Introduction to the Risk of High-Fat Diets
From fast-food to ultra-processed snacks, a high-fat diet eaten over the long term may trigger biological changes in the liver that could raise the risk of cancer. Researchers from the Massachusetts Institute of Technology (MIT) suggested it may be less about how much fatty food is consumed at once — and more about how long the liver is exposed to a high-fat diet.
The Impact on Liver Cells
Over time, a high-fat diet may put liver cells into a kind of survival mode that researchers believe could make them more vulnerable to cancer-related changes, according to the research published in December in the journal Cell. The scientists found that when the liver repeatedly processes large amounts of fat, its main working cells stop focusing on breaking down nutrients and filtering toxins. Instead, they revert to a more primitive state to help them endure the strain of a fatty diet, a shift researchers associate with tumorigenesis, the process by which cancer can develop.
Study Findings
“If cells are forced to deal with a stressor, such as a high-fat diet, over and over again, they will do things that will help them survive, but at the risk of increased susceptibility to tumorigenesis,” Alex K. Shalek, one of the study’s senior authors and director of MIT’s Institute for Medical Engineering and Sciences, said in a statement. The study focused on mice fed a long-term high-fat diet, some of which went on to develop liver cancer. By examining liver cells as the disease progressed, researchers saw that healthy liver functions slowly shut down and survival traits took over. When they examined human liver samples, researchers observed comparable declines in normal liver activity, though without tracking long-term cancer outcomes.
The Trade-Off for Survival
A study found that a high-fat diet over a prolonged period can cause liver cells to change. Rawpixel.com – stock.adobe.com “This really looks like a trade-off, prioritizing what’s good for the individual cell to stay alive in a stressful environment, at the expense of what the collective tissue should be doing,” co-first author and MIT graduate student Constantine Tzouanas said in a statement. “These cells have already turned on the same genes that they’re going to need to become cancerous,” he added. “Once a cell picks up the wrong mutation, then it’s really off to the races, and they’ve already gotten a head start on some of those hallmarks of cancer.”
Implications and Future Research
The findings help explain why fatty liver disease often precedes liver cancer — and why the effects of diet may take years or even decades to show up. Researchers found that patients whose liver cells showed more stress-survival changes and less normal liver function tended to live for a shorter time after cancer developed. While this process unfolds within about a year in mice, scientists estimate it could take decades to occur in humans. The researchers stressed that the findings relate to long-term eating patterns rather than occasional indulgent meals. While the study did not focus on specific foods, experts generally recommend moderation and balanced eating patterns.
Expert Insights
Because the research was conducted primarily on animals, the findings should be interpreted cautiously when applied to humans, said Dr. Ghassan Abou-Alfa, an oncologist specializing in gastrointestinal cancers at Memorial Sloan Kettering Cancer Center in New York City. He was not involved in the new research. Even so, the results offer new insight into the biological processes that may help explain how fatty liver disease can progress to liver cancer, a condition that can also affect people who are not morbidly obese. “This can be any of us, and we need to adapt our lifestyles to avoid turning healthy liver cells into cancer cells,” said Abou-Alfa. He also noted that healthy fats are a necessary part of our diets.
Lifestyle Changes to Lower Cancer Risk
“There is no sure way to prevent cancer, but there are changes you can make to potentially lower your risk,” Karen Smith, an oncology dietitian at Texas Oncology, told Fox News Digital. “Your overall lifestyle matters more than any single food,” added Smith, who was also not involved in the new research. “Maintaining a healthy weight, not smoking, and staying active can all make a difference.” She also recommended limiting red and processed meat, choosing proteins such as fish, chicken, beans and lentils, and eating a balanced diet rich in fruits, vegetables, whole grains, and legumes.
Conclusion
The MIT researchers cautioned that the findings are based largely on mouse models and early genetic changes, do not fully explain how disrupted fat metabolism leads to cancer, and do not account for factors such as insulin resistance, inflammation or alcohol use. The team now plans to study whether shifting to healthier eating patterns or using GLP-1 weight loss medications could help restore normal liver cell behavior and lower future cancer risk. Previous research has also suggested that long-term high-fat diets can disrupt how the gut and brain communicate, affecting appetite, mood and metabolism.
FAQs
- Q: What type of diet may be physically changing the liver and leading to a higher cancer risk?
A: A high-fat diet eaten over the long term may trigger biological changes in the liver that could raise the risk of cancer. - Q: What happens to liver cells when they are exposed to a high-fat diet for a prolonged period?
A: Liver cells may revert to a more primitive state to help them endure the strain of a fatty diet, a shift associated with tumorigenesis, the process by which cancer can develop. - Q: Can occasional indulgent meals lead to the same risk as long-term high-fat diets?
A: No, the findings relate to long-term eating patterns rather than occasional indulgent meals. - Q: What lifestyle changes can help lower the risk of cancer?
A: Maintaining a healthy weight, not smoking, staying active, limiting red and processed meat, and eating a balanced diet rich in fruits, vegetables, whole grains, and legumes can help lower the risk of cancer.
