INDIVIDUALS with Down’s syndrome have for the first time experienced an improvement in cognitive function as the result of receiving daily doses of green tea for a year, according to new research.
The researchers aimed to determine whether epigallocatechin gallate (EGCG), a compound present in green tea, would improve cognition in those diagnosed with the condition. Eighty-four people with Down’s syndrome aged between 16 and 34 years old participated in a randomised double-blind study and were given either decaffeinated green tea containing 9 mg/kg of EGCG or a placebo, each day for 12 months. Cognitive tests and brain imaging were used at different stages of the study and at a 6 month follow-up to measure the effects.
The results showed that when compared to the placebo group, participants receiving the EGCG compound exhibited significant improvements in certain areas of cognitive function. These areas were visual recognition memory, inhibitory control, and adaptive behaviour. Brain scans also revealed that when compared to those receiving the placebo, EGCG treatment had resulted in greater functional connectivity between nerve cells.
“It was surprising to see how the changes are not just cognitive, in the reasoning, learning, memory, and attention capacities, but suggest that the functional connectivity of the neurons in the brain was also modified,” commented study co-leader Dr Rafael de la Torre, Hospital del Mar Medical Research Institute, Barcelona, Spain.
Results of previous studies have indicated that the EGCG compound could reduce the overexpression of the DYRK1A gene in mice, the same gene that is believed to cause Down’s syndrome when overexpressed. The research team now believes that the EGCG compound may also be an effective therapeutic approach for people with Down’s syndrome. “This is the first time that a treatment has shown some efficacy in the improvement of some cognitive tasks in persons with this syndrome,” explained co-author of the study, Prof Mara Dierssen, Group Leader of the Genes and Disease Program, Centre for Genomic Regulation (CRG), Barcelona, Spain.
The team recognise that further trials are needed to investigate the efficacy and safety of EGCG in larger populations, however, the results are promising as there has been a clear improvement in the quality of life. Researchers also plan to assess its potential in treating children with Down’s syndrome where the brain is not yet fully developed and could be more responsive to the treatment as a result.