Internal factors such as inflammation and external factors such as pollution, UV exposure and cigarette smoke can increase free radical production.
Free radicals can damage cells all over the body and cause oxidative stress. Oxidative stress has been closely associated with heart disease, cancer, arthritis, stroke, respiratory diseases, immune deficiency, emphysema, Parkinson's disease and other inflammatory or ischemic conditions.5
Tomatoes are a source of lycopene, an antioxidant that provides them with their red color.
Antioxidants serve as protection against the cell damage that free radicals can cause by terminating the free radicals reaction with those cells. Some antioxidants are products of normal metabolism and others are found in food.
Synthetic antioxidants are widely used in the cosmetic and food industries, but may cause more harm than good due to their high volatility. As a result, it is important to obtain your antioxidants from natural sources as much as possible.5
Micronutrients such as vitamin C, vitamin E and beta-carotene, minerals such as selenium and manganese and many other flavonoids, polyphenols and phytoestrogens found in food all serve as antioxidants.
Each antioxidant serves a different function and is not interchangeable with another. This is why a varied diet is so important.
The best sources of antioxidants are plants (fruits and vegetables). Foods that are particularly high in antioxidants are often referred to as a "superfood" or "functional food" and include many types of berries, leafy greens, eggplant, legumes such as black beans or kidney beans and certain teas. Foods with rich, vibrant colors often contain the most antioxidants.
The following foods are also good sources of antioxidants. Click on each one to find out more about their health benefits and nutritional information:
Cooking particular foods can either increase or decrease antioxidant levels. Lycopene is the antioxidant that gives tomatoes their rich red color. When tomatoes are heat-treated, the lycopene becomes more bio-available (easier for our bodies to process and use).
However, studies have shown that cauliflower, peas and zucchini lose much of their antioxidant activity in the cooking process. Keep in mind that the important thing is eating a variety of antioxidant-rich foods, cooked and raw, so that preparation can be your personal preference.
The following tips could help increase your antioxidant intake:
- Make sure you have a fruit or a vegetable every time you eat, meals and snacks included
- Have a daily green or matcha tea
- Look at the colors on your plate; is all of your food brown or beige? If so, it is likely that the antioxidants are low. Add in foods with rich color like kale, beets and berries
- Spice it up! Make turmeric, cumin, oregano, ginger, clove and cinnamon your go-to spices to amp up the antioxidant content of your meals
- Snack on nuts, seeds (especially Brazil nuts and sunflower seeds) and dried fruit (with no sugar or salt added).
Or, try these healthy and delicious recipes developed by registered dietitians:
- Cherry-almond smoothie
- Spicy cinnamon-ginger roasted carrots
- Roast beet and red quinoa salad with orange-beet balsamic vinaigrette
- Carrot cake power smoothie
- Chickpea, kale and cashew superfood soup
- Spicy Thai lettuce wraps
- Cure-all juice.
There is no set recommended daily allowance (RDA) for antioxidants.
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