Clinical trial · Molecular nutrition & food research · 2020

Calystegines in urine after eating potato products

What it found

In people, levels of natural compounds called calystegines in urine rose with the amount of potato eaten the day before.

The authors say these compounds could be used to estimate potato intake.

What they found

Studies in people

Urine levels after eating potato

In a controlled study, urine levels of calystegine A3 and B isomers the morning after eating potato were higher with larger portions. The relationship was strongest for calystegine A3.

Cooking and other foods

Different cooking methods and other foods in the diet did not significantly affect how well the calystegine levels reflected potato intake.

Validation in Portugal

In a separate group in Portugal, higher reported potato intake was linked to higher calystegine A3 in urine. No such link was found for tomato, pepper, or aubergine.

Excretion over time

After eating a jacket potato, calystegine levels in urine rose during the day and were still elevated the next morning. Levels were very low after avoiding potato for 48 hours.

Other findings

Calystegines in potato

Calystegines are found in many potato varieties, with average total levels around 296 mg per kg dry weight. They are also present in cooked potato products, especially those with skin.

What the authors conclude

“It is concluded that calystegines have many of the characteristics needed to be considered as specific BFIs for potato product intake.”
Beckmann M, Lloyd AJ, Wilson T, et al, 2020

Also in their conclusions

  • They conclude that calystegines have many of the characteristics needed to be considered as specific biomarkers for potato product intake.
  • They suggest that calystegine A3 in particular performs well as a marker of potato consumption.

How it was done

The authors wanted to find an objective way to measure how much potato people eat, because asking people to remember what they ate is often inaccurate.

They developed a lab method to measure calystegines in cooked potato products and urine. They then tested it in a controlled food study in the UK where people ate set meals with potato, and in a survey in Portugal where people reported their diet and gave urine samples.

What it can’t tell you

  • This study measured calystegine levels in urine, not health effects of eating potato.
  • The results show a link between potato intake and urine calystegines, but they do not prove that calystegines cause any health outcome.

The paper

Title
Calystegines are Potential Urine Biomarkers for Dietary Exposure to Potato Products
Type
Clinical trial
Evidence
Studies in people
Summarised from
Full text
Cite
Beckmann M, Lloyd AJ, Wilson T, et al (2020). Calystegines are Potential Urine Biomarkers for Dietary Exposure to Potato Products. Molecular nutrition & food research. doi:10.1002/mnfr.202000515Free full textPubMed 32918337DOI

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