June 4, 2012 Tampa , FL (June 4, 2012) Those cups of coffee that
you drink every day to keep alert appear to have an extra perk – especially if
you're an older adult. A recent study monitoring the memory and thinking
processes of people older than 65 found that all those with higher blood
caffeine levels avoided the onset of Alzheimer's disease in the two-to-four
years of study follow-up. Moreover, coffee appeared to be the major or only
source of caffeine for these individuals.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 will appear in the
online version of an article to be published June 5
in the Journal of Alzheimer's Disease, published by IOS Press
(http://health.usf.edu/nocms/publicaffairs/now/pdfs/JAD111781.pdf). 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."The study shows this
protection probably occurs even in older people with early signs of the
disease, called mild cognitive impairment, or MCI. Patients with MCI already
experience some short-term memory loss and initial Alzheimer's pathology in
their brains. Each year, about 15 percent of MCI patients progress to
full-blown Alzheimer's disease. The researchers focused on study participants
with MCI, because many were destined to develop Alzheimer's within a few
years.Blood caffeine levels at the study's onset were substantially lower (51
percent less) in participants diagnosed with MCI who progressed to dementia
during the two-to-four year follow-up than in those whose mild cognitive
impairment remained stable over the same period.No one with MCI who later
developed Alzheimer's had initial blood caffeine levels above a critical level
of 1200 ng/ml – equivalent to drinking several cups of coffee a few hours before
the blood sample was drawn. In contrast, many with stable MCI had blood
caffeine levels higher than this critical level."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.The researchers
believe higher blood caffeine levels indicate habitually higher caffeine
intake, most probably through coffee. Caffeinated coffee appeared to be the
main, if not exclusive, source of caffeine in the memory-protected MCI
patients, because they had the same profile of blood immune markers as
Alzheimer's mice given caffeinated coffee. Alzheimer's mice given caffeine
alone or decaffeinated coffee had a very different immune marker profile.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."We are not saying that
moderate coffee consumption will completely protect people from Alzheimer's
disease," Dr. Cao cautioned. "However, we firmly believe that
moderate coffee consumption can appreciably reduce your risk of Alzheimer's or
delay its onset."Alzheimer's pathology is a process in which plaques and
tangles accumulate in the brain, killing nerve cells, destroying neural
connections, and ultimately leading to progressive and irreversible memory
loss. Since the neurodegenerative disease starts one or two decades before
cognitive decline becomes apparent, the study authors point out, any
intervention to cut the risk of Alzheimer's should ideally begin that far in
advance of symptoms."Moderate daily consumption of caffeinated coffee
appears to be the best dietary option for long-term protection against
Alzheimer's memory loss," Dr. Arendash said. "Coffee is inexpensive,
readily available, easily gets into the brain, and has few side-effects for
most of us. Moreover, our studies show that caffeine and coffee appear to
directly attack the Alzheimer's disease process."In addition to
Alzheimer's disease, moderate caffeine/coffee intake appears to reduce the risk
of several other diseases of aging, including Parkinson's disease, stroke, Type
II diabetes, and breast cancer. However, supporting studies for these benefits
have all been observational (uncontrolled), and controlled clinical trials are
needed to definitively demonstrate therapeutic value.A study tracking the
health and coffee consumption of more than 400,000 older adults for 13 years,
and published earlier this year in the New England Journal of Medicine, found
that coffee drinkers reduced their risk of dying from heart disease, lung
disease, pneumonia, stroke, diabetes, infections, and even injuries and
accidents.With new Alzheimer's diagnostic guidelines encompassing the full
continuum of the disease, approximately 10 million Americans now fall within
one of three developmental stages of Alzheimer's disease -- Alzheimer's disease
brain pathology only, MCI, or diagnosed Alzheimer's disease. That number is
expected to climb even higher as the baby-boomer generation continues to enter
older age, unless an effective and proven preventive measure is identified.
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