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New research in mice suggests that the combination of a high fat diet and exposure to so-called forever chemicals may drive prostate cancer development. Yuri_Arcurs/Getty Images
  • Researchers examined the effect of per- and polyfluoroalkyl substances (PFAS) exposure and a high fat diet on prostate cells in both mouse and cell culture models.
  • Male mice that the team had injected with malignant prostate cancer cells had a faster tumor growth rate when they ate a high fat diet and had exposure to PFAS.
  • On exposure to PFAS, tumor-forming prostate cells in a cell culture replicated nearly three times as much.
  • This mouse-and-cell-culture study may influence future recommendations from healthcare professionals to beware of PFAS-containing items, especially for males.

Prostate cancer is the second most common type of cancer in males and the fourth most common type overall, according to the American Institute for Cancer Research. A reported 1.3 million new cases of prostate cancer occurred worldwide in 2018.

Previous research found that dietary fat in the typical Western diet can help prostate cancer tumors spread. Now, a new study from researchers at the University of Illinois Urbana-Champaign and the University of Illinois at Chicago has found that a high fat diet and increased exposure to PFAS can speed up the development of prostate tumors.

The findings appear in the journal Nutrients.

PFAS are a wide group of human-made chemicals specially designed to resist grease, oil, water, and heat. Manufacturers usually use a combination of these chemicals as a stain-repellant coating on food packaging and cooking equipment. PFAS can sometimes be present in:

  • nonstick coatings on pots and pans
  • fast food wrappers and containers
  • stain- and water-resistant carpeting and other fabrics
  • firefighting foam and heat-resistant protective gear
  • paints and sealants

PFAS — nicknamed forever chemicals because they do not decompose — can potentially contaminate the surrounding soil and water when people discard them. This contamination can put people at risk of PFAS exposure. A study last year found that PFAS may contaminate the drinking water of 200 million people in the United States.

People can get exposure to PFAS by:

  • drinking contaminated water
  • eating fish that were living in contaminated water
  • eating food covered in paper and other packaging containing PFAS
  • coming into contact with contaminated soil or dust

PFAS occupational hazards exist for those involved in the making of PFAS-containing products, as well as firefighters exposed to PFAS in their protective gear and firefighting foam.

According to the Agency for Toxic Substances and Disease Registry, researchers are still not clear on the total effect of PFAS exposure on the body. However, past research suggests that PFAS exposure may result in:

  • higher cancer risk
  • higher levels of cholesterol
  • immune system issues
  • interference with hormones and some major organs, such as the liver

For the study, Dr. Zeynep Madak-Erdogan, associate professor of nutrition at the University of Illinois Urbana-Champaign, and her research team used a mouse model.

They fed some of the male mice a high fat diet similar to a typical Western diet — also known as the Standard American Diet — which past research has associated with obesity and neurodegenerative issues. The others ate a control diet.

At 10 days after the diets started, the researchers injected the mice with prostate cancer epithelial cells. They then began orally administering the PFAS chemical perfluorooctanesulfonic acid (PFOS) to some of the mice 7 days per week.

Also as part of the study, research team members exposed both non-tumor-forming and tumor-forming human prostate cells suspended in growth media to varying levels of PFOS or perfluorobutane sulfonic acid (PFBS) — another member of the PFAS chemical family — for 2 days.

After 2 days, researchers reportedly found that the tumor-forming prostate cells exposed to PFOS reproduced at triple the rate of those not exposed to PFBS.

In regards to the mouse model, after 40 days, the researchers observed an increase in tumor volume in mice exposed to either PFOS or a high fat diet. However, the fastest tumor growth rate reportedly occurred in mice exposed to a combination of PFOS and a high fat diet.

Based on their research, Dr. Madak-Erdogan and her colleagues believe that PFAS work with dietary fat to switch on a protein-coding gene called peroxisome proliferator-activated receptor alpha. This causes cells to metabolize in such a way that increases the carcinogenic risk in benign prostate cells and also increases tumor development in malignant prostate cells.

Dr. Madak-Erdogan told Medical News Today that her team’s findings will affect future recommendations from healthcare professionals to beware of PFAS-containing items, especially for men. “Our studies provide a basis to reduce PFAS exposure through food wrapping, particularly those used for fast foods or food with high fat content, or occupational exposures,” she added.

MNT also spoke with Dr. Mehran Movassaghi, who is a urologist and director of men’s health at Providence Saint John’s Health Center and an assistant professor of urology at Saint John’s Cancer Institute in Santa Monica, CA. He said this is not just a men’s health issue.

“It’s a general health issue […]. A lot of different chemicals found in plastics are known to be carcinogens, and this is just essentially more evidence.”

Regarding a high fat diet, Dr. Movassaghi said the study’s results can help medical professionals steer patients toward the best diet for protecting against cancer.

Specifically, he mentioned concerns about the ketogenic diet that he has seen become popular over the past 5 years. “It’s concerning because a lot of people look at that as an opportunity to regain control of their health,” he said.

“And in the short term, while they may be able to lose weight, in the long term, we don’t know what the effects will be — whether it be on cardiac disease, dyslipidemia, or related to cancer. It’s important when someone [is] seeking out […] the optimal diet to point to certain studies like these and say although this is not a proven fact, there are definitely things that point to its [being] dangerous, especially if someone decides this is their lifestyle.”

Additionally, Dr. Madak-Erdogan believes that this study may shed light on how PFAS and high fat diets might affect other types of cancers. “We now have a pretty good basis to look into other types of cancers, including colorectal cancer or breast cancer, which are highly associated with high fat diet consumption,” she explained.

In future research, Dr. Madak-Erdogan would like to look further into the molecular mechanisms of PFAS and high fat diet synergy and to investigate this interaction in other cancers associated with a high fat diet.