements.

“The information he’s putting out to the public is extremely misleading and potentially very dangerous,” says Dr. Stephen Barrett, who runs the medical watchdog site Quackwatch.org. “He exaggerates the risks and potential dangers of legitimate science-based medical care, and he promotes a lot of unsubstantiated ideas and sells [certain] products with claims that are misleading.”

Mercola has been the subject of a number of Food and Drug Administration warning letters about his activities, including marketing products as providing “exceptional countermeasures” against cancer, heart disease, diabetes, and a host of other illnesses. He also has marketed coconut oil to treat heart disease, Crohn’s disease, and Irritable Bowel Syndrome. Mercola.com also sold an infrared camera to be used as a cancer screening tool.

Some of Dr. Mercola’s wildest claims include:

• HIV may not be the cause of AIDS. Mercola believes that the manifestations of AIDS (including opportunistic infections and death) could result from "psychological stress" brought on by the belief that HIV is harmful. Mercola.com has also featured positive presentations of the claims of AIDS truthers who deny the existence of AIDS or the role HIV has in the disease.

• Mercola has said that microwave ovens emit dangerous radiation and that microwaving food alters its chemistry.

• Commercial sunscreens increase the likelihood of skin cancer, instead of protecting from it. Of course, he sells his own natural sunscreens on his website.

2. The "Health Ranger,” Mike Adams. Adams runs a website called Natural News that is dedicated to supporting alternative medicine techniques and various conspiracy theories about chemtrails, the link between vaccinations and autism, and the dangers of fluoridated drinking water. Dr. Mercola is a frequent guest blogger on his site.

Natural News, which gets an estimated 7 million unique visitors a month, primarily promotes alternative medicine, raw foods, and holistic nutrition. Adams claims he began the site after curing himself of Type II diabetes by using natural remedies.

Adams seems to revel in going against the grain. He likes to tell readers on his website that if they just exercise, eat the right foods and take the right supplements (he markets supplements on his site) infectious disease cannot harm them. Like Mercola, he is an AIDS denialist, and claims flu vaccines are totally ineffective.

Dr. David Gorski of the Science-Based Medicine website calls Natural News “a one-stop shop, a repository if you will, of virtually every quackery known to humankind, all slathered with a heaping, helping of unrelenting hostility to science-based medicine and science in general.”

Adams also considers himself a scientific researcher, but some of his claims are dubious. He has even bought himself a mass spectrometer which he uses to test various products for toxicity. He recently used this device to show that a flu vaccine containing thiomersal registered 51 parts per million of mercury. But that’s not the news in his findings: Adams went on to insist that his critics must be brain-damaged (or perhaps brainwashed) by mercury:

The only people who argue with this are those who are already mercury poisoned and thus incapable of rational thought. Mercury damages brain function, you see, which is exactly what causes some people to be tricked into thinking vaccines are safe and effective.

Science-Based Medicine blogger Dr. Steven Novella describes Adams' site as “a crank alt-med site that promotes every sort of medical nonsense imaginable. If it is unscientific, antiscientific, conspiracy-mongering, or downright silly, Mike Adams appears to be all for it —whatever sells the ‘natural’ products he hawks on his site.”

What makes Adams unique is that he likes to mix far-right vitriol and conspiracy theories with his alternative medicine advice. He has come out as a climate-change denialist, 9/11 Truther, and a Birther.

Here’s some more quackery from Adams and Natural News:

• Guns don’t kill people, medications do. Adam Lanza and Elliot Rodger committed their horrific mass murders because of the medications they were taking.

• A cold fusion device has been invented and will be a game changer for energy. It wasn't.

• Americans are constantly bombarded by lead coming from airplane chemtrails. (Actually, lead levels in blood have been falling for years.)

• Bill Gates and Microsoft are in the process of developing weaponized, ethnically targeted influenza viruses as part of a sinister eugenics plot.

3. The “Food Babe,” Vani Hari. She doesn’t have a degree in nutrition, chemistry or medicine, and her work background is as a management consultant. Yet without any serious credentials, Hari—the “Food Babe”—bills herself as a voice of consumer protection on the Internet. In just a few years, she’s assembled an army of followers who have joined her on her quest to get hard-to-pronounce ingredients banned from foods.

Hari’s acolytes see her as a muckraking reporter, saving us from nefarious chemicals, GMOs and unappetizing ingredients like beaver anus, yoga mat and fish bladder. The public and the media love her; a “food safety” campaign by the Food Babe can get thousands of signatures, countless media mentions and guest appearances on television shows such as Dr. Oz and The Doctors.

But Hari is really more of a fear-mongerer and conspiracy theorist than a safe-food advocate. Her campaigns are born of misinformation and anxiety. Recently, she published a petition on her website demanding that the top beer companies come clean about the ingredients in their beer. Citing a long list of creepy, chemical-sounding ingredients that are allowed in beer, she implied that the industry was flying under the radar and obscuring the additives it puts in its products.​ It turned out that the beer companies were actually using very few of the ingredients on her list, and some were only used in the production process and were not part of the finished product. When we looked further into it, we found that many of the nefarious ingredients and techniques she described were either misrepresented or entirely misunderstood by her.​

However, at Hari's request, the top two breweries in the U.S. acquiesced and listed their ingredients on their websites, and none of the ingredients would come as a real shock to beer drinkers. Still, Hari continued to insist that GMO corn and other bad ingredients were integral ingredients in beer.

In response to critics who say Hari is not qualified to make hard judgments on food ingredients, Hari says, “I don’t think you need to have those degrees to be intellectually honest, to be able to research, to be able to present ideas.”

Dr. David Gorski, a cancer surgeon who writes for the website Science-Based Medicine takes offense to Hari's food campaigns:

“Her strategy is very transparent, but unfortunately it’s also very effective,” wrote Gorski. “Name a bunch of chemicals and count on the chemical illiteracy of your audience to result in fear at hearing their very names.”​

Gorski says since companies live and die by public perception, it's far easier to “give a blackmailer like Hari what she wants than to try to resist or to counter her propaganda by educating the public.”​

Some of Vani Hari’s more specious ideas about food are:

• Microwaves kill food and remove its nutrients. Also, microwaves change the chemical properties of water. She persists with this theory although it has been persistently debunked by science.

• Water, when exposed to the words “Hitler” and “Satan” changes its physical properties.

• Flu shots contain “a bunch of toxic chemicals and additives that lead to several types of Cancers and Alzheimer [sic] disease over time.” Actually, flu shots are made up mostly of proteins and preservatives that give no indication of being harmful, despite plenty of medical research.

Hari has not provided any scientific evidence to back her claims as of yet.

4. Dr. Mehmet Oz. What do Vani Hari, Dr. Joseph Mercola and Mike Adams have in common? They’re all guest experts appearing on the Dr. Oz Show.

Dr. Oz is a media darling and cardiothoracic surgeon who first appeared on the Oprah Winfrey Show in 2004. In 2009, Oprah produced Oz's namesake show focusing on medical issues and personal health.

But before we label Oz a quack, it’s only fair that we also should note he’s a professor at the Department of Surgery at Columbia University, directs the Cardiovascular Institute and Complementary Medicine Program at New York-Presbyterian Hospital, has authored more than 400 medical research papers and holds several patents.

But unless you’ve been living under a rock for the last month, you probably know Dr. Oz has been exposed as a daytime-television snake oil peddler, while being shamed during testimony before a U.S. Senate subcommittee last month.

Sen. Claire McCaskill, the chairwoman of the Senate subcommittee on Consumer Protection, took Oz to task over false claims he’s made for over-the-counter weight loss cures. For example, Oz proclaims that worthless supplements such as green coffee beans have “miracle” properties.

The Missouri senator made it clear that she thinks Oz abuses his great influence. Products he endorses on his show are almost guaranteed to fly off the shelves.

“People want to believe they can take an itty-bitty pill to push fat out of their body,” McCaskill chided the celebrity doctor. “I know you know how much power you have.”

Oz acknowledged to the subcommittee that while there’s no such thing as a “miracle” supplement, and many he touts wouldn’t pass scientific muster, he insisted he was comfortable recommending them to his fans.

“My job is to be a cheerleader for the audience,” Oz says. ”And when they don’t think they have hope, when they don’t think they can make it happen, I want to look and I do look everywhere, including alternative healing traditions, for any evidence that might be supportive to them.”

As McCaskill then pointed out, Oz was giving people false hope. Isn’t that what quacks do?

Oz often uses his show as a soapbox for the likes of Hari, Mercola and Adams. And when they’re guests on his show, they’re handled with kid gloves. Oz even describes Adams as an “activist researcher,” a “whistleblower” and a “food safety activist." Viewers then open their wallets to Adams, who is there to promote his website. A similar scenario plays out when Mercola, a frequent guest, joins Oz. Hari, for her part, does not market miracle products on her site. She does, however, seem to make money from affiliate advertising.

Oz’s great sin is that he uses his show to promote all types of modern shamanism. Critics find it mystifying that he, a medical doctor, would host and promote people on his show who are anathema to science. It’s Oz’s instant access to millions and his medical degrees and peer-reviewed research papers that have given him credibility, but critics say he loses all of it when he promotes guests who explicitly reject the tenets of reason. So, can Oz still be considered a serious scientist?

Unlike the other three quacks mentioned in this article, Oz is more a ringmaster than a snake-oil salesman. However, he’s not without his list of dubious stances:

• In November 2012, Dr. Oz invited Julie Hamilton, a representative of the National Association for Research and Therapy of Homosexuality, who claimed that she could heal homosexuality with gay reparative therapy. Although the show did include guests who condemned reparative therapy, Dr. Oz never weighed in on the subject, and the audience was led to believe that there were valid arguments on both sides of this issue.

• His proclamation on Oprah that resveratrol is an effective anti-aging supplement sparked a resveratrol marketing craze. Numerous fly-by-night online peddlers used his name and likeness (along with the likenesses of age-defying actresses Jennifer Aniston and Marisa Tomei) to peddle the so-called miracle supplement. But it's anyone's guess what was in those pills.

• Oz has invited a medium on his show who told selected audience members that she was communicating with their lost loved ones.

• Oz once invited a faith healer, Issam Nemeh, to “heal” sick audience members on his show. On his website, Oz bragged about the “Oz Effect”: “Dr. Nemeh has received an overwhelming response from the viewers of the Dr. Oz show. Medical office appointments with Dr. Nemeh are already filled for the next four months.”