Diabetes in Canada's First Nations

William Panton raises an interesting issue regarding the rarity of historical reports of type 2 diabetes among Aboriginal people in Canada. The fact that “the epidemic was not noted earlier” does not preclude a genetic explanation for the susceptibility of Aboriginal people to this disease. Space limitations prevented us from more fully discussing the gene–environment interactions involved in the emergence of the diabetes epidemic in the past 3 decades.¹ James Neel, who first proposed the “thrifty genotype” theory, recently published an update,² which we cited in our review.¹ We also cited several dietary studies, but few dietary culprits have been consistently identified. Panton's comments about nutritional deficiencies or toxic additives in “white man's food” are purely speculative at this stage but perhaps warrant further study.

I appreciate the fact that Bruce Leistikow has pointed out references concerning the association between tobacco use and hyperglycemia. According to data from the First Nations and Inuit Regional Health Survey, current smokers are less likely to be diabetic (8.4%) than people who are not currently smokers (13.4%) (the latter group includes people who have never smoked and people who are former smokers).³ A possible explanation for this finding is that people who are diagnosed with diabetes may make lifestyle changes that include stopping smoking. Because of the cross-sectional nature of the data it is not possible to delineate the temporal sequence between the onset of smoking and the onset of diabetes. However, the potential link warrants further inquiry.

I would, however, caution against hoping that removing a single factor, be it dietary toxins or tobacco smoke, will vanquish the diabetes problem in Canada's Aboriginal population. Current evidence points to a very complex etiology and to date no magic bullets have been found.