Are Seed Oils Fueling Colon Cancer? A Fact-Check
On December 11th, the Daily Mail published an article with the alarming headline “Doctors warn cooking oil used by millions may be fueling explosion of colon cancers in young people.” The story has been widely shared on social media and has raised public concern about the health impacts of seed oils. This fact-check examines the claims made in the article, compares them to the original study, and evaluates them in the context of broader scientific research.
The study referenced in the Daily Mail article investigated lipid imbalances in colorectal cancer tumours and found a pro-inflammatory lipid profile. However, the study did not involve dietary seed oils or their consumption, and no evidence connects seed oils to the lipid dysregulation observed in tumours. Claims that seed oils are fueling colon are unsupported by the research.
Misleading claims like these can create unnecessary fear about commonly used ingredients in everyday diets, diverting attention from proven strategies to reduce risk of colon cancer.
Claim
The article suggests that seed oils, including sunflower, canola, corn, and grapeseed oil, may contribute to the rising rates of colon cancer in young Americans.
The claims centre on a new study that found higher expression of bioactive lipids—microscopic fatty compounds produced derived from arachidonic acid—in colon cancer tumours. These lipids are described in the article as potentially harmful because they promote inflammation and hinder the body’s ability to fight tumours.
The Daily Mail article writes that omega-6 fatty acids in seed oils are converted into arachidonic acid in the body, which can cause inflammation. The article claims that these lipids are then found in cancer cells, so seed oils are supposedly contributing to cancer development.
What the Research Actually Says
The claims in the Daily Mail article are based on a mechanistic study, which investigated gene expression and biochemical markers in colon cancer cells in a laboratory setting. It is crucial to note that this study did not examine seed oil consumption or conduct experiments involving human participants consuming seed oils. The study did not evaluate the relationship between seed oils and colon cancer risk.
While mechanistic studies like this one are valuable for exploring potential biological pathways, they are not designed to establish direct links between dietary factors and disease outcomes. Such studies are low on the hierarchy of scientific evidence because findings in isolated cells do not always translate to effects in living organisms.
Caffeine can harm cells in a Petri dish but we know that it’s beneficial for our brains and exercise performance.
A central claim of the Daily Mail article is the link between seed oils and inflammation. However, several studies have debunked the claim that omega-6 fatty acids in seed oils are converted to arachidonic acid, which fuels inflammation. For instance, research has shown that even a sixfold increase in dietary linoleic acid (an omega-6 fatty acid) does not raise arachidonic acid levels in the body.
The claim that seed oils were responsible for the bioactive lipids found in tumours is reaching beyond what the study can show. Drawing a direct connection to seed oil consumption from this study is a significant leap beyond the evidence presented.
On Instagram, our advisory board member and medical doctor, Dr. Idz, posted a video breaking down this article and its claims:
The article also claims that seed oils cause inflammation in the gut and thus cancer, they wrote “Finding bioactive lipids in the colon suggests the body has metabolized them, which occurs through eating foods that contain omega-6 fatty acids. These have been linked to inflammation in the colon when consumed in excess.”
But when we look at meta-analyses of over 80 randomised controlled trials in humans, you see that omega 6 or total poly-unsaturated fatty acids don’t alter inflammatory markers in healthy or inflammatory bowel disease patient’s guts.
Summary
The presence of bioactive lipids in cancer cells does not prove that consuming seed oils causes cancer, as the Daily Mail article suggests. The referenced study is a mechanistic investigation that did not involve seed oil consumption, human participants, or dietary analysis. Drawing conclusions about seed oils from this research misrepresents its findings and misleads the reader. Seed oils, when consumed in moderation, are considered a safe and widely accepted part of a healthy diet.
Sources
Soundararajan, R. et al. (2024). Integration of lipidomics with targeted, single cell, and spatial transcriptomics defines an unresolved pro-inflammatory state in colon cancer. 10.1136/gutjnl-2024-332535
Ajabnoor, S. et al. (2021). Long-term effects of increasing omega-3, omega-6 and total polyunsaturated fats on inflammatory bowel disease and markers of inflammation: a systematic review and meta-analysis of randomized controlled trials. https://pubmed.ncbi.nlm.nih.gov/33084958/
Rett, B. et al. (2011). Increasing dietary linoleic acid does not increase tissue arachidonic acid content in adults consuming Western-type diets: a systematic review. https://pubmed.ncbi.nlm.nih.gov/21663641/.
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