Tuesday, July 10, 2012

Coffee Every Day Keeps the Dementia Away

Coffee is a daily ritual for many Americans, providing that extra get-up-and-go before starting their routines. But, coffee could be more than just a good way to start the day for older individuals at risk for dementia; daily coffee consumption protects against the development of dementia, according to a new study.

The study, completed at a Veterans Affairs Hospital in Florida, was a retrospective evaluation of 124 people aged 65 to 88 years. At the beginning of the study, all patients underwent a battery of neurologic and cognitive tests and were categorized as having normal cognitive function, mild cognitive impairment (MCI), or dementia. Fasting blood samples were also taken at the beginning of the study. The researchers assessed the participants' cognitive functions annually for the next 2 to 4 years. At the end of the follow-up period, the participants were categorized into five groups based on cognitive function: initially normal function and remained normal, initially normal but converted to MCI, initially MCI and remained MCI, initially MCI and converted to dementia, and initially dementia and remained dementia.

The researchers assessed caffeine levels at baseline and compared them to the cognitive function of the participants over time. At the beginning of the study, patients with MCI and dementia had lower plasma caffeine levels than those with normal cognitive function. Over the course of the study, patients with normal cognitive function who converted to MCI had lower caffeine levels than those who remained normal. Similarly, patients with MCI who converted to dementia had lower caffeine levels that those who remained MCI.

Of the patients initially classified as MCI, none of those who converted to dementia had plasma caffeine levels above 1200 mg/mL. Half of the participants with stable MCI had higher levels. The authors suggest a protective effect above the threshold of 1200 ng/mL of caffeine — the equivalent of consuming 500 mg of caffeine or 5 cups of coffee daily.

Caffeine is not the only factor that contributes to the development of dementia. Coffee itself is rich in antioxidants and anti-inflammatory compounds that reduce the risk for dementia and Alzheimer's disease. Also, physical activity, cognitive engagement, and hypertension also contribute to the development of dementia.

This is not the first study to suggest that coffee may have therapeutic potential for cognitive function. The psychostimulant properties of caffeine have demonstrated reduced or delayed cognitive decline, especially among older people. But, it is still not clear if it is coffee, caffeine, or a combination of the two that provide the protection. In one study, caffeine solution (not coffee) and decaffeinated coffee did not show protective effects on cognition, while regular, caffeinated coffee did, suggesting that there are other components in coffee that synergize with caffeine to ward off dementia.

No study on the effects of caffeine on dementia has proved cause and effect, but the studies are observing increasingly quantifiable results regarding caffeine consumption, and future studies are likely. For now, older adults at risk for dementia should not replace all other drinks with coffee (there are other health risks associated with that much coffee consumption!), but an extra cup o' joe with some friends could do more good than harm.

References

Arendash GW, & Cao C (2010). Caffeine and coffee as therapeutics against Alzheimer's disease. Journal of Alzheimer's disease : JAD, 20 Suppl 1 PMID: 20182037

Cao C, Loewenstein DA, Lin X, Zhang C, Wang L, Duara R, Wu Y, Giannini A, Bai G, Cai J, Greig M, Schofield E, Ashok R, Small B, Potter H, & Arendash GW (2012). High Blood Caffeine Levels in MCI Linked to Lack of Progression to Dementia. Journal of Alzheimer's disease : JAD, 30 (3), 559-72 PMID: 22430531

Cao C, Wang L, Lin X, Mamcarz M, Zhang C, Bai G, Nong J, Sussman S, & Arendash G (2011). Caffeine synergizes with another coffee component to increase plasma GCSF: linkage to cognitive benefits in Alzheimer's mice. Journal of Alzheimer's disease : JAD, 25 (2), 323-35 PMID: 21422521

Ritchie K, Carrière I, de Mendonca A, Portet F, Dartigues JF, Rouaud O, Barberger-Gateau P, & Ancelin ML (2007). The neuroprotective effects of caffeine: a prospective population study (the Three City Study). Neurology, 69 (6), 536-45 PMID: 17679672

Image via Tischenko Irina / Shutterstock.

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