Mild Cognitive Impairment (MCI) is often a precursor diagnosis to dementia, most often of the Alzheimer's neurodegenerative classification, sometimes other types of dementia instead. About 10% (1 in every 10) of those diagnosed with MCI progress to a formal diagnosis of dementia each year... so the longer you have been given that diagnosis, the greater your chance of progressing into a diagnosis of dementia based on further progression of cognitive difficulties.
This study I'm bringing up here was recently published this 2012 summer in the journal Hypertension.
It was a double blind study (the best kind) which means the doctors and the patients involved aren't sure if they're treating/getting treated with the "medication." Only the study designers know.
It is widely believed that polyphenic compounds in plant-based foods, flavanols, are the active health-beneficial ingredients in cocoa, as well as other foods such as grapes and red wine, tea, apples, etc.
90 elderly participants were given various amounts of dietary cocoa flavanols for 2 months, and not only did they produce findings suggestive of significant improvement in thinking on certain cognitive tests, but also found significant benefits on blood pressure and insulin resistance (important for blood sugar management).
In the high dose group, the systolic blood pressure dropped 10 mm Hg and diastolic dropped 4.8 mm Hg (mean).
Glucose fell a mean of 0.6 mmol/L for the highest group.
Keep in mind that this was only two months of study time.... All the medications currently used to treat Mild Cognitive Impairment (MCI) and dementia involve studies lasting much longer than that. So if this study had gone on much longer, we potentially could have seen even greater benefit... or possibly no cognitive benefit in the long run too-- that possibility needs to be considered as well.
But it was a great short-term study showing potential health benefits proclaimed informally by cocoa-drinkers the world over. And it's potentially one of the more enjoyable "treatments" around.
Below is a longer report about the study's findings if you would like to read that as well:
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Hot
Cocoa May Boost Seniors' Brain Power
·
This double blind
study tested the hypothesis that dietary flavanols might improve cognitive
function in elderly subjects with mild cognitive impairment (MCI).
·
Note that elderly
patients with MCI who consumed high or moderate levels of cocoa flavanols for 2
months had significant improvements on certain cognitive assessment tests, as
well as decreases in insulin resistance and blood pressure, compared with those
who took in only small amounts.
Cocoa flavanols have shown some benefits for
the heart, but they may also be good for cognitive function in older people,
researchers found.
In a double-blind study, elderly patients with
mild cognitive impairment who consumed high or moderate levels of cocoa
flavanols for 2 months had significant improvements on certain cognitive
assessment tests compared with those who took in only small amounts,
Giovambattista Desideri, PhD, of the University of L'Aquila in Italy, and
colleagues reported online in Hypertension.
"Although additional confirmatory studies
are warranted, the findings...suggest that the regular dietary inclusion of
flavanols could be one element of a dietary approach to the maintaining and
improving not only cardiovascular health but also specifically brain
health," they wrote.
Evidence suggests eating flavonoids,
polyphenic compounds from plant-based foods, may confer cardiovascular benefits. Flavonols are a subclass of these
compounds that are abundant in tea, grapes, red wine, apples, and cocoa
products including chocolate.
So to assess whether cocoa flavanols could
improve cognitive function in elderly patients with mild cognitive impairment
(MCI), Desideri and colleagues assessed 90 elderly patients with MCI who were
randomized to drink varying levels of a dairy-based cocoa containing flavanols
per day for 8 weeks: 990 mg (high), 520 mg (intermediate), or 45 mg (low).
The researchers found that scores on the Mini
Mental State Examination didn't change significantly in any of the groups ( P=0.13), a finding that was likely due to the
low sensitivity of the test to detect small changes at the upper end of
cognitive performance over time, they wrote.
There were, however, changes in the time
required to complete Trail Making Tests A and B, with significantly greater
improvements for those on high or intermediate doses of flavonols compared with
those who had a low intake (P<0.05):
·
High: -14.3 seconds
for A, -29.2 seconds for B
·
Intermediate: -8.8
seconds for A, -22.8 seconds for B
·
Low: +1.1 second for
A, +3.8 seconds for B
Scores on the verbal fluency test improved
significantly for all groups, but, improvements were significantly greater for
those who had a high versus low intake (P<0.05):
·
High: +8.0 words per
60 seconds
·
Intermediate: +5.1
words per 60 seconds
·
Low: +1.2 words per 60
seconds
Also, the composite cognitive z-score
significantly changed over the study period for the high and intermediate
intake groups (P<0.0001), but did
not change for those with the lowest intake, they reported.
Desideri and colleagues also observed improvements
in several metabolic parameters, including blood pressure and insulin
resistance, for those on high and intermediate doses of cocoa flavanols.
For blood pressure, the high flavanol group
saw mean reductions of 10 mm Hg for systolic and 4.8 mm Hg for diastolic (P<0.0001) while the intermediate group saw a
mean drop of 8.2 mm Hg for systolic and 3.4 mm Hg for diastolic pressures.
There were no significant changes for those taking a low dose of flavanols.
Plasma glucose fell a mean 0.6 mmol/L for those
in the highest group and by 0.5 mmol/L for those on the mid-level dose (P<0.0001) with no differences for low
intake, and both the high and intermediate groups also had significant
reductions in homeostasis model assessment–insulin resistance (HOMA-IR) scores
(-1.7 and -0.9 points, respectively).
Changes in HOMA-IR were found to be the main
determinant of changes in cognitive function, explaining about 40% of composite
z-score variability through the study period, the researchers reported (P<0.0001).
Thus the effect on cognition appears to be
mediated in part by improvement in insulin sensitivity, the researchers wrote.
They noted that there were no changes in
cholesterol or triglycerides in any of the groups.
The study was limited because its short time-frame
didn't allow for conclusions about the extent of cognitive benefits and their
duration. Nor can it establish whether the observed benefits are a consequence
of the cocoa itself or a secondary effect related to general improvements in
cardiovascular function or health. Also, participants were in good health
overall and without known cardiovascular disease, so the population may be
representative of all subjects with MCI.
Still, the researchers concluded that the data
"are suggestive of a possible clinical benefit derived from the regular
dietary inclusion of cocoa flavanol-containing foods in subjects with
MCI."
Primary source: Hypertension
Source reference:
Desideri G, et al "Benefits in cognitive function, blood pressure, and insulin resistance through cocoa flavanol consumption in elderly subjects with mild cognitive impairment" Hypertension 2012.
Source reference:
Desideri G, et al "Benefits in cognitive function, blood pressure, and insulin resistance through cocoa flavanol consumption in elderly subjects with mild cognitive impairment" Hypertension 2012.
