Strawberries Reduce Mental Effects of Aging

A natural compound found in strawberries called fisetin reduces the mental effects of aging, says a study published in the Journals of Gerontology Series A. Researchers found it could help treat age-related mental decline and conditions like Alzheimer’s or stroke.

“Companies have put fisetin into various health products but there hasn’t been enough serious testing of the compound,” says Pamela Maher, a senior staff scientist in Salk’s Cellular Neurobiology Laboratory and senior author of the paper.

“Based on our ongoing work, we think fisetin might be helpful as a preventive for many age-associated neurodegenerative diseases, not just Alzheimer’s,” she said.

Maher has been studying fisetin, which is a type of flavonol that has powerful antioxidant properties, for more than a decade. Previous research found that it reduced memory loss related to Alzheimer’s disease (AD) in mice genetically modified to develop the disease.

When the scientists studied mice with Alzheimer’s, they found that the pathways involved in cellular inflammation were turned on. However, when the mice were given fisetin, they began producing anti-inflammatory molecules, and both memory loss and learning impairments were prevented. That particular research focused on genetic AD, which accounts for only 1 to 3 percent of cases.

For the recent study, Maher used a strain of laboratory mice that age prematurely and show signs of the disease at about 10 months in comparison to signs of physical and mental decline not seen in normal mice until two years of age.

The researchers fed the 3-month-old prematurely aging mice a daily dose of fisetin with their food for 7 months. Another group of the prematurely aging mice was fed the same food without fisetin.

During the study period, mice took various activity and memory tests. The team also examined levels of specific proteins related to brain function, as well as stress and inflammation.

“At 10 months, the differences between these two groups were striking,” says Maher, who hopes to conduct human trials. Mice not treated with fisetin had difficulties with all the cognitive tests as well as elevated markers of stress and inflammation. Brain cells called astrocytes and microglia, which are normally anti-inflammatory, were now driving rampant inflammation.

On the other hand, mice treated with fisetin were not noticeably different in behavior, cognitive ability or inflammatory markers at 10 months than a group of untreated 3-month-old mice with the same condition. In addition, fisetin was found to be safe even at high doses.

Strawberries have also been found to fight esophageal cancer. Chinese researchers gave volunteers freeze-dried strawberries each day for six months. A comparison of before-and-after biopsies showed that precancerous lesions in participants were decreased by 80 percent.