As we age, our bones lose their density and become more fragile, putting us at risk of fractures and fractures.
This is especially a problem in postmenopausal women, who generally have much greater losses in bone density than men in their age group.
Ock Chun, professor of nutritional sciences at UConn’s College of Agriculture, Health and Natural Resources (CAHNR), has been working with blackcurrant, a tart berry, for years, researching its potential to improve a host of conditions, including postmenopausal bone loss and osteoporosis.
Chun previously led a study showing that blackcurrant supplements helped prevent bone density loss after menopause in mice. This study showed that the best time for intervention was the transition between pre- and postmenopause, before bone loss had progressed significantly.
With these findings in hand, Chun and her team wanted to see if they would translate to a human population.
They recently published their findings showing the protective effects of blackcurrants against loss of bone density in the intestines Journal of nutritional biochemistry.
The group includes nutritional sciences graduate student Briana Nosal, the paper’s first author, postdoctoral kinesiology researcher Staci Thornton, and Elaine Choung-Hee Lee, professor of kinesiology, as well as researchers from UConn Health and the Jackson Laboratory for Genomic Medicine.
Forty peri- and early postmenopausal participants between the ages of 45 and 60 took blackcurrant powder capsules daily for six months. Participants were randomly assigned to take one capsule, two capsules, or a placebo. Each capsule was 392 milligrams.
The researchers found that the supplements prevented the loss of bone mineral density throughout the body. The group that took two capsules even showed an overall increase in bone mineral density at the end of the six-month trial period.
The researchers looked at changes in the gut microbiome and the immune system, which interact and play a key role in bone metabolism.
They found that the blackcurrant supplements reduced levels of proteins, interleukin-1 beta and RANKL. Interleukin-1 beta stimulates the expression of RANKL, which causes bone resorption and thus a decrease in bone density.
“The reduction in RANKL is important because it can cause shifts toward excessive bone resorption, so we would like to see a decrease in that,” says Nosal.
This study showed that the decrease in RANKL was directly correlated with an increase in whole-body bone density after six months.
Taking the supplements also increased a bacteria called the gut microbiome Ruminococcus 2. This led the researchers to conclude that it could be one of the bacteria driving blackcurrant’s protective effects on bones.
“It’s all connected and there’s a lot of research showing that the gut can regulate different systems in the body,” says Nosal.
These bacteria help break down polysaccharides and fibers. This is a key function of converting the food we eat into available energy that our body can use.
The researchers identified a total of four proteins that showed increased expression in the group that took two supplement capsules. These could serve as potential biomarkers for the changes they observed in bone density, allowing researchers or medical professionals to quickly and easily assess whether blackcurrant supplementation benefits bone density.
This study is especially important for peri- and early postmenopausal women who have or are at risk of developing osteoporosis. Although medications for osteoporosis exist, compliance is low due to side effects.
If blackcurrant supplements can improve bone density without the same side effects, it could be an effective alternative for this population.
“This study shows that blackcurrants may be a potential dietary strategy to help prevent postmenopausal osteoporosis,” says Nosal.
As the group continues to study the relationship between blackcurrant and its benefits to the body, they will complete additional studies to better understand why exactly they are seeing these results.
“[We want to learn] how all of our findings are connected,” says Nosal. “Conducting that multi-faceted research will really paint a picture of how everything works, the different mechanisms and what we can do for the next steps.”
