study looked at the effect of adding sun-dried raisins to the
diet on colon function. Sixteen healthy adults were placed on
a diet with sun-dried raisin in three two-week cycles, with increasing
quantities of raisins. In the first cycle the participants ate
84 grams of sun-dried raisins a day (3 ounces, roughly 2 servings).
In the second cycle, 126 grams (4 and 1/2 ounces) and in the third
168 grams (6 ounces).
The measurements taken were transit time (the time taken for contents
of the intestinal tract to move through), fecal weight and the
concentration of bile acids found in the stools. A decrease in
transit time (i.e. the intestinal contents move through more quickly)
and an increase in fecal weight promote healthy elimination and
are thought to be protective against diseases of the colon. A
decrease in the concentration of bile acids in the stools is correlated
with a decreased risk of colon cancer.
In this study, adding sun-dried raisins to the diet resulted in
a decrease in transit time and an increase in fecal weigh. The
concentration of bile acids in the stools was significantly reduced
when 3 ounces of sun-dried raisins were added to the diet. This
study suggests that the addition of a reasonable quantity of sun-dried
raisins, 3 ounces per day, is beneficial, helping to prevent constipation
and possibly protect against some colonic diseases.
GA, Story, JA, Lodics, TA, Pollack M, Monyan S, Butterfield G
Spiller, M. Effect of Sun-Dried Raisins on Bile Acid Excretion,
intestinal Transit time, and fecal Weight: A dose-response study.
J. Medicinal Food 6(2) 87-91, 2003