Coffee helps prevent progression to dementia

July, 2012

A 4-year study of older adults has found that low levels of caffeine were linked to MCI progressing to dementia, apparently by mediating lower levels of anti-inflammatory proteins.

Following on from mouse studies, a human study has investigated whether caffeine can help prevent older adults with mild cognitive impairment from progressing to dementia.

The study involved 124 older adults (65-88) who were thoroughly cognitively assessed, given brain scans, and had a fasting blood sample taken. They were then followed for 2 to 4 years, during which their cognitive status was re-assessed annually. Of the 124 participants, 69 (56%) were initially assessed as cognitively normal (average age 73), 32 (26%) with MCI (average age 76.5), and 23 (19%) with dementia (average age 77). The age differences were significant.

Those with MCI on initial assessment showed significantly lower levels of caffeine in their blood than those cognitively healthy; levels in those with dementia were also lower but not significantly. Those initially healthy who developed MCI over the study period similarly showed lower caffeine levels than those who didn’t develop MCI, but again, due to the wide individual variability (and the relatively small sample size), this wasn’t significant. However, among those with MCI who progressed to dementia (11, i.e. a third of those with MCI), caffeine levels were so much lower that the results were significant.

This finding revealed an apparently critical level of caffeine dividing those who progressed to dementia and those who did not — more specifically, all of those who progressed to dementia were below this level, while around half of those who remained stable were at the level or above. In other words, low caffeine would seem to be necessary but not sufficient.

On the other hand (just to show that this association is not as simple as it appears), those already with dementia had higher caffeine levels than those with MCI who progressed to dementia.

The critical factor may have to do with three specific cytokines — GCSF, IL-10, and IL-6 — which all showed markedly lower levels in those converting from MCI to dementia. Comparison of the three stable-MCI individuals with the highest caffeine levels and the three with the lowest levels, and the three from the MCI-to-dementia group with comparable low levels, revealed that high levels of those cytokines were matched with high caffeine levels, while, in both groups, low caffeine levels were matched to low levels of those cytokines.

These cytokines are associated with inflammation — an established factor in cognitive decline and dementia.

The level of coffee needed to achieve the ‘magic’ caffeine level is estimated at around 3 cups a day. While caffeine can be found in other sources, it is thought that in this study, as in the mouse studies, coffee is the main source. Moreover, mouse research suggests that caffeine is interacting with an as yet unidentified component of coffee to boost levels of these cytokines.

This research has indicated that caffeine has several beneficial effects on the brain, including suppressing levels of enzymes that produce amyloid-beta, as well as these anti-inflammatory effects.

It’s suggested that the reason high levels of caffeine don’t appear to benefit those with dementia is because higher levels of these cytokines have become re-established, but this immune response would appear to come too late to protect the brain. This is consistent with other evidence of the importance of timing.

Do note that in mouse studies, the same benefits were not associated with decaffeinated coffee.

While this study has some limitations, the findings are consistent with previous epidemiologic studies indicating coffee/caffeine helps protect against cognitive impairment and dementia. Additionally, in keeping with the apparent anti-inflammatory action, a long-term study tracking the health and coffee consumption of more than 400,000 older adults recently found that coffee drinkers had reduced risk of dying from heart disease, lung disease, pneumonia, stroke, diabetes, infections, injuries and accidents.

Reference: 

Cao, C., Loewenstein, D. a, Lin, X., Zhang, C., Wang, L., Duara, R., Wu, Y., et al. (2012). High Blood Caffeine Levels in MCI Linked to Lack of Progression to Dementia. Journal of Alzheimer’s disease : JAD, 30(3), 559–72. doi:10.3233/JAD-2012-111781

Freedman, N.D. et al. 2012. Association of Coffee Drinking with Total and Cause-Specific Mortality. N Engl J Med, 366, 1891-1904.

Related News

Data from more than 17,000 healthy people aged 50 and over has revealed that the more regularly participants engaged with word puzzles, the better they performed on tasks assessing attention, reasoning and memory.

Unplanned hospitalizations accelerate cognitive decline in older adults

Data from the Rush Memory and Aging Project has found that emergency and urgent hospitalizations are associated with an increased rate of cognitive decline in older adults.

A Finnish study involving 338 older adults (average age 66) has found that greater muscle strength is associated with better cognitive function.

Data from over 11,500 participants in the Atherosclerosis Risk in Communities (ARIC) cohort has found evidence that orthostatic hypotension in middle age may increase the risk of cognitive impairment and dementia 20 years later.

A review of 39 studies investigating the effect of exercise on cognition in older adults (50+) confirms that physical exercise does indeed improve cognitive function in the over 50s, regardless of their cognitive status.

A Canadian study involving 40 older adults (59-81), none of whom were aware of any major memory problems, has found that those scoring below 26 on the Montreal Cognitive Assessment (MoCA) dementia screening test also showed shrinking of the anterolateral

A study involving 35 adults with

In Australia, it has beens estimated that 9% of people aged over 65, and 30% of those aged over 85 have dementia. However, these estimates are largely based on older data from other countries, or small local samples.

In the past few months, several studies have come out showing the value of three different tests of people's sense of smell for improving the accuracy of

A study comparing the language abilities of 22 healthy young individuals, 24 healthy older individuals and 22 people with

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health news