Dietary Flavanols Reverse Age-Related Memory Decline

NEW YORK, NY, October 31, 2014 /3BL Media/ - Dietary cocoa flavanols—naturally occurring bioactives found in cocoa—reversed age-related memory decline in healthy older adults, according to a study led by Columbia University Medical Center (CUMC) scientists. The study, published today in the advance online issue of Nature Neuroscience, provides the first direct evidence that one component of age-related memory decline in humans is caused by changes in a specific region of the brain and that this form of memory decline can be improved by a dietary intervention.

As people age, they typically show some decline in cognitive abilities, including learning and remembering such things as the names of new acquaintances or where one parked the car or placed one’s keys. This normal age-related memory decline starts in early adulthood but usually does not have any noticeable impact on quality of life until people reach their fifties or sixties. Age-related memory decline is different from the often-devastating memory impairment that occurs with Alzheimer’s, in which a disease process damages and destroys neurons in various parts of the brain, including the memory circuits.

Previous work, including by the laboratory of senior author  Scott A. Small, MD, had shown that changes in a specific part of the brain—the dentate gyrus—are associated with age-related memory decline. Until now, however, the evidence in humans showed only a correlational link, not a causal one. To see if the dentate gyrus is the source of age-related memory decline in humans, Dr. Small and his colleagues tested whether compounds called cocoa flavanols can improve the function of this brain region and improve memory. Flavanols extracted from cocoa beans had previously been found to improve neuronal connections in the dentate gyrus of mice.

Dr. Small is the Boris and Rose Katz Professor of Neurology (in the Taub Institute for Research on Alzheimer’s Disease and the Ageing Brain, the Sergievsky Center, and the Departments of Radiology and Psychiatry) and director of the Alzheimer’s Disease Research Center in the Taub Institute at CUMC.

A cocoa flavanol-containing test drink prepared specifically for research purposes was produced by the food company Mars, Incorporated, which also partly supported the research, using a proprietary process to extract flavanols from cocoa beans. Most methods of processing cocoa remove many of the flavanols found in the raw plant.

In the CUMC study, 37 healthy volunteers, ages 50 to 69, were randomized to receive either a high-flavanol diet (900 mg of flavanols a day) or a low-flavanol diet (10 mg of flavanols a day) for three months. Brain imaging and memory tests were administered to each participant before and after the study. The brain imaging measured blood volume in the dentate gyrus, a measure of metabolism, and the memory test involved a 20-minute pattern-recognition exercise designed to evaluate a type of memory controlled by the dentate gyrus.

“When we imaged our research subjects’ brains, we found noticeable improvements in the function of the dentate gyrus in those who consumed the high-cocoa-flavanol drink,” said lead author Adam M. Brickman, PhD, associate professor of neuropsychology at the Taub Institute.

The high-flavanol group also performed significantly better on the memory test. “If a participant had the memory of a typical 60-year-old at the beginning of the study, after three months that person on average had the memory of a typical 30- or 40-year-old,” said Dr. Small. He cautioned, however, that the findings need to be replicated in a larger study—which he and his team plan to do.

Flavanols are also found naturally in tea leaves and in certain fruits and vegetables, but the overall amounts, as well as the specific forms and mixtures, vary widely.

The precise formulation used in the CUMC study has also been shown to improve cardiovascular health. Brigham and Women’s Hospital in Boston recently announced an NIH-funded study of 18,000 men and women to see whether flavanols can help prevent heart attacks and strokes.

The researchers point out that the product used in the study is not the same as chocolate, and they caution against an increase in chocolate consumption in an attempt to gain this effect.

Two innovations by the investigators made the study possible. One was a new information- processing tool that allows the imaging data to be presented in a single, three-dimensional snapshot, rather than in numerous individual slices. The tool was developed in Dr. Small’s lab by Usman A. Khan, an MD-PhD student in the lab, and Frank A. Provenzano, a biomedical engineering graduate student at Columbia. The other innovation was a modification to a classic neuropsychological test, allowing the researchers to evaluate memory function specifically localized to the dentate gyrus. The revised test was developed by Drs. Brickman and Small.

Besides flavanols, exercise has been shown in previous studies, including those of Dr. Small, to improve memory and dentate gyrus function in younger people. In the current study, the researchers were unable to assess whether exercise had an effect on memory or on dentate gyrus activity. “Since we didn’t reach the intended VO2max (maximal oxygen uptake) target,” said Dr. Small, “we couldn’t evaluate whether exercise was beneficial in this context. This is not to say that exercise is not beneficial for cognition. It may be that older people need more intense exercise to reach VO2max levels that have therapeutic effects.”

The dentate gyrus is distinct from the entorhinal cortex, the hippocampal region affected in early-stage Alzheimer’s disease. Previous work, including by the laboratory of senior author  Scott A. Small, MD, had shown that changes in a specific part of the brain’s hippocampus—the dentate gyrus—are associated with normal age-related memory decline in humans and other mammals. Credit: Lab of Scott A. Small, MD

The article is titled, “Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults,” The other contributors are: Lok-Kin Yeung (CUMC), Wendy Suzuki (New York University, New York, NYU), Hagen Schroeter (Mars, Incorporated, McLean VA), Melanie Wall (CUMC and New York State Psychiatric Institute, New York NY), and Richard Sloan (CUMC and New York State Psychiatric Institute).

The study was supported by grants from the National Institutes of Health (AG034618 and AG035015), the James S. McDonnell Foundation, the McKnight Brain Research Foundation, and Mars, Incorporated.

Hagen Schroeter is employed by Mars, Incorporated, a company with long-term research and commercial interests in cocoa flavanols and procyanidins. The other authors declare no financial or other conflicts of interest.

The Taub Institute for Research on Alzheimer’s Disease and the Ageing Brain at Columbia University Medical Center is a multidisciplinary group that has forged links between researchers and clinicians to uncover the causes of Alzheimer’s, Parkinson’s, and other age-related brain diseases and to discover ways to prevent and cure these diseases. It has partnered with the Gertrude H. Sergievsky Center at Columbia University Medical Center, which was established by an endowment in 1977 to focus on diseases of the nervous system, and with the Departments of Pathology & Cell Biology and of Neurology to allow the seamless integration of genetic analysis, molecular and cellular studies, and clinical investigation to explore all phases of diseases of the nervous system. For more information, visit The Taub Institute at http://www.cumc.columbia.edu/dept/taub/.

Columbia University Department of Psychiatry & NYS Psychiatric Institute Columbia Psychiatry is ranked among the best departments and psychiatric research facilities in the nation and has contributed greatly to the understanding and treatment of psychiatric disorders. It is home to distinguished clinicians and researchers noted for their clinical and research advances in the diagnosis and treatment of depression, suicide, schizophrenia, bipolar and anxiety disorders, eating disorders, and childhood psychiatric disorders. Visit http://columbiapsychiatry.org/ for more information.

Columbia University Medical Center provides international leadership in basic, preclinical, and clinical research; medical and health sciences education; and patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Columbia University Medical Center is home to the largest medical research enterprise in New York City and State and one of the largest faculty medical practices in the Northeast. For more information, visit cumc.columbia.edu or columbiadoctors.org.

About Mars, Incorporated

In 1911, Frank C. Mars made the first Mars candies in his Tacoma, Washington kitchen and established Mars’ first roots as a confectionery company. In the 1920s, Forrest E. Mars, Sr. joined his father in business and together they launched the MILKY WAY® bar. In 1932, Forrest, Sr. moved to the United Kingdom with a dream of building a business based on the objective of creating a “mutuality of benefits for all stakeholders” – this objective serves as the foundation of Mars, Incorporated today. Based in McLean, Virginia, Mars has net sales of more than $33 billion, six business segments including Petcare, Chocolate, Wrigley, Food, Drinks, Symbioscience, and more than 75,000 Associates worldwide that are putting its Principles into action to make a difference for people and the planet through its performance.

Mars brands include: Petcare – PEDIGREE®, ROYAL CANIN®, WHISKAS®, BANFIELD® Pet Hospital, CESAR®, SHEBA®, DREAMIES® and NUTRO®; Chocolate – M&M’S®, SNICKERS®, DOVE®, GALAXY®, MARS®, MILKY WAY® and TWIX®; Wrigley – DOUBLEMINT®, EXTRA®, ORBIT® and 5™ chewing gums, SKITTLES® and STARBURST® candies, and ALTOIDS® AND LIFESAVERS® mints. Food – UNCLE BEN’S®, DOLMIO®, EBLY®, MASTERFOODS®, SEEDS OF CHANGE® and ROYCO®; Drinks – ALTERRA COFFEE ROASTERS™, THE BRIGHT TEA COMPANY™, KLIX® and FLAVIA®; Symbioscience – COCOAVIA® and WISDOM PANEL®.

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