A polyphenol found in green tea improves brain function in people with Down syndrome. The year-long Spanish study found that epigallocatechin gallate (EGCG), improved scores on memory and behavior tests.

Brain scans showed that the compound changed the way neurons in the brain connect with one another.

For the trial, young adults with Down syndrome were divided into two groups. One group was given a green tea supplement containing 45 percent EGCG as well as weekly online cognitive training. The second group participated in the same training, but took a placebo instead of the green tea compound.

While functioning in many categories didn't change, there was significant improvement in the green tea group in several categories, such as verbal recall and the ability to remember patterns. As the study continued during the course of a year, their scores continued to improve and their progress remained six months after the end of the study. The compound also improved their quality of life.

"This is the first time that a treatment has shown efficacy in the cognitive improvement of persons with this syndrome," said Mara Dierssen, senior author of the study and a researcher at the Centre for Genomic Regulation in Barcelona.

Normally, each cell contains 23 pairs of chromosomes. Down syndrome is caused by a full or partial extra copy of chromosome 21. According to the National Down Syndrome Society, about 400,000 Americans have Down syndrome, and it is the most common genetic condition.

Children with Down have an upward slant to their eyes and a slightly flattened facial profile combined with mild to moderate intellectual ability. 

EGCG  is the active component in green tea, and studies have shown it to possess anticancer properties as well as properties that help promote heart health and weight loss.

The study was published in The Lancet Neurology.