New MRI research reveals that heavy smoking can shrink key brain regions tied to memory and cognition, and excess weight might intensify the damage, raising fresh questions about dementia prevention.

Cigarettes were once unavoidable in the U.S., in restaurants, airplanes, your mom's living room — until health warnings and cultural pressure put out the hype. The big picture: Something's shifted.

If you started smoking during your teenage years, you might face severe health consequences decades later, even if you eventually kicked the habit. A comprehensive new study has shed light on the ...