>>>Gabz, you're right that they don't test for nicotine itself because it has such a short half-life. They test for the cotinine, which is a product of nicotine metabolization.
Hi Lockjaw,
I have my husband's New England Journal of Medicine here. It says:
"The presence of nicotine and its metabolite cotinine in the body fluids of nonsmokers is usually taken as evidence of exposure to environmental tobacco smoke. Recently, the Centers for Disease Control and Prevention studied 800 people, both smokers and nonsmokers, all of whom tested positive for urinary cotinine" (nicotine oxide) "There is considerable evidence that nicotine is present in certain human foods, especially plants from the family Solanaceae (such as potatoes, tomatoes, and eggplant). Castro and Monji, Sheen, and Davis et al have reported on the nicotine content of foods and drinks."
So, yes, the nicotine is absorbed from the fruits of the nightshade plants.
Howdy, Calpernia! Pleased to meet you.
Yes, you're right. Nicotine can be and is absorbed from fruits and vegetables in the nightshade family. It's even found in certain tea leaves.
However, most bodies do metabolize nicotine rather quickly, though at various rates. So the serum blood levels of nicotine decrease rapidly after being consumed. So testing for nicotine may show trace amounts but it really isn't a good quantitative indicator of how recent and what level of exposure someone was subjected to. That's why they generally measure cotinine in both blood and urine samples. The metabolite stays in the body longer, until excreted as a waste product. Funny thing about cotinine though is that all of us metabolize nicotine at different rates. Researchers assume that's why some people are more predisposed to become tobacco users than others.
Did you know they even found traces of nicotine in thousand year old Egyptian mummies? That has researchers perplexed because there were no known nightshade varieties in ancient Egypt and tobacco is a new world plant. It's not just from exposure to tobacco smoke from smoking crypt robbers and archeologists. The nicotine was fully embedded in hair and nail samples. Some surmise there were ancient overseas trade routes between the continents.
Again though, there are huge differences in levels of nicotine and cotinine found in the blood and urine samples between active smokers and non-smokers. The biggest risk of misclassification for those who regularly consume large amounts nicotine containing plants and beverages is for non-smokers where researchers may assume they are actually exposed to more environmental tobacco smoke when they may not be at all.
So anyway, I'm interested in seeing how this plays out. I can imagine employers start asking for a strand of hair when giving interviews so they can see if you smoked a cigarette or have been socializing with any heavy pot smoking friends for the past so many months... You think women with longer hair would have more of a problem? ;) Oh well, who knows where this will go?