UNIVERSITY PARK, Pa. — Prunes rarely get as much love as other fruits, but researchers from Penn State suggest older, menopausal women should consider adding at least a few prunes to their daily diet. Their study finds prunes can help prevent or delay bone loss in older women.
As far as why this is the case, study authors say prunes reduce both bodily inflammation and oxidative stress, both of which contribute to bone loss.
“In postmenopausal women, lower levels of estrogen can trigger a rise of oxidative stress and inflammation, increasing the risk of weakening bones that may lead to fractures,” says Connie Rogers, associate professor of nutritional sciences and physiology, in a university release. “Incorporating prunes into the diet may help protect bones by slowing or reversing this process.”
Osteoporosis, a condition where the bones become brittle and weak, is quite common in women over the age of 50. In fact, estimates show that about 200 million women live with osteoporosis on a global scale, with the condition causing nearly nine million bone fractures on an annual basis.
While it’s true that there are a number of osteoporosis medications available today, study authors note that more and more women are seeking out ways to treat or avoid the condition altogether primarily through diet and nutrition.
“Fruits and vegetables that are rich in bioactive compounds such as phenolic acid, flavonoids and carotenoids can potentially help protect against osteoporosis,” explains Mary Jane De Souza, professor of kinesiology and physiology, “with prunes in particular gaining attention in previous research.”
Prunes are full of vital nutrients
The adult human body works to maintain its bone health through an ongoing series of processes that are constantly building new bone cells while removing old ones. Around the age of 40, however, the breakdown of old bone cells begins to outpace the aging body’s production of new bone cells. This imbalance can be a result of various factors, two of which are inflammation and oxidative stress.
For reference, oxidative stress doesn’t refer to traditional feelings of stress or being stressed out. Oxidative stress refers to an imbalance between the levels of free radicals and antioxidants in the cells. Luckily, prunes are absolutely chock-full of minerals, fiber, vitamin K, and phenolic compounds. All of those nutritional benefits likely help combat the detrimental effects of inflammation and oxidative stress.
10 prunes a day can strengthen bones
The team analyzed data from 16 preclinical studies on rodents for this study, as well as 10 preclinical studies and two clinical trials. Across all of those projects, the results remained largely the same. Eating prunes produced two attractive outcomes: less oxidative stress and inflammation and stronger bones.
More specifically, the clinical trials found that eating about 10 prunes (100 grams) every day for an entire year improved bone mineral density within the forearms and lower spine. Moreover, this prune diet also decreased indicators of bone turnover.
Similarly, consuming anywhere from 50 to 100 grams of prunes daily for six months prevented total loss of bone density and lowered TRAP-5b levels considerably in comparison to other older women not eating prunes. Scientists consider TRAP-5b a marker of bone resorption.
“Taken together, evidence from in vitro, preclinical studies, and limited clinical studies suggest prunes may help to reduce bone loss,” Rogers concludes. “This may be due to altered bone turnover and by inhibiting inflammation and suppressing markers of oxidative stress.”
The research team hypothesizes that prunes spark healthier changes within the gut microbiome, subsequently lowering inflammation within the colon. Such developments likely diminish levels of both pro-inflammatory cytokines and oxidative damage markers.
Further research is already being planned that will investigate more thoroughly the impact of year-long prune consumption on bone health outcomes, inflammation, and the gut.
The study is published in the journal Advances in Nutrition.