Cell's trend of pharmaceutical science magazine published the latest issue of the two Dutch scientists to write a project review, review in recent years, people's attitudes towards antioxidant health effects from believe to track changes, think it more or less mixed with all kinds of don't understand or misunderstanding and even bad solution, and from the Angle of the pharmacological science and the latest achievements on the knowledge of antioxidants positive solution is given, and this is of great benefit for people to correctly understand and use antioxidant.
In organisms, oxidation and anti-oxidation are a pair of contradictory bodies, which are antagonistic and interdependent. Oxidation reaction is the basic process of life activity, and anti-oxidation reaction is due to oxidation reaction. The oxidative reaction itself is harmless to the body and is harmful to its by-products - reactive oxygen species (ROS), such as superoxide anion free radicals, hydroxyl free radicals, hydrogen peroxide and so on.
The normal body has an antioxidant system capable of removing reactive oxygen species, consisting of macromolecular antioxidant enzymes (such as superoxide dismutase, catalase, glutathione peroxidase, etc.) and small molecule antioxidants (such as vitamin C, vitamin E, etc.). Since antioxidant systems are perfectly capable of protecting themselves from oxidative damage, why should people take on extra antioxidants?
It is generally believed that the body cannot synthesize small molecules of antioxidants and must be ingested from food, while the synthesis capacity of large molecules of antioxidant enzymes will gradually weaken with aging, not enough for "positive energy" (antioxidant activity) to overwhelm "negative energy" (reactive oxygen). Therefore, proper supplementation of antioxidants in the elderly may help to eliminate the excessive production of reactive oxygen in the inflammatory response, otherwise it is likely to promote the occurrence of senile diseases in advance.
So far, though, the relationship between age and antioxidant power has been a contentious issue. At the same time, recent studies in yeast and mice have found that moderate hydrogen peroxide can induce the expression of antioxidant enzyme gene, improve the overall antioxidant capacity of cells, and instead contribute to anti-aging and life extension.
Of course, excess reactive oxygen species that exceed the body's ability to remove them are harmful to health, and this requires the right antioxidants. The following is a detailed explanation of the top 10 misunderstandings people have about antioxidants, and based on the explanation of the reasons for these misunderstandings, the proper understanding and use of antioxidants are proposed.
Misinterpret one antioxidant as a cure-all
The pathogenesis of some diseases promotes the occurrence of reactive oxygen species, so it is believed that antioxidants can be used to treat these diseases. People with copd, for example, can exhale hydrogen peroxide. Cerebral ischemia reperfusion injury is caused by reactive oxygen species. In atherosclerosis, low-density lipoprotein (LDL) is oxidized and consumed by macrophages to form foam cells involving reactive oxygen species (ros). Reactive oxygen species produced by some drugs (furantoin, doxorubicin) can cause heart and lung damage. There is a high expectation that antioxidants will be used to treat many diseases.
However, the effect of antioxidants is mostly based on the results of in vitro experiments, and its effect in vivo may not be effective. In fact, the bioavailability of antioxidants is an important limiting factor. For example, polyphenols are basically difficult to use by the human body.
Misinterpret secondary antioxidants to increase mortality
A recent clinical trial showed that supplementation with antioxidants increased mortality in patients with a variety of diseases, but repeated trials denied that. Still, people tend to think of antioxidants as less safe. Although the protective effect of vitamin E on coronary heart disease has been preliminarily observed, the results of large-scale formal clinical trials have been disappointing, and it is speculated that the dietary interference was caused by the dietary interference of the subjects, and some of the subjects had significantly higher levels of lipid peroxidation than others, and had a higher risk of cardiovascular disease, so the effect of taking vitamin E was better. The role of vitamin E in cardioangiopathy often varies with the broad definition of the disease.
The more antioxidants you get, the better
High doses of antioxidants can also cause toxicity problems, and the claim that more is better is false. The recommended dose of beta-carotene, A precursor to vitamin A, is 2-7 milligrams A day, and men who were given 20 milligrams of beta-carotene A day increased their chances of developing lung cancer by 18 percent. Now it seems that the famous scientist Pauling used to advocate for high doses of vitamin C (1000 mg/day), as it is far beyond the recommended dose (75~90 mg/day).
Misinterpret high doses of antioxidants as pro-oxidants
In the presence of transition metal iron, ascorbic acid (vitamin C), an electron donor, exhibits oxidation. In vitro, iron catalyzes slight lipid peroxidation, while ascorbic acid promotes lipid peroxidation by reducing iron. At higher concentrations, ascorbic acid inhibited lipid peroxidation. Therefore, ascorbic acid is a pro-oxidant at low concentrations and an antioxidant at high concentrations. Some people take 500 milligrams of vitamin C a day, and six weeks after taking it, the plasma level of vitamin C increases by 60 percent, resulting in increased base oxidation in peripheral blood lymphocyte DNA. Critics argue that DNA oxidation does not occur in the body, but results from a process of separation, and that vitamin C levels in lymphocytes are unknown.

Myth # 5: any antioxidant is equivalent


There are many kinds of antioxidants in different structures and properties. In terms of chemical structure, there are sulfhydryl groups, phenols, amine antioxidants. In terms of solubility, there are also water-soluble and fat-soluble antioxidants. Therefore, different antioxidants have different effects. Hydroxytyrosol is best for anti-ldl oxidation because its lipophilic and hydrophilic properties allow it to work on the oil-water interface.
Misunderstanding the behavior of hexadecanes does not meet theoretical expectations
One misconception is that the effectiveness of antioxidants depends on the rate at which they quash reactive oxygen species, and that they provide effective protection only when they react quickly with free radicals (highly reactive hydroxyl radicals). In fact, lipid peroxide radicals on cell membranes have a much longer half-life than hydroxyl radicals and can therefore be neutralized by vitamin E to provide protection. In addition, indirect antioxidant effects, such as anti-inflammation, also provide protection.
Misinterpret seven antioxidant levels to determine health
The current methods of antioxidant status measurement are lack of specificity, but they can reflect the overall antioxidant status, so they can be used to measure the severity of the disease.
Misinterpret the eight antioxidants as inactivation
Dihydrosulfinic acid is still an effective scavenger of hypochlorous acid after being oxidized to sulfinic acid. The antioxidant metabolites of glucoside acidification and methylation can maintain their biological activity. Macrophages and neutrophilic granulocytes release an enzyme called iv-glucosidase, which removes glucosidic acid from flavonoids and restores its natural activity.
Misunderstanding 9 natural antioxidants are best
People always associate nature with safety and conflate synthesis with danger. People prefer biological to chemical antioxidants. In fact, synthetic and natural tocopherol (vitamin E) are the same chemical molecule. Similarly, natural vitamin C has the same chemical structure as l-ascorbic acid.
Ten antioxidants are not effective
The human body has its own antioxidant system, but some compounds (such as n-acetylcysteine, propofol, etc.) can enhance the antioxidant performance of the system, although they have not yet been used as therapeutic drugs. Antioxidants can reduce the effectiveness of the anti-tumor drug doxycycline, but also reduce its induced heart activity.
To sum up, antioxidants are not the only guarantee of health, but they are not "highly toxic drugs". The idea that natural antioxidants are the best choice is not true, and that "antioxidants are not effective" is even more arbitrary.