Oxidative Stress: Difference between revisions

Line 21: Line 21:


== Antioxidants ==
== Antioxidants ==
{{Main|Antioxidants}}


'''[[Antioxidants]]''' are compounds that can prevent or slow down the oxidation of other molecules. Oxidation is a chemical reaction that can produce free radicals, leading to chain reactions that may damage cells. Antioxidants terminate these chain reactions by removing free radical intermediates and inhibiting other oxidation reactions. They do this by being oxidized themselves, making them crucial in the body's defense against oxidative stress.{{pmid|28441057}}
'''[[Antioxidants]]''' are compounds that can prevent or slow down the oxidation of other molecules. Oxidation is a chemical reaction that can produce free radicals, leading to chain reactions that may damage cells. Antioxidants terminate these chain reactions by removing free radical intermediates and inhibiting other oxidation reactions. They do this by being oxidized themselves, making them crucial in the body's defense against oxidative stress.
 
There are several types of antioxidants, each playing a distinct role in combating oxidative stress:
 
* '''Enzymatic Antioxidants:''' These include enzymes such as superoxide dismutase (SOD), catalase, and glutathione peroxidase, which directly neutralize ROS.
* '''Non-enzymatic Antioxidants:''' This group includes Vitamin C, Vitamin E, and glutathione. These small molecule antioxidants scavenge free radicals and contribute to the repair and regeneration of oxidized antioxidants.
* '''Metal-Binding Proteins:''' Proteins such as ferritin and ceruloplasmin that sequester free iron and copper ions, which can catalyze the production of free radicals, thus reducing oxidative stress.
 
=== Dietary Sources of Antioxidants ===
Diet is a significant source of antioxidants. Foods high in antioxidants include:
 
* '''Fruits and Vegetables:''' Berries, citrus fruits, and leafy greens are high in vitamins C and E, as well as various phytochemicals.
* '''Nuts and Seeds:''' These are sources of vitamin E and selenium, another important antioxidant.
* '''Whole Grains:''' Whole grains contain antioxidants like vitamin E and phytochemicals.
* '''Tea and Coffee:''' Rich in flavonoids, these beverages contribute significantly to the total antioxidant intake.
 
===Antioxidant Supplements ===
Antioxidant supplements have gained popularity as potential aids in combating oxidative stress and its related aging processes. These supplements are concentrated forms of antioxidants that can be taken in addition to a regular diet. However, antioxidant supplements have not shown preventive effects and may be harmful with unwanted consequences to our health. The optimal source of antioxidants seems to come from our diet, not from antioxidant supplements.{{pmid|24241129}}
 
Older observational studies and some randomized clinical trials with high risks of systematic errors ('bias') have suggested that antioxidant supplements may improve health and prolong life. A number of randomized clinical trials with adequate methodologies observed neutral or negative results of antioxidant supplements. Recently completed large randomized clinical trials with low risks of bias and systematic reviews of randomized clinical trials taking systematic errors ('bias') and risks of random errors ('play of chance') into account have shown that antioxidant supplements do not seem to prevent cancer, cardiovascular diseases, or death. Even more, beta-carotene, vitamin A, and vitamin E may increase mortality.{{pmid|17327526}} Some recent large observational studies now support these findings. According to recent dietary guidelines, there is no evidence to support the use of antioxidant supplements in the primary prevention of chronic diseases or mortality.{{pmid|22419320}}{{pmid|24241129}}
 
Here's a list of some widely used antioxidant supplements:
 
* '''Vitamin C (Ascorbic Acid)''': A water-soluble vitamin known for its role in boosting the immune system and scavenging free radicals.
* '''Vitamin E (Tocopherol)''': A fat-soluble vitamin that protects cell membranes from oxidative damage, especially in lipid-rich areas of the body.
* '''Beta-Carotene''': A precursor to vitamin A and a powerful antioxidant, particularly effective against singlet oxygen.
* '''Selenium''': A trace mineral that is a component of antioxidant enzymes like glutathione peroxidase.
* '''Zinc''': Essential for the functioning of several antioxidant enzymes and immune function.
* '''[[Coenzyme Q10 (CoQ10)]]''': An important molecule in energy production and also acts as an antioxidant in cell membranes and lipoproteins.
* '''Flavonoids''': A diverse group of phytonutrients found in many fruits and vegetables, known for their antioxidant properties.
* '''Lycopene''': A carotenoid found in tomatoes, watermelon, and other red fruits and vegetables, known for its antioxidant capacity.
* '''[[Resveratrol]]''': Found in the skin of red grapes, berries, and peanuts, resveratrol is studied for its antioxidant and anti-aging properties.
* '''Curcumin''': The active ingredient in turmeric, curcumin possesses strong antioxidant and anti-inflammatory properties.
* '''Alpha-Lipoic Acid''': A compound that works with mitochondria and the body's natural antioxidant defenses.
* '''Green Tea Extract''': Rich in catechins, green tea extract is renowned for its antioxidant properties.


== Conclusion ==
== Conclusion ==