Introduction to antioxidants


Our bodies are extraordinarily complex and are perpetually engaged in internal processes of metabolism to keep us alive. These processes create what are known as free radicals that can cause oxidative stress. In addition, we subject ourselves to a host of environmental circumstances that produce free radicals, such as too much sun exposure, tobacco smoke, deep fried foods, pollution, alcohol, stress, and sugar.


A free radical is an atom or molecule that has an unpaired electron. Oxygen is a highly reactive element that steals electrons from stable molecules and can start a chain reaction of free radicals. This is known as oxidation and it causes the cell damage that can lead to inflammation and diseases such as diabetes, dementia, cardiovascular disease, cancer, cataracts and more. It’s also believed to contribute to accelerated aging. Things such as our DNA, fatty acids, and cellular tissue are vulnerable. We know oxygen is critical to life, which means that free radicals and oxidation are a part of life. Their occurrence is as important as they are damaging.  Our bodies use free radicals in a controlled fashion to kill unwelcome microbial organisms. It is important that we give our bodies the tools to control free radicals as needed; it is a delicate balance.  It should come as no surprise that we maintain the balance, in part, by consuming antioxidants in our daily diet.


Once we understand free radicals, understanding antioxidants is easy. Basically, antioxidants neutralize free radicals by providing electrons thereby terminating the chain reaction that can lead to inflammation and other damage. Ideally one gets antioxidants from the foods they consume and not from supplements.

L-Ascorbic Acid

VITAMIN C as an antioxidant: Vitamin C is a water-soluble vitamin also known as ascorbic acid. Unlike most mammals, humans cannot biologically manufacture Vitamin C, and we must get it from our diet. Vitamin C is important for a number of processes to maintain good health and not just as an antioxidant. Fortunately, there are many sources, including sweet peppers, broccoli, Brussels sprouts, citrus, white potatoes, parsley, kiwi fruit, strawberries, and tomatoes, to name a few. Because it is easily damaged by high heat and time, it’s best to eat these foods soon after picked or purchased. It helps when cooking to do it quickly such as stir frying or microwaving. Buying frozen vegetables instead of fresh can ensure a better source of some nutrients, including Vitamin C. Although it is important to know about the volatility of Vitamin C, simply eating a good variety of plant based foods will ensure you are getting adequate amounts. Supplements can be used, but if you’re healthy and eating a good diet, then supplements are unnecessary. Toxicity is not common with Vitamin C, but if supplementation is desired, it’s ideal to limit it to the RDA of 90 mg/day for men and 75 mg/day for women with an upper limit of 2,000 mg/day and/or under the advisement of a healthcare professional.

VITAMIN E as an antioxidant: Vitamin E is known as α-tocopherol in its natural and biologically preferential form. Although there are many forms that may prove beneficial, this form is the predominant form in human biology. It is a fat-soluble vitamin and is known primarily for its antioxidant properties in lipids (fats and cholesterol). It has an important role to protect the lipids in the cell walls and is thought to facilitate the adaptive immune system and improve cell communication.  Vitamin E prevents the oxidation of the lipid LDL cholesterol, which when oxidized is known to cause cardiovascular damage and heart disease. The best dietary sources of Vitamin E are unsaturated vegetable oils (soybean, safflower, corn, olive, canola, etc.), nuts, nut butters, seeds, avocados, greens, and wheat germ/wheat germ oil. Vitamin E is fairly stable in heat and light, but in the presence of oxygen, it oxidizes more rapidly, such as in deep-frying. In the body, Vitamin C is known to replenish the antioxidant properties of Vitamin E. The adult RDA for Vitamin E is 15 mg/day with an upper limit of 1,000 mg. Like Vitamin C, there is usually enough Vitamin E in a balanced diet that one doesn’t need supplements. Excessive supplementation can encourage bleeding and may interfere with the absorption of vitamins A and K, which are also fat soluble vitamins.

Vitamin E and Vitamin C are two known powerful antioxidants, but there are others. At the very least they include selenium, Vitamin A, the carotenoid family (Β-carotene, α-carotene, lycopene, lutein, Β-cryptoxanthin, and zeaxanthin) and a multitude of other phytochemicals. Science is still researching and learning about many of the phytochemicals and their functions. Phytochemicals are found in abundance in colorful fruits and vegetables, coffee, tea, herbs and spices. When it comes to getting the most from antioxidants in food, the recommendation remains the same: eat a healthy and balanced diet each day with a focus on minimally processed foods, fruit, vegetables, healthy fats, lean proteins, and whole grains.

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