Simply put, too much oxidative stress can have negative health effects. However, a diet rich in antioxidants is essential for good health. But what exactly is oxidative stress and what effects does it have on the body?
What is oxidative stress?
Oxidative stress is a condition in the body in which excessive amounts of free radicals are formed and released. If the body's own protective mechanisms are inadequate or there is a lack of antioxidants, the free radicals can damage cells and lead to cellular stress.
What are free radicals?
Free radicals are molecules or metabolic products that contain an unpaired electron and are therefore extremely reactive. To achieve their natural state of preferentially paired electrons, free radicals react with other molecules, thereby removing an electron (= "oxidation"). This interaction changes the other molecule that loses an electron. This can result in damage to chemical compounds such as proteins or fats, impairing their function.
In the human body, many of the free radicals are unstable oxygen species (ROS), which are formed as metabolic products of energy metabolism. In addition to ROS, there are also reactive nitrogen species (RNS), which can also cause cellular damage.
How is the cell damaged by oxidative stress?
Free radicals can react with fats (lipids), proteins, and genetic material (DNA). The oxidation of unsaturated fatty acids in cell membranes can lead to membrane damage in both the mitochondria (the "power plants of the cells") and the cell membrane. The oxidation of proteins can cause them to fold incorrectly or lose their normal structure, thus no longer performing their function properly. The oxidation of DNA can lead to genetic changes and mutations that result in cell death or altered growth with an increased risk of cancer. These mechanisms can thus accelerate the aging process or promote the development of (chronic) diseases.
External influences can also cause oxidative stress. A visible example is the severely aged and wrinkled skin of smokers, caused by free radicals in cigarette smoke, or by long-term, increased sun exposure, caused by the formation of free radicals from UV radiation.
To counteract oxidative stress, cells have protective mechanisms against free radicals, including antioxidants. Indeed, oxidation processes are constantly occurring in cells. However, oxidative stress is only referred to when there are more free radicals than the body can compensate for, resulting in damage.
What are antioxidants?
In short, antioxidants are substances that can scavenge free radicals. As already mentioned, free radicals steal an electron from other compounds and change them. Antioxidants, on the other hand, can donate an electron and still remain stable. Antioxidants therefore react with free radicals, so that cell structures are not damaged by oxidative stress, or are only damaged to a lesser extent.
Endogenous and exogenous antioxidants
A distinction is made between endogenous antioxidants ( glutathione ), which are produced by the body itself, and exogenous antioxidants. Besides vitamin C , vitamin E , zinc , selenium , curcumin , coenzyme Q10 , and beta-carotene are the best-known antioxidants that are not produced by the body but are ingested through food. Both forms of antioxidants are essential and work together in different ways to neutralize free radicals or prevent their formation.
It's always about balance
The formation of free radicals occurs in the body every day, all the time. Energy production in the mitochondria occurs through a chain reaction of free radicals. However, free radicals are by no means undesirable metabolic products; they are also a crucial part of the immune system, killing bacteria and transmitting signals between cells. However, too many free radicals can damage cells. Therefore, the balance between free radicals and antioxidants determines whether oxidative stress occurs.
Does it make sense to take additional antioxidants?
With our modern lifestyle in today's society, the formation of free radicals is stimulated, particularly by external influences such as air pollution, smoking, medication, pesticides, and UV radiation. At the same time, the absorption of antioxidants is limited by unbalanced dietary habits and processed foods. Furthermore, (chronic) inflammation can contribute to increased production of free radicals. Likewise, digestive disorders or a damaged intestinal mucosa can lead to fewer antioxidants being available to the body. This often shifts the balance toward free radicals, so that chronic oxidative stress has a negative impact on our health and the aging process. With increasing age, the body loses the ability to neutralize free radicals and protect itself from their effects.
Therefore, it is important to protect yourself from the effects of oxidative stress with a healthy, balanced lifestyle as a key to healthy aging. Taking antioxidant supplements can help offset increased demand and restore and maintain the balance between free radicals and antioxidants.
