Daily
consumption of tea may protect the elderly from cognitive decline, study
suggests

Date:

March 16, 2017

Source:

National University of Singapore

Summary:

Tea
drinking reduces the risk of cognitive impairment in older persons by 50 per
cent and as much as 86 per cent for those who are genetically at risk of
Alzheimer’s, new research suggests.

A cup of tea a day can
keep dementia away, and this is especially so for those who are genetically
predisposed to the debilitating disease, according to a recent study led by
Assistant Professor Feng Lei from the Department of Psychological Medicine at
National University of Singapore’s (NUS) Yong Loo Lin School of Medicine.

The longitudinal study
involving 957 Chinese seniors aged 55 years or older has found that regular
consumption of tea lowers the risk of cognitive decline in the elderly by 50
per cent, while APOE e4 gene carriers who are genetically at risk of developing
Alzheimer’s disease may experience a reduction in cognitive impairment risk by
as much as 86 per cent.

The research team also
discovered that the neuroprotective role of tea consumption on cognitive
function is not limited to a particular type of tea — so long as the tea is
brewed from tea leaves, such as green, black or oolong tea.

“While the study was
conducted on Chinese elderly, the results could apply to other races as well.
Our findings have important implications for dementia prevention. Despite high
quality drug trials, effective pharmacological therapy for neurocognitive
disorders such as dementia remains elusive and current prevention strategies
are far from satisfactory. Tea is one of the most widely consumed beverages in
the world. 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,” explained Asst Prof
Feng.

He added, “Based on
current knowledge, this long term benefit of tea consumption is due to the
bioactive compounds in tea leaves, such as catechins, theaflavins, thearubigins
and L-theanine. These compounds exhibit anti-inflammatory and antioxidant
potential and other bioactive properties that may protect the brain from
vascular damage and neurodegeneration. Our understanding of the detailed
biological mechanisms is still very limited so we do need more research to find
out definitive answers.”

In this study, tea
consumption information were collected from the participants, who are
community-living elderly, from 2003 to 2005. At regular intervals of two years,
these seniors were assessed on their cognitive function using standardised
tools until 2010. Information on lifestyles, medical conditions, physical and social
activities were also collected. Those potential confounding factors were
carefully controlled in statistical models to ensure the robustness of the
findings.

The research team
published their findings in scientific journal The Journal of Nutrition, Health
& Aging in December 2016.

Future Research

Asst Prof Feng and his
team are planning to embark on further studies to better understand the impact
of Asian diet on cognitive health in aging. They are also keen to investigate
the effects of the bioactive compounds in tea and test them more rigorously
through the assessment of their biological markers and by conducting randomised
controlled trials or studies that assign participants into experimental groups
or control groups randomly to eliminate biased results.

Story Source:

Materials provided by National University of Singapore. Note: Content may be
edited for style and length.

Journal Reference:

1.    L. Feng, M. -S. Chong, W.
-S. Lim, Q. Gao, M. S. Z. Nyunt, T. -S. Lee, S. L. Collinson, T. Tsoi, E. -H.
Kua, T. -P. Ng. Tea consumption reduces the incidence of neurocognitive
disorders: Findings from the Singapore longitudinal aging study. The
Journal of Nutrition, Health & Aging, 2016; 20 (10): 1002 DOI: 10.1007/s12603-016-0687-0