A study led by Ludwig MIT’s Matthew Vander Heiden compared the effects of calorie restricted diets and ketogenic—high fat, moderate protein and very low carbohydrate—diets in mouse models of pancreatic cancer. Matthew and his colleagues reported in an October issue of Nature that both diets similarly reduced the amount of sugar, an important nutrient, available to tumors, yet only caloric restriction slowed tumor growth. They further found that with caloric restriction, lipid levels also dropped dramatically, while they actually climbed in mice fed a ketogenic diet. Fatty acids are required to make membranes and are therefore essential to rapidly dividing cells. When levels drop, cells can make their own fatty molecules, but this process requires an enzyme known as stearoyl-CoA desaturase (SCD), which converts saturated fatty acids into unsaturated fatty acids. The researchers found that both diets reduced SCD activity, but mice on the ketogenic diet had lipids available to them from their diet, so they weren’t as reliant on the enzyme. Mice on the calorie-restricted diet, however, didn’t have that resource, which is why their tumor growth slowed significantly. The dependence on unsaturated fats exposed by this study suggests how different components of the diet can interact to determine whether they affect the growth of pancreatic cancer.
This article appeared in the February 2022 issue of Ludwig Link. Click here to download a PDF (1 MB).