What is an antioxidant?
This is a compound that inhibits oxidation, a chemical reaction that produces free radicals. This can lead to polymerization and other chain reactions. Antioxidants are often added to industrial products such as fuels and lubricants to prevent oxidation, and especially to foods to prevent oils and fats from spoiling. Oxidatives and enzymatic systems, such as superoxide dismutase, can prevent damage from oxidative stress.
Types of antioxidants
There are hundreds, perhaps thousands, of different substances that act as antioxidants. The best known are vitamin C, vitamin E, beta-carotene and other related carotenoids, and the minerals selenium and manganese. It also contains glutathione, coenzyme Q10, lipoic acid, flavonoids, phenols, polyphenols, phytoestrogens, and more. Most occur naturally and their presence in food may prevent oxidation or act as a natural defense against the local environment.
It is believed that there are hundreds, possibly thousands, of substances that can act as antioxidants. Each has its own role and can interact with other types to help the body function effectively.
"Antioxidant" is not really the name of a substance, but describes what a substance can do.
- Vitamin C
- Vitamin E
- Beta Carotene
Flavonoids, flavones, catenates, poly estrogens, poly estrogenic antioxidants, and phytonutrients are all found in plant foods.
Each antioxidant serves a different function and is not interchangeable with the other and therefore, it is essential to have a varied diet.
Sources of antioxidants
One reason many studies on antioxidant supplements fail to show health benefits is that antioxidants tend to work best in combination with other nutrients, phytochemicals, and even other antioxidants.
For example, one cup of fresh strawberries contains about 80 mg of vitamin C, a nutrient known to be rich in antioxidants. However, a supplement containing 500 mg of vitamin C (667% of the RDA) does not contain phytochemicals (polyphenols) such as proanthocyanins and flavonoids found naturally in strawberries. disease. Polyphenols have many other chemical properties in addition to their ability to act as antioxidants. The question arises whether nutrients with antioxidant activity can produce the opposite effect on prooxidant activity if taken in excess. For this reason, using an antioxidant supplement containing a single isolated compound may not be an effective strategy for everyone.
A prospective epidemiological study found that higher intakes of antioxidant-rich fruits, vegetables, and legumes were associated with lower rates of chronic oxidative stress-related diseases, such as cardiovascular disease, cancer, and all-cause mortality; and plant-based diets are believed to protect against chronic oxidative stress-related diseases. Though it is still not clear if this protective effect is due to the antioxidants, other substances in the foods, or a combination of both. The following are nutrients with antioxidant activity and the foods in which they are found:
- Vitamin C: Broccoli, Brussels sprouts, cantaloupe, cauliflower, grapefruit, leafy greens (turnip, mustard, beet, collards), honeydew, kale, kiwi, lemon, orange, papaya, snow peas, strawberries, sweet potato, tomatoes, and bell peppers (all colors)
- Vitamin E: Almonds, avocado, Swiss chard, leafy greens (beet, mustard, turnip), peanuts, red peppers, spinach (boiled), and sunflower seeds
- Carotenoids including beta-carotene and lycopene: Apricots, asparagus, beets, broccoli, cantaloupe, carrots, bell peppers, kale, mangos, turnip and collard greens, oranges, peaches, pink grapefruit, pumpkin, winter squash, spinach, sweet potato, tangerines, tomatoes, and watermelon
- Selenium: Brazil nuts, fish, shellfish, beef, poultry, barley, brown rice
- Zinc: Beef, poultry, oysters, shrimp, sesame seeds, pumpkin seeds, chickpeas, lentils, cashews, fortified cereals
- Phenolic compounds: Quercetin (apples, red wine, onions), catechins (tea, cocoa, berries), resveratrol (red and white wine, grapes, peanuts, berries), coumaric acid (spices, berries), anthocyanins (blueberries, strawberries)
Pros and cons
What are the pros of antioxidant foods on the brain?
The biochemical integrity of the brain is vital for the normal functioning of the central nervous system (CNS). One of the factors contributing to cerebral biochemical impairment is a chemical process called oxidative stress. Oxidative stress occurs upon excessive free radical production. The brain, with its high oxygen consumption and lipid-rich content, is highly susceptible to oxidative stress. Therefore, oxidative stress–induced damage to the brain has a strong potential to negatively impact normal CNS functions. 1 Luckily, antioxidants, for example, flavinoids, can easily counteract this effectHowever, for flavinoids to reach brain cells, they are absorbed in the intestine and cross the blood-brain barrier (BBB) or blood-cerebrospinal fluid barrierThere is evidence that some flavonoids in onions, such as quercetin, cross this barrier without the need for a transport mechanism.
Once absorbed in the blood and transported to the brain, antioxidants can prevent oxidative stress in brain cells. This is particularly important because the adult brain virtually stops replacing dead or dying neurons.
In fact, most studies have examined the relationship between flavonoids and cardiovascular health. Epidemiological and observational studies have found that high flavonoid intake generally lowers blood pressure or improves cardiovascular health. However, imaging studies have shown that even one flavonoid-rich meal can cause a short-term increase in blood flow to the brain due to the effects on endothelial cells (cells that line blood vessels) that he introduced in his first week. I know
However, the long-term effects of a flavonoid-rich diet appear to be associated with an increase in the number of connections between neurons. It is the primary way to store information and adapt to changing environments and passage of time. This is a process called neuroplasticity.
What are the cons of antioxidant foods on the brain
Not all antioxidants are obviously helpful. Antioxidants such as beta-carotene (from carrots) and lycopene (from tomatoes), as well as vitamins C and E, are said to protect against cancer and aging by reducing or preventing the effects of free radicals. However, reducing the number of free radicals may not help. Free radicals are essential for intracellular energy metabolism and the protective function of neutrophils (a type of white blood cell) against pathogens.
Also, under certain conditions, antioxidants can do the opposite - they become pro-oxidants. Beta-carotene and vitamin C are famous for these effects. In fact, two studies of high-dose beta-carotene supplementation found that beta-carotene supplementation increased cancer risk.
A thorough systematic review by the Cochrane Hepatobiliary Group found that 68 randomized trials involving 232,606 participants found that "beta-carotene, vitamin A, and vitamin E treatment may increase mortality.
In the brain, reactive oxygen species (ROS)damages blood vessels and tissues, causing cells to be deprived of oxygen from poorly perfused tissues. increase. This can damage these cells. However, this situation can be exacerbated when antioxidants become pro-oxidants. FAQs
What are the effects of cooking antioxidant foods?
Boiling usually causes antioxidant loss. It decreases the antioxidant levels in vegetables as they leach into the water.
What are the ways to increase antioxidant intake ?
Plants are the best sources. These include fruits, vegetables, whole grains, nuts, seeds, herbs, spices, and even cocoa. As a bonus, antioxidant-rich fruits, vegetables, and whole grains are typically high in fiber. It's high, and low in saturated fat and cholesterol, and is also a good source of vitamins and minerals.
How much antioxidant foods should I eat?
It is estimated that a man who eats an average of about 2500 calories per day needs at least 11,000 ORAC units. A woman who consumes about 1800 calories per day should consume at least 8000 units.
Is it okay to eat antioxidant foods daily?
Antioxidant supplements are generally considered good for health, but too much can cause problems. In general, the antioxidants your body needs are much better obtained from a healthy diet.
Antioxidants or free radical scavengers are molecules that can reduce or prevent the oxidation of other molecules. Oxidation reactions transfer electrons from a substance to an oxidant. During this process, free radicals are generated that start chain reactions that damage animal cells. Antioxidants slow down these chain reactions by scavenging free radical intermediates and eventually prevent other oxidation reactions by being oxidized themselves. play a role. thiols or polyphenols. In general, water-soluble antioxidants react with oxidants in the cell cytoplasm and plasma, whereas lipid-soluble antioxidants protect cell membranes from lipid peroxidation. These compounds can be biosynthesized or obtained from the diet. Various antioxidants are present in a wide range of concentrations in body fluids and tissues, and some, such as glutathione and ubiquinone, are predominantly intracellular, while others, such as uric acid, are more evenly distributed. In general, they prevent the formation of free radicals, neutralizes those that are formed, or repairs damage caused by free radicals. The use of antioxidants as dietary supplements is not universally proven to replace the use of natural or food-based antioxidants.
Although oxidation reactions are essential to life , they can be harmful. Therefore, all living animals and plants have a complex system of antioxidant enzymes such as catalase, superoxide dismutase, various peroxidases, and other antioxidants such as glutathione, vitamin C and vitamin E. Low levels of antioxidants or inhibition of antioxidant enzymes can cause oxidative stress and damage or kill cells
- Salim, Samina. "Oxidative Stress and the Central Nervous System." The Journal of Pharmacology and Experimental Therapeutics 360, no. 1 (2017): 201-205. Accessed December 17, 2022. https://doi.org/10.1124/jpet.116.237503.