According to the article:

"Of 700 elderly Indonesians, those who ate tofu at least once a day had an increased risk of dementia or memory loss, particularly if they were over age 65. Researchers believe the link might be due to soy products' phytoestrogens, which may offer some neural benefits to the middle-aged and young but could harm those over 65."

The article also stresses that there are many lifestyle choices that could affect the onset of Alzheimer's Disease.