Matcha consumption could lead to significant improvements in social acuity, as evaluated by the perception of facial emotions, and sleep, as measured by the Pittsburgh Sleep Quality Index, among older adults with mild cognitive impairment (MCI) or subjective cognitive decline, new research suggests.

Japanese researchers conducted a randomized, double-blind, placebo-controlled clinical study over 12 months to examine the effect of matcha capsules on cognitive function and sleep quality.

Ninety-nine participants ages 64-85, including 64 with subjective cognitive decline and 35 with MCI, were randomized. Forty-nine received 2 g of matcha and 50 received a placebo daily. Overall, the matcha capsules contributed 170.8 milligrams (mg) of catechins; 48.1 mgs of theanine; and 66.2 mg of caffeine per daily serving.

Participants underwent cognitive assessments at the beginning, end, and 6 months after the study intervention, including the Montreal Cognitive Assessment-Japanese version and the Alzheimer’s Disease Cooperative Study Activity of Daily Living.

Participants’ neuropsychological status, memory, executive functioning, attention, social acuity, and sleep quality were also tested, and neuroimaging was performed at the baseline and end of the study to check the gray and white matter levels in participants’ brains.

The researchers found improvement in emotional perception and a trend to improvement in sleep quality among those who received matcha; however, measures of cognitive decline did not improve. Nevertheless, the authors conclude, “Present findings suggest that the consumption of matcha enhances certain cognitive functions, such as facial expression recognition and attention, and improves sleep quality, which are beneficial for maintaining cognitive function in older adults. Matcha consumption may be considered as a lifestyle improvement strategy for dementia prevention.”

To read the full study, published in PLOS ONE, click here