As well as assessing potential effects of the supplement on bone health, the new study investigated what part the gut microbiome plays in achieving them. They also assessed participants’ health-related quality of life and short-chain fatty acid (SCFA) levels.
The joint French, Swiss and Irish research was funded by Givaudan France Naturals. Four of the authors are company employees.
8-PN: a high potency phytoestrogen
Osteopenia is a condition where people's bone density is lower than is usual for their age. Osteoporosis is a more severe case of bone loss that weakens the bones and makes them more likely to fracture.
It’s estimated that thirty to forty per cent of postmenopausal women are affected by osteoporosis in the USA and Europe.
Oestrogen deficiency increases osteoporosis risk. The authors note that “phytoestrogens are an interesting non-pharmaceutical intervention to prevent bone loss,” because they’re similar in structure to endogenous human oestrogen.
One of the main dietary sources of phytoestrogens is hops. Research shows standardised hop extract can reduce menopausal symptoms. Plus, the authors note that “there is a growing body of evidence indicating that the gut microbiome plays a key role in bone metabolism and osteoporosis pathogenesis even though mechanisms of action have not been clearly elucidated yet.”
Eight-PN’s receptor specificity and potency is higher than other phytoestrogens’. Several studies demonstrate that an oral supplementation with a standardised hop extract prevented oestrogen-deficiency-induced bone loss in osteoporotic rodents. Before this new study, the effect hadn’t been tested in humans.
The study was a 48-week, parallel-design, placebo-controlled, double-blind, randomised clinical trial conducted from August 2019 to December 2020 in Cork, Ireland. Researchers identified 100 eligible participants – all postmenopausal women between 50 and 85 presenting with osteopenia.
The women received either a hop extract standardised in 8-PN (Lifenol capsules) or a placebo. Each Lifenol capsule contained 100 µg of 8-PN, 110 µg of 6-PN, 1.25 mg of X, and 2.94 mg of IX, mixed with maltodextrin.
The authors assessed bone density with a DXA exam carried out by the same healthcare professionals at each visit. Fecal samples were collected at baseline, 24 weeks and 48 weeks.
After 48 weeks the authors found supplementation increased subjects’ total bone mineral density (BMD), with a higher proportion of women experiencing an increase compared to placebo.
However, they recorded no significant effect on BMD at specific areas of the body (lumbar spine, femoral neck and total hip).
Gut microbiome diversity and SCFA levels didn’t differ between groups. Despite this, the HE group had more of genera Turicibacter and Shigella. The authors note both are associated with total body BMD.
Subjects’ quality of life scores also rose. The score measuring physical functioning was significantly increased in the HE group compared to placebo, with half showing increased scores. The authors note this suggests subjects thought it was easier to carry out everyday activities.
The authors conclude: “In postmenopausal women with osteopenia, daily consumption of a standardized hop extract with 100 µg of 8-PN during 48 weeks was found to have a beneficial increase of 1% of the total body BMD compared to placebo, above and beyond an increase associated with a calcium and vitamin D supplementation.”
The authors note that the bone remodelling cycle lasts 120-200 days. This means that during the trial this cycle could have been completed more than once.
Lecomte, M.; Tomassi, D.; Rizzoli, R.; Tenon, M.; Berton, T.; Harney, S.; Fança-Berthon, P.
Effect of a Hop Extract Standardized in 8-Prenylnaringenin on Bone Health and Gut Microbiome in Postmenopausal Women with Osteopenia: A One-Year Randomized, Double-Blind, Placebo-Controlled Trial.