Smoking and Diabetes: A 30 to 40% Higher Risk
Key takeaways
Health Canada says people who smoke have a 30% to 40% higher risk of developing type 2 diabetes than people who have never smoked, and the risk rises with the number of cigarettes. Quitting lowers the risk, and it also helps people who already have the disease.
This page summarizes Health Canada information and is not medical advice. If you have diabetes, ask your care team before changing medication or routines when you quit.
Does smoking increase the risk of type 2 diabetes?
Yes. Health Canada’s page on tobacco and type 2 diabetes says smokers have a 30% to 40% higher risk of developing type 2 diabetes than people who have never smoked. More cigarettes means higher risk. For context, the page reports that about 2.4 million Canadians, 7.5% of the population, had diabetes in 2019-2020.
How does smoking affect insulin?
Health Canada gives two routes. Chemicals in tobacco smoke can cause inflammation and impair the regular functioning of blood vessels, which makes it harder for the body to use insulin well. Nicotine can impair the body’s ability to release insulin, adding to insulin resistance. The page also says smoking raises the risk of central obesity, excess fat around the abdomen, a major risk factor for insulin resistance.
What happens if you smoke and already have diabetes?
The risks stack. Health Canada says unmanaged diabetes raises the risk of heart disease, blindness, kidney failure and nerve damage that can lead to amputation, and that for people with diabetes smoking increases the risk of heart disease, kidney failure and nerve damage. On its circulation page, smokers with diabetes are up to four times more likely to lose a limb. Heart and stroke effects are covered in smoking and heart disease and smoking and stroke.
Does quitting help with diabetes?
According to Health Canada, quitting lowers the risk of type 2 diabetes. For people who already have it, it is not too late: quitting makes the condition easier to manage, lowers the risk of complications, and the body is better able to regulate blood sugar. Quit-line counselling, alone or with medication, improves the chance of success. Options and provincial coverage are on the quit medications page and the free help by province guide. Other body effects are in cigarette side effects.
Health information is general and educational. It does not replace advice from a doctor, pharmacist or nurse. Read the full disclaimer.
Frequently asked questions
Does smoking cause diabetes?
Health Canada says smokers have a 30% to 40% higher risk of developing type 2 diabetes than people who have never smoked, and that risk rises with the number of cigarettes smoked.
Should someone with diabetes quit smoking?
Health Canada says it is not too late: quitting makes type 2 diabetes easier to manage and lowers the risk of complications. Talk to your care team about a plan.
Does diabetes plus smoking raise the risk of amputation?
Health Canada says smokers with diabetes are up to four times more likely to lose a limb, and that smoking also raises amputation risk from peripheral vascular disease.
Sources
- Tobacco and Type 2 Diabetes — Health Canada. Accessed October 27, 2026.
- Tobacco and Peripheral Vascular Disease — Health Canada. Accessed October 27, 2026.