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Background. Aging is associated with a decline in cognitive function; we explored the possible influence of dietary phytoestrogens on this decline. Methods. We conducted a cross-sectional study in 301 Dutch women aged 60-75 years. Dietary isoflavone and lignan intake was assessed with a food-frequency questionnaire covering habitual diet in the year preceding enrolment. The endpoints were cognitive function measured in three domains: memory, processing capacity and speed, and executive function. Data were analyzed using linear regression models, after adjusting for confounders. Results. No association between dietary isoflavone intake and cognitive function was found. High lignan intake was associated with a better performance in processing capacity and speed, and in executive function (p for trend over quartiles = .01 and .02, respectively). Conclusions. This finding calls for further research to elucidate the relatively underexplored role of lignans within the range of phytoestrogens.

Decline in estrogen levels in post-menopausal women coincides with the aging process, and tests were conducted to find out whether soy protein with isoflavones improves cognitive functions, bone mineral density and plasma high lipids. Around 150 women were tested for evidence that soy proteins are really wonder drugs as publicized, but no conclusive evidence was found to support this theory.

INTRODUCTION: Estrogen replacement may protect against memory decline in postmenopausal women; phytoestrogens may have similar effects. The goal of this study is to assess whether there is a relation between the habitual dietary phytoestrogen intake of Dutch postmenopausal women and their performance on visual and verbal memory tests. METHODS: A total of 202 postmenopausal women aged 60-75 y were recruited for a randomized placebo-controlled trial with soy protein. Baseline measurements included a food frequency questionnaire on habitual diet in the year before enrollment. In the literature we identified food sources of phytoestrogens. The concentrations of the different isoflavones, coumestrol, and lignans in each food in the questionnaire were scored in seven categories and multiplied by the serving size of the food and the frequency of its consumption. Verbal memory functions were tested with the Rey Auditory Verbal Learning test, immediate recall, delayed recall (after 25 min), and recognition. Visual memory was tested with the Doors test. Linear regression was used to relate phytoestrogen intake to memory function at baseline. The results were adjusted for age, body mass index, total fiber and energy intake, and intellectual function using the Dutch version of the NART. RESULTS: Compared with the lowest quartile, phytoestrogen intake in the highest three quartiles was associated with improved performance on all verbal memory tests. The results were significant for coumestrol (immediate recall, P = 0.06; delayed recall, P = 0.05) and isoflavones (recognition, P = 0.004). On the visual memory test a positive effect was seen for all groups of phytoestrogens except for lignans. The effect of coumestrol was borderline significant (P = 0.08). CONCLUSIONS: The results suggest that phytoestrogen intake within the Western dietary pattern is associated with improved memory function in postmenopausal women, but further clinical trails are needed to establish causal relations.

OBJECTIVE. Perimenopausal decline in muscle strength may increase risk of falling and may thereby play a role in the increasing number of fractures in postmenopausal women. Hormone replacement therapy increases muscle strength in postmenopausal women. The purpose of our study was to investigate whether phytoestrogens can also improve muscle strength in these women. METHODS: For a randomized placebo-controlled trial with soy protein, we recruited 202 postmenopausal women aged 60-75 y. Baseline measurements included a food frequency questionnaire on habitual diet in the year before enrollment. In the literature we identified food sources of phytoestrogens. The concentrations of the different isoflavones, coumestrol, and lignans in each food in the food frequency questionnaire were scored in seven categories and multiplied by the serving size of the food and the frequency of its consumption. For 42 women we also measured handgrip strength in duplicate. For our analysis we used the results of the second attempt of the handgrip strength test, when women were used to handling the test device. Linear regression was used to study the association between muscle strength and quartiles of phytoestrogen intake. Results were adjusted for age, body mass index, and energy intake. RESULTS: In the lowest quartile of total phytoestrogen intake, the mean handgrip strength was 15.5 kg. For the highest quartile this was 3.4 kg higher (P = 0.109). For isoflavones there was a 4.3 kg increase in handgrip strength in the highest quartile (P = 0.043) compared with the lowest quartile of intake. CONCLUSION: Our results suggest that phytoestrogens positively affect muscle strength in postmenopausal women. Although phytoestrogen intake in Western countries is low, there was a trend that small differences in phytoestrogen intake were also associated with an increase in muscle strength.