Eating more berries may reduce cognitive decline in the elderly

Blueberries and strawberries, which are high in flavonoids, appear to reduce cognitive decline in older adults according to a new study published today in Annals of Neurology, a journal of the American Neurological Association and Child Neurology Society. The study results suggest that cognitive aging could be delayed by up to 2.5 years in elderly who consume greater amounts of the flavonoid-rich berries.

27 april 2012--Flavonoids are compounds found in plants that generally have powerful antioxidant and anti-inflammatory properties. Experts believe that stress and inflammation contribute to cognitive impairment and that increasing consumption of flavonoids could mitigate the harmful effects. Previous studies of the positive effects of flavonoids, particularly anthocyanidins, are limited to animal models or very small trials in older persons, but have shown greater consumption of foods with these compounds improve cognitive function.
According to the 2010 U.S. Census, elderly Americans—those 65 years of age and older—increased by 15% between 2000 and 2010, faster than the total U.S. population, which saw a 9.7% increase during the same time period. "As the U.S. population ages, understanding the health issues facing this group becomes increasingly important," said Dr. Elizabeth Devore with Brigham and Women's Hospital and Harvard Medical School in Boston, Mass. "Our study examined whether greater intake of berries could slow rates of cognitive decline."
The research team used data from the Nurses' Health Study—a cohort of 121,700 female, registered nurses between the ages of 30 and 55 who completed health and lifestyle questionnaires beginning in 1976. Since 1980 participants were surveyed every four years regarding their frequency of food consumption. Between 1995 and 2001, cognitive function was measured in 16,010 subjects over the age of 70 years, at 2-year intervals. Women included in the present study had a mean age of 74 and mean body mass index of 26.
Findings show that increased consumption of blueberries and strawberries appear to slow cognitive decline in older women. A greater intake of anthocyanidins and total flavonoids was also associated with reduce cognitive degeneration. Researchers observed that women who had higher berry intake delayed cognitive aging by up to 2.5 years. The authors caution that while they did control for other health factors in the modeling, they cannot rule out the possibility that the preserved cognition in those who eat more berries may be also influenced by other lifestyle choices, such as exercising more.
"We provide the first epidemiologic evidence that berries may slow progression of cognitive decline in elderly women," notes Dr. Devore. "Our findings have significant public health implications as increasing berry intake is a fairly simple dietary modification to test cognition protection in older adults."

More information: "Dietary Intake of Berries and Flavonoids in Relation to Cognitive Decline." Elizabeth E. Devore, Jae Hee Kang, Monique M.B. Breteler and Francine Grodstein. Annals of Neurology; Published Online: April 26, 2012 (DOI:10.1002/ana.23594).
Provided by Wiley

Blood Sugar Control Linked to Memory Decline, Study Says

By RONI CARYN RABIN
06 jan 2009--Spikes in blood sugar can take a toll on memory by affecting the dentate gyrus, an area of the brain within the hippocampus that helps form memories, a new study reports.

Researchers said the effects can be seen even when levels of blood sugar, or glucose, are only moderately elevated, a finding that may help explain normal age-related cognitive decline, since glucose regulation worsens with age.

The study, by researchers at Columbia University Medical Center and funded in part by the National Institute on Aging, was published in the December issue of Annals of Neurology.

“If we conclude this is underlying normal age-related cognitive decline, then it affects all of us,” said lead investigator Dr. Scott Small, associate professor of neurology at Columbia University Medical Center. The ability to regulate glucose starts deteriorating by the third or fourth decade of life, he added.

Since glucose regulation is improved with physical activity, Dr. Small said, “We have a behavioral recommendation — physical exercise.”

In the study, researchers used high-resolution functional magnetic resonance imaging to map brain regions in 240 elderly subjects. They found a correlation between elevated blood glucose levels and reduced cerebral blood volume, or blood flow, in the dentate gyrus, an indication of reduced metabolic activity and function in that region of the brain.

By manipulating blood sugar levels in mice and monkeys, researchers said, they tried to confirm a cause-and-effect relationship between the glucose spikes and the reduced blood volume, Dr. Small said.

Bruce S. McEwen, who heads the neuroendocrinology lab at Rockefeller University in New York and was not involved in the research, said the study’s findings were “compelling,” with important implications not just for the elderly but for the growing number of overweight children and teens at risk of Type 2 diabetes.

“When we think about diabetes, we think about heart disease and all the consequences for the rest of the body, but we usually don’t think about the brain,” he said. “This is something we’ve got to be really worried about. We need to think about their ultimate risks not only for cardiovascular disease and metabolic disorders, but also about their cognitive skills, and whether they will be able to keep up with the demands of education and a fast-paced complex society. That’s the part that scares the heck out of me.”

Previous observational studies have shown that physical activity reduces the risk of cognitive decline, and studies have also found that diabetes increases the risk of dementia. Earlier studies had also found a link between Type 2 diabetes and dysfunction in the dentate gyrus.

Sheri Colberg-Ochs, an associate professor of exercise science at Old Dominion University in Norfolk, Va., said her research has found that regular exercise, even light physical activity, can offset the potentially negative effects of Type 2 diabetes on cognitive function. It is not clear what the mechanism is, she said, but may have something to do with the effect of insulin.

“This new study is interesting in that it allows for a greater understanding of which region of the hippocampus is likely most affected by poorly controlled diabetes,” she said.

But the elevations in blood glucose seen in the new study are more subtle and would not be considered a disease state, Dr. Small said.

“It’s part of the normal process of aging, much like wrinkling of skin,” he said. “It happens to all of us inexorably, and it worsens progressively across the life span.”