Certain form of nutrition increases colon cancer risk
- KASSEL – While low-carbohydrate diets can offer health benefits, a new study suggests that very restrictive versions may negatively impact the intestinal microbiome and possibly increase the risk...
- The role of nutrition in cancer prevention has long been a subject of interest, with the intestinal microbiome believed to be a key factor.
- The study compared three different diets in mice: a low-carbohydrate diet lacking soluble fiber, a diet high in fat and sugar, and a standard diet.
Low-Carb Diets May Increase Colon Cancer Risk, Study Finds
Table of Contents
- Low-Carb Diets May Increase Colon Cancer Risk, Study Finds
- Low-Carb Diets and Colon Cancer Risk: A Q&A Guide
- Can Low-Carb Diets Increase Colon Cancer Risk?
- What Did the Study Actually Find?
- Diet Comparisons in the Study:
- What’s the Connection Between Gut Bacteria and Colon Cancer?
- Why Might Low-Carb Diets Be a Problem?
- What Role Does Fiber Play?
- what is the Recommended Carbohydrate Intake?
- What are Good Sources of Fiber?
- Does This Meen I Should Stop a Low-Carb Diet?
Published May 17, 2025
KASSEL – While low-carbohydrate diets can offer health benefits, a new study suggests that very restrictive versions may negatively impact the intestinal microbiome and possibly increase the risk of colon cancer.
The role of nutrition in cancer prevention has long been a subject of interest, with the intestinal microbiome believed to be a key factor. Researchers at the University of Toronto in Canada investigated the effects of different diets on specific gut bacteria and the development of colon cancer. Their findings, published in Nature Microbiology, highlight potential risks associated with strict low-carb regimens.
Study Compares Three Diet Types
The study compared three different diets in mice: a low-carbohydrate diet lacking soluble fiber, a diet high in fat and sugar, and a standard diet. The researchers monitored the effects of these diets on the intestinal health of the mice over eight weeks, tracking intestinal cancer markers such as inflammation, polyps, microbiome changes, and tumor development.
Intestinal Bacteria and Nutrition: A Key Connection
For the study, the intestines of the mice were populated with various bacterial strains. Of particular interest was PKS+ E. coli (polyketide synthase-positive E. coli), wich produces colibactin, a molecule known to damage DNA.
the researchers observed a higher incidence of tumors and polyps in mice with PKS+ E. coli in their intestines that were fed a low-carbohydrate, fiber-deficient diet, compared to the other groups. These mice also exhibited increased inflammation and a thinning of the mucus layer in the intestine, which protects against bacterial penetration. A compromised mucus layer allows colibactin easier access to cells in the large intestine.
The protective Role of Fiber
The study also explored the impact of fiber. Mice on the low-carbohydrate diet that were supplemented with inulin, a type of fiber, showed reduced inflammation and fewer polyps after a period. inulin is found in foods such as chicory, Jerusalem artichoke, dandelion greens, and garlic.
Further Research Needed
While the study was conducted on animals, it reinforces previous research highlighting the protective role of fiber against colon cancer. Further studies are necessary to determine if these findings are applicable to humans.
Low-Carb Diets and Colon Cancer Risk: A Q&A Guide
Can Low-Carb Diets Increase Colon Cancer Risk?
A recent study suggests that very restrictive low-carbohydrate diets might potentially increase the risk of colon cancer. Research, published on May 17, 2025 in Nature Microbiology, found a link between these diets and negative impacts on the intestinal microbiome, which plays a key role in gut health.
What Did the Study Actually Find?
Researchers at the University of Toronto in Canada investigated the effects of various diets on mice. They compared a low-carbohydrate diet (lacking soluble fiber), a high-fat/sugar diet, and a standard diet. The study tracked the development of colon cancer markers,including:
Inflammation
Polyps
Microbiome changes
Tumor development
Diet Comparisons in the Study:
The study focused on three dietary approaches. Hear’s a simple overview:
| Diet Type | Key Characteristics | Outcomes Observed in Mice |
|---|---|---|
| Low-Carbohydrate (Fiber-Deficient) | Very limited carbohydrates,lacking soluble fiber. | Higher incidence of tumors and polyps, increased intestinal inflammation, and thinning of the protective mucus layer. |
| High-Fat and Sugar | High in fat and sugar content. | No specific outcomes reported; diet was compared to the other two diets. |
| Standard Diet | normal diet compared to the low-carb and high- fat/sugar diets. | No specific outcomes reported; diet was compared to the other two diets. |
What’s the Connection Between Gut Bacteria and Colon Cancer?
The study specifically examined the role of PKS+ E. coli (polyketide synthase-positive E. coli) bacteria in the mice’s intestines. This particular bacteria produces a molecule called colibactin, known to damage DNA. Higher levels of colibactin could promote tumor growth, especially in mice on a low-carb, fiber-deficient diet.
Why Might Low-Carb Diets Be a Problem?
The study found that mice on a restrictive,low-carbohydrate diet lacking fiber showed a higher incidence of tumors and polyps when they had PKS+ E. coli in their intestines. The lack of fiber appears to be very crucial. Mice also exhibited increased inflammation and a thinning of the intestinal mucus layer. This layer is important in protecting the gut, so when it’s compromised, colibactin can more easily damage cells.
What Role Does Fiber Play?
The study also explored the effects of added fiber. Mice on the low-carb diet who were supplemented with inulin (a type of fiber) showed reduced inflammation and fewer polyps. This reinforces the protective role of fiber in gut health.
what is the Recommended Carbohydrate Intake?
Nutritionists generally recommend that carbohydrates should make up over 50% of your daily food intake. The remainder is usually split between fats and proteins. Complex carbohydrates are especially beneficial because of their fiber content,which helps digestion,promotes regular bowel movements,increases satiety,and facilitates nutrient absorption,thus contributing to healthy gut flora.
What are Good Sources of Fiber?
Good sources of fiber include:
* Inulin-rich foods: chicory, Jerusalem artichoke, dandelion greens, and garlic.
Does This Meen I Should Stop a Low-Carb Diet?
This study was conducted on mice, and emphasizes the protective role of fiber. Further research is needed to determine if these findings are directly applicable to human beings. Further studies are needed which focus on humans to recommend actionable changes.