Acute effect of a high nitrate diet on brain perfusion in older adults.
OBJECTIVE
Poor blood flow and hypoxia/ischemia contribute to many disease states and may also be a factor in the decline of physical and cognitive function in aging. Nitrite has been discovered to be a vasodilator that is preferentially harnessed in hypoxia. Thus, both infused and inhaled nitrite are being studied as therapeutic agents for a variety of diseases. In addition, nitrite derived from nitrate in the diet has been shown to decrease blood pressure and improve exercise performance. Thus, dietary nitrate may also be important when increased blood flow in hypoxic or ischemic areas is indicated. These conditions could include age-associated dementia and cognitive decline. The goal of this study was to determine if dietary nitrate would increase cerebral blood flow in older adults.


RESULTS
In this investigation we administered a high vs. low nitrate diet to older adults (74.7±6.9 years) and measured cerebral perfusion using arterial spin labeling magnetic resonance imaging. We found that the high nitrate diet did not alter global cerebral perfusion, but did lead to increased regional cerebral perfusion in frontal lobe white matter, especially between the dorsolateral prefrontal cortex and anterior cingulate cortex.


CONCLUSIONS
These results suggest that dietary nitrate may be useful in improving regional brain perfusion in older adults in critical brain areas known to be involved in executive functioning.
Presley
Tennille D
TD
Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA.
Morgan
Ashley R
AR
Bechtold
Erika
E
Clodfelter
William
W
Dove
Robin W
RW
Jennings
Janine M
JM
Kraft
Robert A
RA
King
S Bruce
SB
Laurienti
Paul J
PJ
Rejeski
W Jack
WJ
Burdette
Jonathan H
JH
Kim-Shapiro
Daniel B
DB
Miller
Gary D
GD
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply*; D019587:Dietary Supplements; D006801:Humans; D008279:Magnetic Resonance Imaging; D009566:Nitrates / Q000008:administration & dosage* / Q000097:blood; D009573:Nitrites / Q000097:blood*; D012039:Regional Blood Flow / Q000187:drug effects
D009566:Nitrates; D009573:Nitrites