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Oxidative Stress: Difference between revisions
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Additionally, ROS are produced through various physiological and pathological processes, including cellular respiration and inflammatory responses.{{pmid|23063822}} Their generation and subsequent conversion involve enzymes like superoxide dismutase (SOD), catalase, and glutathione peroxidase, which play crucial roles in controlling oxidative stress. | Additionally, ROS are produced through various physiological and pathological processes, including cellular respiration and inflammatory responses.{{pmid|23063822}} Their generation and subsequent conversion involve enzymes like superoxide dismutase (SOD), catalase, and glutathione peroxidase, which play crucial roles in controlling oxidative stress. | ||
==The Oxidative Stress Theory of Aging== | ==The Oxidative Stress Theory of Aging== | ||
The oxidative stress theory of aging posits that the gradual accumulation of oxidative damage to biomolecules is a primary driver of the aging process. This damage increases with age and correlates with a decline in life expectancy in various organisms.{{doi|10.1016/S1566-2772(03)00007-0}} Oxidative damage affects multiple aspects of aging and is a key factor in many age-related diseases. Particularly, telomeres are highly susceptible to oxidative damage, which can lead to accelerated aging and increased risk of age-related diseases.{{pmid|10911951}}{{pmid|12114022}}{{pmid|26785477}} | The oxidative stress theory of aging posits that the gradual accumulation of oxidative damage to biomolecules is a primary driver of the aging process. This damage increases with age and correlates with a decline in life expectancy in various organisms.{{doi|10.1016/S1566-2772(03)00007-0}} Oxidative damage affects multiple aspects of aging and is a key factor in many age-related diseases. Particularly, telomeres are highly susceptible to oxidative damage, which can lead to accelerated aging and increased risk of age-related diseases.{{pmid|10911951}}{{pmid|12114022}}{{pmid|26785477}} | ||
==Controversy and Complexity in Oxidative Stress Research== | ==Controversy and Complexity in Oxidative Stress Research== | ||
While there is substantial evidence linking oxidative damage to aging, the direct relationship between oxidative stress and aging is not conclusively established.{{pmid|12208343}} ROS have complex roles in the body, contributing to cellular homeostasis at physiological levels but causing damage when in excess.{{pmid|28441057}} This dual role is embodied in the concept of mitohormesis, where low levels of ROS can be beneficial. | While there is substantial evidence linking oxidative damage to aging, the direct relationship between oxidative stress and aging is not conclusively established.{{pmid|12208343}} ROS have complex roles in the body, contributing to cellular homeostasis at physiological levels but causing damage when in excess.{{pmid|28441057}} This dual role is embodied in the concept of mitohormesis, where low levels of ROS can be beneficial. | ||
==Impact of Oxidative Stress on Biomolecules== | ==Impact of Oxidative Stress on Biomolecules== | ||
Oxidative stress can lead to damage in various biomolecules: | Oxidative stress can lead to damage in various biomolecules: | ||
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*'''Proteins:''' Oxidation of proteins can alter their structure and function, affecting enzyme activity and signal transduction.{{pmid|9252331}}{{pmid|27026395}}{{pmid|17090414}}{{pmid|2244532}}{{pmid|24632383}} | *'''Proteins:''' Oxidation of proteins can alter their structure and function, affecting enzyme activity and signal transduction.{{pmid|9252331}}{{pmid|27026395}}{{pmid|17090414}}{{pmid|2244532}}{{pmid|24632383}} | ||
*'''Nucleic Acids:''' ROS, especially hydroxyl radicals, can cause oxidative damage to DNA, leading to mutations, strand breaks, and DNA-protein cross-linking, contributing to genome instability and cell death.{{pmid|31733333}}{{pmid|8379000}}{{pmid|23417673}}{{pmid|10720713}}{{pmid|12796402}}{{pmid|2545260}} | *'''Nucleic Acids:''' ROS, especially hydroxyl radicals, can cause oxidative damage to DNA, leading to mutations, strand breaks, and DNA-protein cross-linking, contributing to genome instability and cell death.{{pmid|31733333}}{{pmid|8379000}}{{pmid|23417673}}{{pmid|10720713}}{{pmid|12796402}}{{pmid|2545260}} | ||
== Antioxidants and Their Role in Combating Oxidative Stress == | |||
'''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}} | |||
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.{{pmid|23063822}} | |||
* '''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.{{pmid|29731617}} | |||
* '''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.{{pmid|35159361}} | |||
=== Antioxidants in the Diet === | |||
Diet is a significant source of antioxidants. Foods rich in antioxidants include fruits and vegetables, nuts, grains, some meats, poultry, and fish. These foods provide essential antioxidants like beta-carotene, lycopene, vitamins C and E, and selenium. | |||
=== 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. | |||
=== Limitations and Considerations === | |||
While antioxidants are beneficial, their supplementation is not without limitations. Excessive intake of some antioxidants can be harmful, and the balance between antioxidants and ROS is crucial. The concept of antioxidant supplementation is complex, and more research is needed to fully understand its implications for health and aging. | |||
== Conclusion == | == Conclusion == | ||