Japanese Taste for Soy Protein Spares Them Hot Flashes
Celia Hall on a tasty alternative to HRT
(from The Electronic Telegraph - Saturday, February 8, 1997)
The Japanese language, apparently, has no equivalent words for hot flushes, that common symptom of the menopause. This suggests that Japanese women do not suffer from them - or at least not severely.
Gregory Burke, an American professor of women's medicine, finds this linguistic omission significant. He is one of a growing group of scientists who believe soy protein in the diet may have health benefits for older women. "What we are interested in is plant oestrogens or phytoestrogens and their effects on menopausal women," he says. "Soy is high in phytoestrogen, which is between one in 10,000 and one in 100,000 times less potent than the hormones in Hormone Replacement Therapy - but many women do not want to take HRT drugs. We are trying to find out whether soy protein could be a useful alternative.
He points out that the amount of soy in the diet of the average Briton or American is negligible, while in Japan it is "the major source of protein". Prof. Burke, of the department of public health science at the Bowman Gray School of Medicine, Winston-Salem, North Carolina suffered at least one daily bout of hot flushes or night sweating - classic menopausal symptoms. For six weeks, the women sprinkled 20 grams of soy protein over their morning cereal or juice, and for six weeks they sprinkled on a placebo, a carbohydrate powder. The study found that while using the soy protein, the women had significantly reduced symptoms, although these did not entirely disappear. Prof. Burke is now conducting a bigger trial with 240 women, who will be given much higher doses of soy.
At the University Hospital of South Manchester, Nigel Bundred, a breast cancer surgeon, has already done that. He was concerned about the effects of the menopause on patients who were not taking HRT because of its possible adverse effects. In his trial, 30 Manchester women who took 60 grams of soy protein daily - three times the amount used in the American trial - had their hot lushes reduced by half and their severity cut by 30 per cent. Both doctors are preparing to publish their work. It is widely acknowledged that soy protein can reduce cholesterol in the blood, with implications for reducing the risk of heart disease.
There is so much evidence, in fact, that the American Food and Drug Administration is considering whether to recommend soy as a dietary means of reducing harmful blood fat. Mr. Bundred's patients also had their blood tested. He reasoned that if their cholesterol was reduced, it was an independent sign that the soy was active in their bodies. The trial found that the soy did lower the blood cholesterol of the women. Mr. Bundred is extending his research, funded by the Ministry of Agriculture, Fisheries and Food, to look at the effects of soy on bone loss in older women, with possible implications for osteoporosis. "There is no doubt that the post-menopausal women taking soy felt better, and I think there is pretty convincing evidence that soy is active and may have a role. We are just at the beginning of sorting out what soy does and what its role will be," he says.
Do the doctors recommend that we eat foods that are high in soy oil or protein every day? Not exactly. Both were cautious; if the plant oestrogens in soy are as active as the studies suggest, then they may be undesirable in women prone to breast cancer. But Mr. Bundred says: "There are now a number of groups of scientists working on this. We don't yet know if soy does anything nasty to the breast, but Japanese women have less breast cancer than Western women."
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