Reader response: Pattern of polyphenol intake and the long-term risk of dementia in older persons.

Abstract

I read with interest the Lefevre-Arbogast et al.1 article about polyphenyls and reduced incidence of Alzheimer disease (AD). Chronic bacterial infections are associated with development of AD and cause inflammation through activation of innate immunity.2 The increased permeability of the gut and blood–brain barrier induced by microbiota dysbiosis may mediate AD pathogenesis and other neurodegenerative disorders, especially if associated with aging.3 Toll-like receptor 4 is a host defense receptor against invading microorganisms such as bacteria, and is increased in brain tissue associated with amyloid plaque deposition.4 Plant polyphenols have some antibacterial qualities.5 Reducing the amount of gram-negative bacteria from the gastrointestinal tract and oral flora from foods containing polyphenols might reduce AD occurrence though inhibiting bacteria and other organisms such as fungi, which could contribute to development of AD.