Free Radicals, Oxidative Stress, and Alzheimer’s Disease

Most existing research into the cause of Alzheimer’s disease focuses on the formation of abnormal protein deposits in the brain. Unfortunately, there is a long history of failed experiments for every single medical treatment that has been designed to eliminate these blockages. These repeated disappointments have led some researchers to begin looking elsewhere for clues about the underlying causes of Alzheimer’s disease, like the role of free radicals and similar substances.

What is a Free Radical?

A free radical (usually just called a radical in chemistry) is a chemical substance (atom, ion, molecule, etc.) that is typically highly reactive, which means that it is likely to cause a chemical reaction when it comes into contact with other substances. They are reactive because they have an unpaired electron in their structure and electrons naturally like to be in pairs. The imbalance makes the radical attractive to electrons in other substances and vice versa. This, unfortunately, includes the materials that make up our bodies.

There are many radicals that are constantly produced in nature and they are involved in a wide array of natural processes, like combustion (burning), atmospheric activities, and biochemical processes. It is the latter that we are most interested in when discussing the role of free radicals in Alzheimer’s disease. There has been a growing focus on a specific type of radicals that belong to a group of chemicals called reactive oxygen species (ROS).

Reactive Oxygen Species (ROS) and Oxidative Stress

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ROS are a group of chemical substances that (prepare to not be surprised) are chemically reactive and contain oxygen. Not all free radicals are ROS (many radicals do not contain oxygen, and some are not even reactive) and not all ROS are free radicals (some ROS do not have an unpaired electron, but are reactive in different ways). However, there are several radicals that are categorized as ROS, so the concepts are often discussed together.

The most important link between free radical ROS and other ROS is that they can all cause chemical reactions with other materials, including those within the human body. These reactions can cause damage to cells and tissues. ROS are actually created as a natural byproduct of many biological processes. For the most part, our bodies are well equipped to neutralize these dangerous substances, and/or to repair any damage they may cause before they result in a major health problem. But this success is by no means guaranteed, and a faulty defense against internal ROS may be closely tied to the development of Alzheimer’s disease.

The Alzheimer’s Link

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When the amount of ROS in the body becomes too much for our system to handle, we experience a condition known as oxidative stress. When we are under oxidative stress, the unchecked radicals and other ROS are free to wreak havoc on the body by causing random chemical reactions. It has been linked with several negative biological effects, especially damage at the cellular level.

Multiple pieces of new research have strengthened the theory that oxidative stress is linked to the development of Alzheimer’s disease. For example, postmortem examinations of diseased brains have found damage due to oxidative stress that predates the appearance of protein deposits. Other research has identified the presence of multiple ROS in several key brain areas related to Alzheimer’s disease, even in cases when protein buildup was minor.

There is much promise in the study of free radicals, ROS, and oxidative stress as key players in the development of Alzheimer’s disease. Still, it is likely that this relationship is just a small part of a much more complex puzzle. Continuing research will be needed to confirm and clarify the link, but there is certainly a large potential for new (and hopefully more effective) Alzheimer’s treatments to emerge as a result of this novel approach.

As we continue to search for the physical cause(s) of the disease, we must rely on the early detection of symptoms as our first line of defense against a developing dementia. The BrainTest® app provides the tools we need to monitor our cognitive health as we reach an advanced age, though a professional medical opinion should always be considered.

Steven Pace writes extensively in the fields of neuroscience, mental health, and spirituality. He is an experienced academic writer and researcher from Cape Breton, Nova Scotia, Canada, having obtained his BSc. (Psychology Major) from Cape Breton University in 2010. Steven takes pride in being able to assist others in navigating topics concerning the human mind.

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