Lactose and other FODMAPs linked to diarrhoea during chemotherapy
What it found
In people having chemotherapy for colorectal cancer, those who ate the most lactose-rich foods had more diarrhoea.
The link was strongest when they also ate a lot of other FODMAP-rich foods.
What they found
Studies in people
Lactose and diarrhoea
Patients who consumed lactose-rich foods above the median amount were twice as likely to have diarrhoea during chemo(radio)therapy as those who consumed less. The risk was highest in those who consumed the greatest amounts.
Lactose plus FODMAPs
Patients who consumed both lactose-rich and other FODMAP-rich foods above the median had a higher risk of diarrhoea compared with those who consumed low amounts of both.
Flatulence and lactose
Flatulence was less frequent among those with a high intake of lactose-rich foods. In the final model, low FODMAP intake combined with high lactose intake was a protective factor for flatulence.
Other FODMAPs alone
No statistically significant differences in gut symptoms were found between patients who consumed FODMAP-rich foods above or below the median amount.
Lactose intolerance
The presence of lactose intolerance at baseline was associated with diarrhoea and increased the likelihood of flatulence in the final models.
What the authors conclude
“Consumption of lactose-rich foods results in an increased risk of diarrhoea during adjuvant therapy for colorectal cancer, especially when the consumption of other FODMAP-rich foods is also high.”
Also in their conclusions
- They conclude that patients who consumed high amounts of lactose and other FODMAPs had more diarrhoea during adjuvant therapy of colorectal cancer as compared to patients who consumed low amounts of lactose and FODMAPs.
- They suggest that a diet low in lactose and FODMAPs may be a means to prevent and/or to alleviate the severity of the diarrhoea occurring during adjuvant therapy.
- They state that this hypothesis warrants further evaluation in a prospective randomised study.
How it was done
Chemotherapy can damage the gut lining, which may make it harder to digest and absorb carbohydrates like lactose. The authors wanted to see whether eating foods high in these carbohydrates was linked to gut symptoms during treatment.
They studied 52 people receiving adjuvant 5-fluorouracil chemotherapy for colorectal cancer. Patients kept 4-day food diaries at baseline and during the third cycle, plus symptom diaries, and their lactose tolerance was tested.
What it can’t tell you
- The study was small, with only 52 patients, and the authors note that dietary habits may change when symptoms worsen.
- The authors also note that there might be inaccuracies in estimating FODMAP intakes from food diaries.
Who paid
- Conflicts
- P. Österlund has served as a speaker, a consultant and an advisory board member for Amgen, Bayer, Roche, Sanofi, Merck, Baxalta, Celgene, Nordic Drugs and Eli Lilly and has received research funding from Amgen (Inst), Merck (Inst), Roche (Inst), Sanofi (Inst) and Eli Lilly (Inst). R. Korpela has received a lecture fee from Verman. R. Laatikainen has written a Finnish book on irritable bowel syndrome and diet. He is also founder and owner of Booston Ltd., which provides functional gastrointestinal disorders-related dietetic services to IBS patients, healthcare professionals and various organisations. Other authors did not report competing interests.
- Authors work at
- University of Helsinki, Finland; Helsinki University Hospital, Finland; Helsinki University Hospital and University of Helsinki, Finland
The paper
- Title
- Consumption of Lactose, Other FODMAPs and Diarrhoea during Adjuvant 5-Fluorouracil Chemotherapy for Colorectal Cancer
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Holma R, Laatikainen R, Orell H, et al (2020). Consumption of Lactose, Other FODMAPs and Diarrhoea during Adjuvant 5-Fluorouracil Chemotherapy for Colorectal Cancer. Nutrients. doi:10.3390/nu12020407Free full textPubMed 32033152DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error