Loughborough University,Asby Road,LE11 3TU,UK.
Universitas Indonesia Center for Aging Studies,Depok,Indonesia.
Proc Nutr Soc. 2017 Nov;76(4):437-442. doi: 10.1017/S0029665117000404.
Observational studies and treatment trials investigating nutrition and cognitive function, with a focus on folate and soya and dementia, were reviewed. Data suggested that effects of folic acid based interventions may only be shown before cognitive decline is evident and/or if people are folate deficient. In older people in Indonesia, Hawai'i and China, tofu, which can contain high levels of phytoestrogens, was found to increase dementia risk. This association was not mediated by a vegetarian diet, socioeconomic status, formaldehyde, thyroid function, or loss of teeth. On the other hand, human observational and animal treatment studies suggested that tempe, a fermented soya product containing phytoestrogens and folate, reduced dementia risk and improved memory. High oestrogen levels were found to increase dementia risk in older women. However, in women with adequate serum folate, high oestrogen levels did not confer additional dementia risk and may protect ageing neurons. In conclusion, reviews seem to suggest that folic acid interventions are only effective on cognitive outcomes in people who are folate deficient and do not have cognitive impairment. Frequent consumption of tofu may have detrimental effects on memory and increase dementia risk in older East Asian people, while tempe may reduce these risks. Possibly folate in tempe offsets the potential negative effects of oestrogenic compounds on ageing neurons.
观察性研究和治疗试验调查了营养与认知功能之间的关系，重点关注叶酸、大豆与痴呆。数据表明，基于叶酸的干预措施的效果可能仅在认知能力下降之前或当人们叶酸缺乏时显现。在印度尼西亚、夏威夷和中国的老年人中，豆腐（可能含有高水平的植物雌激素）被发现增加了痴呆的风险。这种关联不受素食饮食、社会经济地位、甲醛、甲状腺功能或牙齿缺失的影响。另一方面，人体观察性研究和动物治疗试验表明，豆豉（一种含有植物雌激素和叶酸的发酵大豆制品）降低了痴呆风险并改善了记忆力。高水平的雌激素被发现会增加老年女性的痴呆风险。然而，在血清叶酸充足的女性中，高水平的雌激素并不会带来额外的痴呆风险，反而可能保护衰老的神经元。总之，综述似乎表明，叶酸干预措施仅对叶酸缺乏且没有认知障碍的人群的认知结果有效。在东亚老年人中，频繁食用豆腐可能对记忆力产生不利影响，增加痴呆风险，而豆豉可能会降低这些风险。可能是豆豉中的叶酸抵消了雌激素化合物对衰老神经元的潜在负面影响。
