Soy-based diets do not improve menopause symptoms but do reduce blood pressure and lower cholesterol, researchers from Monash University in Melbourne have found.
A two-year study involving 220 men and women found, despite Current beliefs, that phytoestrogens in soy products had no impact on the specific conditions related to menopause.
Menopause symptoms include hot flushes, a negative impact on bones and changes to the way the liver processes protein.
Helena Teede, a menopause expert at Monash University who headed the research, presented the findings at the 5th Australasian Menopause Society Congress in Melbourne last month.
Ms Teede said half the study group was given a dietary supplement of soy protein, and the other half a placebo of milk-based product, for three months.
She said the researchers were particularly interested in whether the phytoestrogens in the soy supplement would "turn on" the oestrogen receptors in the body.
"We looked at the sort of things that we know change with oestrogen, like the liver protein," she said.
"All of the evidence suggests that there was no significant oestrogen benefit."
But Ms Teede said the researchers did find the soy protein caused a significant drop in cholesterol and blood pressure, and did not cause blood clots.
"Soy is not a bad thing for menopause, it's actually good health advice to consume soy products, but there are now many, many studies where none have really shown any menopausal symptoms have improved," she said.
In what could be considered to be controversial Ms Teede warned that soy supplement tablets were of little or no use because they did not include the entire soy protein and therefore offered no cholesterol or blood pressure relief.