In recent months, the media has become increasingly impatient with high-profile health advocates who dispense unsubstantiated medical advice. Among the highlights have been John Oliver’s continued humiliation of Dr. Oz, who repeatedly touted the power of energy healing and “miracle” weight-loss solutions, and a viral Gawker takedown of Vani Hari, aka “the Food Babe,” a blogger and food activist who once advised her followers that “there is just no acceptable level of any chemical to ingest, ever.” Even the American Medical Association has had enough, and just announced that it would draft guidelines for disciplining physicians who dispense pseudo-scientific advice.

Yet despite this heightened concern about the accuracy of health information, best-selling celebrity neurologist Dr. David Perlmutter seems to have escaped much scrutiny, even though he has a decades-long history of offering — and profiting from — suspect medical advice.

In fact, he remains one of the most influential physicians in the U.S. His 2013 book Grain Brain reached No. 1 on the New York Times best-seller list, and after nearly two years, sales remain so strong that it has still not come out in paperback. This extraordinary success led to a long profile in The Atlantic and won him a 90-minute TV special: Perlmutter’s “BRAINCHANGE” aired on over 110 PBS affiliates, and has continued to air on a regular basis since it was first released in late 2013. In April, he released his newest book, Brain Maker, and within a month it, too, became a New York Times bestseller.

Despite Perlmutter’s popularity, most mainstream medical authorities do not endorse the advice he dispenses. In Grain Brain, Perlmutter revealed “the surprising truth”: Gluten is a “silent germ,” and declining brain health can be blamed in large part on gluten-containing grains. Brain Maker, for its part, promises to help readers harness “the power of gut microbes to heal and protect your brain — for life” — it even purports to offer groundbreaking preventative measures and treatments for allergies, autism, Alzheimer’s, ALS, dementia, Parkinson’s, and cancer.

Perlmutter has always been unorthodox in his approach to medicine. For well over a decade, and long before he was a household name, he has claimed to offer his readers “miraculous” — his word — treatments capable of preventing or reversing all sorts of devastating medical problems. He has also claimed that supplements and “detoxification” regimens — available for purchase on his various websites — are crucial to optimizing brain health. Earlier this year, he stated that the conversation about childhood vaccines and autism is “ill-defined,” and that parents should ask their pediatricians about spacing out their children’s vaccinations — an approach the CDC disagrees with, and which 90 percent of doctors surveyed by the journal Pediatrics in 2013 said would put children and communities at greater risk of contracting preventable diseases.

As Perlmutter’s megaphone has grown, so, too, has his brand empire — he has sold everything from “Empowering Coconut Oil” to supplement blends tailored for specific demographics, like the $90 “Scholar’s Advantage Pack” for “young adults seeking to optimize cognitive function,” and the $160 “Senior Empowerment Pack,” a “combination of formulas designed to help keep you cognitively sharp as you age.” One book pointed readers to an $8,500 brain detoxification retreat run by Perlmutter, which included shamanic healing ceremonies. (He even has his own organic foaming hand soap.)

In light of all this, it’s worth asking: Should Dr. Perlmutter’s millions of fans really trust him?

***

Since Perlmutter presents himself as a distinguished medical expert, a natural place to start is with his credentials. “[Dr. Perlmutter] contributed extensively to the world medical literature,” reads his website, “with publications appearing in The Journal of Neurosurgery, The Southern Medical Journal, Journal of Applied Nutrition, and Archives of Neurology.” Earlier bios also list the Journal of the American Medical Association.

Yet a closer look at his publications reveals that Perlmutter hasn’t actually conducted much research. In the scientific community, full-length peer-reviewed articles, especially widely cited ones, are the gold-standard of significant research. But his contribution to JAMA — an extremely prestigious medical journal — is actually just a letter to the editor. The Southern Medical Journal? A case report and a clinical brief, both co-authored with his father when the younger Perlmutter was still a medical student. Archives of Neurology? Another case report. (Case reports and clinical briefs are short discussions around 1-4 pages long.)

As for the prestigious-sounding Journal of Applied Nutrition, you’ll be hard-pressed to find a legitimate nutrition scientist who’s even heard of it — and quackwatch.com cites it as a “fundamentally flawed” publication that has carried ads for “questionable potions, services, books, and/or publications.” (As far as I can tell, Perlmutter’s article in it is unavailable on any reputable scholarly database.)

Perlmutter does have two legitimate peer-reviewed articles in The Journal of Neurosurgery, co-authored nearly four decades ago with his mentor, the decorated neurosurgeon Dr. Albert Rhoton. Neither has anything to do with Perlmutter’s current theories about nutrition or the gut microbiome.

I spoke with Dr. Rhoton at the University of Florida, who fondly recalled the young lab partner who wrote a total of four articles on microsurgical anatomy under his tutelage. “David did a nice job in our lab,” Rhoton told me. “He did good research and wrote up those studies. I wanted him to be a neurosurgeon, but he became a neurologist instead.”

Rhoton was unfamiliar with Perlmutter’s recent work. “Something about grains?” he asked. “Grain … Brain? I’m so focused in on neurosurgery I don’t know anything about it.” (Perlmutter declined to comment for this article.)

The basic premise of Grain Brain doesn’t fit with the current neurological literature: The latest reviews of evidence-based dietary approaches to preventing Alzheimer’s support a Mediterranean-style diet, complete with whole grains. Nevertheless, Perlmutter describes the science of Grain Brain as “undeniably conclusive.” He is similarly confident about the treatment regimens proposed in Brain Maker, telling his readers about astonishing transformations accomplished through simple dietary changes such as going gluten-free, eating fermented foods, and taking probiotics. “I can’t wait to share with you the countless stories of individuals with myriad, enfeebling health challenges … who experienced a complete vanishing of symptoms following treatment,” he writes. “These stories are not outlier cases for me, but by standard measure of what might typically be expected, they seem almost miraculous.”

He’s right. The stories do seem miraculous: dramatic improvements in autistic symptoms after probiotics and DIY fecal transplants; Tourette’s symptoms gone after a regimen of probiotic enemas; multiple sclerosis successfully treated with nutritional supplements, probiotic enemas, and fecal transplants. (At this time, fecal transplants are only indicated for a bacterial infection called Clostridium difficile.)

But for medical researchers, claims of dramatic improvements as a result of unproven treatments generally raise red flags. A 2014 commentary on Grain Brain, published in the American Journal of Cardiology, puts it bluntly: “The declaration that a single, simple ‘cure’ can successfully treat numerous diverse diseases and symptoms is reminiscent of the oratory of the ‘snake oil’ merchants of generations ago.” Yale physician and nutrition researcher David Katz, no friend of the food industry, is equally dismissive, describing Grain Brain’s arguments as “the raw power of pop culture repetition, not the staying power of truth,” he said. “Whole wheat does not make us fat; whole grains do not make us stupid.”

I asked Jonathan Eisen, a microbiome expert at the University of California, Davis, about Brain Maker. “To think we can magically heal diseases by changing to a gluten-free diet and taking some probiotics is idiotic, quite frankly,” he told me. After Eisen read the case study of an autistic boy that Perlmutter highlights in Brain Maker and on his website — “from a scientific perspective, [fecal transplantation for autism] makes absolute sense” — his words were even harsher. “It resembles more the presentation of a snake-oil salesman than that of a person interested in actually figuring out how to help people,” said Eisen.

Perlmutter has a stock answer for skeptics like Katz and Eisen. “Each progressive spirit,” he tweeted in October of 2014, “is opposed by a thousand mediocre minds appointed to guard the past.” The problem, in other words, isn’t with Perlmutter — it’s with all the so-called experts hamstrung by traditional thinking. In one book Perlmutter even parallels his situation to Galileo’s, a genius initially persecuted for his scientific theories only to be triumphantly vindicated by history.

Setting aside the response to his two most recent books, does Perlmutter’s broader body of work lend credibility to his self-understanding as a path-breaking genius?

To answer this question we’ll start with his second book, the self-published BrainRecovery.com (2000). Named after Perlmutter’s personal website at the time, it promises powerful techniques for preventing or reversing Alzheimer’s, multiple sclerosis, stroke, Parkinson’s, post-polio syndrome, ALS, and much more. (His first book, LifeGuide: Your Guide to a Longer and Healthier Life, was self-published in 1993.)

Like Perlmutter’s latest best sellers, BrainRecovery.com includes dietary recommendations. But it is strikingly devoid of any discussion of gluten, grains, or probiotics. Gut bacteria are only mentioned once, in passing. Instead of emphasizing the importance of cholesterol and saturated fat for promoting brain health — as he does in Grain Brain, Brain Maker, and on his blog — Perlmutter cautions against them. “Meat and eggs are rich inflammation producing fatty acids [sic],” he declares. “It is this inflammation that leads to the enhanced production of brain damaging free radicals. The best diet is vegetarian with added fish.” There’s no doubt, Perlmutter writes, about “the direct relationship between multiple sclerosis mortality and dietary fat, especially saturated fats and animal fats.”

Given Perlmutter’s current alarmism about grains, it’s hard to make sense of the numerous recovery stories in BrainRecovery.com. If one is to believe the “undeniably conclusive” science of Grain Brain, then the early Perlmutter was somehow healing his patient’s intractable neurological conditions despite putting them on a diet that was full of poisonous whole grains and dangerously low in saturated fat and cholesterol.

It’s not just that Perlmutter is remarkably sure of himself, even when presenting an opinion that’s precisely the opposite of what he’s been advising for years. It’s that his confidence in unproven treatments often appears to profit him directly. During the BrainRecovery.com stage of Perlmutter’s career, for example, dietary changes were secondary. At that time, his main weapons in the battle for brain health were hyperbaric oxygen chambers, special nutritional supplements (BrainRecovery.com encouraged customers to purchase Perlmutter’s proprietary BrainSustainTM for $49.50 per 600 grams), and intravenous glutathione — an antioxidant naturally produced by the liver that is covered in a section of the book entitled “The Glutathione Miracle.” Glutathione’s effectiveness in Parkinson’s patients, writes Perlmutter, “is nothing short of miraculous.”

What does science say about these cutting-edge treatments, which Perlmutter prescribed regularly through the end of 2014? Let’s start with hyperbaric oxygen chamber treatment. Perlmutter sings its praises as “powerful therapy” for stroke, Parkinson’s, multiple sclerosis, Bell’s palsy, and Lyme disease, and until very recently he directed the Perlmutter Hyperbaric Center. (Though Perlmutter’s website doesn’t list prices, off-label HBOT therapy usually starts at around $200 per one-hour session, and it’s generally only covered by insurance in a very limited number of instances.) But a 2015 Cochrane review — the most comprehensive research review currently available — is skeptical of HBOT’s ability to improve stroke outcomes: “The evidence is insufficient to confirm that HBOT significantly affects outcomes after acute ischemic stroke. Use of HBOT as routine therapy for people with stroke cannot be justified by this review.”

The science on HBOT for other neurological ailments is even worse. In fact, it’s so bad that in 2013 the FDA had to issue a consumer warning about unapproved HBOT therapy for precisely the conditions that Perlmutter claimed to treat.

What about the “incredible effectiveness” of the “glutathione miracle”? Perlmutter has been an enthusiastic proponent of this substance for over a decade. In one 2010 online video posted by “Protandim Anti Aging” — more on that product soon — Perlmutter treats an elderly Parkinson’s sufferer with glutathione, effecting a remarkable recovery. BrainRecovery.com describes similar successes, multiple patients reversing Parkinson’s and getting off of medication after following Perlmutter’s “Parkinson’s protocol,” a combination of intravenous glutathione and supplements (available for purchase on his website).

These case studies raise an obvious question: If glutathione injection is such a miracle procedure, why hasn’t the protocol been more widely adopted? Perlmutter’s answer points to the profit-driven influence of Big Pharma: “Glutathione … cannot be owned exclusively by any particular pharmaceutical company and therefore won’t find its way to the highly influential advertising sections of the medical journals.”

Sure, maybe. Or it could be that doctors don’t prescribe intravenous glutathione for Parkinson’s because it doesn’t work. And they know it doesn’t work thanks, in part, to work done by a man named … David Perlmutter. In 2009, he collaborated on a randomized, double-blind study of intravenous glutathione for Parkinson’s. The results are clearly stated in the study’s conclusion: “We did not observe a significant improvement in parkinsonian signs and symptoms in the glutathione group when compared with the placebo group.” Based on these results, the National Parkinson Foundation put out a strongly worded statement about intravenous glutathione: “First, there is a lack of evidence it actually works; second, the therapy requires an intravenous line which has both short and long term risks; and finally, insurance does not cover the costs of this therapy. .. Patients should beware of any medical practices offering a fee for glutathione treatment of Parkinson’s disease.”

Once the glutathione study was finished, Perlmutter had various opportunities to disclose its results. Yet in 2009, shortly before the study was published, he told fellow celebrity doctor Andrew Weil that the treatment was “quite effective.”

It’s possible that Perlmutter just didn’t understand the results of the study, or perhaps he disagreed with the statistical analysis of his co-authors. The responsible thing to do, then, would be to acknowledge the study’s conclusion, state his dissent, and admit that it did not replicate the miraculous 80-90 percent effectiveness he claimed to have achieved in his clinic.

But he does no such thing. Instead, in his 2011 book Power Up Your Brain, Perlmutter doubles down on glutathione — “we shout the praises of glutathione,” he writes — not just as a treatment for Parkinson’s, but also for fibromyalgia, cancer, and the common cold. As evidence, Perlmutter cites a series of outdated studies but never once mentions the double-blinded study in which he himself participated (and no, there’s no solid evidence of glutathione’s efficacy in treating those other conditions, either).

Perlmutter co-wrote Power Up Your Brain with a “medical anthropologist and shaman” named Alberto Villoldo. The book opens with the tale of a woman suffering from chronic progressive multiple sclerosis, who, one afternoon, suddenly recovers and begins walking unassisted. “We are putting you on our miracle list,” Perlmutter tells her, a list that is apparently quite long:

Over the coming months, I began to notice that we were putting more and more people on the miracle list. And it was becoming clear to me that, overwhelmingly, the patients who achieved the most profound recoveries were those engaged in some form of meditative or spiritual practice … Virtually all of these patients were somehow connecting with what the shaman had referred to as the Great Spirit.

According to Perlmutter, open-minded healers like himself and the shaman are capable of achieving miraculous results that traditional doctors cannot. And the reason these miracles go unacknowledged is due, at least in part, to the effects of industry corruption (the Food Babe uses the same strategy to tarnish her critics.) Perlmutter regularly stresses how food and pharmaceutical companies cover up the effects of poisonous foods and deny the efficacy of life-changing “alternative” approaches to chronic illness. Companies profit, doctors and scientists line their pockets with kickbacks, and it’s all at the expense of public health.

Perlmutter is right, in a broad sense, to bring up the pernicious influence of money on medicine. Indeed, “mainstream” doctors — like Marcia Angell, the former editor of The New England Journal of Medicine, and epidemiologist Ben Goldacre, the author of Bad Pharma — have dedicated substantial parts of their careers to exposing corruption and financial conflict of interest in medical science. (Their efforts have met with near-universal acclaim from the scientific Establishment.)

But Perlmutter might not be the ideal whistle-blower when it comes to the issue of profiting from questionable medical treatments. Starting with BrainRecovery.com through Brain Maker, his books have pointed readers to ever-slicker websites where he has sold his “scientifically proven” supplements, often developed by him and manufactured by companies in which he had a direct financial interest as an employee. There was brainrecovery.com for Brainrecovery.com; kidsbrainsustain.com for Raise a Smarter Child By Kindergarten; powerupyourbrain.com for Power Up Your Brain; and finally, slickest of all, drperlmutter.com for Grain Brain and Brain Maker. (The store section of his website came down in March of 2015.)

Perlmutter has also had a long-standing involvement with shady supplement companies. One of those companies, LifeVantage, fraudulently said one of its best-selling substances, Protandim, was developed by a biochemist, when it was really cooked up by a business executive. In various videos and interviews, Perlmutter has testified to the undeniable efficacy of Protandim for treating and preventing many brain disorders.

It’s not just supplements. Up until late last year, Perlmutter offered a “6-day Power Up Your Brain Personal Intensive Program” on Powerupyourbrain.com. The most expensive package cost $8,500 (that is, a touch under $1,500 per day), and it was designed to “cleanse your body” and “detox your brain” using “neuro-nutrients, hyperbaric oxygen treatments under medical supervision, and ancient energy medicine practices.” In addition to being granted access to “shamanic sessions” — the administration of which was taken over from Albert Villoldo by Perlmutter’s wife, Leize — participants received the following:

. 90-minute intake evaluation with Dr. David Perlmutter

. One 30-minute follow-up 3 weeks after program completion with Dr. David Perlmutter

. 90-minute evaluation with nutritionist

. Five 60-minute Hyperbaric Chamber Oxygen Treatments

And naturally, no course of treatment with Dr. Perlmutter would be complete without his go-to miracle substance: “Five intravenous Glutathione treatments.”

***

Taken as a whole, Perlmutter’s career — his support for unproven treatments, his profiting from those treatments, his endless “miracle”-talk — suggests he probably isn’t a misunderstood genius who will be vindicated by time. Rather, his work places him squarely in the medical arm of the self-help industry, which stars figures like Dr. Oz (who has hosted Perlmutter and blurbs his books) and the notorious anti-vaccine quack Dr. Joseph Mercola (Perlmutter wrote the foreward to Mercola’s latest best seller, Effortless Healing).

The industry has clear rules: Endorse fellow gurus, even if they make extravagant, untested claims. Cherry-pick studies performed by Establishment scientists, but deflect Establishment criticism by accusing it of industry corruption. Take promising medical research that’s in its infancy, on subjects ranging from gluten sensitivity to the microbiome, and repackage it as settled science. If you do all this, then your unproven message will reach a giant audience of eager believers that’s far larger than the one reached by doctors like Marcia Angell and Ben Goldacre, whose criticisms of industry malfeasance do not serve as prelude to the promise of miracles.

Perlmutter’s pitch is nothing new. Here’s food historian Harvey Levenstein comparing early-20th-century diet gurus to faith healers, in a passage that still rings true today: “[They] would tell of their own devastating health problems, miraculously cured by the proposed diet — mysterious or common physical or psychological ailments that had defied the greatest of modern medical minds had disappeared once certain foods were added or deleted from the diet.”

There’s no problem with exploring the gut microbiome and the potential of dietary changes for treating neurological conditions. These are areas of ongoing study among genuine microbiome experts and nutrition scientists. After all, it’s their promising research that gets appropriated in Grain Brain and Brain Maker. But there’s a crucial difference between them and Perlmutter: legitimate researchers are humble about what they know and wait on proof before claiming to have discovered a cure, while Perlmutter forges ahead with marketing BrainSustainTM, intravenous glutathione, and other completely unproven products.

Grain Brain ends with a warning that, in the context of Perlmutter’s full dossier, is a bit surreal. The epilogue tells the story of Dr. Mesmer, an 18th-century physician and charlatan who duped the public into believing he could “cure nervous system problems using magnetism,” which happens to be the origin of the word “mesmerized.”

According to Perlmutter, “the medical and scientific community feared Mesmer,” and eventually they exposed him as a fraud. Perlmutter writes of this exposure approvingly, warning readers to stay alert for other like-minded crooks.

It’s now generally accepted that Mesmer was actually treating psychosomatic illness, and he profited mightily from people’s gullibility. In retrospect, his theories and practices sound ridiculous, but in truth, the story of Mesmer parallels many stories of today. It’s not so ridiculous to imagine people falling prey to products, procedures, and health claims that are brilliantly marketed. Every day we hear of some news item related to health. We are bombarded by messages about our health — good, bad, and confusingly contradictory. And we are literally mesmerized by these messages. Even the smart, educated, cautious, and skeptical consumer is mesmerized. It’s hard to separate truth from fiction, and to know the difference between what’s healthful and harmful when the information and endorsements come from “experts.”

It may be tempting to ignore all of Dr. Perlmutter’s advice, but this paragraph, at least, deserves everyone’s attention.

Alan Levinovitz is an assistant professor of religion at James Madison University. He is the author of The Gluten Lie. Follow him on Twitter: @top_philosopher.