I don't know how much would need to be consumed to be an issue but the problem with the internet and the modern food crazes is that most companies don't bothering refuting accusations be they true or false, because no one will trust them as objective and doctors and scientists just don't have the time and resources to look into and prove or disprove every rumor. You'll get a hundred hits of people claiming something is bad and proven bad and most don't even bother citing anything but if you follows the ones that do cite down the 'proof' tends to be from either an iffy source or from a reputable one but says 'test results inconclusive, may have...' which is generally 'no, no significant threat has been detected' and people misunderstand 'no significant'.

Which is to say if they tested in as part of a diet of a 500 people and normally 50 would manifest cancer during the duration but 60 did instead the study would rightly conclude nothing significant had occurred, because on a sample like that one is assuming 10% ± 4% or so will get cancer so out of any given sample nothing weird has occurred if 30-70 people got cancer. So if 65 get cancer the scientist conclude nothing significant is happening but the populace concludes this stuff is dangerous. The problem is I could run two such samples, one on placebos and one on a gram a day of orange zest and get 47 and 67 and nothing has really been shown yet, but people will conclude the orange zest is like cyanide, and that will be hard to quash even if a subsequent study of 500 gets 38 people developing cancer. Take a hundred different foods and run one on each and even if they have no real danger to them you'll get several hit that 60+ range and some spiking over 70. That's just how the numbers game works. Others will be low 30's or even 20's and be labeled as anti-cancer.

That isn't to there's no reason to run such studies or that there aren't risky food and additives just that our modern setup tends to spread rumors of danger with around as much scientific accuracy as we got a couple centuries back, and it doesn't heart to remember that a lot of the people who spread this stuff but more faith in colon cleansing and homeopathic remedies then they do vaccines and pharmaceuticals. I can't help but point out your link is rather low on citations from places like the USDA or Mayo and so on.