Assistant Professor Feng Lei from NUS Yong Loo Lin School of Medicine led a research team which found that regular consumption of tea reduces elderly persons’ risk of cognitive decline by 50 per cent, and potentially up to 86 per cent for persons genetically at risk of Alzheimer’s. The study was published in The Journal of Nutrition, Health & Aging in December 2016.
Involving close to a thousand Chinese elderly aged 55 years or older, the study began with data-gathering in 2003. The research team followed up with the participants every two years until 2010 to obtain further information on cognitive status, tea consumption, lifestyle, medical conditions, as well as physical and social activities.
Asst Prof Feng from NUS Psychological Medicine said that while the study was conducted on Chinese elderly, the results could well apply to other races. “I believe the cognitive benefits of drinking tea should be the same across all the ethnic groups because we share the same biology of ageing; the pathology of dementia is the same, and also because the bioactive compounds from tea are the same,” he explained.
Effective pharmacological therapy and current prevention strategies for neurocognitive disorders remain lacking despite high quality drug trials, shared Asst Prof Feng. "The data from our study suggests that a simple and inexpensive lifestyle measure such as daily tea drinking can reduce a person’s risk of developing neurocognitive disorders in late life," he said.
Tea drinkers will be pleased to learn that the neuroprotective role of tea consumption is not limited to a specific type of tea. As long as the tea — whether black, green or oolong — is brewed from tea leaves, daily consumption of at least 200ml can help to reduce cognitive impairment. Asst Prof Feng said that the benefit of tea is due to the bioactive compounds present, including catechins, L-theanine, theaflavins and thearubigins.
Asst Prof Feng and his team aim to embark on further research to better understand the effect of Asian diet on cognitive health during ageing. One of the new studies, known as the Diet and Healthy Ageing (DaHA) study, will investigate the biomarkers of tea intake, where the team will collect blood and urine samples to measure participants’ levels of catechins and L-theanine. The research team also plans to conduct an interventional study where the impact of drinking tea on non-tea drinkers’ brain function and biological ageing will be tested.