What does oxidative stress actually mean - and how does it affect you?

Oxidative stress is often mentioned in the same context as antioxidants, inflammation, and aging. But what exactly is being "stressed"? And when does a completely natural process in the body become something that can actually damage our cells?

When cells use oxygen, including to produce energy, reactive oxygen species are formed - often abbreviated as ROS, from the English Reactive Oxygen Species.

Reactive oxygen species are a natural part of the body's chemistry and serve important functions, including acting as signals between the body's cells and in the immune system. But at the same time, the amount kept in check.

And that is precisely why the body has its own antioxidant defenses, which continuously help neutralize reactive substances and limit the damage they can cause. When production exceeds what the body's own defenses can handle, this is known as oxidative stress.

What happens to cells during oxidative stress?

When the amount of ROS/reactive oxygen species becomes too high, they can begin to react with and change the substances that cells are made of. These include cell membranes, proteins, and the body's DNA.

1. Cell membranes contain a lot of fat, and some fats are sensitive to oxidation. When they oxidize, the membrane can change and become less effective at protecting the cell, so control over what enters and leaves the cell no longer works as it should.
   
   
2. Proteins can also oxidize. Since proteins serve as everything from enzymes to receptors and transporters in the body, oxidation can change a protein's shape and cause it to function less effectively or not at all.
   
   
3. If the damage reaches the body's DNA the genetic material itself can change. Cells have repair systems that correct much of this, but if the damage becomes too extensive or is not properly repaired, mutations can occur.

Do you notice these changes? Not directly. But if oxidative damage is high for a long time, the damage may eventually affect how well your cells and tissues function. 

Oxidative stress is therefore involved in the body's aging process and several chronic disease processes, including cardiovascular disease, type 2 diabetes, and neurodegenerative diseases such as Alzheimer's and Parkinson's.

What causes oxidative stress to increase?

Some are produced naturally as part of life itself. But ROS levels can also increase due to factors such as smoking, air pollution, excessive UV radiation, high alcohol consumption, chronic inflammation, and prolonged high blood sugar.

Even exercise increases the production of ROS – but only temporarily. And this is where something happens that shows why an increase is not only negative: the increase acts as a signal that causes the body to strengthen its own defenses. In other words, regular exercise makes cells better equipped for the next challenge of oxidative stress.

The goal is therefore not to eliminate all oxidation. However, you want to avoid the burden becoming too great over an extended period.

The body has its own antioxidant defense

Among other things, the body produces the antioxidant glutathione and enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, which together help neutralize reactive substances.

For a long time, antioxidants in berries, herbs, cocoa, and brightly colored vegetables were discussed mainly in terms of their ability to neutralize reactive substances.

But today we know that some plant compounds, including various polyphenols, can also influence Nrf2 – a system in the body that helps cells increase their own defense against oxidative stress.

This gives us a slightly deeper understanding of why plant compounds are important: They can both help neutralize reactive substances and get the body to strengthen its own defenses against them.

We cannot, and want to not to stop oxidation completely. But we want to do what we can to reduce things that unnecessarily drive it and give the body's own defenses the best possible conditions to do their job.

Sources:

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