Curing removes most of the natural sugars in the leaves.
Sucrose etc. and/or invert sugars are approved for inclusion as additives in tobacco products... usually "American" style cigarette tobaccos, though it's done worldwide and I'd presume pipe tobacco with their "casing" (flavoring) techniques might exceed the cigarettes' 10% (by weight) permitted maximum.
However...
Sugar is about 4 grams per teaspoon.
Amount of additive sugars (worst case per NIH)... approx. 0.2 mg per cigarette.
Total daily dose for a 2 PAD smoker (factoring uptake & bio-availability)... ~8mg. Yes... 8 milligrams.
I'm not going to get bent out of shape over the sugar in cigs.
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https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296517/
Table 1
Estimate of ingredient sugar uptake (worst case assumptions) by smoking American-blend cigarettes.
Parameter Estimate
Number of cigarettes per day
§ 40 cig.
Maximum use level for all sugar sources 5%
Tobacco weight 0.8 g/cig.
Transfer of unchanged sugars 0.5%
Bioavailability (deposition) 100%
Dose per cigarette 0.2 mg
Daily dose 8 mg