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'I have learnt so much from indigenous and traditional approaches to health’ – Dr Vivien Rolfe [Interview]
Dr Vivien Rolfe is a gut physiologist who specialises in herbal and nutritional interactions with the human body.
Blackcurrant supplementation may help to mitigate bone loss in post-menopausal women, according to US researchers.
Study participants supplemented with daily blackcurrant powder capsules demonstrated an increase in whole-body bone mineral density at six months compared with placebo, they found.
In ageing bodies, bones lose density and become more fragile – a particular concern for post-menopausal women, who generally experience much greater losses in bone density than men in the same age group.
Traditional osteoporosis medications often come with side effects that make compliance challenging. Supplementation with blackcurrant could offer a more palatable alternative with fewer adverse effects, according to researchers from the University of Connecticut (UConn) and the Jackson Laboratory for Genomic Medicine.
“This study shows that blackcurrant may be a potential dietary strategy to help in preventing post-menopausal osteoporosis,” said first author Briana Nosal.
Blackcurrants, tart berries known for their health benefits, are brimming with antioxidants such as vitamin C, making them effective against a range of conditions. They contain anthocyanins, which are known to fight free radicals in the body, reducing oxidative stress and cell damage.
Previous research by UConn scientists found that blackcurrant supplementation helped prevent post-menopause bone density loss in mice. The findings showed that the best time for intervention was during the transition between pre- and post-menopause, before bone loss had significantly progressed.
The recent study, published in the Journal of Nutritional Biochemistry, aimed to assess the effects of blackcurrant on gut microbiota abundance and composition, inflammatory and immune responses, and their relationship with bone mass changes.
Forty peri- and early post-menopausal women aged between 45 and 60 years were randomly assigned to receive one or two capsules of blackcurrant powder (392 mg each) daily, or a placebo, for six months. The group that took two capsules showed overall increases in bone mineral density at the end of the trial period.
Blackcurrants’ protective effects on bone health are thought to stem from two key mechanisms.
The first is cytokine suppression: the study revealed that blackcurrant supplementation significantly reduced levels of interleukin-1 beta and RANKL, proteins involved in bone resorption. Interleukin-1 beta stimulates the expression of RANKL, which causes bone resorption and thus a decrease in bone density.
The decrease in RANKL was directly correlated with an increase in whole-body bone density after six months.
“The reduction in RANKL is important because that can cause shifts toward excessive bone resorption, so we’d want to see a decrease in that,” said Nosal.
The researchers also looked at changes to the gut microbiome and immune system, which are known to play a key role in bone metabolism, and found that supplementation increased levels of Ruminococcus 2, a beneficial gut bacterium linked to the degradation of polysaccharides and fibres.
As blackcurrant dose-dependently increased the relative abundance of Ruminococcus 2, the researchers suggested that it might be the key bacteria behind bone-protective effects.
Nosal added: “It’s all related, and there’s a lot of research showing the gut can regulate various systems in the body.”
The group concluded that larger-scale clinical trials on the connection between Ruminococcus 2 and bone mineral density maintenance in postmenopausal women are warranted. They plan to continue investigating the relationship between blackcurrant and its benefits on the body to better understand their results.
“[We want to learn] how all our findings connect to each other,” Nosal said. “Conducting that multi-faceted research will really paint the picture of how everything works, the different mechanisms, and what we can do for next steps.”