Nature offers us a wide variety of foods with unique compositions. Aside from basic nutrients like sugars, fats, and proteins, there are other substances and elements that our body needs to stay healthy, including vitamins, minerals, and a very special, sometimes forgotten group: antioxidants. In this article, we present why we need to consume antioxidants and which foods contain them.

Why We Need to Consume Antioxidants

The main metabolism that occurs within cells to generate energy and keep us alive is aerobic, meaning it requires oxygen to function. It consists of a set of biochemical reactions performed in a specific sequence.
In several of these steps, what are known as free radicals and ROS (Reactive Oxygen Species) are generated, which, if not neutralized, can cause oxidative damage to biomolecules such as lipids present in cell membranes, proteins that make up receptors and hormones, and DNA, which contains our genetic information.
Fortunately, our cells are equipped with mechanisms through which they can nullify the reactivity and/or inhibit the generation of these free radicals. These mechanisms, which make up our internal or endogenous antioxidant system, consist of molecules that have the capacity to neutralize these oxidizing agents. They work together with the common goal of restoring balance to avoid the emergence of oxidative stress. (Oxidative stress: myth or reality)

How and Why Oxidative Stress Occurs

Endogenous antioxidants (What are antioxidants in simple words) are a set of enzymes produced by the body in moderate but theoretically sufficient amounts to neutralize the excess of free radicals and other oxidizing agents. The problem arises when, through our lifestyle, we increase the generation of free radicals by pathways other than metabolic. Preservatives in processed foods, sun exposure, smoking, and many other factors generate substances with oxidizing power, free radicals. This excess of oxidizing agents makes our endogenous antioxidant system insufficient to neutralize them.
It’s also important to add another factor: as we age, the production of endogenous antioxidant enzymes decreases, contributing to the imbalance between oxidation and antioxidation, favoring oxidation, and thus the feared oxidative stress appears.
To restore the balance, we need to reinforce the internal antioxidant system with external antioxidants, which we can do in only two ways: through foods rich in antioxidants or through antioxidant supplements.

The Best Antioxidant Foods

A source of external antioxidants comes from an antioxidant-rich diet. Exogenous antioxidants include vitamin E, vitamin C, carotenoids, polyphenols, flavonoids, and other phytochemicals.
Not all antioxidants have the same properties, the same mechanism of action, and therefore the same antioxidant capacity. For example, vitamin C is water-soluble (aqueous medium), while vitamin E is fat-soluble (fatty medium), indicating that each acts in a different environment.
An antioxidant-rich diet is one that contains a good amount of nutrients rich in the variety of exogenous antioxidants we've mentioned. Considering that the various groups are distributed among many fruits, vegetables, and other sources, it’s as simple as knowing these sources and creating a menu that incorporates them into daily breakfasts, lunches, and dinners. The Mediterranean diet is just one example, but you can create your own according to your preferences.
Let’s look at some of the most common antioxidant-rich foods:

Vitamin E (tocopherols). Found in olive oil and seeds like walnuts, almonds, hazelnuts, sunflower seeds, wheat germ, and soybeans; as well as turkey, cabbage, bell pepper, and asparagus.
Vitamin C (ascorbic acid). Found in spinach, cabbage, tomatoes, strawberries, kiwi, oranges, tangerines, grapefruit, melons, guavas, and papayas.
Vitamin A (retinol). Consumed through fish liver, carrots, spinach, watercress, cheese, and butter.
Carotenoids. Found in Swiss chard, watercress, lettuce, celery, cucumber, tomatoes, zucchini, carrots, cabbage, as well as asparagus, guava, tangerines, melons, mangoes, watermelons, grapes, and papayas.
Selenium. Found in pasta, wheat flour, wheat bread, brown rice, onions, tomatoes, broccoli, melons, as well as tuna, sardines, cod, salmon, trout, and nuts.
Flavonoids. In addition to antioxidant properties, flavonoids have anti-inflammatory, antiviral, and antibacterial properties, which is why some authors have named them super antioxidants. You can consume them through pomegranate, oranges, lemons, onions, cherries, apples, soy, grapes, olives, celery, broccoli, lettuce, and pears.

What If I Can’t Get Antioxidants from My Diet?