Thursday, June 1, 2023

How green tea protects against memory loss

Catechin compounds in green tea help protect against Alzheimer's disease through four different mechanisms.

Executive Summary

Green tea has antioxidants called catechins that help prevent neuro-degenerative damage in brain cells. Green tea helps in memory loss conditions such as Alzheimer’s by four different mechanisms. Since brain changes in Alzheimer’s start fifteen to thirty years before you see the symptoms, daily consumption of three cups of green tea is helpful.

Read the full article for various dosages, consumption options, and possible problems.

Green tea has many healthful compounds. However, its claim to fame comes from compounds called catechins. They are terrific antioxidants that prevent oxidative degeneration and ageing, especially in the brain.

Why Does the Brain Age?

Brain has all the ingredients for degenerating faster than most body organs. Your brain:

  1. Generates nearly twenty per cent of body’s energy for its functions. The process by which cells produce energy is highly inflammatory, generating free radicals—the compounds that cause damage and destruction;
  2. Has cells that have a lot of unsaturated fats, which are more vulnerable to oxidation and resultant damage; and
  3. Does not have very good antioxidant protective mechanism of its own.

If the brain is not protected adequately against the oxidative damage, it degenerates fast and leads to many ageing related conditions. Cells in different parts of the brain get damaged and die. Depending on the brain region where those cells reside, we lose certain abilities prematurely. The prominent ones are:

  • Mobility-related losses (For example, Parkinson’s Disease);
  • Memory-related losses (For example, Dementias and Alzheimer’s Disease).

Why Is It Difficult to Protect The Brain ?

The brain is protected well physically:

  1. It is shielded inside a thick skull;
  2. It is covered in protective liquid called cerebrospinal fluid;
  3. Three layers of membranes called meninges cover the brain.

These barriers don’t let the brain to be hit from outside easily.

Blood-Brain Barrier

To reach the brain internally through its blood supply is also difficult. The contents of blood are prevented from reaching the brain directly through a protective layer of cells called Blood-Brain Barrier (BBB). It is your brain’s security cordon. The cells of BBB allow only a few substances to get through to the brain.

But this protection also makes it hard for many medicines and protective nutrients to get to the brain. Something as common as vitamin C is prevented from reaching the brain. It needs to find an alternate way to end up in the brain region. So it is very hard to find curative or preventive compounds that can help the brain.

Enter the catechins (pun unintended). Not only are they top-notch antioxidants, but they can also cross BBB with ease to reach the brain and work their magic.

Memory Loss, Dementias, and Alzheimer’s Disease

Dementia or memory loss is not a single disease. There are many types of dementias caused by abnormal brain changes. They usually involve some kind of memory loss as well as reduction in the thinking skills.

But every minor memory problem is not a dementia. For example, if you forget a few things, it does not mean you have disease. As long as it does not cause serious problems in everyday life, you are fine.

Alzheimer’s Disease

The most common type of dementia (seventy percent of the cases) is the Alzheimer’s disease. It differs from other dementias in the sense that it is progressive and its symptoms worsen over time.

The most common early symptom of Alzheimer’s is trouble remembering new information because the disease typically first impacts the part of the brain associated with learning. As Alzheimer’s advances, symptoms get more severe and include disorientation, confusion and behaviour changes. Eventually, speaking, swallowing, and walking become difficult.

How Does Alzheimer’s Disease Develop?

Science does not fully understand how Alzheimer’s develops. However, there are many hints to what is happening from observing various correlations. For example, improper glucose metabolism, poor blood supply, etc.

Without going into technical details, the most widely accepted reason is inadequate clearing of waste products generated in brain functioning. And the most common reason for this failure is neuroinflammation—the toxic environment caused by harmful oxidative processes in brain cells. The inflammatory compounds produced in such processes lead to malfunction in the cells that clean the brain.

Conditions such as Alzheimer’s take at least fifteen years before you can see their symptoms. Some new research claims that brain changes may start as early as 34 years before you see the symptoms. That means, we have enough time to act in a preventive manner.

Catechins in Preventing Alzheimer’s

There are many studies that show the benefit of green tea on memory loss and Alzheimer’s. The exact mechanisms are still not understood. But the scientists think there are four possible ways it could be happening. Green tea catechins:

  1. Prevent oxidative damage through its antioxidant mechanisms;
  2. Reduce the production of toxic neuroinflammatory chemicals;
  3. Prevent formation and accumulation of toxic waste products in the brain (amyloid beta); and
  4. Keep the inner linings of brain blood vessels healthy.

How Much Green Tea to Consume

Experts generally advise three cups (one cup = 250 mL) of green tea a day.

Keep in mind that catechins are metabolised (broken down into other compounds by the body) quite quickly after consumption. So for the best benefits, do what the wise Chinese do: consume smaller amounts more frequently through the day. Instead of gulping down Instagram-photo-friendly large mugs (400 mL) of green tea a day, consider drinking small bowlfuls (80 mL) of green tea every two to three hours. Read on this website: You are drinking green tea wrongly. Avoid drinking at night, since green tea also has caffeine.

If your work schedule does not allow you to drink green tea at times of your choice, consider taking green tea extract supplements. Hundred milligrams of green tea extract is typically equivalent of a cup of green tea. Aim for 400 mg a day for preventive purposes. If you already have an onset of disease, consider 800 mg a day.

Do not exceed eight cups (two litres) of green tea or 800 mg of extract a day. While two litres is a huge amount to drink daily, it also has too much caffeine. On the other hand, most green tea extracts are decaffeinated. So you won’t have caffeine-related disturbances. Eight cups of green tea will lower absorption of vitamin B1, iron, copper and chromium, if consumed around meal times. So don’t overdo your green tea affection.

To Read More

This information is from my upcoming book to be published by Macmillan Publishers in Nov 2023. It discusses twenty superfoods, their nutrients, health benefits, recommended amounts and excess levels. It also covers how to select and store and who should avoid them.

The superfoods: Tomatoes, carrots, spinach, beetroot, coconut, capsicum (Shimla mirch), drumsticks, pineapples, papaya, amla (Indian gooseberry), jamun (Java plum), turmeric, garlic, ginger, cinnamon, flax seeds, aloe vera, green tea, asafoetida (hing), and sabja (sweet basil seeds).

First published on: 8th January 2023
Image credit: Mareefe on Pexels



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