Which nutrient is considered the primary fuel for cancer cells?

The primary fuel for cancer cells is often considered to be glutamine. Cancer cells have an increased demand for certain nutrients to support their rapid growth and proliferation. Glutamine, an amino acid, plays a crucial role in cellular metabolism, particularly in the context of cancer.

Cancer cells utilize glutamine not only as a carbon source for energy but also for the synthesis of nucleotides and other biomolecules required for cell division. Additionally, glutamine can be converted into α-ketoglutarate, which feeds into pathways such as the tricarboxylic acid (TCA) cycle, thereby providing energy and supporting biosynthetic processes essential to cancer cell survival and growth.

While glucose is widely recognized for providing energy through glycolysis in various tissues, especially under aerobic conditions, cancer cells often exhibit a preference for glutamine in high-stress environments or when rapidly dividing. This phenomenon is referred to as "glutaminolysis," which further underscores the importance of glutamine in cancer metabolism. Other nutrients, such as fatty acids and proteins, play roles in cellular function and may support cancer cell activities, but they are not the primary fuel source in the same way that glutamine is utilized under the metabolic demands of cancer cells.