Fasting: A New Ally in the Fight Against Cancer

Fasting has long been lauded for its myriad health benefits, and now, groundbreaking research suggests it could be a potent weapon in the battle against cancer. A study conducted by researchers at Memorial Sloan Kettering Cancer Center (MSK) in New York has revealed that fasting can reprogram the metabolism of natural killer cells, enhancing their ability to survive and combat tumors.

The study, led by immunologist Joseph Sun and published in the journal Immunity, demonstrates that fasting may deprive cancer cells of the nutrients they need to thrive, creating an inhospitable environment for tumor growth. “Tumors are very hungry. They take up essential nutrients, creating a hostile environment often rich in lipids that are detrimental to most immune cells,” explained Sun.

Natural killer (NK) cells, a type of white blood cell, are critical components of the immune system’s defense against cancer. The researchers discovered that fasting reprograms these NK cells to better withstand the suppressive conditions found in and around tumors. This metabolic adaptation allows them to survive and function more effectively in lipid-rich environments.

In the study, mice with cancer underwent a regimen of 24-hour fasting periods twice a week, followed by unrestricted feeding in between. Similar to humans, the fasting mice experienced a drop in glucose levels and an increase in free fatty acids. These fatty acids, released by fat cells, serve as an alternative energy source when glucose is scarce, according to Rebecca Delconte, the study’s lead author.

Throughout the fasting cycles, NK cells adapted to use fatty acids as fuel instead of glucose. This metabolic shift optimized their anti-cancer response, enabling them to infiltrate tumors and survive in the lipid-rich tumor microenvironment. “This metabolic training allows NK cells to enter the tumor and survive better, improving their ability to fight cancer,” Delconte noted.

While the findings are based on animal models, they offer promising insights into potential new strategies for cancer treatment. The researchers emphasize that more studies are needed to determine if fasting can similarly enhance human immune responses and improve the effectiveness of immunotherapy.

This pioneering research opens new avenues for understanding how dietary interventions like fasting might bolster the body’s natural defenses against cancer, potentially offering a simple yet powerful adjunct to existing cancer therapies. As science continues to unravel the complex relationship between metabolism and immunity, fasting could emerge as a crucial tool in the fight against one of humanity’s most formidable foes.