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

Abstract

Sun-dried raisins are a source of dietary fibre and tartaric acid. The effects of tartaric acid on colon function have not been the focus of extensive research. The purpose of the present study was to evaluate 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 (SCFA) excretion in healthy adults. Thirteen healthy subjects were fed 120 g sun-dried raisins/d or 5 g cream of tartar (equivalent to the tartaric acid in 120 g sun-dried raisins)/d for 9 weeks, divided into 3-week cycles. The experimental diets were fed in a crossover design after an initial control period. Faeces were collected for the last 4 d of each cycle for analysis of SCFA and bile acids. Intestinal transit time decreased from 42 h on the baseline diet to 31 h on cream of tartar (P, 0·1) and to 28 h on sun-dried raisins (P,0·05). Faeces were softer on both sun-dried raisins and cream of tartar, but sun-dried raisins increased faecal wet weight (P, 0·05), while cream of tartar did not. Sun-dried raisins caused significant reductions from baseline values in total bile acid concentration (from 1·42 (SD 1·03) to 1·09 (SD 0·76) mg/g, P,0·05), whereas cream of tartar did not (1·40 (SD 1·06) mg/g). Sun-dried raisins also significantly reduced the lithocholic (LC):deoxylithocholic acid (DC) ratio (from 1·63 (SD 0·85) to 1·09 (SD 0·50), P,0·02), whereas cream of tartar reduced the ratio, but to a lesser extent (1·29 (SD 0·79), NS). Both faecal bile acids and the LC:DC ratio are indicators of reduced risk for colon cancer. Sun-dried raisins increased total SCFA excretion (from 5·6 (SD 3·4) to 7·6 (SD 3·0) g/4 d, P,0·05), which remained unchanged with cream of tartar (5·6 (SD 3·0) g/4 d). Both sun-dried raisins and cream of tartar appear to be good stool softeners and to shorten intestinal transit time, although the fibre in sun-dried raisins has the added benefit of increasing faecal weight. Both sun-dried raisins and cream of tartar modulate the composition of faecal bile acids and SCFA in a way that has potential health benefits.

Significance of Urinary Tartaric Acid

“…The US Food and Drug Administration considers it a generally recognized as safe (GRAS) human food ingredient (3 ). Gram quantities of tartaric acid are commonly consumed in grapes and grape products, and many prepared foods contain large quantities of the acid or its salts (4,5 ). Dietary intake of tartaric acid by the two individuals in the study by Shaw et al (1 ) was not evaluated.…”

Effect of Sun-Dried Raisins on Bile Acid Excretion, Intestinal Transit Time, and Fecal Weight: A Dose–Response Study

“…We previously showed that the combination of dietary fiber and tartaric acid has beneficial effects on intestinal transit time (TT), fecal weight (FW), and fecal bile acid (FBA) composition. 1,2 Grapes and raisins are the only common foods that contain reasonable levels of tartaric acid in temperate climates, tamarind being the other fruit in tropical regions. Tamarind is used in some countries to help normalize bowel function.…”

“…8 Dietary fiber has been shown to decrease the concentration of bile acids in the feces. 1,2,9 The purpose of this study was to determine the effect of SDR on colon function and health by measuring the response to increasing doses of raisins per day after a period free of consumption of raisins and other dried fruits. The key measurements were fecal weight, intestinal TT, and FBA.…”

Can raisins ameliorate the hypercholesterolaemia-induced cardiac affection?

“…This hypolipidaemic effect of raisins might be due to polyphenols content interference with cholesterol absorption [60] and decrease of hepatic cholesterol concentrations as observed in guinea pigs [61] after diet supplementation with lyophilised grape powder. Similarly, the hypocholesterolaemic effects of raisins were proven by Spiller et al [51]. In addition, Bruce et al [11] and Gardner et al [24] reported that daily consumption of raisins improved lipid profile and increased plasma antioxidant capacity.…”

“…Animals were split randomly into four equal groups (n = 10). Group I served as control and received only saline through a nasogastric tube; group II represented the positive control and received 0.5 g of raisin homogenate through a nasogastric tube daily for 13 weeks, according to Spiller et al [51], after adjusting the human dose for a rat according to Paget and Barnes [40]; group III was the induction group where animals were fed a HCD, consisting of 95% rat chow supplemented with 4% cholesterol and 1% cholic acid, according to Thiruchenduran et al [54], for 13 weeks; and group IV represented the treated group, where the rats were fed a HCD along with raisin homogenate at the same dose. Food and water consumption, and body weight were measured at the start of the experiment, after 6 weeks, and by the end of the experiment.…”