California Dried Plums

Plasma Antioxidant Capacity Changes Following a Meal as a Measure of the Ability of a Food to Alter In Vivo Antioxidant Status
Journal of the American College of Nutrition 26, no.2 (2007):170-181.
Prior, R. L., Gu, L., Wu, S., Jacob, R.A., Sotoudeh, G., Kader, A.A. and Cook, R.A.

This study was undertaken to determine if the consumption of meals of blueberries, grapes, kiwifruit, strawberry, cherry and dried plums increased plasma antioxidant capacity (AOC) measured as Oxygen Radical Absorbance Capacity (ORAC_fl); whether macronutrient composition of the meal alters postprandial changes in AOC; and whether preliminary recommendations can be developed for antioxidant intake. Results suggest that certain berries and fruits increased postprandial AOC. Plasma AOC did not change after a meal with dried plums or prune juice. The authors comment that chlorogenic acid or its isomers which predominate in dried plums may be poorly absorbed. Low absorption of these compounds or metabolism into compounds with lower AOC may account for the limited in vivo antioxidant response to these phytochemicals.

LC/ES-MS Detection of Hydroxycinnamates in Human Plasma and Urine

Journal of Agricultural and Food Chemistry 49, no. 4 (2001): 1747–1750
Cremin, P., Kasim-Karakas, S. and Waterhouse, A.L.

Hydroxycinnamates are present in high concentration in prunes. Little is known about the absorption and metabolism of these compounds and their metabolites after consumption of normal foods. This study developed a sensitive method using HPLC with electrospray mass spectrometric detection to measure caffeic, ferulic and chlorogenic acids in human plasma and urine. The method was tested on samples from volunteers consuming a single dose of 100 grams of prunes, and increased levels were observed, demonstrating that the method is capable of detecting changes in hydroxycinnamate levels from dietary intake.

Lipophilic and Hydrophilic Antioxidant Capacities of Common Foods in the United States

Journal of Agricultural and Food Chemistry  52, no. 12 (2004): 4026–4037
Wu, X., Beecher G.R., Holden, J.M., Haytowitz, D.B., Gebhardt, S.E. and Prior, R.L.

Lipophilic and hydrophilic antioxidant capacities were determined by the ORACfl assay on more than 100 different kinds of foods. Total antioxidant capacity (TAC) was calculated by combining L-ORACfl and H-ORACfl. Total phenolics were also measured; 85 grams (½ cup) prunes has a TAC of 7,291/serving. (NOTE: This reference is used for the TAC value for dried plums, replacing the ORAC value as reported in the February 1999 issue of Agricultural Research, the USDA/ARS magazine).

Effect of Drying Conditions and Storage Period on Polyphenolic Content, Antioxidant Capacity and Ascorbic Acid of Prunes

Journal of Agricultural and Food Chemistry 52, no. 15 (2004): 4780–4784
Del Caro, A., Piga, A., Pinna, I., Fenu, P.M. and Agabbio, M.

Two varieties of prunes were dried by high and low temperatures and chemical parameters were monitored during storage. Temperature significantly affected the polyphenol content with different effects according to the class of polyphenols. Storage decreases polyphenol content (apart from chlorogenic acid) although the antioxidant capacity increases probably due to the formation of Maillard reaction products.

Antioxidant Activity of Prune (Prunus domestica L.) Constituents and a New Synergist

Journal of Agricultural and Food Chemistry 50, no. 13 (2002): 3708–3712
Kayano, S., Kikuzaki, H., Fukutsuka, N., Mitani, T. and Nakatani, N.

Antioxidants from prunes were isolated, identified and antioxidant activity assessed by the ORAC assay. The synergistic effect of a new chromanone on caffeoylquinic acid isomers is described.

Quantitative Evaluation of Antioxidant Components in Prunes (Prunus domestica L.)

Journal of Agricultural and Food Chemistry 51, no. 5 (2003): 1480–1485
Kayano, S., Yamada, N.F., Suzuki, T., Ikami, T., Shioaki, K., Kikuzaki, H., Mitani, T. and Nakatani, N.

The study determined the contribution of caffeoylquinic acid isomers to the ORAC of prunes and investigated the existence of other antioxidant components.

Phenolic Composition and Antioxidant Activity of Prunes and Prune Juice (Prunus domestica)

Journal of Agricultural and Food Chemistry 46, no. 4 (1998): 1247–1252
Donovan, J.L., Meyer, A.S.  and Waterhouse, A.L.

Commercial prune and prune juice extracts were analyzed for phenolics by reverse phase HPCL with diode array detection and tested for ability to inhibit oxidation of human LDL. Hydroxycinnamates, especially neochlorogenic and chlorogenic acids predominated. These compounds as well as the prune and prune juice extracts inhibited the oxidation of LDL.

Carbohydrate Composition of Selected Plum/Prune Preparations

Journal of Agricultural and Food Chemistry 52, no. 4 (2004): 853–859
Dikeman, C.L., Bauer, L.L., Fahey Jr., G.C.

Eighteen plum/prune preparations and byproducts were analyzed for proximate constituents and carbohydrate profiles.

Chemical Composition and Potential Health Effects of Prunes: A functional food?

Critical Reviews in Food Science and Nutrition 41, no. 4 (2001): 251–286

Stacewicz-Sapuntzakis, M., Bowen, P.E., Hussain, E.R., Damayanti-Wood, B.J. and Farnsworth, N.R.

This systemic literature review summarizes the chemical composition of prunes and their biological effects on human health.

Prune Juice Has a Mild Laxative Effect in Adults with Certain Gastrointestinal Symptoms
Nutrition Research 27 (2007): 511-513.
Piirainen, L., Peuhkuri, K., Bäckström, K., Korpela, R, and Salminen, S.

The study was undertaken to investigate whether prune juice affects gastrointestinal function in adults with certain gastrointestinal (GI) symptoms. Subjects were otherwise healthy but had certain GI symptoms not as severe as a disorder. The study was for 4 weeks; 1 week baseline, 2 weeks prune juice, and 1 week follow up. Subjects drank 125 mL prune juice twice a day during the prune juice period. Results indicate that prune juice reduced the occurrence of difficulty in defecation in these subjects and the effect continued to the follow-up week. The authors concluded that regularly ingested prune juice had a mild laxative effect in adults with certain GI symptoms; however, prune juice also increased flatulence. Prune juice may offer a user-friendly alternative to laxatives, at least in cases of mild constipation.

Effect of Dried Plums on Colon Cancer Risk Factors in Rats

Nutrition and Cancer 53, no. 1 (2005): 117–125
Yang, Y. and Gallaher, D.D.

The study examined the effect of dried plums on the number of precancerous lesions (aberrant crypts, ACs), fecal bile acid concentration and cecal bacterial enzyme activities related to colon cancer risk. Dried plum powder was fed at a low concentration (LC 4.75 percent) and a high-concentration (HC 9.5 percent). Azoxymethane was administered to the rats two times, one week apart after the rats received either the experimental or control diets for 10 days. The rats continued to be fed their respective diets for nine weeks until terminated. Although the number of AC foci did not differ among the different animal groups, the dried plum diets favorably altered other colon cancer risk factors as measured by bacterial enzyme activities.

Prune Suppresses Ovariectomy-induced Hypercholesterolemia in Rats

Journal of Nutritional Biochemistry 11, no. 5 (2000): 255–259
Lucas, E.A., Juma, S., Stoecker, B.J. and Arjmandi, B.H.

This study investigated the efficacy of prunes on lowering cholesterol in an ovariectomized (ovx) rat model. Animals were divided into four groups: sham-operated+contol diet; ovx+control diet; ovx+5 percent prune diet and ovx+25 percent prune diet. OVX raised serum total cholesterol 22 percent compared with sham, and the 25 percent prune diet prevented this increase without affecting HDL-C. The authors report that prune exhibits hypocholesterolemic properties in an animal model of ovarian hormone deficiency.

Prune Fiber or Pectin Compared with Cellulose Lowers Plasma and Liver Lipids in Rats with Diet-Induced Hyperlipidemia

Journal of Nutrition 124 (1994): 31–40
Tinker, L.F., Davis, P.A. and Schneeman, B.O.

The study tested the hypotheses that dietary fiber extracted from dried plums lowers plasma and liver cholesterol compared with purified cellulose in rats with diet-induced hyperlipidemia and that the response is dose dependent. The dietary fiber sources included 6 percent cellulose, 3 percent dried plum fiber, 6 percent dried plum fiber or 3 percent pectin. The nonhyperlipidemic control was fed a 6 percent cellulose diet without cholesterol or cholic acid.
Results showed that groups of rats fed the pectin or dried plum fiber diets had lower plasma, LDL and liver cholesterol concentrations than those on the hyperlipidemia diet with 6 percent cellulose. There were, however, no differences in plasma or liver cholesterol concentrations between the two levels of dried plum dietary fiber (3 percent or 6 percent), or between the groups fed the 6 percent dried plum dietary fiber and pectin. Results indicated that dietary fiber extracted from dried plums lowers plasma and liver cholesterol in hyperlipidemic rats, but a dose-dependent response was not detected. Feeding fiber extracted from dried plums rather than the whole dried fruit product indicates that the dietary fiber in dried plums has hypocholesterolemic activity.

Consumption of Prunes as a Source of Dietary Fiber in Men with Mild Hypercholesterolemia

American Journal of Clinical Nutrition 53 (1991): 1259–65
Tinker, L.F., Schneeman, B.O., Davis, P.A., Gallaher, D.G. and Waggoner, C.R.

The study tested the hypothesis that dietary fiber in dried plums can lower plasma cholesterol levels in men with mild to moderate hypercholesterolemia. Dried plums provide approximately 5 to 7 grams of dietary fiber per 100 grams, about 60 percent of which is pectin. Pectin as a type of soluble dietary fiber previously had been shown to lower serum cholesterol in those with hypercholesterolemia. These studies used purified pectin rather than pectin-containing foods. This study tested the ability of pectin-containing whole foods to lower blood cholesterol levels. It also tested the hypothesis that dried plums would increase fecal bile acid excretion as a result of the dietary fiber and that this might help explain the cholesterol-lowering effect. Dietary fiber had been shown to absorb bile acids in-vitro and in-vivo.
This eight-week crossover trial involved 41 free-living adult men with mild hypercholesterolemia (5.2–7.5 mmol/L) serving as his own control. The eight-week period was divided into two experimental diet periods of four weeks each. Subjects were randomly assigned to a fruit juice supplement diet or a dried plum supplement diet. During the dried plum supplement period, subjects supplemented their usual diet with 12 dried plums (100 grams; 6 grams of dietary fiber). During the fruit juice control period, subjects ate their usual diet supplemented with 360 ml of a fruit juice control that was similar to dried plums in simple carbohydrate, but contained negligible dietary fiber. Results indicated that plasma LDL-cholesterol was significantly lower after the dried plum period (3.9 mmol/L) than the fruit juice control period (4.1 mmol/L). Fecal bile acid concentration of lithocholic acid was significantly reduced after the dried plum supplement period compared to the fruit juice control period. Both fecal wet and dry weights were higher after both the dried plum and fruit juice supplement periods. There was no significant difference in total bile acids between experimental periods.

Effect of Prune Consumption on the Ratio of 2-hydroxyestrone to 16a-hydroxyestrone

American Journal of Clinical Nutrition 76 (2002): 1422–1427
Kasim-Karakas, S.E., Almario, R.U., Gregory, L., Todd, H., Wong, R. and Lasley, B.L.

High fiber intake has been associated with a decreased breast cancer risk. This study investigated the effects of prunes as a source of fiber on the concentrations and ratios of two estrogen metabolites: 2OHE1 and 16aOHE1. A higher urinary ratio of 2OHE1 to 16aOHE1 may be associated with a lower risk of breast cancer. Healthy premenopausal women ate their usual diet for three menstrual cycles and then consumed 100 grams (10–12 prunes) for the next three cycles. Urinary 2OHE1 and 16aOHE1 were determined during the follicular and luteal phases. Prune supplementation significantly decreased excretion of 16aOHE1 during the follicular phase of the first menstrual cycle and during the luteal phases of the first and third menstrual cycles. The 2OHE1 to 16aOHE1 ratio did not change significantly. The significance of the decrease in 16aOHE1 without a change in ratio of the two estrogen metabolites on the prevention of estrogen-dependent cancers remains to be determined.

Dried Plums Improve Indices of Bone Formation in Postmenopausal Women

Journal of Women’s Health and Gender-Based Medicine 11, no. 1 (2002): 61–68
Arjmandi, B.H., Khalil, D.A., Lucas, E.A., Georgis, A., Stoecker, B.J., Hardin, C., Payton, M.E. and Wild, R.A.

The study assessed the effect of daily consumption of 100 grams (10–12) of dried plums for three months on markers of bone turnover. Compared to baseline, dried plums significantly increased serum levels of IGF-I and BSAP activity. According to the authors, higher levels are associated with greater rates of bone formation.

Dried Plum Polyphenols Attenuate the Detrimental Effects of TNF-a on Osteoblast Function Coincident with Up-regulation of Runx2, Osterix and IGF-1

Dried Plum Polyphenols Inhibit Osteoclastogenesis by Downregulating NFATc1 and Inflammatory Mediators.

Calcified Tissue International (DOI 10.1007/s00223-008-9139-0).  Bu SY, Lerner M, Stoecker BJ, Boldrin E, Brackett DJ, Lucas EA and Smith BJ. 

This study investigated dried plum polyphenols' effect on osteoclast differentiation and activity in cell cultures.  Results of this study, combined with results of the authors' previous reports, suggest that the antiresorptive properties of dried plums observed in animal studies are in part mediated by polyphenols suppression of osteoclast differentiation and activity under normal, oxidative stress, and inflammatory conditions.

Dried Plum Reverses Bone Loss in an Osteopenic Rat Model of Osteoporosis

Menopause (2005)12:755-762.

Deyhim F, Stoecker BJ, Brusewitz GH, Devareddy L, and Arjmandi BH.

This study evaluated whether dried plum was able to restore bone mass in osteopenic ovariectomized rats.  Dried plum at 5% of the diet was effective in restoring femoral and tibial bone density and increased lumbar bone density.  The increase in femoral bone density in rats fed dried plum diets resulted in improved bone quality as indicated by 6.9% and 6.0% improvement in overall yield and ultimate force respectively.  The improvement in biomechanical properties of long bones due to dried plum, in part, may be due to the favorable microstructural changes as evident by enhanced tibial bone volume and connectivity.

Dried Plum Prevents Bone Loss in a Male Osteoporosis Model via IGF-I and the RANK Pathway

BONE 39, no. 6 (2006): 1331–1342
Franklin, M., Bu, S.Y., Lerner, M.R., Lancaster, E.A., Bellmer, D., Marlow, D., Lightfoot, S. A., Arjmandi, B.H., Brackett, D.J., Lucas, E.A. and Smith, B.J.

The study was designed to determine the extent to which dried plum prevents skeletal deterioration in gonadal hormone deficient male animals and to begin to understand the mechanism. Sham operated on orchidectomized male rats fed dried plum diets at 5, 15 and 25 percent (w/w) levels. The 15 and 25 percent dried plum diets prevented the ORX-induced decrease in whole body, femur and lumbar vertebrae bone mineral density. Results of other biomechanical testing are discussed. The authors conclude that dried plum prevents osteopenia in androgen deficient male rats and that the benefits may be attributed in part to a decrease in osteoclastogenesis via down-regulation of the RANKl and stimulation of bone formation mediated by IGF-I.

Dried Plums Prevent Ovariectomy-Induced Bone Loss in Rats

Journal of the American Nutraceutical Association 4 (2001): 50–56
Arjmandi, B.H., Lucas, E.A., Juma, S., Soliman, A., Stoecker, B.J., Khalil, D.A., Smith, B. J. and Wang, C.

In an animal model of hormone deficiency, female rats were fed dried plums at 5 percent and 25 percent (w/w) of the diet. Ovariectomy significantly reduced bone mineral density of the 4th lumbar vertebrae and femurs and decreased trabecular bone area of the tibia. The high dose dried plum diet prevented this bone loss and the dried plum diet’s dose dependently enhanced circulating IGF-I, known to stimulate bone formation.