
37. Smoking can cause cancer.
There are 4,800 toxic substances found in cigarettes, and you inhale every single one of them every time you light up. Tobacco smoke contains at least 70 cancer-causing chemicals. If you smoke, your life expectancy is at least ten years shorter than non-smokers, and your risk of heart attack, lung disease, and various cancers is increased.

The good news: if you stop smoking before age 40, you reduce your risk of dying from a smoking-related disease by almost 90%. And even if you’re over 40, your body notices increased benefits from quitting almost instantly. After three months, your lung capacity is improved, and after five years, your risk of dying from stomach, mouth, throat, lung, or esophageal cancer is cut in half.