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 (ORACfl); 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 comlbs or metabolism into comlbs with lower AOC may account for the limited in vivoantioxidant response to these phytochemicals.

Journal of Agricultural and Food Chemistry 52, no. 4 (2004): 853–859

Dikeman, C.L., Bauer, L.L., Fahey Jr., G.C.

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).

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.

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 it

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.

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 comlbs 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

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

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

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

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 comlbs as well as the prune and prune juice extracts inhibited the oxidation of LDL.

Chun, O. K., D. O. Kim, et al. (2003). “Contribution of individual polyphenolics to total antioxidant capacity of plums.” J Agric Food Chem 51(25): 7240-5.

The effect of polyphenolics on antioxidant capacities of plums, the amounts of total phenolics, total flavonoids and individual phenolic comlbs, and vitamin C equivalent antioxidant capacity (VCEAC) of 11 plum cultivars was determined.

Kim, D. O., O. K. Chun, et al. (2003). “Quantification of polyphenolics and their antioxidant capacity in fresh plums.” J Agric Food Chem 51(22): 6509-15.

Total phenolics, total flavonoids, and antioxidant capacity of 11 cultivars of fresh plums were determined using spectrophotometric methods.

Fang, N, S Yu and R.L. Prior (2002). “LC/MS/MS characterization of phenolic constituents in dried plums.” J Agric Food Chem 50: 3579-3585.

Four different conditions were used to analyze the phytochemicals in commercial dried plums. Major components were neochlorogenic acid and cryptochloroenic acid. Forty minor components were also characterized. The diagnostic fragmentation patterns of different phenolics are presented on the basis of electrospray ionization (ESI) MS/MS data of components in dried plums and 14 authentic standards.

ORIGINAL STUDY

Critical Reviews in Food Science and Nutrition 2013.53:1277-1302.

Stacewicz-Sapuntzakis M.

This paper updates the 2001 review conducted by the same author and published in the same journal and describes the composition of the dried plums, prune juice and dried plum powder with attention to possibly bioactive comlbs. There are several composition tables on nutrients, carbohydrates, carotenoids and antioxidant capacity as measured by various assays. The paper discusses potential health effects of various dried plum components and can serve as a resource for those seeking a summary of the existing research on dried plums.

D.V. Seidel1, K.K. Hicks1, S.S. Taddeo1, M.A. Azcarate‐Peril2, R.J. Carroll3, N.D. Turner1

1Nutrition & Food Science, Texas A&M University, College Station; 2Cell Biology & Physiology, and Microbiome Core Facility, University of North Carolina, Chapel Hill; 3Statistics, Texas A&M University, College Station

Differences in microbial populations in the proximal and distal colon may impact apparent site-specific differences in pathology. Diet is known to alter metabolism and composition of colon microbiota, which has major implications for disease prevention and treatment. The hypothesis tested by this experiment was that consumption of dried plums would promote retention of beneficial microbiota and patterns of microbial metabolism throughout the colon, and that by doing so would reduce colon cancer incidence. Male Sprague-Dawley rats were provided either a control (CD, n=25) or plum diet (PD, 5% of calories, n=26) 3 wk. before being given two injections of AOM (15 mg/kg BW) or saline, and sacrificed 8 wk. later. Tissues were resected and fecal contents isolated separately from the proximal and distal colon. Irrespective of treatment, the PD increased Bacteroidetes (p<0.0001) and reduced Firmicutes (p<0.0001) in the distal colon without affecting their proximal proportions, compared to the CD, which suppressed Bacteroidetes and increased Firmicutes in the distal colon. Additionally, rats consuming PD had significantly reduced numbers of aberrant crypts (p=0.0025), aberrant crypt foci (p=0.0060), and high multiplicity aberrant crypt foci (p=0.0008) compared to CD rats. These data support our hypothesis that dried plums protect against colon cancer, and this may be due in part to their ability to establish putatively beneficial colon microbiota compositions in the distal colon.  

Supported by California California Prune Board PN 12-20.

Alimentary Pharmacology and Therapeutics 2011; 33: 822-28.. Attaluri A, Donahoe R, Valestin J, Brown and Rao SSC.

Although dried plums/prunes and prune juice have been traditionally used for the treatment of constipation, dried plums have not been systematically assessed in patients with well-defined constipation. This study investigated and compared the effects of dried plums and psyllium in patients with chronic constipation.

Forty constipated subjects (m/f = 3/37, mean age = 38 y) participated in an 8-week, single-blind, randomized cross-over study. Participants received dried plums (50 g b.d, 6 gm fibre/d) or psyllium (11 g b.d., 6 gm fibre/d) for 3 weeks each, in a crossover trial with a 1-week washout period.  Participants maintained a daily symptom and stool diary. Assessments included number of complete spontaneous bowel movements per week, global relief of constipation, stool consistency, straining, tolerability and taste.

The number of complete spontaneous bowel movements per week (primary outcome measure) and stool consistency scores improved significantly.

The Internet Journal of Nutrition and Wellness 2009: Vol 7. No. 2. Cheskin LJ, Mitola AH, Ridore M, Kolge S, Hwang K and Clark B.

This controlled study involving 36 adults reporting chronic constipation symptoms, evaluated the effects of consuming a daily portion of plum juice (PlumSmart) prior to a meal for 14 days, compared with psyllium (Metamucil), a non-fruit source of fibre, and equicaloric, fibre-free clear apple juice as the placebo control.

According to the results: Softer stools were associated with plum juice compared to apple juice alone and apple juice with Metamucil; Plum juice was as likely as psyllium to provide immediate relief (within 24 hours of first use) of constipation symptoms and both performed better than the placebo/apple juice alone; The taste of plum juice was equal to apple juice alone and was preferred over apple juice with psyllium.

The study provides preliminary evidence to support the daily use of natural product, plum juice, as an accepted and effective treatment for stool softening and immediate relief of constipation 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.

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 fecal 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 favourably altered other colon cancer risk factors as measured by bacterial enzyme activities.

Mini Review of Medical Chemistry-Marteau, P., P. Seksik, et al. (2004). “Cellular and physiological effects of probiotics and prebiotics.” Mini Rev Med Chem 4(8): 889-96.

The biological mechanisms of action of probiotics and prebiotics include direct effects in the intestinal lumen or on intestinal or immune cells, and indirect mechanisms through modulation of the endogenous microflora (composition or functions such as butyrate production) or of the immune system.

Nutrition- Aller, R., D. A. de Luis, et al. (2004). 20(9): 735-7.

A modest fibre intake in patients with irritable bowel syndrome relieved symptoms, but this therapeutic benefit of fibre may have been due to a placebo effect because the results were similar in the low-fibre group.

Journal of Nutrition: Ajani, U. A., E. S. Ford, et al. (2004). 134(5): 1181-5.

High concentrations of C-reactive protein (CRP) are considered a marker for inflammatory disease based on data from the National Health and Nutrition Examination Survey 1999-2000, fibre intake is associated with lower serum CRP concentration thereby supporting the recommendation of a diet with a high fibre content.

Obesity Surgery Clements, R. H., Q. H. Gonzalez, et al. (2003). 13(4): 610-4.

Morbidly obese patients experience more intense GI symptoms than control subjects and many of these symptoms return to control levels six months after laparoscopic Roux-en-Y gastric bypass (LRYGBP).

European Journal of Nutrition: “Relationship of prebiotics and food to intestinal microflora.” Eur J Nutr 41 Suppl 1: 11-6. Blaut, M. (2002).

Prebiotics are non-digestible but fermentable oligosaccharides that specifically change the composition and activity of the intestinal microflora to promote the health of the host. Dietary fibre and non-digestible oligosaccharides are the main growth substrates of intestinal microflora. In spite of the interesting nutritional properties of prebiotics, it is questionable whether a wholesome diet rich in fruit and vegetables needs to be supplemented with prebiotics for optimal health effects.

Journal of Pediatric Gastroenterological Nutrition Roma, E., D. Adamidis, et al. (1999). “Diet and chronic constipation in children: the role of fibre.” J Pediatr Gastroenterol Nutr 28(2): 169-74.

Lack of fibre may play an important role in the etiology of chronic idiopathic constipation in children.

Journal of Nutritional Biochemistry. 32 (2016)73-82. Shahnazari M, Turner RT, Iwaniec UT, Wronski TJ, Li M, Ferruzzi MG, Nissenson RA, Halloran BP.

Building on previous work in which diets with dried plum (DP) were shown to increase bone volume and strength, the investigators studied DP in skeletally mature (6-month) and growing (1 and 2- month-old) C57Bl/6 male mice. In adult mice, DP rapidly increased bone volume (+32%) and trabecular thickness (+24%) within 2 weeks. These changes were associated with decreased osteoclast surface (OcS/BS) and decreased serum CTX, a marker of bone resorption. Osteoblast surface (Ob.S/BS) and bone formation rate were also decreased suggesting that bone gain in adult mice is related to diminished bone resorption and formation, with resorption being reduced more than formation. There was also a decline in interleukins, TNF and MCP-1, suggesting that dried plums’ effect on bone is in part through the immune system to suppress inflammatory activity and reduce the size of osteoclast precursor pool. Feeding dried plum resulted in an increase in plasma phenolics, some of which have been shown to stimulate bone accrual. At levels as low as 5% of the diet (w/w), DP increased bone volume in growing and young adult mice. At 25% of the diet, bone volume was increased as much as 94%. The investigators state that these data demonstrate that DP dramatically increases bone mass during growth.

British Journal of Nutrition, April 2014. doi:10.1017/S0007114514000671.Shirin Hooshmand, Jayme R. Y. Brisco and Bahram H. Arjmandi

The mechanisms by which dried plums impart bone-protective properties remain unclear. Recent research has shown that osteocytes may control bone formation via the production of sclerostin and bone resorption via the receptor activator of NF-kB ligand (RANKL) and its inhibitor osteoprotegerin (OPG). In this study, the researchers measured serum levels of RANKL, OPG and sclerostin in osteopenic postmenopausal women (n 160) to investigate the mechanism of action of dried plum in reversing bone loss.

Participants were randomly assigned to the treatment group of either 100 g dried plum/d or 75 g dried apple/d (comparative control) for 1 year (Previously reported in “Comparative Effects of Dried Plum and Dried Apple on Bone in Postmenopausal Women”). All participants received 500mg Ca plus 400 IU (10 mg) vitamin D daily. Bone mineral densities (BMD) of the lumbar spine, forearm, hip and whole body were assessed at baseline and at the end of the study using dual-energy X-ray absorptiometry. Blood samples were collected at baseline and after 12 months to assess bone biomarkers. Dried plum significantly increased the BMD of the ulna and spine in comparison with the control group. In comparison with corresponding baseline values, dried plum increased the RANKL levels by only +1.99 v. +18.33% and increased the OPG levels by +4.87 v.-2.15% in the control group. Serum sclerostin levels were reduced by -1.12% in the dried plum group v. +3.78% in the control group. Although percentage changes did not reach statistical significance (P <0•05), these preliminary data may indicate that the positive effects of dried plum on bone are in part due to the suppression of RANKL production, the promotion of OPG and the inhibition of sclerostin.

Scientific Reports 6, Article number 21343 (2016). Schreurs A-S, Shirazi-Fard Y, Shahnazari M, Alwood JS, Truong TA, Tahimic CGT, Limoli CL, Turner ND, Halloran B and Globus R.

In the abstract, the authors state that bone loss caused by ionizing radiation is a potential health concern for radiotherapy patients, radiation workers and astronauts. In animal studies, exposure to ionizing radiation increases oxidative damage in skeletal tissues, and results in an imbalance in bone remodeling initiated by increased bone-resorbing osteoclasts. The researchers evaluated various candidate interventions with antioxidant or anti-inflammatory activities (antioxidant cocktail, dihydrolipoic acid, ibuprofen, dried plum) both for their ability to blunt the expression of resorption-related genes in marrow cells after irradiation with either gamma rays (photons, 2 Gy) or simulated space radiation (protons and heavy ions, 1 Gy) and to prevent bone loss. Dried plum was most effective in reducing the expression of genes related to bone resorption (Nfe2l2, Rankl, Mcp1, Opg, TNF-α) and also preventing later cancellous bone decrements caused by irradiation with either photons or heavy ions. Thus, according to the authors, dietary supplementation with DP may prevent the skeletal effects of radiation exposures either in space or on Earth.

ORIGINAL STUDY

Food and Function (Food Funct). 2015,6:1719. Hooshmand S, Kumar A, Zhang JY, Johnson SA, Chaid SC and Arjmandi BH.

According to the abstract, the researchers investigated the anti-inflammatory and antioxidative properties of dried plum (Prunus domestica L.) polyphenols in macrophage RAW 264.7 cells. They hypothesized that dried plum polyphenols have strong anti-inflammatory and antioxidant properties against lipopolysaccharide (LPS)-induced production of the pro-inflammatory markers, nitric oxide (NO) and cyclooxygenase-2 (COX-2), and the lipid peroxidation product, malondialdehyde, in activated macrophage RAW 264.7 cells. Macrophage RAW 264.7 cells were stimulated with either 1 μg ml−1 (for measurement of NO production) or 1 ng ml−1 (for measurement of COX-2 expression) of LPS to induce inflammation and were treated with different doses of dried plum polyphenols (0.0, 0.1, 1, 10, 100 and 1000 μg ml−1). Dried plum polyphenols at a dose of 1000 μg ml−1 was able to significantly (P < 0.05) reduce NO production by 43%. Additionally, LPS-induced expression of COX-2 was significantly (P < 0.05) reduced by 100 and 1000 μg ml−1 dried plum polyphenols. To investigate the antioxidant activity of dried plum polyphenols, macrophage RAW 264.7 cells were stimulated with 100 μg ml−1 of FeSO4 + 1 mM ml−1 of H2O2 to induce lipid peroxidation. Dried plum polyphenols at a dose of 1000 μg ml−1 showed a 32% reduction in malondialdehyde production. These findings indicate that dried plum polyphenols are potent anti-inflammatory and antioxidative agents in vitro. The investigators state that these cell culture findings cannot be directly extrapolated to in vivo conditions and that additional studies are needed to explore the bioactivity, metabolism, and tissue distribution and excretion mechanisms of dried plum polyphenols using an animal model of inflammation to confirm the findings.

Dina Metti, Pouneh Shamloufard, Amanda Cravinho, Paulina Delgado, Mark Kern, Bahram H. Arjmandi, Shirin Hooshmand

April 2015 The FASEB Journal vol. 29 no. 1 Supplement 738.12

Our previous findings in osteopenic postmenopausal women indicated that daily consumption of 100 g dried plum for one year is highly effective in increasing bone mineral density (BMD), as well as improving indices of bone turnover. The objective of our current study was to examine whether 50 g dried plum would be as effective as 100 g dried plum in reversing bone loss in osteopenic older postmenopausal women. Forty Eight osteopenic women (65-79 years old) were randomly assigned into one of three treatment groups: 1) 50 g dried plum; 2) 100 g dried plum; and 3) control (0 g dried plum) with forty two subjects completing the study. All groups received 500 mg calcium and 400 IU vitamin D as a daily supplement. Blood samples were collected at baseline, three and six months to assess biomarkers of bone turnover. Physical activity recall and three-day food records were obtained at baseline, three and six months to examine physical activity and dietary confounders as potential covariates. Both doses of dried plum were able to prevent the loss of BMD of the total body compared with that of the control group. Tartrate resistant acid phosphatase-5b (TRAP-5b, a marker of bone resorption) decreased at three months and six months in both dried plum groups. These results confirm the ability of dried plum in improving BMD in older postmenopausal women and suggest that lower doses of dried plum (i.e. 50 g) may be as effective as 100 g dried plum in preventing bone loss in older, osteopenic postmenopausal women. Hence, our findings suggest that the consumption of a reasonable amount of dried plum is beneficial for older, osteopenic women.

British Journal of Nutrition 2011;106:923:-930. Hooshmand S, Chai SC, Saadat RL, Payton ME, Brummel-Smith K and Arjmandi BH.

This study examined the extent to which dried plum reverses bone loss in osteopenic postmenopausal women. Participants were 1-10 years postmenopausal and not on hormone replacement therapy or other prescribed medication known to influence bone metabolism. Qualified participants (n 160) were randomly assigned to one of two treatment groups: dried plum (100g/d) or dried apple (comparative control). Participants also received 500 mg calcium and 400 IU vitamin D daily. Bone mineral density (BMD) of lumbar spine, forearm, hip and whole body was assessed at baseline and at the end of the study using dual-energy X-ray absorptiometry. Blood samples collected at baseline, 3,6, and 12 months assessed bone biomarkers. Physical activity recall and 1-week-food frequency questionnaires were obtained at baseline, 3,6, and 12 months to examine physical activity and dietary confounders as potential covariates.

Dried plum significantly increased BMD of ulna and spine compared to dried apple. Compared to corresponding baseline values, only dried plum significantly decreased serum levels of bone turnover markers including bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase-5b. The authors maintain that the findings confirmed the ability of dried plum to improve BMD in postmenopausal women in part due to suppressing the rate of bone turnover.

PLoS ONE 2013; 8(3): e60569.Rendina E, Hembree KD, Davis MR, Marlow D, Clarke SL, Halloran BR, Lucas EA and Smith BJ.

This study compared the effects of dried plum on bone to other dried fruits (apple, apricot, grape or mango) and further explored the potential mechanisms of action by which dried plum may exert its osteoprotective effects. Adult osteopenic ovariectomized (OVX) mice were fed a control diet or diet supplemented with 25% (w/w) dried fruit for 8 weeks. Whole body and spine bone mineral density improved in mice fed the dried plum, apricot and grape diets compared to the OVX control; but only dried plum had an anabolic effect on trabecular bone in the vertebra and prevented bone loss in the tibia. Restoration of biomechanical properties occurred along with the changes in trabecular bone in the spine. According to the researchers, compared to other dried fruits in this study, dried plum was unique in its ability to down-regulate osteoclast differentiation while up-regulating osteoblast and glutathione activities. These alternations in bone metabolism and antioxidant status compared to other dried fruits provide some insight into dried plum’s unique effects on bone.

1787. Nutr. October 1, 2010 vol. 140 no. 10 1781-1787.Halloran BP et al.

Therapies to prevent or restore bone progressively lost with advancing age are limited.  The only effective proanabolic regimen presently available to restore bone is intermittent treatment with teriparatide (parathyroid hormone 1–34). Previous studies suggest that dietary supplementation with dried plum (DP) can prevent bone loss due to estrogen deficiency. This study was undertaken to investigate whether dietary DP supplementation can prevent the loss of bone with aging and whether bone that has already been lost can be restored in an animal model. Adult (6 mo) and old (18 mo) male mice were fed a normal diet or isoenergetic, isonitrogenous diets supplemented with DP (0, 15, and 25% DP by weight) for 6 mo. MicroCT analysis and bone histomorphometrically assessed bone volume, structure, and metabolic activity before, during, and after dietary supplementation. The researchers report that mice fed the 0% DP diet (control diet) lost bone, whereas both adult and old mice fed the 25% DP-supplemented diet gained bone. Adult but not old mice fed the 15% diet also gained bone. Cancellous bone volume in mice receiving 25% DP exceeded baseline levels by 40–50%. Trabecular structure varied with diet and age and responses in old mice were generally blunted. Trabecular, but not cortical, mineral density varied with age and measures of bone anabolic activity were lower in aged mice. Findings suggest that DP contains proanabolic factors that can dramatically increase bone volume and restore bone that has already been lost due to aging. In turn, DP may provide effective prophylactic and therapeutic agents for the treatment of osteoporosis.

Journal of Nutritional Biochemistry DOI:10.1016/j.jnutbio.2007.11.012 Published online ahead of print May 20, 2008. Bu, S.Y., Hunt, T.S., and Smith, B.J.

This cell culture study investigated how dried plum polyphenols and different concentrations ((0, 2.5, 5, 10 and 20 μg/ml) might influence osteoblast activity and mineralized nodule formation under normal and inflammatory conditions. Polyphenol doses of 5, 10 and 20 μg/ml enhanced the production of comlbs linked to bone formation and countered the detrimental effects of TNF-a addition.

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.

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.

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 favourable microstructural changes as evident by enhanced tibial bone volume and connectivity.

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.

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.

Ageing Research Reviews 2009. 8:122-127. Hooshmand S and Arjmandi BH.

This review summarizes findings of studies published to date which examine the beneficial effects of dried plum on bone in both female and male animals models of osteoporosis as well as a published clinical trial. Animal studies indicate that dried plum protects against but more importantly reverses bone loss in two separate models of osteopenia. A 3-month clinical trial indicated that consumption of dried plum daily by postmenopausal women significantly increased serum markers of bone formation, total alkaline phosphatase, bone-specific alkaline phosphatase and insulin-like growth factor-1 by 12, 6, and 17% respectively.

Osteoporosis International, published online February 22, 2016. Hooshmand S, Kern M, Metti D, Shamloufard P, Chai SC, Johnson SA, Payton ME, and Arjmandi BH.

Building on their previous research that demonstrated the ability of 100 g of dried plums/prunes to help prevent bone loss in older, osteopenic postmenopausal women, the investigators examined the possible dose-dependent effects in 48 osteopenic postmenopausal women (65-79 y). The three treatment groups included a control, 50 g dried plums or 100 g dried plums for 6 months. Total body, hip, and lumbar bone mineral density (BMD) were measured at baseline and 6 months using dual-energy X-ray absorptiometry. Bone biomarkers measured at baseline, 3 and 6 months included bone-specific alkaline phosphatase (BAP), tartrate-resistant acid phosphastase (TRAP-5b, a marker of bone resorption), high-sensitivity C-reactive protein (hs-CRP), insulin-like growth factor-1 (IGF-1), and sclerostin. In addition, osteoprotegerin (OPG)), receptor activator of nuclear factor kappa-B ligand (RANKL), calcium, phosphorous, and vitamin D were measured at baseline and 6 months.

According to the results, both doses of dried plums prevented the loss of total body BMD compared to the control (P<0.05). TRAP-5b decreased at 3 months and was sustained at 6 months for both 50 g and 100 g doses. There were no significant changes in BAP for either dose of dried plum groups, although the BAP/TRAP-5b ratio was significantly (p<0.05) greater at 6 months in both dried plum groups whereas there were no changes in the control group.

The results suggest that a lower dose (50 g) of dried plums may be as effective as 100 g in preventing bone loss in older, osteopenic postmenopausal women. The investigators suggest that this may be due in part to the ability of dried plums to prevent bone resorption.

ORIGINAL STUDY

J Acad Nutr Diet 2012.;112:1158-1168. Chai SC, Hooshmand S, Saadat R, Payton ME, Brummel-Smith K and Arjmandi BH.

This 1-year clinical trial investigated the effect of dried apple (75 g) vs dried plum (about 100 g) matched for calories, carbohydrate, fat and fibre on lowering cardiovascular disease (CVD) risk factors in postmenopausal women. There were no significant differences between the dried fruit interventions in altering serum levels of atherogenic cholesterol levels except at 6 months with the dried apple intervention. Dried plum consumption lowered serum total and LDL cholesterol by 3.5% and 8% respectively at 12 months compared to baseline, but the decline was not statistically significant. Both dried fruits lowered serum levels of lipid hydroperoxide and C-reactive protein (CRP). However, serum CRP levels were significantly lower in the dried plum group compared with the apple group at 3 months. The investigators concluded that consumption of both dried apple and dried plum are beneficial to human health in terms of anti-inflammatory and antioxidative properties.

J Am Diet Assoc. 2010;110:1322-1327. doi: 10.1016/j.jada.2010.06.002. Howarth L, Petrisko Y, Ferchner-Evanson A, Nemoseck T and Kern, M.

Results of this study suggest that relative to a commercially processed low-fat cookie snack, dried plums promote more favourable plasma triglyceride responses, improved dietary quality, and slightly improved bowel function. The study investigated the influence of a 2-week intervention incorporating 100 kcal servings of dried plums vs low-fat cookies twice daily on total energy, nutrient intake, biochemical parameters and bowel habits in a randomized crossover design of two-2-week trials separated by a 2-week washout period. The study involved 26 women aged 25-54 with a body mass index (BMI) between 24 and 25. Incorporation into the diet of dried plums or the low-fat cookies did not change energy intake or weight. However, compared to cookies, dried plums promoted greater (P<0.05) intake of fibre, potassium, riboflavin, niacin, and calcium. Total fat intake tended to decrease with dried plum consumption as did cholesterol intake. Plasma triglyceride concentration remained unchanged by dried plum consumption (P>0.05) and was 17.0 +/-29.2 mg/dL higher ((P<0.05) after consumption of the low-fat cookies at the end of 2 weeks. Dried plums promoted a softer (P<0.05) stool consistency vs usual intake and in comparison to intake of low-fat cookies.

British Journal of Nutrition2009;101 (2):233-239.  Gallaher, C.M. and Gallaher, D.D

The apoE-deficient mouse, which develops atherosclerotic lesions rapidly when fed cholesterol, was used to determine the ability of dried plums at different dose levels to reduce atherosclerosis.  Arterial trees were dissected, stained to visualize lesions, and lesion area was quantitated by imaging software. Percentage arterial tree atherosclerotic lesion area was significantly lower in the low dose dried plum diet with a trend in difference with the higher dried plum diet.  These results suggest that consuming dried plums may help slow the development of atherosclerosis. The study also reported on other measures of oxidative stress and inflammation.

Duthie, G. G., P. T. Gardner, et al. (2003). “Plant polyphenols: are they the new magic bullet?” Proc Nutr Soc 62(3): 599-603

Epidemiological evidence suggests that diets rich in fruit and vegetables decrease the risk of premature mortality from major clinical conditions, including cancer and heart disease. It is not yet clear which components or combination of components in fruit and vegetables are protective or what their mechanism of action is.

ORIGINAL STUDY

fibre, particularly cereal fibre, consumption among the elderly is associated with lower risk of cardiovascular disease.

Mozaffarian, D., S. K. Kumanyika, et al. (2003). “Cereal, fruit, and vegetable fibre intake and the risk of cardiovascular disease in elderly individuals.” JAMA 289(13): 1659-66.

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.

Jenkins, D. J., C. W. Kendall, et al. (2001). “Effect of a very-high-fibre vegetable, fruit, and nut diet on serum lipids and colonic function.” Metabolism 50(4): 494-503

High fruit and vegetable fibre intakes reduce risk factors for cardiovascular disease and possibly colon cancer.

ORIGINAL STUDY

Journal of Nutrition 124 (1994): 31–40

Tinker, L.F., Davis, P.A. and Schneeman, B.O.

The study tested the hypotheses that dietary fibre 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 fibre sources included 6 percent cellulose, 3 percent dried plum fibre, 6 percent dried plum fibre 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 fibre 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 fibre (3 percent or 6 percent), or between the groups fed the 6 percent dried plum dietary fibre and pectin. Results indicated that dietary fibre extracted from dried plums lowers plasma and liver cholesterol in hyperlipidemic rats, but a dose-dependent response was not detected. Feeding fibre extracted from dried plums rather than the whole dried fruit product indicates that the dietary fibre in dried plums has hypocholesterolemic activity.

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 fibre 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 fibre per 100 grams, about 60 percent of which is pectin. Pectin as a type of soluble dietary fibre 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 fibre and that this might help explain the cholesterol-lowering effect. Dietary fibre 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 fibre). 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 fibre. 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.

Eating Behaviors 11 (2010)201-203. Farajian P, Katsagani M, Zampelas A.

This study investigated the effect of a preload including dried prunes eaten as a snack prior to a meal compared to a preload of an isoenergetic and equal weighed bread product.  Researchers investigated short-term effect on satiety measured by subsequent ad lib meal intake and reduced appetite for dessert after lunch; and assessed satiety by visual analogue scales (VAS).

Participants in the randomized within-subject crossover study included 45 healthy, normal-weight subjects. Results indicated that when subjects consumed the preload that included dried prunes, they consumed less of the dessert and had lower total energy intake at the meal. Subjects’ feeling of hunger, desire and motivation to eat as assessed by VAS, were lower at all time points between the snack and meal.  Macronutrient content of both preloads was similar. The authors suggest that the satiating power of prunes could be due to the fibre content.

Appetite 54 (2010); 564-569. Furchner-Evanson Al, Petrisko Y, Howarth L, Memoseck T, and Kern M.

This study assessed the effect of different snack foods on satiety, plasma glucose and hormone responses in 19 adult overweight women. The test snacks included dried plums, low-fat cookies, white bread and water only on separate days. With the exception of water, the snacks provided 238 kcal and were similar in macronutrient content but differed in fibre and sugar content.  Subjects rated feeling of hunger using satiety index scales at 15-minute time points for 2 hours following initiation of intake. Blood samples were collected at baseline and at 15,30, 45,60, 90 and 120 minutes following intake. At the end of the 2-hour test period, subjects were presented with a meal to be consumed until satisfied.

The satiety index AUC was greater for the dried plum trial versus the low-fat cooking trial (p<0.05). There was no difference in post-snack intake between the dried plum and cookie trials.  The dried plum trial elicited lower plasma glucose and insulin AUC than the low-fat cookie trial (p<0.05) and tended to promote a greater plasma ghrelin AOC. Results suggest that eating dried plums as a snack suppresses hunger relative to a low-fat cookie as evidenced by lower glucose and/or satiety-regulating hormone concentrations.

International Journal of Food Sciences and Nutrition. Published online: 14 Jul 2016 DOI: 10.1080/09637486.2016.1207061. Sadler MJ.

According to the abstract, a thorough litreature review found that common perceptions about dried fruits – that they are “sticky”, adhere to teeth, and are detrimental to dental health because of their sugar content – are based on weak evidence. The lack of good quality scientific data to support restrictive advice for dried fruit intake on the basis of dental health parameters requires further research. The potentially positive attributes for dental health, such as the need to chew dried fruits which encourages salivary flow, and the presence of anti-microbial comlbs and of sorbitol, also require investigation to establish the extent of these effects and whether they balance any potentially negative attributes of dried fruit. Advice on dried fruit consumption should also take account of their nutritional benefits, being high in fibre, low in fat and containing useful levels of micronutrients.

Zawilski Alexandra, Nelson Stephanie, McGill Brittany, McIntosh Marian, Hong Mee Young, Shirin Hooshmand, Kern Mark

School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA 92812.

Smokers suffer from decreased antioxidant capacity, a risk factor for numerous chronic diseases. Consumption of antioxidant-rich foods such as dried plums may increase antioxidant capacity and reduce disease risk. Nonsmokers (n=14) and smokers (n=6) between the ages of 18 and 45 years were recruited to participate in 2 randomly ordered trials in which they received 100 g of dried plums at one visit and a refined isocaloric control food (muffins) at another. Antioxidant capacity was examined in blood samples collected at baseline and 60, 90, and 120 minutes post-feeding. No significant differences in postprandial antioxidant capacity were detected over time when consuming the muffin snack in smokers or nonsmokers. Dried plum consumption elicited significant increases (p<.05) in antioxidant capacity in both groups together from baseline throughout all time points, with peak values achieved at 90 minutes. Dried plums promoted higher antioxidant capacity compared to muffins at all time points (p<.05). Smokers had significantly lower (p<.05) levels of antioxidant capacity at all time points compared to nonsmokers. Although antioxidant capacity remained elevated (p<0.05) at each time point in comparison to baseline, it decreased (p<0.05) from minutes 90 to 120 for smokers but continued to rise up to the 120 min time point for nonsmokers. Results suggest that dried plums are efficient in increasing antioxidant capacity for both smokers and nonsmokers and that they may be an effective way to reduce disease risk factors in smokers that are struggling with cessation. Future research should evaluate the use of dried plums as a chronic intervention to promote health of smokers. This study was funded by the California California Prune Board.

Nelson Stephanie, Zawilski Alexandra, McGill Brittany, McIntosh Marian, Hong Mee Young, Shirin Hooshmand, Kern Mark

School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA 92812.

Neutrophil elastase, a marker of pulmonary inflammation, is secreted by macrophages within minutes of cigarette smoking to combat inflammation. Excessive levels of neutrophil elastase have been implicated in the pathogenesis of emphysema. Oxidative stress induced by smoking destroys the inhibitors of neutrophil elastase, further exacerbating the uncontrolled release and activity of the enzyme. To determine the effect of dried plums, a high antioxidant food, on neutrophil elastase, nonsmokers (n=14) and smokers (n=5) underwent two trials in which they consumed 100 g dried plums at one visit and an isocaloric control food  (muffins) during the other. Neutrophil elastase concentrations were evaluated in blood samples that were taken at baseline and at 60, 75, 90, and 120 minutes post-feeding, and smokers smoked one cigarette at 45 minutes post-feeding. Results demonstrated that there were no significant changes in neutrophil elastase from baseline in nonsmokers at any time point. However, smokers, experienced a significant decrease in neutrophil elastase 90 minutes after consuming dried plums (p<0.05) that did not occur after consuming muffins. The results suggest that dried plums may control the secretion and activity of neutrophil elastase, which could potentially prevent the pathogenesis of emphysema associated with smoking cigarettes. This study was funded by the California California Prune Board.

Rock, C. L., S. W. Flatt, et al. (2004). “Effects of a high-fibre, low-fat diet intervention on serum concentrations of reproductive steroid hormones in women with a history of breast cancer.” J Clin Oncol 22(12): 2379-87.

A high-fibre, low-fat diet intervention is associated with reduced serum bioavailable estradiol concentration in women diagnosed with breast cancer, in whom the majority did not exhibit weight loss.

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 fibre intake has been associated with a decreased breast cancer risk. This study investigated the effects of prunes as a source of fibre 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.

McIntosh, M. and C. Miller (2001). “A diet containing food rich in soluble and insoluble fibre improves glycemic control and reduces hyperlipidemia among patients with type 2 diabetes mellitus.” Nutr Rev 59(2): 52-5.

Subjects with type 2 diabetes who consumed a diet containing food naturally rich in fibre (e.g., 50 g fibre/day, 50% soluble) for 6 weeks had significant improvements in glycemic control and lipid levels when compared with patients who consumed a diet with moderate amounts of fibre (e.g., 25 g fibre/day, 50% soluble).