The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth

by Zoë Schlanger

People with the “lung cancer gene” are much more likely to develop lung cancer, especially if they smoke. Due to genetic mutations, they lack a certain enzyme that most people have, which normally works to clear cancer-causing chemicals from hazards like tobacco smoke out of the lungs. So that was one trend line, at a steep angle upward; the more these “lung cancer gene” people smoked, the more likely they were to get lung cancer. But then she drew a second line and labeled it “broccoli.” People with the lung cancer gene who ate a significant amount of cruciferous vegetables, including broccoli, appeared to have a lower risk of lung cancer proportional to how much broccoli they ate. At high enough intake, broccoli nearly erased the impact of the gene mutation. (In a different study, it even appeared to help people without the genetic anomaly clear carcinogens from smoking.) This is likely because cruciferous vegetables like broccoli produce compounds that, when broken down in our bodies, turn into the enzymes that detoxify cancer-causing chemicals. In other words, these vegetables make the thing that does what the “lung cancer gene” people lacked the genetic ability to do. Here, genes weren’t everything. The environment a person experienced—in this case, what they ate—had a place in the story too. Possibly even a bigger place than genes.