The Role of Antioxidants in Preventing Cellular Damage and Promoting Health

We have all seen the food packaging that screams “HIGH IN ANTIOXIDANTS”!

That sounds amazing and I, for one, have been known to grab that product, wolf it down, and immediately feel better because I just did something wonderful for my body. At least I think I did. Did I? If so, what did I do? 

Eventually, I started to realize that I might not be able to trust those labels. And, even if there are antioxidants in the product, how does that help me? Clearly,  I really didn’t understand what antioxidants were or why they were good for me. So, I decided to find out. If you are interested in learning about this also, read on!

Very simply, an antioxidant is a compound that will sacrifice one of its own electrons to neutralize a free radical in our bodies. This sounds kind of complicated, I know. But it’s also pretty amazing. These antioxidants are like tiny superheroes moving around our bodies looking for a molecule (called a free radical) that is unstable and is itself searching for an electron to stabilize it. If the antioxidants don’t find these free radicals and neutralize them with one of their electrons, the free radicals will find other cells to take the electron from and, therefore, cause damage to that cell. This process impacts our cells and our DNA. When this happens frequently, it leads to cell damage and eventually contributes to cardiovascular issues, cancer, inflammatory diseases, and neurodegenerative diseases. The imbalance of free radicals and antioxidants (when there are more free radicals and not enough antioxidants to neutralize them), is called oxidative stress. 

Free radicals sound horrible and it might seem like a good idea to avoid them altogether. But, unfortunately, we can’t. Our bodies make free radicals all on their own. When cells use oxygen to generate energy, free radicals are formed. When our immune systems ramp up, we make free radicals to fight off infections and viruses and to destroy damaged cells. We also create free radicals when we exercise. Additionally, chemicals from the environment in the form of certain air pollutants, ultraviolet rays, and smoking initiate a reaction in our bodies that results in free radicals. These free radicals are particularly damaging to our DNA and fatty acids (ie our brains). 

Clearly, given that we are not able to avoid free radicals, we want to make sure we have enough antioxidants to neutralize them so that we can minimize the damage to our healthy cells. 

Because our bodies are pretty amazing, we actually make our own antioxidants. These are called endogenous antioxidants. Because they are made by our own bodies, they are super powerful in neutralizing the free radicals and minimizing oxidative stress. The endogenous antioxidants are enzymes that work by breaking down the free radical molecules into different components (like hydrogen peroxide, water and oxygen) that can be harmlessly removed from our bodies. 

In an ideal world where we are not bombarded by toxins and pollutants, endogenous antioxidants might be enough to protect our cells. However, we live in the real world where we are constantly assaulted by things that are not ideal for our cellular health. This is where exogenous antioxidants become crucial. As you can probably guess, exogenous antioxidants are antioxidants that come from outside of our bodies, from what we ingest. 

The most potent endogenous antioxidants are Vitamin C, Vitamin E, carotenoids and polyphenols. 

Vitamin C is pretty cool. When we eat foods high in this vitamin (citrus fruits, berries, cruciferous vegetables and red, yellow and orange vegetables), we are filling our blood with a water-soluble scavenger that not only neutralizes free radicals in the fluids of our bodies but also gives a boost to another antioxidant, Vitamin E!

Vitamin E works in the cell membranes to protect them from damage due to oxidative stress. So, Vitamin E finds a free radical, neutralizes it by giving it an electron, and then IT becomes a free radical. But, wait! Along comes Vitamin C which regenerates Vitamin E by giving it a hydrogen atom and Vitamin E is back in business! How amazing is that!

Beta-carotene and carotenoids are also pretty cool antioxidants. These are converted to Vitamin A and work to find singlet oxygen molecules (which are highly active free radicals) and neutralize them. 

One last group of potent exogenous antioxidants are polyphenols (also known as flavonoids). These are the chemicals that give fruits and vegetables their colors and they are powerful! Not only do they fight free radicals, but they also help us fight off inflammation, cancer and cardiovascular problems. 

Now that we have a better understanding of how antioxidants prevent cellular damage, let’s take a closer look at how they promote health. It seems obvious that damage to the cells in our bodies would lead to issues with our health, and there is a significant amount of research that connects oxidative stress with chronic diseases, including cardiovascular diseases, cancer, neurodegenerative diseases, and diabetes. So, it follows that decreasing oxidative stress by increasing antioxidants would mitigate some of that damage and help to prevent these diseases and promote health.

To understand how antioxidants promote health, we first need to wrap our heads around the ways the damage caused by free radicals leads to symptoms and illnesses. 

Let’s start with cardiovascular diseases. In this instance, the free radicals oxidize our LDL cholesterol. In other words, the free radicals steal an oxygen atom from the LDL cholesterol. This changes the structure of the LDL which causes it to accumulate as plaque in the arterial walls and eventually become atherosclerosis. As the plaque builds up, it thickens and stiffens the artery walls, which narrows the arteries and reduces blood flow to vital organs, thus leading to organ damage. 

Now let’s look at cancer. We mentioned before that oxidative stress can damage DNA. The free radicals can cause breaks in the strands of DNA and lead to modifications in the base of the DNA. This leads to cells misbehaving, the formation of lesions, and eventually the growth of tumors, aka cancer. 

As scary as cancer is, the thought of my brain deteriorating is even more terrifying to me. And, because our brains are made of lots of fat and they use up a lot of oxygen and energy, they are particularly susceptible to oxidative stress. The damage caused by free radicals in our brains leads to neurodegenerative diseases like Alzheimer’s and Parkinson’s. It also speeds up the progression of dementia. And, because the brain is highly connected with our moods, increased oxidative stress has also been linked to increased depression and anxiety. 

One more super scary way oxidative stress can lead to health issues is that it can damage the beta-cells in our pancreas. These beta-cells are responsible for insulin production and when they are damaged we don't make as much insulin. And, when we don't make enough insulin to clear the glucose from our bloodstream, we get diabetes. Ugh. Terrifying. 

But, the good news is that antioxidants are available all over the place! We just need to eat the right things for exogenous antioxidants and move our bodies to increase our endogenous antioxidants.  And, not surprisingly, the foods that contain the most antioxidants are the same ones that promote health for many other reasons. Let’s review them:

• A variety of colorful fruits and vegetables. These provide lots of different polyphenols. Also filled with polyphenols are green tea and red wine (in moderation, of course!). Smoking and excessive alcohol intake can increase the production of free radicals and oxidative stress. 
• Nuts and seeds. Almonds, walnuts, chestnuts, sunflower seeds and flax seeds are some of the best sources of Vitamin E and other antioxidants. 
• Healthy oils like olive and flaxseed oil are packed with antioxidants. The fats in these oils are also great for cardiovascular health.
• If you needed another reason to limit processed foods and added sugars here it is - both of these things increase oxidative stress and decrease the availability of antioxidants in our bodies. 

Okay! To recap, we are constantly bombarded with things that cause free radicals to form in our bodies. These free radicals can cause damage in many ways. However, we have both an internal and external defense system to neutralize the free radicals so we do not experience oxidative stress. To prevent cellular damage from free radicals and promote health, we simply need to move our bodies and make good food choices. I love this because it is empowering when we realize that we have some control over our future health and may be able to avoid scary diseases like cancer and Alzheimer’s disease by making good choices today!