RSS Feed Print
High blood caffeine levels in older adults linked to avoidance of Alzheimer’s disease
Posted: Sunday, December 30, 2012 4:50 AM
Joined: 4/24/2012
Posts: 484

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:

Posted: Sunday, December 30, 2012 5:15 AM
Joined: 4/24/2012
Posts: 484

Caffeine suppresses TNF-α production via activation of the cyclic AMP/protein kinase A pathway



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.



Lane Simonian
Posted: Sunday, December 30, 2012 10:37 AM
Joined: 12/12/2011
Posts: 4854

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. 


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 donor. Sin-1 also induced CREB depletion in a dose dependent manner when added to the culture media for 48 hours. 


There are better antioxidants, but caffeine potentially has some useful qualities.