For many years, people have been told that some fats are healthier than others. Olive oil, for example, is often praised as a heart-friendly food and is a key part of the Mediterranean diet.
Because of this reputation, many people assume that foods rich in olive oil are beneficial for overall health. However, a new study suggests that when it comes to pancreatic cancer, the story may be more complicated.
Researchers from Yale School of Medicine have discovered that different types of dietary fat may have very different effects on the development of pancreatic cancer. Their findings, published in the journal Cancer Discovery, suggest that the kind of fat people eat could matter more than the total amount of fat they consume.
Pancreatic cancer is one of the deadliest forms of cancer. The most common type, called pancreatic ductal adenocarcinoma, is difficult to detect early and often spreads before it is diagnosed.
As a result, survival rates remain low compared with many other cancers. Each year, tens of thousands of people are diagnosed with the disease in the United States, and researchers continue searching for better ways to prevent and treat it.
Scientists have known for years that high-fat diets are linked to a greater risk of pancreatic cancer. However, they have struggled to understand exactly which fats might be responsible and how they affect cancer cells. To answer this question, researchers designed a detailed study using mice that develop a disease similar to human pancreatic cancer.
Instead of using a single high-fat diet, the team created 12 different diets. Each diet contained the same number of calories. The only major difference was the type of fat included. This allowed the researchers to isolate the effects of specific fatty acids and study them more accurately.
One of the most surprising discoveries involved oleic acid, the main fatty acid found in olive oil. The researchers found that mice fed diets rich in oleic acid developed pancreatic tumors more quickly. Oleic acid is also found in foods such as peanuts, lard, and certain cooking oils.
The result surprised the scientists because oleic acid is generally considered beneficial for heart health. While it may still have cardiovascular benefits, the new findings suggest that its effects on cancer biology could be different.
In contrast, diets rich in polyunsaturated fatty acids produced very different results. These fats, particularly omega-3 fatty acids found in fish oil, appeared to slow the development of pancreatic cancer. In some experiments, fish oil reduced disease severity by about half compared with standard-fat diets.
To understand why these fats behaved differently, researchers examined what was happening inside cancer cells. They focused on a process called ferroptosis, a natural form of cell death. Cancer cells often try to avoid dying, allowing tumors to grow and spread.
The study showed that polyunsaturated fats make cancer cells more vulnerable to damage and death. Monounsaturated fats such as oleic acid, on the other hand, appeared to protect cancer cells from this damage. As a result, cancer cells survived longer and tumors grew more aggressively.
The researchers also found that male and female mice did not respond in exactly the same way. The cancer-promoting effect of oleic acid was much stronger in males. Female mice appeared to be less affected. Scientists believe biological sex may influence how dietary fats interact with cancer pathways, but more research is needed to understand these differences.
Although the study was performed in mice, the findings could eventually have important implications for people at high risk of pancreatic cancer. Individuals with obesity, chronic pancreatitis, diabetes, or a family history of pancreatic cancer may particularly benefit from future dietary recommendations based on this research.
The researchers stress that these findings do not mean people should immediately stop consuming olive oil or other foods containing oleic acid. Human nutrition is extremely complex, and many foods contain mixtures of different fats and nutrients. Much more research will be needed before doctors can make specific dietary recommendations.
This research is valuable because it moves beyond the simple idea that all dietary fat is either good or bad. Instead, it shows that different fats may influence cancer in very different ways. The carefully designed diets allowed researchers to isolate specific fatty acids, making the findings more convincing.
However, the work was conducted in mice, and human studies will be needed before firm conclusions can be drawn. The results suggest that future cancer prevention advice may focus not only on how much fat people eat but also on the balance between different types of fat in the diet.
If you care about cancer, please read studies that a low-carb diet could increase overall cancer risk, and vitamin D supplements could strongly reduce cancer death.
For more information about health, please see recent studies about how drinking milk affects the risks of heart disease and cancer and results showing higher intake of dairy foods linked to higher prostate cancer risk.
Source: Yale School of Medicine.
