|POULOSE, SHIBU - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 12/22/2017
Publication Date: 4/2/2017
Citation: Poulose, S., Shukitt Hale, B. 2017. Polyphenol- and PUFA-rich walnuts protect against age-associated cognitive decline through epigenetic modulation. [abstract]. American Chemical Society Abstracts. 253rd American Chemical Society National Meeting Program #AGFD 201.
Technical Abstract: A demographic shift towards an aging population and the incidence of age-related brain disorders are on the rise worldwide. A rapid decline in brain health with aging is primarily caused by the brain’s exceptionally high demand for energy which drives high oxygen consumption, leading to a subsequent increase in reactive oxygen species, a dysregulation of the immune-inflammatory system, cellular damage, and, ultimately, the death of neurons. Walnuts are rich in bioactives and hormones such as polyphenols, flavonoids, phenolic acids, folates, melatonin, and selenium, with known effects on epigenetic modulation as well as neuroprotection. In a cognitively healthy adult, transcription of immediate-early genes (IEGs) is essential in memory formation and synaptic plasticity. We investigated whether feeding walnuts (0%, 6% or 9%) to young (3 months, n=30, 10/group) and old (19 months, n=45, 15/group) male Fischer 344 rats for 10 weeks would have any effect on the transcription of IEGs. All animals were tested on the radial arm water maze (RAWM), which measures spatial learning and memory. While age increased cognitive deficits, 9% walnut diet improved performance in the RAWM in both young and old rats. In hippocampus, target gene expression using the comparative CT method revealed differential regulation of IEG signaling for the different walnut treatments. Transcripts of brain derived neurotropic factor (BDNF) increased among old animals fed with the walnut diet. Significant increases were also observed for transcript levels of memory-related genes, zif268 and EGR, among the 9% walnut group. Although these experiments were done in rodents and need to be translated into human studies, our study indicates that walnuts may provide protection against age-associated inflammation in the central nervous system, and may also regulate protein homeostasis, modulate IEGs, and improve neuronal signaling, ultimately improving cognitive function in humans.