Effect of sun-dried raisins on Bile Acid Excretion, Intestinal Transit Time, and fecal Weight: A Dose-Response Study This 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. * Spiller, GA, et al. Published in Journal of Medicinal Food (2003) Effect of tartaric acid and dietary fiber from sun-dried raisins on colonic function and on bile acid and volatile fatty acid excretion in healthy adults. This study investigated the effect of sun-dried raisins and tartaric acid (as cream of tartar) on intestinal function. 13 healthy adults consumed a low fiber, grape-free diet for three weeks. They then added 120 grams (a little over 4 ounces) of sun-dried raisins per day for another three weeks, and, lastly, substituted the sun-dried raisins with 5g of cream of tartar, approximately equivalent to the amount of tartaric acid in the sun-dried raisins, for the final three weeks. Measurements taken were transit time, fecal weight and the concentration of bile acids in the stools. The results of this study showed that both tartaric acid and sun-dried raisins reduced transit time, but the effect was stronger for the sun-dried raisins. Fecal weight and moisture increased with the addition of raisins, but not with the cream of tartar. In addition, the participants reported greater ease of elimination when they were taking the sun-dried raisins and the cream of tartar, compared to the low-fiber, grape-free diet. The addition of sun-dried raisins reduced the concentration of bile acids, whereas the cream of tartar did not. Another interesting finding was that sun-dried raisins, and to a lesser extent, cream of tartar, altered the concentration and ratios of bile acids in the colon in a way that, according to some research, could help prevent colorectal cancer. This study suggests that tartaric acid works in synergy with the fiber in raisins, resulting in a healthier digestive system and colon. * Spiller, GA et al. British Journal of Nutrition (2003) Effects of a plant-based diet rich in whole grains, sun-dried raisins and nuts on serum lipoproteins. Numerous studies have demonstrated that single nutrients or compounds extracted from foods, such as saturated fat, cholesterol, dietary fiber, and phytochemicals, influence cholesterol levels and heart disease risk. We set out to test, instead, the effect of real, whole foods as part of a plant-based diet rich in whole grains, nuts and sun-dried raisins on total cholesterol and lipoproteins. Fifteen healthy adults with high blood cholesterol consumed their usual diet for one week, and their blood cholesterol and lipoproteins were measured. After this period, they were instructed to consume a plant-based diet based on whole and unrefined foods for four weeks with daily set amounts of olive oil, nuts, nut butters, sunflower seeds, legumes, whole grain and raisin breads, and 3 oz of sun-dried raisins. At the end of the study the blood measurements were repeated. Although total fat did not change with the plant-based diet, saturated fat was greatly reduced while monounsaturated fat increased, dietary cholesterol dropped and dietary fiber more than doubled. The results of the blood analyses showed that the plant based diet caused significant reductions in total cholesterol and "bad cholesterol". From these findings we can derive that sun-dried raisins can be consumed as part of cholesterol-lowering plant-based diets, rich in whole, unrefined and minimally processed foods. * Bruce, B. et al. Published in Vegetarian Nutrition, An International Journal (1997). Sun-dried raisins as an energy source in adolescents during soccer. Sun-dried raisins are an excellent source of natural sugars. They can be a good source of energy during endurance type exercise. Twelve 12- to 14-year old boys and girls played two regular soccer games on two different days. During the break the players were randomized to take either two servings (3 oz, or 84 g) of sun-dried raisins with a glass of water, or just water. During the second game the players switched treatments, so that each subject was tested with and without sun-dried raisins. The players’ blood sugar was measured at the beginning and within one minute after the end of the game. The comparison of blood sugar levels between the two treatments showed that consumption of sun-dried raisins resulted in significantly higher blood sugar levels at the end of the game compared to when only water was consumed. Therefore, the sun-dried raisin snack maintained higher blood sugar levels to support the constant demand for fast energy required during the soccer match. Sun-dried raisins are an effective, practical way to maintain blood sugar levels and support the demand of energy during sports activities in young players. * Spiller et al. Presented at the 16th International Congress of Nutrition, 1997 (Montreal, Canada). The effects of two pre-event snacks in young soccer players playing a soccer match.* The composition of a pre-event meal has been shown to influence the performance during athletic events that require a high level of endurance in adults. In this study we compared the effect of two pre-event snacks (one including sun-dried raisins) on activity levels during a soccer match and blood levels of glucose (blood sugar), insulin and lactic acid following the match. Fourteen boys and girls, 10-12 years, and experienced soccer players, consumed one of two snacks of equal energy content (350 kcal) one hour prior to the a soccer match. One snack consisted of a bagel with 12 oz lemonade drink and was high in carbohydrates and contained negligible protein or fat. The other comprised 56g of sun-dried raisins (2 oz) of and 31g (1 oz) of dry roasted, unsalted peanuts and had moderate carbohydrates, some fat and protein. The players’ blood samples were collected before they consumed the snack and immediately after the soccer match. When the players ate the raisin/peanut snack, blood insulin level dropped and their blood sugar rose less compared to when they had the bagel/lemonade snack. The lower blood sugar and insulin levels after the raisin/peanut snack signifies a more steady, sustained fuel supply to the muscle, not an initial spike followed by a drop, often seen with snacks high in carbohydrate/sugar only. Lower insulin levels are advantageous because high levels of circulating insulin can promote the laying down of fat and may lead to insulin resistance, a concern among US children today, where rates of obesity and type 2 diabetes are increasing. The results of this study suggest that every effort should be made to promote snacks, such as the raisin and nut combinations, that supply steady fuel levels and maintain low levels of circulating insulin for children’s activities. Such snacks are good not only for the optimal performance of the activity but may also be useful in preventing obesity and type 2 diabetes, so pervasive among America’s youth. * Haskell, W. et al. Published in Medicine and Science in Sports and Exercise (2002). Sun-dried raisins help prevent oxidative DNA damage during intense athletic activity.* Intense athletic activity leads to oxidative stress , where the production of free radicals, exceeds what the body can eliminate. Free radicals tend to attack our cells and damage our DNA. Antioxidants quench free radicals by reacting with them and, thereby, saving our cells. Sun-dried raisins are an excellent source of antioxidants. In this study, we investigated the effect of consuming sun-dried raisins during a triathlon event on a compound found in the urine known to be an indicator of DNA damage due to oxidative stress. The higher the concentration of this compound in the urine, the greater the DNA damage. Eight trained athletes, four men and four women, ages 28-42 years, ran a triathlon twice, two weeks apart. The triathlon consisted of a 1500 m swim, 40 Km bicycle ride, and a 10 Km run. The athletes were randomly divided into two groups. Half the subjects received a total of 170 g (about 6 oz) of sun-dried raisins prior to the swim, at midpoint of the bike ride, and at midpoint of the run. The other half received a glucose (sugar) drink of equivalent energy (520 Kcal), at the same three points. During the second triathlon the group who had taken sun-dried raisins switched to the sugar drink, and vice versa. At the end of the triathlon, six of the eight athletes (all the women and two of the men) showed lower or no DNA damage after consuming sun-dried raisins, compared to when they consumed the sugar drink (see DNA damage graph). These encouraging results invite to further study the use of sun-dried raisins during strenuous exercise and investigate the influences of age, gender, level of training and body antioxidant status on the degree of protection from oxidative stress. What we observed in this small study suggests that foods rich in antioxidants, such as sun-dried raisins, when used as a source of energy before and during intense athletic activity, can protect the body from DNA damage due to oxidative stress. * Spiller et al. Published in the Journal of the American College of Nutrition (2002). |