July 13, 2022
Experts often advise a heart-healthy diet rich in fruits and vegetables for optimal brain health. Now a new study suggests a food you can add to the list: cranberries.
The study, published in Frontiers in Nutrition, looked at 60 healthy adults who ranged in age from 50 to 80. Half were given a freeze-dried cranberry extract, equivalent to eating about a cup of fresh cranberries, daily for 12 weeks. The other half were given a look-alike placebo powder.
They underwent comprehensive tests of thinking and memory skills, before and after the study. The researchers found that those who consumed the cranberry extract showed improvements in visual episodic memory, or the ability to remember everyday events.
They also had increased blood flow in parts of the brain critical for memory consolidation and retrieval, and showed decreases in levels of LDL cholesterol, the “bad” kind that can cause hardening of the arteries.
The lead investigator, David Vauzour, of the University of East Anglia Norwich Medical School in Britain, noted that because there is no known cure for Alzheimer’s disease, “it is crucial that we seek modifiable lifestyle interventions, such as diet, that could help lessen disease risk and burden.”
Cranberries are rich in flavonols (a type of flavonoid) and other plant compounds that are known to have antioxidant and anti-inflammatory effects. These colorful foods are high in naturally occurring antioxidants, which help to neutralize highly reactive oxygen compounds that can damage cells throughout the body, including in the brain. They also have inflammation-fighting effects, and increasingly doctors recognize that inflammation plays a critical role in a growing list of chronic conditions of age, including Alzheimer’s disease.
“Past studies have shown that higher dietary flavonoid intake is associated with slower rates of cognitive decline and dementia,” Dr. Vauzour said. “And foods rich in anthocyanins and proanthocyanidins, which give berries their red, blue or purple color, have been found to improve cognition.” Anthocyanins and proanthocyanidins are two other types of flavonoids and are typically responsible for the red, blue and purple colors of various fruits and vegetables.
The study was supported by a grant from The Cranberry Institute, though the group had no input into the design or results of the study.
Other studies have shown that other kinds of berries, such as blueberries and strawberries, may have “memory-boosting” benefits. Other fruits rich in various types of antioxidants, like pomegranates, have shown similar effects.
Experts say that eating a rich variety of colorful fruits and vegetables, rather than any one food, may have the greatest benefits for brain health, and the body’s health in general. It’s also important to choose fruits and vegetables in their natural forms, rather than in highly processed foods; to benefit fully from their beneficial health properties, fresh fruits will also be preferable to frozen or dried fruits. Studies suggest that as little as a half a serving a day of such foods may lower the risk of cognitive decline by up to 20 percent.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Emma Flanagan, Donnie Cameron, Rashed Sobhan, et al: “Chronic Consumption of Cranberries (Vaccinium macrocarpon) for 12 Weeks Improves Episodic Memory and Regional Brain Perfusion in Healthy Older Adults: A Randomised, Placebo-Controlled, Parallel-Groups Feasibility Study.” Frontiers in Nutrition, May 22, 2022
