Joined: 4/24/2012
Posts: 484
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High blood caffeine levels in older adults linked to avoidance of Alzheimer’s disease, USF-UM study reports
Researchers from the University of South Florida and the University of Miami
say the case control study provides the first direct evidence that
caffeine/coffee intake is associated with a reduced risk of dementia or
delayed onset. Their findings appear in the online version of an
article published June 5 in the Journal of Alzheimer’s Disease. The collaborative study involved 124 people, ages 65 to 88, in Tampa and Miami.
“These intriguing results suggest that older adults with mild memory
impairment who drink moderate levels of coffee — about 3 cups a day —
will not convert to Alzheimer’s disease — or at least will experience a
substantial delay before converting to Alzheimer’s,” said study lead
author Dr. Chuanhai Cao, a neuroscientist at the USF College of Pharmacy and the USF Health Byrd Alzheimer’s Institute.
“The results from this study, along with our earlier studies in
Alzheimer’s mice, are very consistent in indicating that moderate daily
caffeine/coffee intake throughout adulthood should appreciably protect
against Alzheimer’s disease later in life.”
“We found that 100 percent of the MCI patients with plasma caffeine
levels above the critical level experienced no conversion to Alzheimer’s
disease during the two-to-four year follow-up period,” said study
co-author Dr. Gary Arendash.
Since 2006, USF’s Dr. Cao and Dr. Arendash have published several
studies investigating the effects of caffeine/coffee administered to
Alzheimer’s mice. Most recently, they reported that caffeine interacts
with a yet unidentified component of coffee to boost blood levels of a
critical growth factor that seems to fight off the Alzheimer’s disease
process.
Link to article:
http://hscweb3.hsc.usf.edu/blog/2012/06/04/high-blood-caffeine-levels-in-older-adults-linked-to-avoidance-of-alzheimers-disease-usf-um-study-reports/
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Joined: 4/24/2012
Posts: 484
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Caffeine suppresses TNF-α production via activation of the cyclic AMP/protein kinase A pathway
Abstract
This
study investigated the effect of in vitro exposure to caffeine, and its
major metabolite paraxanthine, at concentrations relevant to typical
caffeine consumption in humans, on lipopolysaccharide (LPS)-stimulated
cytokine production in human whole blood. In addition, a role for the
cyclic AMP/protein kinase A (PKA) pathway in the immunomodulatory effect
of caffeine was investigated. Diluted whole blood (taken following ≥15 h
abstinence from caffeine-containing food and beverages) was
preincubated with caffeine or paraxanthine (10–100 μM) and stimulated
with LPS (1 ∝g/ml) for 24 h. The proinflammatory cytokines tumour
necrosis factor (TNF)-α, interleukin (IL)-1β and IL-12, and the
antiinflammatory cytokine IL-10 were measured in cell-free supernatants.
Whilst caffeine and paraxanthine had little or no effect on IL-10,
IL-1β, or IL-12 production, TNF-α production was suppressed in all
individuals studied. The effect was statistically significant at 100 μM
and consistent across seven experiments performed. Although not
statistically significant, a similar effect was observed with
paraxanthine. Caffeine (100 μM) also increased intracellular cyclic AMP
concentrations in LPS-stimulated monocytes isolated from whole blood.
Moreover, the effect of caffeine on TNF-α production was abolished by
pretreatment with the protein kinase A inhibitor Rp-8-Br-cAMPS (10−4 and 10−5M).
To conclude, this study demonstrates that concentrations of caffeine
that are relevant to human consumption consistently suppress production
of the proinflammatory cytokine TNF-α in human blood and that this
effect is mediated by the cyclic AMP/protein kinase A pathway.
Link:
http://www.sciencedirect.com/science/article/pii/S1567576904001924
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Joined: 12/12/2011
Posts: 4854
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Thanks for this very good research, Serenoa.
By various means, including limiting the production of tumor necrosis factor alpha, caffeine limits the production of peroxynitrites. Peroxynitrites limit the production of the cyclic AMP response binding element and in doing so contribute to brain atrophy.
http://en.wikipedia.org/wiki/CREB
Peroxynitrite is a very reactive molecule and there are no methods to measure ONOO− as such in physiological conditions. It can be assayed indirectly by either measuring nitrotyrosine or using SIN-1 as a peroxynitrite donor20. Sin-1 also induced CREB depletion in a dose dependent manner when added to the culture media for 48 hours.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3155008/
There are better antioxidants, but caffeine potentially has some useful qualities.
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