Your Cells Are Changing: Roxanne Khamsi on the DNA We Acquire as We Age

Right now, inside your body, cells are dividing. Each time they divide, they must copy an enormous instruction manual: your DNA. Most copies are remarkably accurate. Some acquire changes. We tend to think of DNA as fixed. You receive it from your parents, carry it through life, and perhaps pass part of it to your children. But scientists are finding that inheritance is only the opening chapter. As we grow older, our cells collect mutations. Sunlight can leave its mark on skin cells. Tobacco smoke can alter cells in the lungs. Inflammation, infection, copying errors, environmental exposures, and simple chance can all play a part. Most of those changes may never matter. Some help our immune system recognize new threats. A few give one population of cells an advantage over its neighbors. And some are associated with cancer, cardiovascular disease, or other health risks. That means the cells in your body do not all carry precisely the same genetic story. For those of us in our 60s, 70s, 80s, and beyond, this raises a fascinating question: How much of our health is inherited, and how much continues to be written as we live? Our guest is award-winning science journalist and Smithsonian Associate Roxanne Khamsi. Her work has appeared in The Atlantic, The New York Times, WIRED, The Economist, and other leading publications. Her new book is Beyond Inheritance: Our Ever-Mutating Cells and a New Understanding of Health. Roxanne Khamsi, welcome to The Not Old Better Show.