Key points
Research in preliminary stages indicates that fructose could play a role in the spread of certain cancer cells.
Scientists suggest that fructose may impact cancer through various mechanisms, including alterations in the tumor environment and its metabolism in the liver.
Experts advise cutting back on added sugars and sugary drinks instead of avoiding naturally occurring fructose found in nutritious foods like fruits and vegetables.
Fructose is naturally found in fruits, vegetables, and honey, but it’s also a prominent ingredient in high-fructose corn syrup, commonly used in sodas and packaged snacks. Recent studies are beginning to uncover potential implications of this well-known sugar on cancer development.
A preclinical study in Nature Aging has shown that fructose produced by cancer cells weakened by chemotherapy seems to assist neighboring ovarian cancer cells in detaching and spreading. This doesn’t imply that consuming fruit or fructose directly causes cancer, but it opens up new avenues for understanding how nutrients might affect tumor dynamics.
This isn’t the first time researchers have hinted at a connection between fructose and cancer growth; prior reviews have linked it to metabolic disorders, and different studies have displayed its association with increased tumor growth in models for melanoma, breast, and cervical cancers. Another study has indicated that fructose can encourage prostate cancer to thrive and progress.
What research suggests about fructose and cancer progression
With nearly 40% of Americans expected to face a cancer diagnosis in their lifetime, understanding factors that might influence cancer is crucial.
In this study, researchers examined ovarian cancer cells, laboratory mice, and human tumor and blood samples. While the results are preclinical and haven’t been verified in humans yet, they raise intriguing questions about dietary influences on cancer progression.
The study supports earlier findings which indicated that chemotherapy could trigger certain cancer cells to enter a state where they stop dividing but continue releasing factors that promote cancer growth. For instance, platinum-based chemotherapy, a common treatment for ovarian cancer, effectively kills cancer cells but often allows the disease to return.
In this analysis, some senescent cancer cells damaged by chemotherapy were found to produce fructose. This simple sugar seemed to change the behavior of nearby cancer cells, helping them break away and invade other areas of the body. Mice given a diet high in fructose even showed cancer spread without prior chemotherapy treatment.
What is fructose and where is it found?
Fructose is a monosaccharide, often referred to as “fruit sugar,” because it appears naturally in many fruits and various plant-based foods like honey, sugar beets, and certain vegetables such as zucchini and asparagus.
It’s also commonly added to products, particularly as high-fructose corn syrup, which can be found in many sodas, commercially baked goods, and sweets.
How fructose may influence cancer growth and spread
Fructose has the potential to reduce cancer cell adhesion, making it easier for these cells to detach and migrate throughout the body. Study coauthor Katherine M. Aird explains that processing fructose leads to cholesterol loss on the surface of cancer cells, which typically helps them stick together. With that ‘glue’ diminished, the chances of cancer spreading increase.
Additionally, dietary fructose may affect tumors through another mechanism: the liver metabolizes it into fats that tumors can utilize for growth. Ana Gomes mentions that fructose might operate not only as a dietary sugar fueling cancer growth but also as a metabolite influencing cancer biology within the tumor environment.
Collectively, these discoveries suggest fructose could affect cancer progression through various pathways, rather than solely targeting cancer cells. Nutrients might influence cancer through complex interactions involving tumors, the liver, the immune system, the microbiome, and surrounding tissues, according to Tracy Crane.
How to spot added sugar on a nutrition label
You don’t need to search an ingredient list for “fructose” to determine added sugar content. The Nutrition Facts label can clearly indicate this.
Check “Added Sugars.” This will appear below “Total Sugars” and shows how many grams of added sugar are present in each serving.
Observe the % Daily Value. The FDA says that 5% Daily Value or lower is low, while 20% or higher is high in added sugars.
Think about serving size. If you consume two servings, that also doubles the added sugar content listed.
Distinguish between total and added sugars. Total sugars include both natural sugars, like those in fruits and milk, and any added sugars.
Does this mean you should stop eating fructose?
The research doesn’t imply that fructose should be completely removed from your diet, experts conclude. Crane argues that the notion that “sugar feeds cancer” oversimplifies a complex issue and may cause unnecessary anxiety. While cancer cells do utilize glucose—the primary sugar in blood—for energy, so too do healthy cells. Completely eliminating all dietary sugar won’t selectively starve a tumor.
Colorectal surgeon Ketan Thanki supports this perspective, noting that there’s no current necessity for individuals to cut out fructose from their diets entirely. Naturally occurring fructose found in fruits and vegetables can still be part of a healthy eating pattern.
The larger issue concerns added sugars, particularly high-fructose corn syrup found in processed foods and sugary drinks, which can introduce significant fructose amounts quickly and without beneficial fibers. Thanki encourages limiting these types of sugars.
Crane reiterates existing guidance to reduce consumption of sugary drinks and heavily processed foods high in added sugars, especially those containing high-fructose corn syrup. The main takeaway is to be mindful of added sugars while still enjoying natural, nutrient-dense foods.
Reviewed by
Lauren Manaker MS, RDN, LD, CLEC: An award-winning registered dietitian with over 22 years of experience, Lauren is also a three-time author.
