Does Fructose Support Cancer Cells?

Does a type of sugar called fructose impact cancer cells? Glucose, the main form of sugar in the blood, is known to be used by all cells, including cancer cells. Fructose is naturally found in certain fruits and vegetables but has also been increasingly added to food products over the last 50 years, notably as high-fructose corn syrup—an artificial mixture of fructose and glucose.

Researchers have been exploring whether fructose impacts specific types of solid-tumor cancer cells in mice. The findings of these studies offer new insights into how different sugars could affect cancer growth.

Oncology Registered Dietitian Shares Thoughts on Sugar and Cancer 

Before examining these findings, it’s beneficial to understand some fundamental concepts about sugar and cancer, shared by Joan Elizondo, a registered dietitian specializing in oncology nutrition at the Huntsman Cancer Institute. During a webinar hosted by HealthTree, Elizondo explained:

"Foods containing any type of sugar or carbohydrate are broken down into glucose by the body. This glucose then pairs with insulin to enter our cells and provide them with energy. Excess energy gets stored for later use. While all cells utilize glucose, it does not necessarily mean that sugar causes cancer to spread or grow. Additionally, even without sugar or carbohydrate intake, the body can produce glucose from other sources like protein and fat. Thus, you cannot starve cancer cells of glucose without also starving your healthy cells."

Elizondo also highlighted the link between added sugars and obesity, a known risk factor for cancer. By reducing intake of added sugars, one can decrease excess calorie consumption and maintain a healthier weight. 

Reviewing Fructose’s Impact on Solid-Tumor Cancer Cells 

Building on this knowledge, researchers specifically looked at how fructose affected melanoma, breast cancer, and cervical cancer cells in mice. They discovered that cancer cells cannot directly use fructose.

Instead, after fructose is metabolized in the liver, they use one of the byproducts—lysophosphatidylcholines (LPCs), a type of fat molecule— to build their outer membranes and grow. It is not yet known if this is how all cancer cells use fructose or only the ones in the study.

A significant aspect of the study involved blocking the protein KHK, which is responsible for breaking down fructose. This inhibition lowered the levels of the fat molecules or LPCs, thereby hindering the growth of cancer cells. 

Contrary to what might be expected, feeding mice fructose supplements did not lead to weight gain or insulin resistance, which are commonly associated with increased cancer risk.

It's crucial to note that these findings are based on animal models, and the exact implications for humans are still to be determined. Further studies are planned to explore whether inhibiting KHK could slow cancer growth in humans without requiring dietary changes.

The researchers emphasized that this does not mean people should eliminate fructose from their diets but rather encourage moderation of fructose-containing foods in their natural forms, like fruits and vegetables. 

An additional study that echoes the use of fructose in moderation studied people who ate it in excess. Excessive consumption of fructose, particularly in processed forms like high-fructose corn syrup, not only differs in how it’s metabolized from whole fruits and vegetables but can also increase inflammation, a known promoter of cancer growth. A notable finding was that this effect was observed more frequently in Black populations. 

Understanding your risk status can help you take preventive measures. If you are concerned about ways to manage inflammation, please consult your doctor. 

Summary

Researchers have discovered that while certain solid tumor cancer cells cannot directly utilize fructose, they can use LPCs—fat molecules produced when fructose is metabolized in the liver—to construct their outer membranes. 

Although these findings are based on animal studies and are preliminary, they advocate for moderation in fructose consumption, encouraging individuals to favor natural sources over processed forms like high-fructose corn syrup, which are metabolized differently. 

This study not only highlights the unique ways fructose affects cancer cell metabolism but also suggests new avenues to restrict cancer cell growth, such as with KHK inhibitors. 

Are you interested in helping researchers understand the correlation between diet and blood cancer? Click the button below to participate in our survey. Your answers are anonymous to researchers. 

Take the Survey

Sources: 

• Dietary fructose enhances tumour growth indirectly via interorgan lipid transfer
• 40 years of adding more fructose to high fructose corn syrup than is safe, through the lens of malabsorption and altered gut health–gateways to chronic disease
• Fructose Fuels Cancer Growth Indirectly, Lab Study Finds
• High-fructose corn syrup promotes proinflammatory Macrophage activation via ROS-mediated NF-κB signaling
• Glucose Metabolism in Cancer: The Warburg Effect and Beyond