Oxidative stress is caused by an imbalance between the production of reactive oxygen and the biological system’s ability to rapidly detoxify intermediate reagents or easily repair the resulting damage.
All forms of life have a reducing environment inside the cells. The average reduction is preserved by a series of enzymes that act to maintain this environment with a constant stock of metabolic energy. Disturbances that might occur in the normal state can cause toxic reactions embodied in the production of peroxides and free radicals, which will affect all cellular components, including lipids, proteins and DNA.
It is believed that oxidative stress causes the appearance of several diseases. The process was quantified by measuring the level of oxidative stress as a result of the oxidation state of small molecules called glutathione. Normally, the glutathione protects cells from oxidative stress. Oxidative stress is caused by reactive oxygen compounds, which include free radicals. If a cell is exposed to more reactive oxygen compounds, it may degrade instantly. The result is damage to proteins, DNA, lipids, and other macromolecules in the body.
Causes and consequences of oxidative stress
Oxidative stress is induced by several environmental factors such as UV rays, invasion of pathogens, herbicides and pollution.
Also, dietary factors are a major cause of oxidative stress. Vitamins E and C are important for strengthening the network of antioxidants that fight oxidative stress. Another cause of oxidative stress is strenuous physical exercise.
Glycation occurs when a sugar molecule, such as glucose, attaches to a protein lipid molecule in the same cell. This process can trigger a series of chemical reactions that can induce oxidative stress, and the occurrence of health complications.
Many drugs contain toxins that can cause underlying processes triggering oxidative stress. They can, in some cases, inhibit DNA functionality or production of enzymes, both crucial in glycolysis and oxidation steps. Limiting these activities could produce large amounts of free radicals.
In chemical terms, oxidative stress indicates a sharp increase in cellular reduction potential. Effects of stress depend on how a cell is able to overcome oxidative stress modifications and how quickly it can regain its original state.
The long term effect consists of DNA damage. Most chemical oxygen species are produced at low levels of normal aerobic metabolism and damage to cells is repaired constantly. However, there is also the case when the cell may simply fail under constant aggressive action and oxidative stress.
In humans, oxidative stress is involved in the development of several diseases including atherosclerosis, Parkinson’s disease, heart failure, myocardial infarction, Alzheimer disease, cataracts, cancer, fragile X syndrome and chronic fatigue syndrome. Also, when present the short-term oxidative stress may play an important role in the aging process through a process called mitohormesis. Reactive oxygen species can be beneficial for the body if used by the immune system as a way to attack and kill pathogens.
Oxidative stress and antioxidants
To counteract the effects of oxidative stress, the body produces an armory of antioxidants. However, the domestic production of antioxidants of the human body is apparently not enough to neutralize the harmful action of free radicals. Antioxidants protect the body by assessing the oxidative stress damage to the DNA and by slowing abnormal cell division down.
You can help your body to defend itself by increasing the dietary antioxidants. Antioxidants are found primarily in the composition of fruits and vegetables. Therefore, a diet rich in fruits and vegetables can prevent cell damage caused by free radicals.
– Tomatoes – They contain a pigment called lycopene which gives the red color and is a powerful antioxidant. Tomatoes in all their forms are a major source of lycopene (including tomato juice, ketchup, canned and so on). Lycopene is also found in large enough quantities in watermelons.
– Citrus fruits – Oranges , grapefruit and lemons have many natural substances that protect the organism from diseases. Among these, the most important are carotenoids, flavonoids, terpenes, and limonoidele cumarinele. Together, these phytochemicals act stronger than separated. Appropriate would be to eat whole fruits in their natural form, as their positive effect can be dimmed when drinking their juice.
– Tea – Black tea, green tea, and other teas have antioxidant properties. Most contain catechins, which are antioxidants, with a positive effect on overall health.
– Carrots – Beta-carotene is an orange pigment found in concentrated form in the orange and green vegetables (chlorophyll pigment orange cover). Beta-carotene is an antioxidant that has been associated with lower probability of occurrence of lung cancer. However, to confirm this theory more extensive studies are needed.