Free radicals – a term often associated with health, ageing and nutrition. But what exactly are these molecules, and how can we protect ourselves from their potential damage? In this article, we take a detailed look at free radicals, how they are formed and how they affect the body, as well as practical tips on how we can reduce their negative effects through antioxidants and a targeted diet.
Free radicals are unstable molecules or atoms that have at least one unpaired electron. They occur naturally in the body, for example as a result of metabolic processes, but also due to external factors such as environmental pollution, UV radiation or excessive stress.
Due to their instability, they are highly reactive and try to ‘steal’ electrons from other molecules, which can lead to a chain reaction of cell damage. This process is called oxidative stress and is associated with premature skin aging, inflammation and various chronic diseases.
Free radicals can be formed in the body in a number of different ways. A distinction is made here between endogenous (produced by the body itself) and exogenous (external) factors.
Internal processes:
External influences:
Free radicals are produced naturally during our metabolic processes. However, these unstable molecules can cause significant damage if they get out of hand and the body is no longer able to neutralise them sufficiently. Here are some examples of how they can affect the body:
Antioxidants are the natural antagonists of free radicals. They have the ability to neutralise the unstable molecules by providing them with an electron without becoming unstable themselves. In doing so, they interrupt the chain reaction of cell damage and help to protect against oxidative stress. This is why antioxidants are also referred to as radical scavengers.
The most important antioxidants include:
A healthy lifestyle is the key to maintaining a balance between free radicals and antioxidants. Here are some helpful tips:
Eating the right foods is a key part of the fight against free radicals. It is especially important to eat foods that are rich in antioxidants.
|
Food group |
Examples |
Important antioxidants |
|
Fruit |
Berries (blueberries, strawberries, apples, grapes, citrus fruits) |
e.g. vitamin C, flavonoids, anthocyanins |
|
Vegetables |
Green leafy vegetables (spinach, kale, broccoli, pepper,s, carrots, tomatoes) |
e.g. beta-carotene, vitamin E, polyphenols |
|
Nuts & seeds |
Walnuts, almonds, brazil nuts, sunflower seeds, linseeds |
e.g. vitamin E, selenium |
|
Legumes |
Lentils, beans, chickpeas |
e.g. polyphenols, flavonoids |
|
Spices |
Turmeric, ginger, cinnamon |
e.g. curcumin, zingerone, polyphenols |
|
Drinks |
Green tea, coffee |
e.g. catechins, polyphenols |
Sources:
Alkadi, H. (2020). A review on free radicals and antioxidants. Infectious Disorders-Drug Targets (Formerly Current Drug Targets-Infectious Disorders), 20(1), 16-26. https://pubmed.ncbi.nlm.nih.gov/29952268/
Di Meo, S., & Venditti, P. (2020). Evolution of the knowledge of free radicals and other oxidants. Oxidative medicine and cellular longevity, 2020(1), 9829176. https://pubmed.ncbi.nlm.nih.gov/32411336/
Halliwell, B. (2011). Free radicals and antioxidants–quo vadis?. Trends in pharmacological sciences, 32(3), 125-130. https://pubmed.ncbi.nlm.nih.gov/21216018/
Holecek, V. et al. 2004. The significance of free radicals and antioxidants due to the load induced by sport activity. Cesk Fysiol. 53(2):76-9. https://pubmed.ncbi.nlm.nih.gov/15709642/
Kumar, S. (2011). Free radicals and antioxidants: Human and Food System. Adv Appl Sci Res, 2(1), 129-35. https://www.primescholars.com/articles/free-radicals-and-antioxidants-human-and-food-system.pdf
Mathew, B. B., Tiwari, A., & Jatawa, S. K. (2011). Free radicals and antioxidants: A review. Journal of Pharmacy Research, 4(12), 4340-4343. https://www.researchgate.net/publication/262175269_Mathew_B_B_Tiwari_A_Jatawa_S_K_2011_Free_Radicals_and_Antioxidants_A_Review_Journal_of_Pharmacy_Research_412
Phaniendra, A., Jestadi, D. B., & Periyasamy, L. (2015). Free radicals: properties, sources, targets, and their implication in various diseases. Indian journal of clinical biochemistry, 30, 11-26. https://pubmed.ncbi.nlm.nih.gov/25646037/
Tvrdá, E., & Benko, F. (2020). Free radicals: what they are and what they do. In Pathology (pp. 3-13). Academic Press. https://www.sciencedirect.com/science/article/abs/pii/B9780128159729000019?via%3Dihub
