Health Benefits of Prunes

Throughout the past decade, research on prunes has increased due to their association with bone health and potential preventative measures, as well as their contribution to normal bowel function. In 2012, the European Commission approved the health claim[1] that consuming 100 grams a day of prunes contributes to normal bowel function. Additionally, prunes have been shown to possess antioxidant and anti-inflammatory properties, and their consumption has been associated with improved cardiovascular risk factors[2].

 

A scientific study[3] published in Clinical Nutrition in 2018 investigated the effect of prunes on stool output, gut transit time and gastrointestinal microbiota.

The study included a total of 120 healthy adults who had a low fiber intake and a stool frequency of 3-6 times per week. Each participant took one of the three following treatments: 80 g/day of prunes (plus 300 ml/day of water); 120 g/day of prunes (plus 300 ml/day of water) or control (300 ml/day water) for 4 weeks. Stool weight was the primary outcome and determined by 7-day stool collection. Secondary outcomes as stool frequency and consistency were also measured, among others.

Results showed that both groups supplemented with prunes increased the stool weight and improved stool frequency when compared with the non-prunes consumer group (control). This is of interest because low stool weight and delayed gastrointestinal transit time are considered risk factors for diseases such as colorectal cancer. There was also a greater increase in Bifidobacteria across the prune-groups. Bifidobacteria are probiotics in the human gut and may contribute towards host health.

A range of studies have demonstrated the link between consuming prunes and the prevention and reverse of bone loss, especially in postmenopausal women[4-7]. In fact, a recent case study[8] published in Bone Reports describes how a woman reversed the 7.6% bone loss at the lumbar spine she experienced as a participant in the control group. After she completed the initial clinical trial and on her own initiative, she began eating 6 prunes daily (in addition to calcium and vitamin D3) for about 16 months while enrolled in a different study at Penn State University that also measured bone mineral density. She experienced a 7.8% improvement in bone mineral density (BMD) at the lumbar spine improving her BMD to slightly more than her previous baseline.

A 2019[9] study published in the Journal of Medicinal Food explored how prune consumption related to bone health, particularly bone resorption and vascular function. In total, twenty-seven postmenopausal women took party in the study and were instructed to consume either two or six prunes daily for two weeks. After 2 weeks, the groups were crossed over and proceeded to consume the other number of prunes. It was observed that those intaking six prunes each day experienced a decrease in bone resorption –or bone breakdown.

In 2011, researchers published a study[10] in the British Journal of Nutrition to show the effects of prune consumption on bone loss in osteopenic postmenopausal women. The one-hundred and sixty qualified participants were divided into two groups, one consuming 100 grams/day of prunes and the other 100 grams/ day of dried apples. The results of the study showed that the prune group saw significantly improved bone mineral density (BMD) and this was most likely due to the lower rate of bone turnover found in those who consumed prunes.

As mentioned previously, prunes have been associated with reductions in cardiovascular risk[11]. Additionally, a publication from the journal Advances in Nutrition examined the relationship between the consumption of traditional dried fruits, including prunes, and cancer risk in humans[12].

The study concluded that increasing dried fruit consumption to 3-5 or more servings a week may produce beneficial health effects for some cancers, including pancreatic, prostate, stomach, bladder, and colon. The prospective cohort studies determined significant reductions in relative risk of precancerous colorectal polyps, incidence of prostate cancer, and mortality of pancreatic cancer. The study suggests that increased consumption of dried fruits, including prunes, may be important in the prevention of digestive system cancers.

 

References
1. Commission Regulation (EU) No 432/2012 of 16 May 2012.
2. Hong, M. Y., Kern, M., Nakamichi-Lee, M., Abbaspour, N., Ahouraei Far, A., & Hooshmand, S. (2021). Dried Plum Consumption Improves Total Cholesterol and Antioxidant Capacity and Reduces Inflammation in Healthy Postmenopausal Women. Journal of Medicinal Food.
3.Lever, E., Scott, S. M., Louis, P., Emery, P. W., & Whelan, K. (2019). The effect of prunes on stool output, gut transit time and gastrointestinal microbiota: A randomised controlled trial. Clinical Nutrition, 38(1), 165-173.
4. Al-Dashti, Y.A., Holt, R.R., Carson, J.G., Keen, C.L., Hackman, R.M. (2019). Effects of Short-Term Dried Plum (Prune) Intake on Markers of Bone Resorption and Vascular Function in Healthy Postmenopausal Women: A Randomized Crossover Trial. Journal of Medicinal Food, doi: 10.1089/jmf.2018.0209.
5. Hooshmand, S., Chai, S. C., Saadat, R. L., Payton, M. E., Brummel-Smith, K., & Arjmandi, B. H. (2011). Comparative effects of dried plum and dried apple on bone in postmenopausal women. British Journal of Nutrition, 106(6), 923.
6. Franklin, M., Bu, S. Y., Lerner, M. R., Lancaster, E. A., Bellmer, D., Marlow, D., … & Smith, B. J. (2006). Dried plum prevents bone loss in a male osteoporosis model via IGF-I and the RANK pathway. Bone, 39(6), 1331-1342.
7. Rendina, E., Hembree, K. D., Davis, M. R., Marlow, D., Clarke, S. L., Halloran, B. P., … & Smith, B. J. (2013). Dried plum’s unique capacity to reverse bone loss and alter bone metabolism in postmenopausal osteoporosis model. PloS one, 8(3), e60569.
8. Strock, N. C., Koltun, K. J., Weaver, C., & De Souza, M. J. (2021). Dried plum consumption improves bone mineral density in osteopenic postmenopausal woman: A case report. Bone Reports, 14, 101094.
9. Al-Dashti, Y.A., Holt, R.R., Carson, J.G., Keen, C.L., Hackman, R.M. (2019). Effects of Short-Term Dried Plum (Prune) Intake on Markers of Bone Resorption and Vascular Function in Healthy Postmenopausal Women: A Randomized Crossover Trial. Journal of Medicinal Food, doi:
10.1089/jmf.2018.0209. 10. Hooshmand, S., Chai, S. C., Saadat, R. L., Payton, M. E., Brummel-Smith, K., & Arjmandi, B. H. (2011). Comparative effects of dried plum and dried apple on bone in postmenopausal women. British Journal of Nutrition, 106(6), 923.
11. Hong, M. Y., Kern, M., Nakamichi-Lee, M., Abbaspour, N., Ahouraei Far, A., & Hooshmand, S. (2021). Dried Plum Consumption Improves Total Cholesterol and Antioxidant Capacity and Reduces Inflammation in Healthy Postmenopausal Women. Journal of Medicinal Food.
12. Mossine, V. V., Mawhinney, T. P., & Giovannucci, E. L. (2019). Dried Fruit Intake and Cancer: A Systematic Review of Observational Studies. Advances in Nutrition.
13. Foster-Powell, K., Holt, S. H., & Brand-Miller, J. C. (2002). International table of glycemic index and glycemic load values: 2002. The American journal of clinical nutrition, 76(1), 5-56.