One thing most people don't consider is how smoking affects their brain. After each puff, the nicotine reaches your brain within seconds. "They go to this part of the brain just above the ear … called the insula," Dr. Oz says.
In the insula, the nicotine opens your brain's receptors and allows dopamine to flow in. "Dopamine is the ultimate addictive element in our body," he says. "When we have really good sex, dopamine comes out. When we have a double chocolate cheesecake, dopamine goes out. You do drugs, dopamine gets stimulated. … Cigarettes are as addictive as heroin.