It’s an urban legend truism that “drinking alcohol kills brain cells.” According to expert scientists, not so much, although heavy alcohol consumption can damage dendrites — the ends of neurons. Alcoholics can also develop a neurological disorder called Wernicke-Korsakoff syndrome, that can result in a loss of neurons in some parts of the brain, causing memory problems, confusion, paralysis of the eyes, lack of muscle coordination and amnesia, and even lead to death, but it’s actually caused by a deficiency of the essential B vitamin. thiamine, which extreme alcohol consumption can block the body’s absorption.
However, a team of researchers from the University of Texas Medical Branch at Galveston, The University of Kentucky, and The University of Maryland found that for people 60 and older who do not have dementia, light alcohol consumption during late life is associated with higher episodic memory — the ability to recall memories of events.
The researchers report that moderate alcohol consumption was also linked with a larger volume in the hippocampus, a brain region critical for episodic memory. The relationship between light alcohol consumption and episodic memory goes away if hippocampal volume is factored in, providing new evidence that hippocampal functioning is the critical factor in these improvements.
The findings are published in the American Journal of Alzheimer’s Disease and Other Dementias, “Effects of Alcohol Consumption on Cognition and Regional Brain Volumes Among Older Adults” (Published online before print September 7, 2014, doi: 10.1177/1533317514549411), coauthored by Brian Downer, PhD of the University of Texas Medical Branch, Sealy Center on Aging, Galveston; Yang Jiang, PhD, of the University of Kentucky, Department of Behavioral Science, Lexington, KY; Faika Zanjani, PhD of the University of Maryland, SPHL-Behavioral & Community Health, College Park, MD; and David Fardo, PhD of the University of Kentucky, Department of Biostatistics, Lexington, KY.
The researchers note that their study utilized data from more than 660 patients in the Framingham Heart Study Offspring Cohort to examine the relationship between midlife and late-life alcohol consumption, cognitive functioning, and regional brain volumes among older adults without dementia or a history of abusing alcohol. These patients completed surveys on their alcohol consumption and demographics, a battery of neuropsychological assessments, the presence or absence of the genetic Alzheimer’s disease risk factor APOE e4 and MRIs of their brains.
The researchers found that results from multiple linear regression models indicate that late life, but not midlife, alcohol consumption status is associated with episodic memory and hippocampal volume. Amount of alcohol consumption had no impact on executive function or overall mental ability. They found that light and moderate alcohol consumption in older people is associated with higher episodic memory and is linked with larger hippocampal brain volume.
Findings from animal studies suggest that moderate alcohol consumption may contribute to preserved hippocampal volume by promoting generation of new nerve cells in the hippocampus. In addition, exposing the brain to moderate amounts of alcohol may increase the release of brain chemicals involved with cognitive, or information processing, functions.The differences in episodic memory according to late life alcohol consumption status were no longer significant when hippocampal volume was included in the regression model.
The coauthors conclude that the findings from this study provide new evidence that hippocampal volume may contribute to the observed differences in episodic memory among older adults and late life alcohol consumption status.
“There were no significant differences in cognitive functioning and regional brain volumes during late life according to reported midlife alcohol consumption status,” says lead author Brian Downer, UTMB Sealy Center on Aging postdoctoral fellow in a UTNB release. “This may be due to the fact that adults who are able to continue consuming alcohol into old age are healthier, and therefore have higher cognition and larger regional brain volumes, than people who had to decrease their alcohol consumption due to unfavorable health outcomes.”
The researchers conclude that although the potential benefits of light to moderate alcohol consumption to cognitive learning and memory later in life have been consistently reported, extended periods of abusing alcohol, often defined as having five or more alcoholic beverages during a single drinking occasion is indeed known to be harmful to the brain.
University of Texas Medical Branch at Galveston
American Journal of Alzheimer’s Disease and Other Dementias