Dietary fructose's potential role in fostering the growth of melanoma and breast cancer tumors is under investigation.
Natural fructose, found in fruits, vegetables, and honey, is generally harmless to human health.
However, when consumed as high-fructose corn syrup in processed foods like soft drinks and baked goods, fructose can become detrimental to one's health.
Previous studies have connected the consumption of high-fructose corn syrup to numerous health issues, including cancer.
Researchers from Washington University in St. Louis discovered that dietary fructose may contribute to tumor growth in animal models of melanoma, breast cancer, and cervical cancer.
Fructose present in natural sources like fruits and vegetables is non-harmful to human health.
On the other hand, if consumed in processed foods such as sodas and packaged pastries as high-fructose corn syrup, it could pose health risks.
Several earlier studies have linked intake of fructose or high-fructose corn syrup to an increased risk of various conditions, including Alzheimer's, type 2 diabetes, fatty liver disease, and kidney disease.
As Gary Patti, PhD, the Michael and Tana Powell Professor of Chemistry, Genetics, and Medicine at Washington University in St. Louis, stated to Medical News Today, "Fructose occurs naturally in some fruits and vegetables – so humans have always been exposed to it. What has changed over the past four to five decades is that we started using it as an artificial sweetener in processed foods. As a result, many people are exposed to much higher levels than ever before."
In his role as the senior author of a recent study published in, Patti found that dietary fructose may promote tumor growth in animal models of melanoma, breast cancer, and cervical cancer.
Investigating fructose and cancer growth
In this research, researchers employed an animal model of cancer tumors. During the trial, the animals were given a diet rich in fructose.
"It has been established for over a century that cancer cells are addicted to glucose," Patti highlighted. "We utilize this in the clinic frequently. Patients are given a radioactive form of glucose that appears in PET scans. Because cancer cells absorb more glucose than most other healthy cells, they illuminate in the images."
"Glucose and fructose consist of the same atoms," he continued. "The only difference between them is the arrangement of the atoms. Given the avidity that cancer cells have for glucose, it's enticing to imagine that they might use fructose in a comparable manner."
Fructose, lipids, and tumor growth
Upon examination, Patti and his team found that the body's liver converts fructose into a type of carbohydrate called lysophosphatidylcholine (LPC), which are connected with inflammation.
When cancer cells divide, they require a substantial amount of lipids. Having a larger amount of LPCs in the bloodstream assists cancer cell replication, consequently aiding tumor growth.
"When you consume an excessive quantity of food, your body converts it into fat," Patti explained. "That is your body's way of storing energy. High levels of dietary fructose trigger a similar process. The fructose is changed into a precursor of fat in the liver, called lipids. Those lipids can then feed the tumor."
"Cancer cells are unique from most other cells in the body because they are rapidly dividing, which is what allows tumors to grow larger," he continued. "For a cancer cell to divide into two, it has to make a new set of cellular contents. That requires a lot of nutrients, which ultimately come from the diet. It is therefore intuitive to imagine that dietary modifications could influence the process of tumor growth."
"The complication is that there are many variables to consider such as where the tumor is located in the body, which oncogenes it has, what drugs the patient is using, what dietary components are transformed into prior to reaching the tumor, etc," Patti added. "Our understanding of these issues is still only at its early stages, but an increasing number of studies are starting to reveal important details. I hope our study will be part of that equation."
Processed foods' impact on cancer risk: Understanding the mechanisms
MNT spoke with Anton Bilchik, MD, PhD, surgical oncologist, chief of medicine and Director of the Gastrointestinal and Hepatobiliary Program at Providence Saint John's Cancer Institute in Santa Monica, CA, regarding this study.
"We've been suspicious for quite some time that certain food supplements such as sweeteners and processed food may increase the risk of getting cancer, but we've never really known the mechanism," Bilchik, who was not involved in the research, commented.
"This is one of the few studies that offers a potential mechanism for fructose, which is found in high-fructose corn syrup, processed food, and sweeteners, a mechanism that may cause different types of cancers. Therefore, there may be some truth to the fact that people should be very cautious about using sweeteners or using sugars that are not from fruits and vegetables, but are in processed foods."
– Anton Bilchik, MD, PhD
"Fructose, being abundant in processed foods, could potentially contribute to certain mechanisms. To explores this further, clinical studies should be conducted on individuals consuming artificial sweeteners versus natural sugars, to ascertain if there's a difference in cancer rates. This translation into the clinical realm could yield significant benefits, according to Bilchik."
Decreasing Fructose Intake: Tips from Monique Richard, MS, RDN, LDN
In conversation with MNT, Monique Richard, a registered dietitian nutritionist and the owner of Nutrition-In-Sight, offered some strategies to help readers lower their fructose consumption.
Richard suggested a straightforward, though not always practical, method to avoid excessive or unhealthy types of fructose: opt for fresh, unpackaged fruits and vegetables instead.
"Embrace the fructose in fresh fruit and politely decline the fructose in fruit roll-ups," she recommended.
The fiber, vitamins, and minerals inherent in fruits and vegetables, which accompany the carbohydrates such as fructose, are less likely to be overconsumed, Richard noted, even though portion control remains essential. Additionally, these nutrients positively impact our gut microbiota, which researchers are discovering is susceptible to damage from excessive fructose consumption from ultra-processed foods.
Richard also emphasized the importance of reading labels and comprehending the ingredients in the food you consume:
"Understanding the various names for sugar can help you avoid unhealthy sugar alternatives. Be mindful that food manufacturers often employ clever marketing tactics to promote their products, so be on the lookout for terms like 'no high fructose corn syrup' that could still contain high levels of other sugars or fructose sources like glucose, glucose-fructose syrup, or even table sugar."
While there's no need to be overly restrictive, Richard cautioned against consuming excessive processed foods:
"Maintain balance – indulging in sweet treats during special occasions is perfectly acceptable. However, be conscious of portion sizes and be sure to make healthy choices the majority of the time, ensuring that real, nutrient-dense food remains the focus of your diet."
The finding that high-fructose corn syrup consumption may lead to an increased risk of various health issues, including cancer, raises concerns about other nutrition sources containing high fructose, such as some processed foods and beverages.
In light of these concerns, researchers in the field of oncology are investigating the role of fructose in tumor growth. For instance, studies have shown that dietary fructose may promote tumor growth in animal models of melanoma, breast cancer, and cervical cancer.
This research has significant implications for dietary recommendations in cancer prevention and treatment, as understanding the mechanisms behind the impact of fructose on cancer risk could lead to potential interventions and treatments.
