Green Tea Compound Significantly Improves Cognitive Function in Fragile X Patients, Study Finds

Treatment with a compound found in green tea leaves significantly improved cognitive function in patients with fragile X syndrome, a study shows.

This new clinical data came from a study of the epigallocatechin-3-gallate (EGCG) compound, a major component of green tea leaves. The study, “A phase 1, randomized double-blind, placebo controlled trial to evaluate safety and efficacy of epigallocatechin-3-gallate and cognitive training in adults with Fragile X syndrome,” was published in the journal Clinical Nutrition.

Fragile X is a common genetic cause of intellectual disability and autism. Despite the wide array of experimental therapeutics that have been tested in clinical trials, none to date have shown effectiveness in improving cognitive and behavioral features of the disease.

Spanish researchers had previously shown that EGCG was associated with a significant improvement in intellectual disability in mouse models, and in patients with Down syndrome.

With mounting evidence that Down syndrome and fragile X share common nervous signaling abnormalities, the team hypothesized that EGCG could mimic those benefits observed in Down syndrome, and help improve cognitive deficits in fragile X patients.

To test this hypothesis, the team first conducted a preclinical study in a mouse model of fragile X. After treatment with three different doses of EGCG, the researchers found improved cognition in the mice. This was demonstrated through a novel object recognition test, which measures learning and memory.

Based on the positive results from the mouse study, the researchers conducted a placebo-controlled Phase 1 trial (NCT01855971) to assess the safety and effectiveness of EGCG in patients with fragile X.

A total of 27 patients were given either EGCG as a dietary supplement or a placebo, in combination with cognitive training for three months, with three additional months of follow-up cognitive training after stopping treatment. Cognitive training is a program of regular mental activities designed to help maintain or improve one’s cognitive abilities.

Results revealed that patients who received EGCG in combination with cognitive training significantly improved cognition, as measured by an improvement in visual associate memory, compared with patients who received the placebo plus cognitive training. The patients who received the EGCG also showed significant improvement in functional competence, as measured by improvement in home living adaptive skills, compared with the other group.

Improvement in home living adaptive skills implies that the patients experienced an increase in self-autonomy and were able to perform routine household tasks, such as preparing meals and cleaning, by themselves, leading to higher daily competence.

Further, after discontinuing the EGCG treatment, and continuing cognitive training for three months, the researchers found that the treatment effects were sustained, and persisted in both memory and home living adaptive skills.

In addition, quality of life, physical well-being, and relationships with parents improved in patients treated with EGCG plus cognitive training. However, “no beneficial effects were detected in executive functioning,” the researchers said.

“This Phase I study provides support to the benefits of using EGCG combined with CT [cognitive training] as a promising therapeutic intervention for improving cognition, functionality in everyday life in adults with FXS [fragile X], in the absence of substantial adverse effects,” the researchers wrote.

However, “Phase 2 clinical trials in larger groups of subjects are necessary to establish the therapeutic potential of EGCG for the improvement of cognition and daily life competences in FXS,” they added.