New research suggests that high consumption of green tea may reduce your risk of dementia. However, it is important to note that this result is based on a preliminary study consisting of just under 500 participants and the result is yet to be published in a peer-reviewed scientific journal.
Where did this claim come from?
This result was recently presented at Alzheimer’s Disease and Parkinson’s Disease Conference in Nice, France by researchers from the Kanazawa University Graduate School of Medical Science in Japan.
The research in brief
In 2007 and 2008, 723 participants (60 or older, without dementia) had their cognitive function evaluated by two cognitive assessments, a Mini-Mental State Examination (MMSE) and a Clinical Dementia Rating (CDR). They also had a blood test taken, including an assessment of their APOE genotype. Participants were asked to record their consumption of green tea, black tea and coffee (i.e. not at all, 1-6 times a week or every day) and give details on their general health, physical exercise regime and level of education.
In 2011-2013, 490 of the participants underwent a follow-up survey.
In their analysis, the researchers grouped participants based purely on their green tea drinking status. They found that those who did not drink green tea had slightly lower MMSE scores; however, these scores were not at levels that would be considered a cognitive impairment or dementia.
While the researchers conclude that drinking green tea could be beneficial for cognitive function, more evidence is required as to how long participants had been drinking green tea throughout their lives, and how much, to fully understand the effects of green tea on brain health.
The evidence around green tea and brain health
According to the Alzheimer’s Australia Your Brain Matters website, green tea contains antioxidants which according to previous research may help to reduce the risk of developing dementia. All types of tea contain antioxidants – they just contain different antioxidants in different amounts.
Green tea also contains an antioxidant known as resveratrol which Dementia News has previously covered here. Resveratrol in also found in small doses in red wine.
The Your Brain Matters website suggests that if you like green tea, then drink it. However more research is required to fully understand the mechanisms that antioxidants in green tea might have in being able to enhance brain health and reduce dementia risk.
Just last week a study published in the Journal of Alzheimer's Disease also found that a green tea extract along with exercise was able to slow down the progression of Alzheimer's disease pathology in the brains of mice - find out more here.
Dementia News will keep you posted on future research in this area.
ADPD conference website - http://www2.kenes.com/adpd/Pages/Home.aspx (Abstract 932)
MedScape - http://www.medscape.com/viewarticle/842042
Journal of Alzheimer's Disease - http://www.j-alz.com/content/green-tea-extract-and-exercise-hinder-progress-alzheimers-disease-mice