Smoking damage heals
It’s never too late to stop smoking—and your lungs may even make a partial recovery. That’s the surprising conclusion of a new study, which found that quitting cigarettes can spark a healing process even in people who puffed a pack a day for 40 years. The chemicals in tobacco smoke corrupt the DNA in lung cells, gradually turning them from healthy to cancerous. Researchers at University College London examined lung biopsies taken from 16 people—including current smokers, ex-smokers, and people who’d never smoked—and found that nine out of 10 lung cells in current smokers had up to 10,000 more genetic mutations than in nonsmokers. Study co-author Kate Gowers calls these genetic alterations “mini time bombs, waiting for the next hit that causes them to progress to cancer.” But a tiny proportion of lung cells remains unaffected, and when a person stops smoking, these cells grow and replace the damaged cells around them. In ex-smokers, up to 40 percent of their cells looked like those of people who’d never smoked. Why these cells remain unscathed—and how many cells they can replenish—is unclear, reports BBC.com. The researchers say answering those questions could help them improve the repair process.