Antioxidants: What are they? What are they used for?
Antioxidants have become trendy and essential molecules in the fight against oxidative stress. They are found in fruits and vegetables, but also in many "health" and cosmetic products. They are credited with numerous benefits. But is this always true? What exactly are these famous antioxidants? Should we consume them, and what are their benefits? Which are the best natural antioxidants? Are there any precautions to take when consuming antioxidants? Are they always good for our health?
A few reminders about free radicals
We had dedicated a short article to free radicals, it can be found HERE .
There are a few key points to remember regarding free radicals :
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Free radicals are unstable molecules that cause oxidative stress, which contributes to aging, the development of pathologies, and the alteration of "cellular structures and proteins".
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The presence of free radicals is normal and our body is equipped to defend itself
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An excess of free radicals, beyond our defense capabilities, is harmful.
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The factors responsible for the excessive appearance of these free radicals or for the reduction of defense capacities are present in our daily lives: diet, stress, environmental pollution...
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A balanced diet, rich in fruits and vegetables, is essential to effectively combat free radicals.
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Antioxidant supplementation is a beneficial complement to a healthy lifestyle for effectively combating free radicals.
Free radicals are produced naturally by the body
The normal functioning of the body, and more specifically cellular respiration at the mitochondrial level, produces free radicals from oxygen.
Mitochondria are intracellular organelles found in most eukaryotes. They possess their own DNA. They are essential for the cell's energy production by producing ATP and metabolic cofactors such as NADH and FADH2 .
This results in the creation of ROS (reactive oxygen species).
Reactive oxygen species : these are oxygen derivatives made highly reactive by the presence of unpaired electrons, i.e., a single electron. One of the best known is the superoxide anion.
What is oxidative stress?
Oxidative stress is the effect that ROS (reactive oxygen species) have on our cells and their components. ROS are naturally produced by our bodies, which have appropriate defense mechanisms. However, when these defenses are overwhelmed, an imbalance occurs between the production of free radicals and antioxidant defense.
What are the effects of oxidative stress?
Free radicals can interact with various cell components: lipids, proteins, and DNA. They react with different molecules and create new, hybrid molecules called adducts. Free radicals can also damage DNA, which is a mechanism in the development of cancer (carcinogenesis).
Oxidative stress plays a role in, among other things:
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to aging
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to vision impairment through the development of cataracts or AMD (age-related macular degeneration)
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to the development of cardiovascular diseases , and in particular to atherosclerosis
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to certain brain diseases : neurodegenerative diseases, such as Alzheimer's disease.
What is an antioxidant?
The name “antioxidant” is a good clue to its definition: an antioxidant is a molecule that will inhibit the oxidation of other molecules or slow it down.
What is the role of antioxidants?
Our body uses oxygen for energy production, which leads to the production of ROS (reactive oxygen species). These ROS are toxic to cells and can damage various cell components. When cell components are damaged, cell efficiency decreases, abnormalities appear, ROS production increases—in short, a harmful vicious cycle begins. Fortunately, the body has developed defense mechanisms to control and neutralize these ROS and limit oxidative stress, thanks to endogenous and exogenous antioxidants.
What are the endogenous antioxidants?
Endogenous antioxidants are necessary for controlling oxidative stress. Their role is to prevent the production of free radicals or to deactivate free radicals produced by the body's functions.
There are three key players in antioxidant defense; these are specific antioxidant enzymes:
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Glutathione peroxidase (or GPx ) is an enzyme that contains selenium (making it a selenoprotein). It reduces organic peroxides using reduced glutathione, which is then oxidized. Glutathione is essential for the proper functioning of glutathione peroxidase.
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Superoxide dismutases (or SODs) are enzymes with oxidoreductase activity that catalyze the dismutation reactions of superoxide anions (very reactive). They are metalloproteins that require metals within their active site to function: copper, iron, zinc, manganese, nickel .
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Catalase is an oxidoreductase enzyme that uses heme (a component of hemoglobin), making it a hemoprotein. It transforms hydrogen peroxide into oxygen and water using the iron contained in heme.
Where can I find antioxidants?
In addition to endogenous antioxidants, there are many exogenous antioxidants that originate from food.
It is found particularly in fruits and vegetables, tea or coffee , especially when they are fresh and have not undergone any processing.
Their antioxidant capacity comes in particular from the presence of:
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vitamins such as vitamins A, C and E which are powerful antioxidants.
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trace elements that are necessary for the functioning of antioxidant enzymes: zinc, copper, selenium .
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Carotenoids are the pigments found in yellow and orange foods.
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polyphenols such as resveratrol, coumarins, tannins...
What foods are richest in antioxidants?
Antioxidants are found in plant-based foods. There's no need to create a "Top 10 list of the foods richest in antioxidants"; as is often the case in nutrition, it's beneficial to diversify your diet. You can choose from these food groups:
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Red fruits and berries : such as strawberries, raspberries, blueberries or blackberries, ...
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Fruits : apple, orange, kiwi, fig, ...
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Vegetables : cruciferous vegetables, colorful vegetables, artichoke, ...
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Spices : turmeric, ginger, ...
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The lily family : garlic, onion, shallot
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Fresh herbs : classic herbs used in cooking
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Drinks rich in polyphenols such as tea or coffee
What is the best natural antioxidant?
Two examples can be cited, one endogenous and one exogenous:
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Glutathione , naturally produced by our body and essential to the functioning of glutathione peroxidase .
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Astaxanthin is the most powerful natural antioxidant. It is sometimes called the king of antioxidants. It possesses a particularly interesting property: it can penetrate the brain and eyes, thus protecting these two organs.
What are the benefits of antioxidants?
By combating free radicals and oxidative stress, antioxidants help slow skin aging , fight cardiovascular disease, preserve eye and brain health, and contribute to reducing the risk of developing certain cancers. The benefits of antioxidant supplementation were notably demonstrated in men in the SU.VI.MAX study. In short, antioxidants, in the right dose, have the ability to help prevent disease.
What are the dangers of antioxidants?
There are dangers associated with consuming antioxidants. In fact, there are situations where antioxidants become toxic, particularly with chronic consumption of excessive doses.
Clinical studies have observed that chronic, high-dose supplementation can have adverse effects, the opposite of those expected. A few examples are emblematic:
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Beta-carotene supplementation in smokers may increase the risk of lung cancer, as observed in the CARET study.
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Excessive vitamin E supplementation increases the risk of prostate cancer, as observed in the SELECT study where the doses used were nearly 30 times the recommended intake.
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Antioxidant supplementation can be detrimental to the success of cancer treatment. It is crucial not to interfere with cancer treatments, whether chemotherapy or radiation therapy. The goal of these treatments is to kill cancer cells, which taking antioxidants can hinder. As a general rule, all supplementation should be avoided during cancer treatment without the approval of your oncologist.
The best recommendation is to try to maintain an antioxidant intake close to the recommended daily allowance. It is perfectly acceptable to consume antioxidant supplements, but chronic high doses should be avoided.
Antioxidants at Phytocea
At Phytocea, we strive to create the best possible products with real benefits. We've incorporated antioxidants into some of our supplements, particularly our ORetine, a premium dietary supplement. ORetine was developed based on scientific data, aiming to create a super multivitamin designed to support optimal brain and eye function. ORetine contains numerous ingredients specifically formulated to protect the function of these organs.
We have put the best in ORetine, including asthaxanthin and reduced glutathione.
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Sources
Nutritional reference values for vitamins and minerals
