In a breakthrough that could change the way we approach cancer treatment, scientists have discovered that a specific type of intermittent fasting might enhance the body’s natural ability to combat cancer.

Researchers at Memorial Sloan Kettering Cancer Center have published their findings in the journal “Immunity,” showcasing a fascinating connection between fasting and the immune system. Their study focused on natural killer cells, which play a crucial role in attacking cancer cells and virus-infected cells without the need for prior exposure.

Natural killer cells act as the special forces of our immune system, and having more of them within a tumor generally increases the chances of beating cancer. However, tumors create a harsh environment where immune cells often struggle to survive, making it difficult for natural killer cells to function effectively.

This is where intermittent fasting comes into play. The researchers found that fasting periods could “reprogram” natural killer cells, enhancing their ability to survive in the hostile tumor environment and making them more potent in fighting cancer.

“During each of these fasting cycles, NK cells learned to use these fatty acids as an alternative fuel source to glucose,” the lead author of the study, Dr. Rebecca Delconte, said in a press statement. “This really optimizes their anti-cancer response because the tumor microenvironment contains a high concentration of lipids, and now they’re able enter the tumor and survive better because of this metabolic training.”

The study, conducted on mice, involved a fasting regimen where the animals were denied food for 24 hours twice a week, resuming regular eating in between. The results were remarkable. The fasting induced a drop in glucose levels while elevating the levels of free fatty acids — a type of fat that serves as an alternative energy source when nutrients are scarce. The natural killer cells adapted by using these fatty acids as fuel instead of glucose, which is their usual energy source.

Fasting also prompted the natural killer cells to migrate to various parts of the body, including the bone marrow, where they encountered high levels of a protein called Interleukin-12. This exposure primed the natural killer cells to produce more Interferon-gamma, a protein essential for combating tumors.

“Tumors are very hungry,” the study’s senior author, immunologist Joseph Sun, said in the press release. “They take up essential nutrients, creating a hostile environment often rich in lipids that are detrimental to most immune cells. What we show here is that fasting reprograms these natural killer cells to better survive in this suppressive environment.”