DRESDEN, Germany – “An apple a day keeps the doctor away”, especially when it comes to fighting dementia. An international study found that the famous healthy fruit is rich in chemicals that fuel neurons, improving learning and memory.
Experiments on mice found that the gray matter increased after they were injected with phytonutrients, such as flavonoids, which are abundant in fruits and vegetables. The effects were similar to those seen after exercise, which can also increase brain function.
The corresponding author, Professor Gerd Kempermann, from the German Center for Neurodegenerative Diseases, says that these dietary compounds are “vital for maintaining cognitive function”.
“They can have positive effects on different parts of the body – including the brain,” said Kempermann in a statement to SWNS.
How do these substances stimulate the brain?
These antioxidants reduce inflammation and strengthen the immune system. The researchers took stem cells from the brain of laboratory rodents and cultured them in Petri dishes. After adding apple extracts like quercetin or DHBA (dihydroxybenzoic acid), more neurons grew and fewer died.
“High concentrations of phytonutrients in apples stimulate the generation of new neurons – a process called neurogenesis”, explains Kempermann.
The results, published in Stem cell reports, were then confirmed in trials involving real mice. The stem cells multiplied and produced more neurons after scientists added high doses of quercetin or DHBA.
Specifically, this applies to distinct structures in the adult brain, including the hippocampus, which are vital for memory, learning and navigation.
“Apples contain pro-neurogenic compounds in both their skin and their meat,” write the study’s authors in their report.
Quercetin resides in the apple peel. The pigment gives color to the fruit and belongs to the family of flavonoids. DHBA is a natural preservative unrelated to flavonoids. It is responsible for giving the fruit its distinctive aroma. Both chemicals act similarly, however, protecting cells by destroying harmful free radicals.
“‘An apple a day keeps the doctor away.’ There may be some truth to this aphorism, “write the researchers.” In addition to being a source of energy, food is known to influence an individual’s overall fitness. An increasing number of studies have demonstrated the health benefits of phytochemicals, chemicals found in plants. ”
Finding ways to prevent diseases in our food?
These substances include resveratrol in red grapes and EGCG (epigalo-catechin-3-gallate) in green tea. Previous studies have found that they have a link to reduce the risk of diseases like cancer, heart disease and dementia. The researchers believe that quercetin and DHBA act in combination to promote neurogenesis and brain function when consumed in large quantities.
“The effects were comparable to those seen after exercise – a known stimulus for neurogenesis,” Kempermann told SWNS.
When the mice were given apple juice, however, the study authors said there was no benefit to brain health as it contains smaller amounts of the beneficial ingredients. The findings may have implications for protection against Alzheimer’s disease. With no cure in sight for the degenerative condition, there is an increased focus on lifestyle factors that can help stop or delay its onset.
“As mammals evolved with exposure to specific diets, naturally abundant compounds may have become part of the set of environmental codeterminants that shaped the structure and function of the brain,” write the study’s authors.
“Future studies will be needed to determine whether these and other phytonutrients can improve learning and cognitive function in animal models – and in humans,” adds Kempermann.
SWNS writer Mark Waghorn contributed to this report.