Antioxidants

Reactive Oxygen Species and Antioxidants: What They Are and Why They Matter

Senior Summary Box

- Oxidation is normal; Oxidative Stress is not.
- Antioxidants help maintain cellular balance
- Real food and regular movement matter more than supplements
- Consistency over time beats quick fixes

You don’t need a science degree to understand what’s going on inside your body—but a few simple ideas can make a big difference to your health.

Two of those ideas are 1) reactive oxygen species (free radicals) the Bad Guys, and 2) antioxidants (the Good Guys. They sound complicated, but the concepts are actually very simple.

Let’s break them down in plain English.

What Are Reactive Oxygen Species (ROS)?

Reactive oxygen species—often shortened to ROS—are a natural by‑product of living. (the Bad Guys), But they're not all bad.

Every time you breathe oxygen, eat food, exercise, or fight an infection, your body produces energy. During that process, tiny unstable molecules are created. These are reactive oxygen species, (Bad Guys).

The easiest way to think about ROS is this:

They are like what happens when you slice an apple or potato and leave it sitting on the cupboard for a few hours. The surface slowly turns brown. That browning is oxidation.

A small amount of oxidation or a few Bad Guys is normal. Too many of them cause damage.

What Is Oxidative Stress?

Oxidative stress happens when reactive oxygen species build up faster than your body can control them. Bad Guys out number the Good Guys.

Just like metal rusts when exposed to air, cells can be damaged when oxidation runs unchecked.

Over time, excess oxidation (too many Bad guys) can damage cell walls, proteins, and even DNA. This process contributes to aging and many chronic conditions.

What Are Antioxidants?

Antioxidants are the body’s clean‑up crew. (Good Guys)

If reactive oxygen species are sparks, antioxidants are the firefighters.

They neutralize unstable molecules before damage occurs and help repair stressed cells.

How Do Antioxidants Work in the Body?

Reactive oxygen species are unstable because they are missing an electron. They try to steal one from nearby cells, causing damage.

Antioxidants solve this problem by donating an electron without becoming unstable themselves.

In simple terms: ROS want to steal, antioxidants are willing to give.

Food First: Where Antioxidants Come From

Your body makes some antioxidants, but most come from food—especially colorful, whole foods like vegetables, fruits, herbs, and spices.

Variety matters more than chasing a single supplement.

Exercise, Antioxidants, and Aging

Exercise briefly increases oxidative stress, which signals your body to strengthen its own antioxidant defences. Look at this as one way exercise slows aging instead of speeding it up.