Researchers have found that the simple sugar fructose may act as a molecular signal that drives cancer cells that survive chemotherapy to spread again in the body, which may explain why the disease returns after treatment.
Naturally occurring simple fructose sugar is also known as "fruit sugar" because it is found naturally in fruits, honey, and some vegetables. However, in modern diets, it is used as an artificial sweetener added in large quantities to soft drinks, sweetened juices, sweets, processed foods, and fast food.
The study, led by a team from the Wistar Institute in Philadelphia and published in the journal Nature Ageing, focused on ovarian cancer, but the researchers suspect the findings may also apply to other types of cancer.
When cancer patients undergo chemotherapy, not all cancer cells are killed; some survive. Researchers have discovered that these surviving cells, although they may stop dividing, remain biologically active and continue to send out molecules that act as signals to neighboring cancer cells, stimulating them to spread to other parts of the body.
"Our study is among the first to show that one nutrient – fructose – can act as one of those signals," said Aidan Cole, lead author of the study
The study focused on ovarian cancer patients treated with platinum-based chemotherapy. While they initially respond well, the cancer tends to recur in most of them, spreading to the abdominal cavity. This subsequent metastasis after chemotherapy is responsible for approximately 90% of ovarian cancer-related deaths.
The study confirmed that molecules released by cells that have survived chemotherapy alone are capable of significantly increasing the spread of cancer cells, and this is the first time this effect has been demonstrated in animal models and not just in the laboratory.
By analyzing these molecular signals, researchers discovered that fructose produced by surviving cells is the key signal that leads to increased cancer spread. Fructose stabilizes cholesterol levels within neighboring cancer cells, and cholesterol acts like "glue," helping cells to stick together. When cholesterol levels drop, cells become less cohesive, allowing surviving cancer cells to break free and spread more easily throughout the body.
Researchers warn that even without undergoing chemotherapy, consuming large amounts of fructose – as in sugary drinks and sweetened juices – may also stimulate cancer cells to spread.
Although the effectiveness of reducing fructose intake has not yet been tested on patients, the results open the door to a new understanding of the role of nutrition in cancer development.
Researchers believe these findings may not be limited to ovarian cancer, and they are planning further trials to test whether they apply to other types of cancer. This could open up a new field for understanding the relationship between nutrition, chemotherapy and tumor spread, and raise new questions about how to improve the effectiveness of current treatments and reduce the chances of disease recurrence.
