Heavy Snus Use: Possible Link to Type 2 Diabetes

A Swedish research study finds that heavy consumption of snus is associated with type 2 diabetes (abstract here). 

Analyzing data from six groups of Swedish men, researchers found no risk of type 2 diabetes in all snus users combined, but they reported a modest elevated risk with higher levels of consumption, at 5-6 cans per week (Relative risk, RR = 1.42, 95% Confidence Interval, CI = 1.07 – 1.87) or 7+ cans per week (RR = 1.68, CI = 1.17 – 2.41).

In a Karolinska Institute press release (here), lead research author Sofia Carlsson said, “We can confirm earlier suspicions that snus-users have a higher risk of type 2 diabetes.”  In fact, the new study confirmed only one “earlier suspicion”, as Carlsson’s is only the second study to show an association at higher consumption levels.  Here are the results from the four studies that have been published to date:

Studies of Snus Use and Type 2 Diabetes in Sweden
Author, Year, Snus Users	Relative Risk (95% CI)
Eliasson et al., 2004
Current snus users (prevalent diabetes)	1.06 (0.43 – 2.64)
Current snus users (follow-up diabetes)	No cases
Ӧstenson et al., 2012
Current snus users	1.1 (0.6 – 2.0)
1-5 cans per week	0.6 (0.2 – 1.4)
6+ cans per week	3.3 (1.4 – 8.1)
Rasouli et al., 2017
A. Current snus users	0.96 (0.67 – 1.37)
A. Ever snus users
Less than 5 boxes per week	0.78 (0.56 – 1.09)
5+ boxes per week	0.95 (0.57 – 1.58)
B. Ever snus users	0.91 (0.75 – 1.10)
Less than 3 boxes per week	0.88 (0.72 – 1.08)
3 + boxes per week	0.92 (0.46 – 1.83)
Carlsson et al., 2017
Current snus users	1.15 (1.00 – 1.32)
1-2 boxes per week	1.14 (0.86 – 1.50)
3-4 boxes per week	1.03 (0.82 – 1.29)
5-6 boxes per week	1.42 (1.07 – 1.87)
7+ boxes per week	1.68 (1.17 – 2.41)

A.    Swedish snus users

B.    Norwegian snus users

    Significantly elevated RRs

While those two studies suggest that high snus consumption is associated with type 2 diabetes, more research is needed to confirm a link. Many other factors are known to contribute to this type of diabetes (here), including age, overweight or obesity, inactive lifestyle, smoking (here), family history, high blood pressure and high blood cholesterol levels.  Research and analysis must fully account for these factors in order to confirm or refute a snus link.