Eating high levels of some soy products, such as tofu, could raise the risk of memory loss.
A study that examined more than 700 elderly Indonesians found that high tofu consumption (at least once a day) was associated with worse memory, particularly among those over age 68.
Soy contains phytoestrogens, which may heighten the risk of dementia.
However, tempeh, a fermented soy product made from the whole soy bean, has been associated with better memory. This could be related to the fact that it contains high levels of the vitamin folate, which is known to reduce dementia risk.