Burnt, I already researched this. Take a look at the numbers and you'll be shocked.
Quote:
Based on animal data and a margin-of-safety factor of 100, a dose of 0.66 mg safrole per kg body weight is considered hazardous for humans; the dose obtained from sassafras tea may be as high as 200 mg (3 mg/kg)
I know this has been discussed previously but I am bringing it up again anyway because I have some more comments.
Is this referring to asingle doses or chronic use? Or its referring to the dose given to animals in animal studies? But you have to realize the purpose of such animal studies is not always to figure out how likely a substance is to cause cancer in humans but sometimes to simply answer the question of can it cause cancer in experimental animals. The next step is then to figure out mechanisms and do epidemological studies etc. Although animal studies can give quantitative risk assessments its not the whole story.
The often reported 200 mg of safrole per cup used in scare tactics spread by the FDA is incorrect. 32 mg of safrole is the maximum solubility per cup for room temperature water. And it often contains less because it distills away easily.
I don't believe this is scare tactics but probably an estimate of the maximum amount of safrole possible in tea. The 32mg per cup is that based on solubility of safrole? Because the solubility can change in teas which contain substances which can help solubilize other substances better. Just curious where these numbers are coming from.
No one will ever take 4999.5 mg of pure safrole. NO ONE. That's a massive amount. That's the amount needed to be potentially carcinogenic in man according to those lab tests.
Agree that's a massive dose but your conclusion is totally misleading. All it takes is one carcinogenic molecule to get cancer. But in reality we are all exposed to carcinogens fairly regularly so in essense its an odds game. The more carcinogens you are exposed to, as well as genetic and dietary/lifestyle factors, the more likely you are to get cancer.
So it doesn't matter if you take 1mg of safrole its still potentially carcinogenic. Thats how carcinogens work. There is no cancer causing dose. However if you take 200mg obviously the risk is higher. It works like this.
Now with the possibility that elemicin is aminated to TMA in humans, as many believe, then if that's true this whole subject doesn't even apply to it.
I don't think this happens at all. But thats another discussion which I think we should have but later.
Now as far as claiming there is no evidence that safrole causes cancer in humans this is simply not true.
Betel nut chewing (which certain kinds contain safrole 15mg/g) has been linked to oral cancer in humans:
Abstract. Betel quid (BQ) chewing has been associated with an increased risk of oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSF). Pipe
carcin.oxfordjournals.org
And Areca quids:
Epidemiological studies have demonstrated that areca quid chewing can be an independent risk factor for developing esophageal cancer. However, no studies are available to elucidate the mechanisms of how areca induces carcinogenesis in the esophagus. Since the areca nut in Taiwan contains a high...
www.ncbi.nlm.nih.gov
Again I would like to reaffirm that the risk of cancer from drinking sassafrass tea is probably low. No studies that I am aware of found a significant risk and since its been banned its even harder to say. However there are also no studies that demonstrated that drinking the tea is safe long term either.
There are other confounding factors such as other compounds in the tea which change the metabolism of safrole making it less risky when compared to pure safrole or vise versa. There are many other factors that could come into play.
Basically the reason I am posting all this is to point out that taking safrole is not without risk. Don't pretend that its harmless.
