Two New Research Studies Reinforce Prunes’ Role in Optimal Health

Prunes may help reduce belly fat and the risk for cardiovascular disease while improving gut health, among other health benefits, according to new research.

ROSEVILLE, CALIF. (May 9, 2024) – Two newly published studies add to an already robust body of clinical research on prunes’ myriad health benefits. This tasty pantry staple is a nutritional powerhouse that may benefit gut microbiome health, bone health, heart health and more.

The latest discoveries come from The Prune Study, a 12-month randomized controlled trial conducted with 183 postmenopausal women aged 55 to 75, who were divided into three groups instructed to either consume 50 grams or 100 grams of prunes daily, or none at all.

Prunes, Belly Fat & Heart Health

A new study published in theJournal of Nutrition showed that eating 100 grams of prunes daily may help prevent changes in fat distribution around the central region of the body, especially belly fat. The increase of belly fat is common in postmenopausal women and when excessive, can be a risk factor for cardiovascular disease. Not only is this good news for the waistline; it’s good news for the heart as well [i].

“While changes in body fat distribution and body mass index (BMI) are related generally to aging, a growing body of research shows that where the body holds its fat mass is strongly associated with menopause transition,” said principal investigator Mary Jane De Souza, PhD, professor, Department of Kinesiology, Pennsylvania State University. “Increased belly fat matters when it comes to disease risk, and dietary patterns can help impact fat distribution. Findings from this research show a daily diet that includes prunes may help reduce that belly fat.”

Prunes & the Gut-Bone Health Connection

Published in Frontiers in Nutrition, a second study delved deeper to uncover differences in the gut bacteria of the women who experienced a positive change in their bone density compared with those who saw no change after eating 50 to 100 grams of prunes daily over a 12-month period [ii]. Interestingly, those who had an increase in bone density after eating prunes had a higher abundance of a certain type of “good” gut bacteria that is associated with more efficiently breaking down nutrients and bioactive parts of prunes for the body’s use. This same group also experienced a drop in inflammation throughout the body [iii].

“As a nutrient-rich fruit, prunes have a combination of minerals, vitamin K, phenolic compounds and fiber that is unique among foods and is important for bone integrity,” De Souza said. “These study findings add to the growing body of precision nutrition research and highlight a greater potential for prunes to positively impact health outcomes through a personalized dietary recommendation approach.”

Exploring the Full Spectrum of Prunes’ Health Benefits

Prunes pack a powerful punch of important vitamins, minerals, antioxidants and fiber, and the scientific evidence of their nutritional power continues to build.

Gut Health Guardians

Studies have indicated that prunes are superior to psyllium, the primary component in numerous over-the-counter laxatives, for relieving constipation [iv]. A 2022 study found that consumption of prunes is linked to an increase in a particular gut bacteria associated with lowering inflammatory markers in the body [v].

Bone Protectors

Numerous studies have demonstrated the bone-protective effects that prunes may provide, particularly for women with an increased risk for osteoporosis. Findings from a review study show post-menopausal women who consumed 100 grams of prunes daily for one year better retained bone mineral density compared to those in the control group over the next five years [vi].

Heart Health Heroes

A 2021 study showed that postmenopausal women who ate 50 to 100 grams of prunes daily over a six-month period reduced their levels of total cholesterol, oxidative stress and inflammatory markers—risk factors for cardiovascular disease—when compared to a group that did not include prunes in their diet [vii].

“Collectively, the studies conducted on prunes show that the body is a synergistic machine—it’s highly interconnected when it comes to health outcomes and risks for chronic diseases,” said Leslie Bonci, MPH, RDN, CSSD, LDN. “The key takeaway across all of these studies is that incorporating prunes daily into a healthy dietary pattern can be a simple and delicious way to help women reduce their risk of chronic diseases and age more healthfully.”

How to Add Prunes to Your Diet

Incorporating prunes into your diet doesn’t have to be boring or mundane. Aside from eating a few as a snack, there are plenty of tasty ways to add prunes to recipes:

For further details on prune nutrition research and ways to incorporate prunes into your diet, visit californiaprunes.org.

ADDITIONAL STUDY DETAILS:

Study #1: “Effects of Prune (Dried Plum) Supplementation on Cardiometabolic Health in Postmenopausal Women: An Ancillary Analysis of a 12-Month Randomized Controlled Trial, The Prune Study

This publication included 183 post-menopausal women who completed the 1-year investigation and were separated into three test groups: no prune diet, 50-gram daily prune diet and 100-gram daily prune diet. Beyond the daily prune consumption requirements, participants did not follow any specific diet, but were required to get 1,200 mg of calcium and 800 IU vitamin D through diet plus supplements, daily.

To evaluate the effect of 12-month prune supplementation on cardiometabolic risk factors, blood was collected and body composition was assessed at the beginning of the trial, at the 6-month point and at the 12-month conclusion. Markers of glycemic control, blood lipid profile, anthropometric data and regional fat distribution were measured.

Findings show no significant differences in glycemic control markers, blood lipid profiles, BMI, lean body mass or fat free mass. There was a significant reduction in android total mass (central mass/abdominal mass) among the 100-gram prune group that completed the entire 12-month trial. Specifically, android total mass increased 3.19% from the start of the trial through 12-months in the group eating no prunes, while android total mass decreased 0.02% in the 100-gram prune group over the same time period.

Study limitations include the inability to test for intent-to-treat; likelihood of type 1 errors; and high attrition in the 100-gram prune group.

Study #2: Gut microbes differ in postmenopausal women responding to prunes to maintain hip bone mineral density

This publication is an ancillary analysis of the Prune Study that originally included 183 post-menopausal women who completed the 1-year investigation and were separated into three test groups: no prune diet, 50-gram daily prune diet and 100-gram daily prune diet.

For this analysis a subset of participants (52 total) only from the 50-gram and 100-gram prune groups, who were ≥80% compliant to the prescribed prune dose and had gut microbiome data were included. Participants were divided into ‘responders’ and ‘non-responders’, where responders were defined as those who exhibited at least 1.0% increase in total hip bone mineral density (BMD) from baseline (n=20) and non-responders were defined as those who exhibited at least 1.0% decrease in total hip BMD from baseline (n=32).

At the start of the trial and at the 12-month conclusion, several tests were performed to see differences between responders and non-responders, including blood draws (metabolic and lipid panels), urine samples (total phenolics and target phenolic metabolites), fecal samples (microbiome analysis), sequence analysis, BMD, body composition and immune markers.

Findings show that responders had significantly lower secretions of immune markers compared to non-responders by the end of the 12-month trial. Significant microbiome changes were also observed with responders versus non-responders at the 12-month mark, where responders had significantly higher/trended higher in the diversity of gut bacteria (alpha diversity) and structure of the gut microbial community (beta diversity).

Study limitations include the inability to determine if effects present at the beginning of the trial were due to low bone mineral density or a higher ability to respond to prunes, and demographic homogeneity of participants.

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ABOUT THE CALIFORNIA PRUNE BOARD
The California Prune Board was established in 1952 to represent growers and handlers under the authority of the California Secretary of Food and Agriculture. California is the world’s largest producer of prunes with orchards across 14 counties in the Sacramento and San Joaquin valleys. Promoting a lifetime of wellness through the enjoyment of California Prunes, the organization leads the premium prune category with generations of craftsmanship supported by California’s leading food safety and sustainability standards. California Prunes. Prunes. For life.

For more information, contact:
Kiaran Locy, Dir. of Brand & Industry Communication
California Prune Board
klocy@californiaprunes.org  
916-749-3442

[i] Damani JJ, Rogers CJ, Lee H, Strock NC, Koltun KJ, Williams NI, Weaver C, Ferruzzi MG, Nakatsu CH, De Souza MJ. “Effects of prune (dried plum) supplementation on Cardiometabolic Health in postmenopausal women: An ancillary analysis of a 12-month randomized controlled trial, the prune study.” J Nutr. 2024 Mar 13:S0022-3166(24)00161-5. https://doi.org/10.1016/j.tjnut.2024.03.012.

[ii] Simpson AMR, De Souza MJ, Damani J, Rogers CJ, Williams NI, Weaver CM, Ferruzzi MG, Nakatsu CH. Gut microbes differ in postmenopausal women responding to prunes to maintain hip bone mineral density. Front Nutr. 2024 Apr 18;11:1389638. doi: 10.3389/fnut.2024.1389638.

[iii] Damani JJ, Oh ES, De Souza MJ, Strock NC, Williams NI, Nakatsu CH, Lee H, Weaver C, Rogers CJ. Prune consumption attenuates proinflammatory cytokine secretion and alters monocyte activation in postmenopausal women: Secondary outcome analysis of a 12-mo randomized controlled trial: The Prune Study. J Nutr. 2023 Nov 19:S0022-3166(23)72732-6. doi: 10.1016/j.tjnut.2023.11.014. Epub ahead of print. PMID: 37984741.

[iv] Attaluri A, Donahoe R, Valestin J, Brown K, Rao SS. Randomized clinical trial: Dried plums (prunes) vs. psyllium for constipation. Aliment Pharmacol Ther. 2011 Apr;33(7):822-8. doi: 10.1111/j.1365-2036.2011.04594.x. Epub 2011 Feb 15. PMID: 21323688.

[v] Simpson, AMR, De Souza, MJ, Damani, J, Rogers, C, Williams, NI, Weaver, C, Ferruzzi, MG, Chadwick-Corbin, S, Nakatsu, CH. Prune supplementation for 12 months alters the gut microbiome in postmenopausal women. Food Funct. 2022 Nov 28;13(23):12316-12329. doi: 10.3390/horticulturae9050584

[vi] Arjmandi BH, Johnson SA, Pourafshar S, Navaei N, George KS, Hooshmand S, Chai SC, Akhavan NS. Bone-protective effects of dried plums (prunes) in postmenopausal women: Efficacy and possible mechanisms. Nutrients. 2017 May 14;9(5):496. doi: 10.3390/nu9050496. PMID: 28505102; PMCID: PMC5452226.

[vii] Hong MY, Kern M, Nakamichi-Lee M, Abbaspour N, Ahouraei Far A, Hooshmand S. Dried plum consumption improves total cholesterol and antioxidant capacity and reduces inflammation in healthy postmenopausal women. J Med Food. 2021 Nov;24(11):1161-1168. doi: 10.1089/jmf.2020.0142. Epub 2021 May 11. PMID: 33978491.