Twitter has become a forum for political discussion – and amusing gifs – but it shouldn’t one for medical advice. Rob Gronkowski, the recently retired tight end for the New England Patriots, has been up front about the toll football has taken on his body and brain. After an interview in which he detailed the effects of the 20 concussions he received while playing, Gronkowski took to social media claiming that he had cured his CTE with CBD products.

He directed this tweet, asserting that CTE is fixable, at Chris Nowinski, a former WWE wrestler and the co-founder and CEO of the Concussion Legacy Foundation and co-founder of the Boston University CTE Center.

It is fixable. I fixed mine. There are plenty of methods in this world that allow the brain to recover from severe damage. That is also why I would allow my kid to play football. https://t.co/9aI1olAdqP — Rob Gronkowski (@RobGronkowski) September 13, 2019

“It is fixable. I fixed mine. There are plenty of methods in this world that allow the brain to recover from severe damage. That is also why I would allow my kid to play football.”

Nowinski, who also happens to have a PhD in behavioral neuroscience from Boston University, responded with this, “You are right about brain plasticity, and I am glad you are feeling great today, but neurodegenerative diseases (CTE, Alzheimer’s, etc.) cannot be ‘fixed’ or cured today. They eventually win. Please come on over to the BU brain bank next week and we can discuss the nuance”

Nowinski believes that Gronkowski has been able to find relief for his post-concussion symptoms, rather than symptoms of CTE. That seems to be backed up by Gronkowski himself later tweeted that he was “not saying I cured it” but he had found “unconventional methods to improve my conditions.”

Nowinski says Gronkowski’s stance risks muddying the water around an important issue. “Gronk is a powerful spokesman for caring about these issues,” he told the Guardian. “But there’s confusion in the public about concussions and CTE and we need to clear that up. You can treat the symptoms that can linger after a concussion, and that’s still a positive message, but CTE can’t be fixed.”

Nowinski also has an issue with furthering the sense that every brain injury is fixable, therefore giving parents and kids the idea that years of repetitive trauma can be reversed. Since years of exposure is the strongest risk factor for CTE, one of the missions of the Concussion Legacy Foundation is to urge parents not to let kids play until high school.

While research continues to expand our understanding of CTE, there are still many myths and misconceptions surrounding the disease. Here are some of the more prevalent

Misconception 1: People can say with certainty that they have CTE

First documented years ago as “punch-drunk syndrome” in boxers, CTE is a neurodegenerative disease, much like Parkinson’s or Alzheimer’s, that is believed to be the result of repetitive brain injury. Researchers haven’t yet defined what symptoms constitute CTE, but family members and others report depression, anxiety, as well as memory, mood or personality changes.

CTE can only be diagnosed with certainty after death through an examination of the brain. Currently, there are no formerly accepted criteria that can be used to diagnose CTE based on clinical signs and symptoms. Meaning that Gronkowski, or others, can’t say with certainty that they have the condition.

Misconception 2: The number of concussions is linked to CTE

Research suggests that CTE is the result of repetitive subconcussive impacts (ie hits or blows that do not cause a concussion) and is not linked to the number of documented concussions. In fact, CTE has been found in athletes without a history of concussion. “The reality is a concussion diagnosis is based on many factors and a broad array of symptoms,” said Nowinski. “In my mind, because a person’s recollection of the number may not be clear, the number is flawed at baseline.”

Misconception 3: CTE can’t be treated

While CTE is neurodegenerative disease and there isn’t a cure, the symptoms often associated with the condition – like depression or anxiety– can be treated. Nowinski urges those that believe they have symptoms to see their doctor because the situation isn’t hopeless. Also, symptoms such has cognitive problems, depression or headaches, which may lead some to believe they have CTE, can be caused by other conditions that mimic CTE. Nowinski’s foundation urges the consideration of other diagnoses before focusing on CTE.

Misconception 4: The governing bodies of sports now recognize the problem

According to Nowinski, the NFL has started to address CTE, acknowledging a link between head trauma and the disease. However, the NHL and Fifa are lagging far behind. In fact, after a 2017 study confirmed the presence of CTE on post-mortem exams of former professional soccer players, Fifa doubled down on its denial. “To our very best knowledge, there is currently no true evidence of the negative effect of heading or other subconcussive blows,” said a Fifa representative, “Results from studies on active and former professional football players in relation to brain function are inconclusive.”

Nowinski believes it’s hard to change hearts and minds, but even harder to change the business of sports. “There’s also the business of sports,” he says. “The job of the CEOs and directors of youth sports leagues isn’t to manage the future of kids 20 years from now, their job is to keep participation numbers as high as possible. Nobody wants to raise their hand and say we need to change the sport and risk losing participation.”

Illustrating Nowinski’s point, Jon Butler, Pop Warner’s executive director, in an interview with CBS Sports, expressed his frustration with the media’s focus on safety. “First, we have a duty to football. This means too much to people and has for so long we can’t turn our back on it. We figured out tobacco. We figured out asbestos. We’ll figure this out.

Misconception 5: There isn’t a link between youth football and CTE

Many use the fact that CTE has not been documented in young football players as evidence that youth football is safe. “That’s like saying there is no link between youth smoking and lung cancer because you’ve never seen a 13-year-old with lung cancer,” says Nowinski. “We haven’t seen CTE in a 13-year-old because they rarely die and rarely have their brain donated if they die. He points out that there may well be a delay between someone’s exposure to football and them developing the disease: “It’s not because they can’t develop CTE,” he says.

Misconception 6: Helmets can prevent concussions and CTE

A recent study, performed by researchers from the University of Rochester, found that a single season of college football can cause changes in the brain. Adnan Hirad, the lead author of the study, believes that helmets don’t do a very good job of protecting the brain from subconcussive or concussive forces.

“Helmets are optimized to prevent catastrophic injury and skull fractures and are not optimized to prevent concussion,” says Hirad. “Primarily because helmets don’t dissipate rotational force, the force more correlated with brain injury. They do a better, or adequate, job of preventing absorbing linear acceleration force., the force involved with fractures.”