MONDAY, July 13, 2009 (HealthDay News) -- Older adults with no history of dementia could cut their odds of Alzheimer's and other cognitive decline by regular moderate drinking, new research suggests.
Defining "moderate" as having one to two drinks a day, the study authors observed that drinking in this range was associated with a nearly 40 percent drop in dementia risk, compared with non-drinkers.
However, those with a history of even moderate brain health issues did not appear to benefit from any amount of alcohol consumption, and appeared to face a significantly greater risk for dementia in the face of a heavy drinking habit.
"We found that for cognitively normal older adults, the lowest risk of dementia was for those who drank an average of one to two alcoholic drinks per day," said study author Dr. Kaycee M. Sink, an assistant professor of medicine with the department of internal medicine in the Gerontology and Geriatric Medicine section at Wake Forest University School of Medicine in Winston-Salem, N.C. "However, for older adults who started the study with mild cognitive impairment, alcohol use was not protective."
Sink and her colleagues were slated to present their findings Monday at the Alzheimer's Association annual meeting, in Vienna.
The findings are based on work with 3,069 dementia-free adults over the age of 75 who were living in their community.
Nearly all were white, and all underwent initial testing to identify those who already had a mild form of cognitive impairment. Over the six-year study, participants also reported their drinking behavior, and were divided into abstinent, light (one to seven drinks a week), moderate (eight to 14 drinks a week), and heavy (more than 14 drinks a week) alcohol-consumption groups.
Sink and her team found that 482 of the participants had mild cognitive impairment when the study launched, and by the end of the study 523 new cases of dementia were diagnosed.
After accounting for other illnesses, depression, activity levels and cognitive health, the authors concluded that moderate alcohol intake conferred a 37 percent drop in the risk for dementia for those whose cognitive health was normal when the study began.
"Based on this study, we cannot recommend that older adults who don't drink start drinking alcohol," Sink cautioned. "But it is reasonable to say that if you are already a light to moderate drinker, you may be at a lower risk of developing Alzheimer's disease or other dementias. However, if you already have memory or thinking problems, drinking alcohol may accelerate memory decline."
Dr. Laurel Coleman, a geriatric physician at Maine Medical Center in Portland, said the findings were "in line with what I would expect."
"It's very believable because it's very consistent with other studies around this issue and heart disease prevention work," she noted. "And moderate alcohol use has been shown to be protective against heart disease, so it makes sense to me that it might also be protective for brain health."
Greg M. Cole, associate director of the Alzheimer's Disease Research Center at the UCLA David Geffen School of Medicine in Los Angeles, agreed.
He noted that while the apparent protective effect of moderate alcohol consumption seemed surprisingly high, "the fact that you would see a related risk reduction is not so surprising."
Cole added, "Alzheimer's has a strong overlap with cardiovascular disease. And you have had a number of studies that have associated reduced cardiovascular disease risk with a rise in HDL levels -- so-called 'good' cholesterol' -- that can come with consuming small amounts of alcohol. And it has been thought that this could potentially impact in a positive way on the risk for vascular dementia and Alzheimer's. So there is a solid rationale for this finding."
The Alzheimer's-cardiovascular health connection are, in fact, the subject of another study also being presented at the meeting.
In this case, a team from the University of Connecticut found that nearly two-thirds of 690 adults polled incorrectly thought there is no association between Alzheimer's and either obesity or high blood pressure, two significant risk factors for heart health complications. In light of this and other misconceptions highlighted by the survey, the study authors called for a stronger effort to promote improved "dementia literacy."
In addition, a third study at the meeting reveals that having post-traumatic stress disorder (PTSD) increased the risk of developing dementia.
The University of California San Francisco researchers came to this conclusion after examining records from 2001 through 2007 provided by the U.S. Department of Veterans Affairs National Patient Care Database, concerning more than 181,000 U.S. veterans. The upshot: during the seven-year study, those with PTSD went on to develop dementia at a rate of nearly 11 percent, while those with no history of PTSD developed dementia at a rate of nearly 7 percent.
More information
For more on Alzheimer's disease risk factors, visit the Alzheimer's Association.
