Pancreatic tumors in mice grow more slowly when the animals eat a calorie-restricted diet, findings suggest. The results, published in Nature, do not mean that anyone with cancer should embark on a special diet, especially given that people aren’t mice. But more research in this area could identify combinations of specifics diets and drug therapies that enhance cancer treatments.
Scientists have long known that cancer cells are ravenous, consuming loads of glucose as they grow. The question is whether starving them of glucose would slow this growth without harming the rest of the body. To get an answer, the researchers worked with mice carrying pancreatic tumors. They fed a low-calorie diet to one group, a normal diet to one group, and a high-protein, high-fat, low-carbohydrate ketogenic diet to a third group.
Only tumors in animals eating the low-calorie diet showed slower growth, implying that the tumors needed more than glucose to keep growing. Glucose levels were lower with both calorie restriction and the keto diet, but lipids also were lower with calorie restriction.
All cells, including cancer cells, use lipids to build their protective outer membranes. The increased lipid levels in the keto diet may have given tumors all the lipids they needed to build new cell membranes.
The results suggest that the key to slowing cancer in these mice was to starve tumors of both glucose and lipids, as only the calorie-restricted diet did. The healthy tissues of the body still need these nutrients, one reason patients with cancer shouldn’t change their diets without clinical guidance. But the findings hint that using diet or drugs to restrict intake of some lipids or their use cells could be a path to starving a tumor without starving the person.