Tartaric acid and raisins for colon function in healthy adults
What it found
In 13 healthy adults, both sun-dried raisins and cream of tartar (tartaric acid) softened stools and shortened gut transit time.
Raisins also increased stool weight and changed bile acids and short-chain fatty acids in ways the authors link to potential health benefits.
What they found
Studies in people
Gut transit time
Intestinal transit time fell from 42 hours on the baseline diet to 31 hours on cream of tartar and to 28 hours on sun-dried raisins. The authors say both appear to shorten transit time.
Stool weight and softness
Stools were softer on both sun-dried raisins and cream of tartar. Sun-dried raisins increased daily faecal weight from 132 g to 177 g, while cream of tartar did not.
Bile acids
Sun-dried raisins reduced total bile acid concentration from 1.42 to 1.09 mg/g and lowered the lithocholic to deoxycholic acid ratio from 1.63 to 1.09. Cream of tartar did not significantly change total bile acids but reduced the ratio to a lesser extent.
Short-chain fatty acids
Sun-dried raisins increased total short-chain fatty acid excretion from 5.6 to 7.6 g over 4 days. Cream of tartar left short-chain fatty acid excretion unchanged at 5.6 g over 4 days.
Bowel habits
Subjects reported that stools were softer and easier to eliminate during both the sun-dried raisin and cream of tartar periods.
What the authors conclude
“In conclusion, the results of the present investigation suggest that sun-dried raisins have beneficial effects on intestinal function that appear to be mediated by both its dietary fibre and tartaric acid contents.”
Also in their conclusions
- They conclude that sun-dried raisins have beneficial effects on intestinal function that appear to be mediated by both dietary fibre and tartaric acid.
- They state that sun-dried raisins and tartaric acid appear to have potential benefits in decreasing the risk for colorectal cancer.
- They call for further mechanistic studies in human subjects to examine and substantiate these relationships.
How it was done
The authors note that the effects of tartaric acid on colon function have not been the focus of extensive research. They wanted to test the effects of dietary fibre and tartaric acid from sun-dried raisins on colon function and on faecal bile acid and short-chain fatty acid excretion.
Thirteen healthy adults (seven men and six women, aged 27 to 65) ate either 120 g sun-dried raisins a day or 5 g cream of tartar a day for 9 weeks, split into 3-week cycles. The study used a randomised crossover design with an initial control period. Stools were collected for the last 4 days of each cycle.
What it can’t tell you
- The study lasted only 3 weeks per treatment, so it cannot show what happens over longer periods.
- The study measured indicators linked to colon cancer risk, not whether cancer actually develops.
- The findings are from 13 healthy adults, so they may not apply to other groups.
Who paid
- Authors work at
- Sphera Foundation, USA
The paper
- Title
- Effect of tartaric acid and dietary fibre from sun-dried raisins on colonic function and on bile acid and volatile fatty acid excretion in healthy adults
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Spiller GA, Story JA, Furumoto EJ, Chezem JC, Spiller M (2003). Effect of tartaric acid and dietary fibre from sun-dried raisins on colonic function and on bile acid and volatile fatty acid excretion in healthy adults. The British journal of nutrition. doi:10.1079/bjn2003966Free full textPubMed 13129449DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error