Brussels sprouts and detox enzymes in the gut of people
What it found
Eating 300 g of cooked Brussels sprouts a day for one week slightly raised two detox enzyme levels in the rectum of healthy volunteers.
Overall enzyme activity and blood cell enzyme levels stayed about the same.
What they found
Studies in people
Rectal detox enzymes rose
After one week of eating Brussels sprouts, two types of detox enzymes in the rectum went up by 30% and 15%. These enzymes help the body process unwanted chemicals.
Overall enzyme activity unchanged
The total activity of detox enzymes in the upper gut, rectum and white blood cells did not change after eating Brussels sprouts.
Blood marker increased
A substance in the blood that shows exposure to glucosinolates was 1.8 times higher during the Brussels sprouts week compared with the control week.
Glutathione levels steady
Levels of glutathione, a molecule that works with detox enzymes, were similar in both diet periods across all tissues tested.
What the authors conclude
- They conclude that eating Brussels sprouts for one week raises certain detox enzyme levels in the rectum.
- They suggest this boost in detox enzymes might partly explain why people who eat more cruciferous vegetables tend to have lower colorectal cancer rates.
How it was done
Diets rich in cruciferous vegetables like Brussels sprouts are linked to lower cancer rates, but scientists do not yet know why. The authors wanted to see if these vegetables boost natural detox enzymes in the human gut.
Ten healthy non-smoking volunteers ate either 300 g of cooked Brussels sprouts daily or a diet free of glucosinolates for one week, then switched diets for another week. At the end of each week, researchers took blood samples and small tissue samples from the upper gut and rectum.
What it can’t tell you
- This trial lasted only one week, so it cannot show what happens when people eat Brussels sprouts over months or years.
- The study measured enzyme levels rather than actual cancer outcomes, so it cannot directly show whether Brussels sprouts prevent cancer.
Who paid
- Authors work at
- University Hospital St Radboud, The Netherlands
The paper
- Title
- Effects of consumption of Brussels sprouts on intestinal and lymphocytic glutathione S-transferases in humans
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Nijhoff WA, Grubben MJ, Nagengast FM, et al (1995). Effects of consumption of Brussels sprouts on intestinal and lymphocytic glutathione S-transferases in humans. Carcinogenesis. doi:10.1093/carcin/16.9.2125Free full textPubMed 7554064DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error