What are free radicals and antioxidants?
Antioxidants and free radicals are naturally occurring molecules. Oxidation is a fundamental process in our nature: We breathe in oxygen, eat food containing glucose, and use both to fuel our body, build cells, tissues, and organs. Carbon dioxide is the useless rest we breathe out. Plants take this carbon dioxide and add water to make oxygen and glucose. Each time a substance combines with water chemically, you call it hydration. In this case, glucose contains carbon and you call the product carbohydrate.
Oxidations can be observed when a cut apple turns brown, iron rusts, and shiny copper turns gets a green patina. It is a form of maturing.
Oxidizing glucose to make energy has many other side-effects: e.g. it produces free radicals. Free radicals are a natural byproduct of our body’s metabolism. And, they are known for their harmful impact. They lack an electron and, therefore, they steal electrons from any nearby substances which alter their function or structure. This can cause a snowballing effect. So, free radicals cause some serious oxidative stress-related diseases such as DNA and neuronal damage, cancer, ischemic stroke, cerebral infarction, and coronary heart diseases.
Parkinson’s and Alzheimer’s disease as well as cataracts can result from free radical damage. Plus, various cardiovascular disorders including arteriosclerosis, cardiac hypertrophy, heart failure, and myocardial infarction are can be caused by excessive oxidative stress.
Furthermore, free radicals can make a circulating low-density lipoprotein molecule (LDL) which is known as „bad cholesterol“ more likely to get trapped in an artery wall.
How do free radicals develop?
Not only after each meal our body produces free radicals, but there are also several other inner causes for free radicals: Being stressed, having a bad cold, drinking alcohol, smoking, and sleeping too little can cause them. Even after having a good workout our body generates free radicals on behalf of the oxidation. Detrimental external effects can be provoked by environmental toxins such as ultraviolet rays, chemicals, and other harmful substances in food, water, and air.
But our body is not defenseless. Naturally occurring antioxidants made by our bodies are able to make them harmless. But our natural antioxidant production declines with age. Besides these self-made molecules to deal with a small number of free radicals, we can get free-radical fighters from our daily food. These defenders are known as antioxidants which are phytonutrients. The fresher and less processed the plant, the fewer antioxidants get lost.
How can antioxidants help?
Plants are experts in self-defense and protection against harmful molecules and free radicals. Unlike us, they cannot run away from intensive sun, aridity, and variations in temperature. So, they have sophisticated protective mechanisms that we can adopt by eating them.
There are hundreds of different substances phytonutrients such as Coenzyme Q10, beta (β-)carotene, lycopene, polyphenol, flavonoids (in berries, wine), folate, vitamins A, C, E, etc.
Antioxidants can be preventive and radical-trapping. Some of them can disable free radicals by giving them electrons generously without becoming free radicals themselves.
They can decelerate natural oxidation due to aging. For example, they can catch free radicals, enhance the DNA enzyme repair systems, and slow down the skin damage process when being exposed to UV radiation.
In a study that lasted more than 10 years with over 17.000 participants, those consuming the most fruits and vegetables appeared to have the lowest risk of suffering cardiovascular and many more diseases.
Antioxidants protect us from ageing
To sum it up: Several studies have reported beneficial effects of antioxidants including dilution of inflammation and protection from DNA damage. Plus, they affect the proliferation rates of malignant cells which is equal to cancer prevention. They even tend to inhibit our body’s absorption of bad cholesterol from food.
Spices and herbs appear to have the highest amount of antioxidants followed by green leafy vegetables and vitamin C-rich fruits. Also, other fruits, nuts, chocolate, and vegetables contain these protective phytonutrients. Just legumes appear to have fewer antioxidants than other vegetables. Several studies showed that plant-based foods contain significantly more antioxidants than non-plant foods. Animal products and processed food tend to have just traces of these beneficial phytonutrients.
Where can I find antioxidants?
Sources of vitamin C are citrus fruits, strawberries, leafy green vegetables, cantaloupe, cabbage, and tomatoes. Cooking can destroy vitamin C because it is water-soluble.
Just as vitamin E, β-carotenes (a vitamin a precursor) are fat-soluble. Sources for both β-carotenes are fruits, yellow-orange vegetables like carrots, squash, sweet potatoes, and deep-green vegetables such as spinach and broccoli. You can find Vitamin E in vegetable and seed oils, wheat germ, fruits, and vegetables. Because they are fat-soluble you should combine them with oil (e.g. salad dressing) to be able to absorb them.
We live in a world which is getting faster and faster and we tend to be more and more stressed. We are exposed to harder mental pressure at work, tend to sleep too little, and eat more processed food lacking fiber and antioxidants. Stress is getting heavier while we tend to neglect our body’s defenses. For thousands of years, our inner defense had to deal with the simple problems of hunters and gatherers in their tiny little world.
Nowadays, we have to deal every day with various problems at work, with our children’s schooling, safety, and future, with more environmental toxins, cosmic and manmade radiation and world problems. Our stress level is way higher than years ago and our own antioxidants are unable to cope with this situation. Therefore, we need to provide external support by providing them antioxidants. There is no one best superfood for all – it is better to eat the whole rainbow, 5-a-day.
Here you can find all sources used for this blog post
Bull-Cosiales, P./Martinez-Gonzalez, M. A./Ruiz-Canela, M./Diez-Espino, J./García-Arellano, A./Toledo, E. 2017: Consumption of Fruit or Fiber-Fruit Decreases the Risk of Cardiovascular Disease in a Mediterranean Young Cohort, in: Nutrients, Vol. 9, 2017, No. 3.
http://www.mdpi.com/2072-6643/9/3/295/htm
Carlsen, M. H./Halvorsen, B. L./Holte, K./Bøhn, S. K./Dragland, S./Sampson, L./Willey, C./Senoo, H./Umezono, Y./Sanada, C./Barikmo, I./Berhe, N./Willett, W. C./Phillips, K. M./Jacobs, D. R. Jr./Blomhoff, R. 2010: The total antioxidant content of more than 3100 foods, beverages, spices, herbs and supplements used worldwide, in: Nutrition Journal, Vol. 9, 2010, No. 3.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2841576/
Choe, H./Hwang, J.-Y./Kim, J.-M./Song, T.-J./Chang, N./Kim, Y.-J./Kim, Y. 2016: Intake of antioxidants and B vitamins is inversely associated with ischemic stroke and cerebral atherosclerosis, in: Nutrition Research and Practice, Vol. 10, 2016, No. 5, pp. 516-523.
https://e-nrp.org/DOIx.php?id=10.4162/nrp.2016.10.5.516
Godić, A./Poljšak, B./Adamić, M./Dahmane, R. 2014: The Role of Antioxidants in Skin Cancer Prevention and Treatment, in: Oxidative Medicine and Cellular Longevity, Vol. 2014, 2014.
https://www.hindawi.com/journals/omcl/2014/860479/
Jain, A. K./Mehra, N. K./Swarnakar, N. K. 2015: Role of Antioxidants for the Treatment of Cardiovascular Diseases: Challenges and Opportunities, in: Current Pharmaceutical Design, Vol. 21, 2015, No. 30, pp. 4441-4455.
Johnson, I. T. 2004: New approaches to the role of diet in the prevention of cancers of the alimentary tract, in: Mutation Research, Vol. 551, 2004, No. 1-2, pp. 9-28.
Joshipura, K. J./Ascherio, A./Manson, J. E./Stampfer, M. J./Rimm, E. B./Speizer, F. E./Hennekens, C. H./Spiegelman, D./Willett, W. C. 1999: Fruit and vegetable intake in relation to risk of ischemic stroke, in: JAMA, Vol. 282, 1999, No. 13, pp. 1233-1239.
http://jamanetwork.com/journals/jama/fullarticle/191962
Joshipura, K. J./Hu, F. B./Manson, J. E./Stampfer, M. J./Rimm, E. B./Colditz, G./Ascherio, A./Rosner, B./Spiegelman, D./Willett, W. C. 2001: The effect of fruit and vegetable intake on risk for coronary heart disease, in: Annals of Internal Medicine, Vol. 134, 2001, No. 12, pp. 1106-1114.
Kristo, A. S./Klimis-Zacas, D./Sikalidis, A. K. 2016: Protective Role of Dietary Berries in Cancer, in: Antioxidants, Vol. 5, 2016, No. 4.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5187535/
Li, B./Pratt, D. A. 2015: Methods for determining the efficacy of radical-trapping antioxidants, in: Free Radical Biology & Medicine, Vol. 82, 2015, pp. 187-202.
Poljšak, B./Dahmane, R./Godić, A. 2013: Skin and antioxidants, in: Journal of Cosmetic and Laser Therapy, Vol. 15, 2013, No. 2, pp. 107-113.
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