Al, type 2 from Wyoming, asks: How does the use of chewing tobacco affect blood sugar?

Wil@Ask D’Mine answers: It looks like chaw, as my Southern friends call it, raises blood sugar both in the short-term, and in the long run. Let’s start with that long view.

First off, let me make it clear that while tobacco is heavily researched, there really aren’t all that many studies that look specifically at chewing tobacco, much less chaw and blood glucose! But that said, there’s a lot to learn from the few we have. Most notable among these is a Swedish study of more than 54,000 people over 23 years, which concluded that the use of snus, a distant cousin of chewing tobacco that’s popular in Scandinavia, increases the risk of developing type 2 diabetes to the same degree that smoking cigarettes does.

And what, you might ask, does that have to do with the price of tea in China or the price of tobacco leaves in North Carolina?

More than you might think, because the way in which snus increased the risk of diabetes has a direct bearing on your inquiry. The snus raised the risk of developing diabetes, in part, by inhibiting insulin sensitivity and increasing insulin resistance. What’s the catalyst behind that? The researchers placed their bets on nicotine, writing: “mechanistic studies point to nicotine as the possible mediator of such a risk increase. Nicotine can inhibit insulin sensitivity and may stimulate release of cortisol, thus promoting abdominal obesity and subsequently insulin resistance.”

So, while snus and chaw aren’t exactly the same, they’re both powered by nicotine — and if the Swedes are correct that it’s the nicotine that’s causing the problem, then it’s safe to say that chewing tobacco will have a similar effect on your body.

The nicotine and other ingredients in chewing tobacco should, in theory, raise blood sugar.

But who cares if it raises the risk for developing diabetes when you already have diabetes?

Looking to research on other tobacco products, for decades, researchers observed that people with diabetes who smoke had higher blood sugars than non-smoking PWDs, but no one was quite sure why. Then in 2011, California Polytechnic professor Xiao-Chaun Liu announced findings of a lab study pointing to nicotine as the ‘smoking gun’ in smoking’s blood-sugar elevating effect. Conducted in Petri dishes, this research exposed human blood to various levels of nicotine and then ran A1C tests on the blood samples. A previous study that compared the glucose bump of conventional smokes to the glucose response of nicotine-free cigarettes seems to bear out Liu’s findings.

His results apply equally to chewing tobacco as they do to cigarettes because he essentially distilled the nicotine out of the cigarette. Unlike other smoking studies, there’s no risk of confounding factors from the more than 4,000 compounds generated by a burning cigarette. Meanwhile, other studies show that, as the Swedes mentioned in passing, nicotine also increases the release of cortisol, an infamous blood sugar-raising stress hormone.

So it’s clear that chewing tobacco, thanks to its nicotine content, will both drive insulin resistance and raise cortisol, a combination that’s pretty much guaranteed to raise blood sugar.

That said, personally, my blood sugar goes down when I break out my nicotine of choice—either a tobacco pipe or a cigar—which is the opposite of what the science says I should expect. Perhaps, for me, smoking helps me relax and de-stress enough to offset any glucose spike from nicotine absorption—which is likely less in the first place than it would be with either cigarettes or chewing tobacco, as pipes and cigars are puffed, not inhaled.

Or maybe I’m just a mutant.

While chewing tobacco is safer health-wise than cigarettes (with a much reduced cardiovascular disease risk, and pretty much zero lung cancer risk), there is one more surprising blood sugar risk beyond the effects of nicotine: Chewing tobacco has added sugar.

Yep! It’s no different than chewing “regular” gum.

So, with all of that, maybe instead of Blake Shelton’s riff, “Chew tobacco, chew tobacco, chew tobacco, spit!” we should be singing, “Chew tobacco, chew tobacco, chew tobacco, inject!”

Or maybe not. The rhythm is all wrong. Forget I suggested it.

Meanwhile, is nicotine found in anything other than tobacco? Yep! As a matter of fact, all members of the nightshade plant group, to which tobacco belongs, have at least some nicotine. What other plants would those be? Tomatoes, potatoes, eggplant, peppers, and cauliflower to name a few.

How do these levels of nicotine compare to chewing tobacco? Chewing tobacco has around 12.5 milligrams of nicotine per gram, while the tomato has only a tiny trace of about 7 nanograms of nicotine per gram. To get the same happy buzz from tomatoes that you do from a pouch of chaw, you’d need to eat one million, seven hundred eighty-five thousand grams, or about 10,504 average-sized tomatoes.

And at that point, your increased blood sugar would be the least of your problems.


Wil Dubois lives with type 1 diabetes and is the author of five books on the illness, including “Taming The Tiger” and “Beyond Fingersticks.” He spent many years helping treat patients at a rural medical center in New Mexico. An aviation enthusiast, Wil lives in Las Vegas, NM, with his wife and son, and one too many cats.