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Randomised trial · Scientific reports · 2025Conflicts declared

Alpha-tocopherol with a meat-based diet and colon cancer risk markers

Dinu M, Ristori S, Pagliai G, et al · Free full text

What it found

In 103 healthy adults, a meat-based diet raised markers linked to colorectal cancer risk over 12 weeks, and taking 100 mg of alpha-tocopherol daily with that diet reduced some of those changes.

The study measured markers, not cancer itself.

What they found

Studies in people

DNA damage in stool water

DNA damage in fecal water rose significantly after the meat-based diet, by about 16 percent. No significant rise was seen in the alpha-tocopherol or pesco-vegetarian groups.

Lipid peroxidation markers

Fecal TBARS increased more after both meat-based diets compared with the pesco-vegetarian diet. A specific peroxidation marker, 4-HNE, rose more after the meat-based diet than after the pesco-vegetarian diet.

Iron and inflammation

Blood ferritin, IL-6, and TNF-alpha increased more after the meat-based diet than after the pesco-vegetarian diet. The pesco-vegetarian diet was linked to lower ferritin and drops in several inflammatory markers.

Alpha-tocopherol effects

The group taking alpha-tocopherol with the meat-based diet did not show the significant rise in DNA damage seen with meat alone. They also had a reduction in TNF-alpha, an inflammatory marker.

Short-chain fatty acids and bile acids

No significant changes were found in fecal short-chain fatty acids or bile acids across any of the diets.

What the authors conclude

“These findings reflect short-term modulation of mechanistic biomarkers rather than CRC outcomes.”
Dinu M, Ristori S, Pagliai G, et al, 2025

Also in their conclusions

  • They conclude that a meat-based diet may have a detrimental effect on mechanistic biomarkers associated with colorectal cancer risk within a relatively short time frame.
  • They say these adverse effects appear to be attenuated by concurrent intake of alpha-tocopherol, while the pesco-vegetarian diet showed more favorable modulation of oxidative and inflammatory markers.
  • They stress that these outcomes represent short-term changes in mechanistic biomarkers rather than validated clinical endpoints, and should not be interpreted as evidence of altered cancer risk.

How it was done

Red and processed meat have been linked to higher colorectal cancer risk, possibly through heme-driven oxidative damage. The authors wanted to see whether adding alpha-tocopherol or switching to a pesco-vegetarian diet could change biological markers involved in this process.

They randomly assigned 113 healthy adults aged 18 to 50 to one of three diets for 12 weeks: a meat-based diet, the same diet plus 100 mg of alpha-tocopherol daily, or a pesco-vegetarian diet. A total of 103 people finished the study, and the researchers measured markers in stool, blood, and urine before and after.

What it can’t tell you

  • This study measured markers linked to cancer risk, not whether people actually developed colorectal cancer.
  • The 12-week study in adults aged 18 to 50 cannot show what happens over many years or in older people.
  • The results apply to the specific diets and the 100 mg daily dose of alpha-tocopherol used here, not to other amounts or patterns.

The paper

Title
Effects of meat-based, meat-based with α-tocopherol, and pesco-vegetarian diets on biomarkers associated with colorectal cancer risk: a randomized behavioral intervention trial
Type
Randomised controlled trial
Evidence
Studies in people
Summarised from
Full text
Cite
Dinu M, Ristori S, Pagliai G, et al (2025). Effects of meat-based, meat-based with α-tocopherol, and pesco-vegetarian diets on biomarkers associated with colorectal cancer risk: a randomized behavioral intervention trial. Scientific reports. doi:10.1038/s41598-025-31410-6Free full textPubMed 41361349DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error