Fifty grams of prunes a day preserved hip bone density in postmenopausal women over a full year. The women who skipped them lost bone.
That is the finding from the Prune Study, a twelve-month randomized controlled trial run at Penn State and published in The American Journal of Clinical Nutrition in 2022.
Researchers randomized 235 postmenopausal women, average age sixty-two, into three groups: no prunes, fifty grams a day, or one hundred grams a day. Bone density was measured by DXA scan every six months.
The fifty-gram group held onto their total hip bone density across the year. The control group did not.
The hundred-gram group did not show the same clear benefit, largely because it was hard to sustain. Dropout there reached forty-one percent, compared with fifteen percent at fifty grams.
The likely mechanism is the polyphenols in prunes, which appear to slow bone resorption and dampen the inflammatory signaling that accelerates once estrogen drops.
Prunes also supply vitamin K, boron, and potassium, all tied to bone metabolism, though the researchers credited the whole-food effect rather than any single compound.
That inflammatory shift is what makes the years right after menopause the fastest bone-loss window of your life. Losing hip density in that window is what turns a fall at seventy-five into a fracture that changes everything.
The move is fifty grams of prunes a day, which is roughly five to six prunes. Eat them however you like, as long as it is every day.
The fifty-gram dose matters for a reason beyond biology. It was the amount women could actually stick with, and a food only protects bone if you keep eating it.
This does not replace a bone-density scan or treatment if you already have osteoporosis. The women studied ranged from healthy bone down to osteopenia, not severe loss.
Fifty grams a day, about five prunes. It is the rare food with a year-long controlled trial behind it, showing it can keep hip bone density steady when the default at this stage is decline.
