Gum trees in North Country not used for chewing pleasure
Thursday, December 25, 2014 - 4:08 pm


Recently, I heard there are gum trees abound in northern New York state. I couldn’t believe it until the person making this claim produced a pack of gum that was “made from northern hardwoods,” according to its label. There it was in writing, and they wouldn’t print it if it wasn’t true, right?

These days commercial chewing gum is made from butadiene-based synthetic rubber, which sounds yummy, not to mention healthful. Until the 1960s, though, it was derived from the sapodilla tree, native to Central America. But what about locally grown gum?

Years ago I used to indulge occasionally in spruce gum, a substance which, while making your mouth taste like turpentine for a week, will pull out your fillings if chewed for longer than three seconds. It’s an acquired taste, let’s say.

The sour gum or black gum, Nyssa sylvatica, a tree known for its intensely red fall foliage, can be found as far north as the southern Adirondacks. But Nyssa sylvatica is not used to make chewing gum.

In addition to medicinal uses, the resin of the sweet gum tree, Liquidambar styraciflua, was once used to make chewing gum. But sweet gum is primarily a southern species. It can survive, though, in subtropical New York state (i.e., south of Albany).

Further inspection of the label in question revealed it wasn’t the gum that was made from birch trees, it was the sweetener it contained, xylitol. Xylitol is derived from the same Greek root as xylem, which is what normal people refer to as “wood.” So it’s not a surprise this naturally occurring sweetener is found in birch sap.

Turns out that Xylitol is more than just sweet. It’s effective at cutting the frequency of childhood ear infections, and possibly in reducing the severity and duration of the ailment. Research suggests that gum is better than xylitol-based candy in this regard.

And it may improve oral health. The Journal of the American Dental Association recently cited a study that found “Xylitol is an effective preventive agent against dental caries.” Six to seven grams of xylitol per day is reportedly an ideal quantity for cavity prevention.

Because it has a low glycemic index (a scale ranking carbs on how fast we convert them to glucose) of 7 (compared to 68 for sugar), xylitol is safe for diabetics. Plus, it has one-third fewer calories than sugar. Wow, what’s not to like about this birch-based miracle?

With the exception of a few small health-food companies, most commercial xylitol is made in an industrial lab. Xylan, a precursor compound found in hardwood fiber, corn cobs and other plant material, is transformed to xylose. This in turn is hydrogenated to form xylitol using a nickel-aluminum alloy. (Someone is probably checking for metals residue in commercial xylitol from overseas on a regular basis. That’s a safe assumption, isn’t it?)

In addition to its dubious source, xylitol can cause bloating and gas in some people. Oh, and it’s extremely toxic to dogs. Well, nothing’s perfect, I guess.

My evaluation? If it contains xylitol, gum from trees is probably good. Gum (or candy) from heavy metals catalyst-driven chemistry labs, though? Let me think about that for a bit while I chew some spruce gum.

Paul Hetzler is a forester and a horticulture and natural resources educator for Cornell Cooperative Extension of St. Lawrence County.