Soya isoflavones, kiwifruit and bone health
What it found
In lab tests, DHA from fish oil blocked the formation of bone-destroying cells, and combining it with soy isoflavones made the effect stronger.
In rats and mice, green kiwifruit slowed bone loss after ovary removal, and in menopausal women it improved blood lipids and bone markers.
What they found
Studies in people
Kiwifruit affects women positively
In menopausal women, green kiwifruit improved blood lipids and bone markers.
Animal and lab studies
DHA blocks bone-destroying cells
In two mouse cell models, DHA stopped osteoclasts from forming. It also reduced markers like cathepsin K, NFATc1 and actin ring formation.
Soy isoflavones boost DHA effect
When DHA was combined with soy isoflavones, the effect on osteoclasts was stronger than with DHA alone.
Kiwifruit slows bone loss in animals
In ovary-removed rats and mice fed green kiwifruit for 8 weeks, the rate of bone loss was reduced. In mice, CTX levels and RANKL expression also went down.
What the authors conclude
- They conclude that DHA inhibits osteoclast formation and that soy isoflavones enhance this effect.
- They report that green kiwifruit reduces bone loss in ovary-removed animals and positively affects blood lipids and bone markers in menopausal women.
How it was done
New Zealand has many food components that may affect bone. The authors wanted to test DHA, soy isoflavones and kiwifruit carotenoids for their effects on bone.
They used mouse monocyte and bone marrow cells to grow osteoclasts and exposed them to the agents for 5 to 21 days. They also fed kiwifruit to ovary-removed rats and mice for 8 weeks, and gave green kiwifruit to menopausal women.
What it can’t tell you
- We summarised it from the abstract only.
- The cell and animal results cannot show what happens in people.
- The human study cannot prove that kiwifruit causes the changes seen in blood lipids and bone markers.
Who paid
- Authors work at
- Massey University, New Zealand
The paper
- Title
- Effects of Soy Phytoestrogens and New Zealand Functional Foods on Bone Health
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Abstract only
- Cite
- Kruger MC, Tousen Y, Katsumata S, et al (2015). Effects of Soy Phytoestrogens and New Zealand Functional Foods on Bone Health. Journal of nutritional science and vitaminology. doi:10.3177/jnsv.61.S142PubMed 26598831DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error