Tempereversed effects of ovariectomy on brain function in rats: Effects of age and type of soy product.

BACKGROUD: The aims of this study were to analyze the differences in nutrient content and isoflavones in tempe flour and tofu flour, and to analyze the effect of tempe and tofu flour on cognitive function of female rats after ovariectomy. METHOD: Seventy two (72) white female Sprague Dawley strain rats, aged 12 months were used for this study. Before the intervention 52 rats underwent ovariectomy (OVx) and they were grouped into 4 intervention groups: tempe flour (Tp), tofu flour (Tf), estradiol (E2), and casein as a control protein (Cs). The remaining 20 rats were classed as controls and had no ovariectomy (NO). Cognitive function was measured using a maze test. Oneway ANOVA with polynomial contrasts and post hoc LSD were used with a p-value<0.05 to indicate significance. RESULTS: The content of nutrients (vitamin B6, vitamin B12, folic acid) and isoflavones (genistein) were all higher in tempe flour higher than in tofu flour. After 8 weeks, the Tp group had showed significantly increased cognitive function (P<0.05), while the Tf group, the E2 group and the Cs group also all had increased performance, but not significantly so (P>0.05). There was no change in scores in the NO group. CONCLUSIONS: Intervention by tempe flour can increase cognitive function in female ovariectomized female rats. Further research should focus onother aspects of cognitive function and the content of amyloid plaques and neurotransmitter synthesis in the brain.

High tofu intake is associated with worse memory in elderly Indonesian men and women.

BACKGROUND/AIMS: Cell culture studies suggest that phytoestrogens, abundant in soy products such as tempe and tofu, could protect against cognitive decline. Paradoxically, the Honolulu Asia Aging Study reported an increased risk for cognitive impairment and other dementia markers with high tofu (soybean curd) intake. METHODS: A cross-sectional study was carried out in 2 rural sites (Borobudur and Sumedang) and 1 urban site (Jakarta) among mainly Javanese and Sundanese elderly (n = 719, 52-98 years of age). Memory was measured using a word learning test sensitive to dementia and soy consumption was assessed using Food Frequency Questionnaire items. RESULTS: High tofu consumption was associated with worse memory (beta = -0.18, p < 0.01, 95% CI = -0.34 to -0.06), while high tempe consumption (a fermented whole soybean product) was independently related to better memory (beta = 0.12, p < 0.05, 95% CI = 0.00-0.28), particularly in participants over 68 years of age. Fruit consumption also had an independent positive association. The analyses were controlled for age, sex, education, site and intake of other foods. CONCLUSION: The results for tofu consumption as a risk factor for low memory function may tie in with the Honolulu Asia Aging Study data. It is unclear whether these negative associations could be attributed to potential toxins or to its phytoestrogen levels. Estrogen (through which receptors phytoestrogens can exert effects) was found to increase dementia risk in women over 65 years of age. Tempe contains high levels of phytoestrogens, but (due to fermentation) also exhibits high folate levels which may exert protective effects. Future studies should validate these findings and investigate potential mechanisms.