New NIFA-funded research at Penn State and San Diego State explores whether eating prunes every day can reduce bone loss in midlife women, providing an effective nutrition-based treatment.
Researchers newly funded by USDA’s National Institute of Food and Agriculture (NIFA) and the California Prune Board are exploring an unlikely hero in the fight against osteoporosis: prunes.
Penn State University and San Diego State University scientists are leading large-scale clinical trials to determine whether eating as few as three to four prunes a day can slow or prevent the significant bone loss women experience during the transition to menopause.
“This is the time when women are losing bone most rapidly,” said Dr. Mary Jane De Souza, principal investigator at Penn State. “If we can show that a simple food like prunes can help slow that loss, it could change how we prevent osteoporosis.”
De Souza’s research focuses on a three-year window around a woman’s final menstrual period when bone loss can reach 6% to 7% at the hip and spine. Her team’s study will examine how a daily, 50-gram prune intake affects bone density, bone strength, inflammation and gut health over 18 months.
At San Diego State University, Dr. Shirin Hooshmand is leading a separate study examining how prunes support bone health during late perimenopause as well as whether a more practical dose of 30 grams per day has similar effects. Her previous work that started in the mid-2000s showed that daily prune intake of 100 grams per day preserved bone in postmenopausal women.
Subsequent research showed similar effects regarding bone density in men 50 years or older, and that 50 grams per day of prunes was sufficient to prevent bone loss of postmenopausal women and improved bone density of younger women using hormonal contraceptives.
“Prunes are nutrient-rich, shelf-stable, affordable and safe to eat every day,” Hooshmand said. “We believe they could be a powerful tool to help women maintain strong bones through midlife.”
Osteoporosis Affects Women More
Osteoporosis affects approximately 10 million Americans with low bone density affecting another 44 million. It leads to more than two million fractures each year, especially among women over 50. These injuries often require surgery and extended rehabilitation and can be life-threatening, according to the Bone Health & Osteoporosis Foundation.
One in two women and up to one in four men will break a bone in their lifetime due to osteoporosis, according to the foundation. For women, the incidence is greater than that of heart attack, stroke and breast cancer combined.
Osteoporosis-related bone breaks cost patients, their families and the healthcare system $19 billion annually. By 2025, experts predict that osteoporosis will result in three million fractures resulting in $25.3 billion in costs, the foundation said.
“Preventing just one hip fracture can save tens of thousands of dollars in medical costs,” De Souza said. “If prunes prove effective, the return on investment for public health will be massive.”
The San Diego State trial will conclude in 2030, and the Penn State trial will run through 2029. Both studies will track changes in bone density, inflammation and gut health to understand how prunes support bone strength at the biological level. The study by Hooshmand will assess if prunes improve calcium metabolism.
“Women want non-medication options for prevention,” Hooshmand said. “We’re excited to continue to test one that’s as simple as eating a few prunes a day.”
USDA Grant Program Supports Grower-Driven Research
The studies were funded under the Commodity Board Co-funding Topics program area priority, a part of NIFA’s Agriculture and Food Research Initiative (AFRI) Foundational and Applied Sciences grant program. This public-private partnership was introduced in the 2014 Farm Bill to enable national and state commodity boards to propose research topics that they are willing to co-fund alongside NIFA. The deadline for federal and state commodity boards to submit topics for consideration for inclusion in the FY27 AFRI Foundational and Applied Science Notice of Funding Opportunity is Jan. 20, 2026.
To qualify, a commodity board must represent an agricultural commodity; conduct activities related to promotion, research, industry information or consumer information; be funded by mandatory assessments on producers or processors; and be designed to maintain or expand markets and uses for the commodity, as determined by the Secretary of Agriculture.
The California Prune Board submitted a co-funding topic on prune consumption and bone health for the FY 2024 AFRI funding cycle. After peer review, both the Penn State and San Diego State proposals were selected for funding.
“We’ve long believed in the potential of prunes to support healthy aging, and we’re proud to partner on research that puts real science behind that promise,” said Donn Zea, executive director of the California Prune Board. “These studies could be game changers, not just for our growers, but for millions of women seeking simple ways to protect their health.”
The U.S. prune crop is valued at roughly $173 million annually on more than 40,000 acres. California is the world’s leading premium prune supplier, responsible for virtually all U.S. output.
Food as Prevention
The research reflects USDA’s continued commitment to preventive health through diet, an idea championed by the administration’s Make America Healthy Again (MAHA) initiative.
“We must do more to improve the health outcomes of our kids and families, and President Trump knows agriculture is at the heart of the solution,” said Agriculture Secretary Brooke L. Rollins in May 2025.
In May, the administration released the MAHA Commission Report. The report is a call to evaluate the many reasons American families face high rates of chronic health issues. It encourages additional research and education on diet, environmental exposure, lack of physical activity and overmedicalization.
“America’s farmers and ranchers dedicate their lives to the noble cause of feeding their country and the world, and in doing so, have created the safest and most abundant and affordable food supply in the world,” Rollins said. “We are working to make sure our kids and families are consuming the healthiest food we produce.”