Coffee reported to ward off dementia

Robin Wulffson MD's picture
cognitive impairment, dementia, Alzheimer's disease, coffee, caffeine, MCI
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Coffee is a beverage enjoyed regularly not only for its flavor but also for its pick-me-up-properties. A new study has reported that, beyond flavor and mild stimulation, the beverage may ward off dementia. The results of the study were published in the June issue of the Journal of Alzheimer’s Disease.

A research team led by Gary W. Arendash, PhD, a research scientist at Bay Pines Veterans Affairs Hospital, St. Petersburg, Florida noted that both human epidemiologic and animal model studies have suggested that coffee and other caffeine-containing substances might protect against Alzheimer’s disease; however, direct human evidence for this theory has been lacking. To elucidate the situation, the researchers evaluated two groups of seniors (124 total; age 65-88 years). Their cognitive ability was assessed and a blood sample was drawn for caffeine/biomarker analysis. The individuals were then monitored for cognitive status over the next two-to-four years to determine the extent to which initial plasma caffeine/biomarkers levels would be predictive of changes in cognitive status.

At the study onset, the researchers noted that plasma caffeine levels were significantly lower (-51%) in seniors with mild cognitive impairment (MCI) who later progressed to dementia (MCI > DEM) compared to levels in stable MCI subjects (MCI > MCI). None of the MCI > DEM subjects had initial blood caffeine levels that were above a critical level of 1,200 ng/ml; however, half of stable MCI > MCI subjects had blood caffeine levels above that critical level. The researchers found that plasma caffeine levels greater than 1,200 ng/ml in MCI subjects were associated with no conversion to dementia during the ensuing 2-4 year follow-up period.

The investigators also measured the level of 11 different cytokines in the study participants. Cytokines are small cell-signaling protein molecules, which are secreted by numerous cells; they are a category of signaling molecules used extensively in intercellular communication. Among the cytokines measured in plasma, three of them (GCSF, IL-10, and IL-6) were decreased in MCI→DEM subjects; however, they were not decreased in stable MCI > MCI subjects with high plasma caffeine levels. The researchers noted that coffee was apparently the major––or perhaps only–– source of caffeine for the stable MCI patients.

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The study authors concluded that their case-controlled study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset, particularly for those who already have MCI.

Dementia is a loss of brain function that occurs with certain diseases. Alzheimer's disease is one form of dementia that gradually worsens over time. It affects memory, thinking, and behavior. Memory impairment, as well as problems with language, decision-making ability, judgment, and personality, are necessary features for the diagnosis. As one ages, the risk of developing Alzheimer’s disease increased; however, the disease is not a part of normal aging. Having a close blood relative, such as a brother, sister, or parent who developed AD increases one’s risk. Having certain combination of genes for proteins that appear to be abnormal in Alzheimer's disease also increases the risk. Other risk factors that are not as well proven include: longstanding high blood pressure; history of head trauma; and female gender.

There are two types of Alzheimer’s disease: early onset and late onset. In early onset Alzheimer’s disease, symptoms first appear before age 60. Early onset is much less common than late onset; however, it tends to progress rapidly. Early onset disease can run in families. Several genes have been identified. Late onset Alzheimer’s disease, the most common form of the disease, develops in individuals age 60 and older. The late onset form may run in some families; however, the role of genes is less clear.

The cause of Alzheimer’s disease is not entirely known; however, it is thought to include both genetic and environmental factors. A diagnosis of Alzheimer’s disease is made when certain symptoms are present, and by making sure other causes of dementia are not present.

Reference: Journal of Alzheimer’s Disease

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