All About Antioxidants

By: Camryn Murray, Winthrop University Nutrition Student

So often, people are shocked when they receive a poor health diagnosis and wonder how it got to that point or how they could have prevented it. There are many reasons that disease occurs, but oxidative stress and free radicals are common factors that are linked to several conditions such as cancer, Alzheimer’s disease, heart disease, diabetes, Parkinson’s disease, cataracts, macular degeneration, and even aging.

What is a free radical?

A free radical, or radical oxygen species (ROS), is an unstable molecule in your body that can cause damage to your metabolism and body. A molecule has an outer ring or “valence” ring that contains electrons (negative particles); a stable molecule has 8 electrons in that ring, while an unstable molecule only has 7. Molecules are always looking for ways to reach stabilization by donating or accepting electrons from other molecules to reach 8 valence electrons, which is why these free radicals are highly reactive. The scientific term for the imbalance and excess of free radicals is “oxidative stress.”

A closer look at oxidative stress:

The buildup of free radicals, also called oxidative stress, can lead to several reactions in the body that lead to disease. You might find it helpful to define oxidative stress as simply the imbalance between oxidants and antioxidants. Some interesting results of the molecular damage that stems from oxidative stress include:

• DNA alteration

• Alteration in lipid profiles

• Protein alterations

• Eventual disease

How are free radicals created and why?

These molecules are beneficial at low levels for normal cellular reactions and immune responses, but harmful at high levels due to the reasons stated above. Free radicals can generate for many different reasons including:

• Some internal sources:

  • Inflammation

  • Metabolism

  • Exercise

  • Injury or disease

• Some external sources:

  • Cigarette smoke

  • Air pollution

  • Radiation

  • Drugs, pesticides

  • Industrial materials

  • Sunlight

What are antioxidants?

Antioxidants are molecules with an additional electron that can be donated to free radicals to stabilize it before it affects important molecules like DNA, lipids, and proteins in the body. Think of these two pieces as a puzzle; the extra electron in an antioxidant fills in for the missing electron in a free radical to create two stable molecules that do not easily react with other molecules. Some examples of antioxidants from food include:

• Vitamin C

• Vitamin E

• Vitamin A

• Selenium and Zinc

• Carotenoids like beta-carotene, lycopene, lutein, and zeaxanthin

How to eat more antioxidants

There are several ways to incorporate antioxidants into your diet to help your body stay young and healthy. Here is a small list from the Academy of Nutrition and Dietetics that lists a few food groups that contain the most antioxidants:

• Fruits; notably cranberries, raspberries, strawberries, pears, guavas, oranges, mango, papaya, tomatoes, and more

• Dried fruits; like dried pears, peaches, figs, and raisins

• Vegetables; like broccoli, spinach, carrots, potatoes, etcetera

• Spices and herbs; like cinnamon, oregano, turmeric, cumin, parsley, basil, and more

• Cereals and nuts; corn flakes and oatmeal or walnuts, hazelnuts, pistachios, almonds, cashews, and more

• Beverages; like cider, tomato juice, pomegranate juice, grapefruit juice, coffee, green teas, and black tea

Some additional tips include not overcooking your vegetables to avoid losing too much of their nutrients and focus on having a lot of color in your snacks, meals, and desserts! To start, shoot for at least 1 ½ cups of fruit and 2 ½ cups of vegetables per day.

Notes on supplementing antioxidants

If you choose to supplement an antioxidant, note that you will usually get more out of simply eating antioxidant-rich foods. For example, vitamin E supplements usually contain only 1 form of vitamin E, alpha-tocopherol, but there are 8 different forms of it found in foods. For instance, you would want to look for a vitamin E supplement containing mixed tocopherols if a vitamin E supplement was recommended or needed.

It's worth noting, supplementing high doses of antioxidants can have the opposite effect on free radicals and can even produce some potentially dangerous side effects, so speak to a provider before starting a supplement and do your best to focus on healthy foods first.

References

1. Pham-Huy LA, He H, Pham-Huy C. Free radicals, antioxidants in disease and health. Int J Biomed Sci. 2008 Jun;4(2):89-96. PMID: 23675073; PMCID: PMC3614697.

2. Lobo V, Patil A, Phatak A, Chandra N. Free radicals, antioxidants and functional foods: Impact on human health. Pharmacogn Rev. 2010 Jul;4(8):118-26. doi: 10.4103/0973-7847.70902. PMID: 22228951; PMCID: PMC3249911.

3. Ellis CE. Antioxidants - protecting healthy cells. EatRight. https://www.eatright.org/food/vitamins-and-supplements/types-of-vitamins-and-nutrients/antioxidants-protecting-healthy-cells. Published March 25, 2021. Accessed November 11, 2022.