Drinking Tea Reduces Dementia Risk
Tea polyphenols like EGCG fight oxidative stress and boost brain health. They activate key pathways, offering potential treatment for conditions like Dementia and Alzheimer's.
Are you one of those who enjoy a daily cup of tea? If so, you’re not alone. Tea is a popular beverage consumed daily in more than 160 countries.
And you’d be happy to know that drinking tea goes beyond a simple daily indulgence. Scientists are examining how tea exerts its effects on mood and cognition. They even concentrated on the neuroprotective benefit of tea and its potential to prevent dementia.
What is Dementia
Dementia symptoms include memory loss and difficulties with thinking, problem-solving, or language. It also involves changes in mood, perception, or behavior.
With the accelerated aging population in the world, neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s disease are increasing over time. The World Alzheimer Report has shown that the number of people with dementia worldwide was 46.8 million in 2015, and it will be 131.5 million in 2050.
It is important to note that dementia is not a natural part of aging. All types of dementia are caused by diseases that affect the brain. And yes, there are risk factors that you can’t control, like genes; but there are still many things you can do to reduce your risk of developing dementia.
One such way is drinking tea daily. But how can tea help? To understand that, we must first look at the main tea components.
Main Tea Components
1. Epigallocatechin-3-gallate (EGCG)
The majority of catechins present in tea are epigallocatechin-3-gallate, which is a type of polyphenol. (1)
Research has found that EGCG increases the production and activity of essential antioxidants such as glutathione peroxidase, superoxide dismutase, and catalase. (2)
EGCG has been shown to protect the brain and prevent cognitive impairment associated with Alzheimer’s.
L-theanine has anti-anxiety effects and can increase mental sharpness. (5) It can cross the blood-brain barrier via the leucine-preferring transport system.
Also, L-theanine improves neurotransmitters in the brain: GABA, dopamine, and serotonin. (6)
In a double-blind, controlled trial, L-theanine improved stress response in 12 undergraduate men. (7)
Neuroprotective Effects and Mechanisms of Tea Polyphenols
The brain, the most oxygen-consuming organ in the body, is easily damaged by oxidative stress, such as free radicals and redox-active metals (10). Tea polyphenols are natural antioxidants with radical-eliminating capacity.
In addition, EGCG has been reported to scavenge free radicals by directly or indirectly blocking free radical chain reactions, activating intracellular antioxidant enzyme activity, chelating metal ions (11), reducing lipid peroxidation (12), and releasing intracellular calcium (13).
Also, much evidence has indicated that tea polyphenols exert a neuroprotective role in neurodegenerative diseases through their antioxidant properties and the regulation of signaling pathways.
A variety of intracellular signaling pathways play an essential role in the neuroprotective effect of EGCG, including protein kinase C (PKC).
PKC is related to merging different kinds of memories (14) and activated PKC has been shown to prevent the toxic effects of induced amyloid-beta on hippocampal neurons. In other words, the activation of PKC by EGCG may serve as a treatment for the aging brain, such as Alzheimer’s disease. (15) (16)
Many population-based studies have shown that drinking tea is related to a lower risk of cognition impairment.
A follow-up study for 5.7 years involving 13,645 Japanese over 65 years old showed that green tea consumption significantly reduced the risk of dementia. (17)
Another study among 278 Parkinson’s disease patients revealed that the onset of Parkinson's was delayed by 7.7 years when tea consumption was more than 3 cups a day. (18)
Another study of people over 55 in Singapore found that those who drank as little as one cup of tea per week performed better at memory and information-processing tasks than non-tea drinkers. (19)
Many meta-analysis studies have also shown that tea intake has neuroprotective effects. For example, data from 26 previous observations, including 52,503 participants, showed that daily tea consumption could significantly lower the risk of cognitive decline, cognitive impairment, and mild cognitive impairment in the elderly. (20)
A study including 34,4895 participants showed that daily consumption of 2 cups of tea a day decreased Parkinson’s disease risk by 26%. (21)
The medicinal value of tea has been the subject of many studies to test its effects on everything from stress levels to diabetes.
In addition, tea is easy to make, whether you brew tea leaves or use bagged tea. And you can easily find your favorite flavor and add it to your daily diet.
So if you’re a tea drinker, you can gain the potential of these excellent benefits.