On average, plant foods contain 64 times the antioxidant power of animal products. This may be why those eating a plant-based diet, even for a relatively short amount of time, generally have higher antioxidant levels. The meat industry has considered adding plant foods to meat in order to boost antioxidant levels, though ironically this may make processed meat more carcinogenic.
Antioxidant supplements do not appear to have the same benefits as whole foods, and may even decrease lifespan. Antioxidant intake from foods, not supplements, is associated with lower risk for asthma, depression, non-Hodgkin’s lymphoma, stomach cancer, and esophageal cancer.
Antioxidants help protect against free radicals (see also here) and DNA damage (see also here), including countering possible DNA damage caused by high-intensity exercise or ionizing radiation exposure from air flights.
Antioxidants may enhance dental health, protect against skin aging, slow general aging (see also here), reduce Alzheimer’s risk, reduce inflammation, maintain male fertility (see also here) and sexual function, prevent and treat chronic obstructive pulmonary disease (COPD), prevent and treat asthma, prevent the hardening of arteries, reduce risk for stroke, heart attack, heart disease, and cancer (see also here and here), lower cholesterol, block the formation of nitrites into carcinogens, and increase stool size (associated with lower cancer risk).
A daily antioxidant goal in the U.S. for men to aim for is at least 11,000 units a day, while the daily goal for women is least 8,000, with no apparent upper limit. To stay out of oxidative debt, one should try to eat antioxidant-rich plant foods at every meal, especially if we’re under stress, as antioxidant levels can plummet within two hours of a stressful event.
There are some potential antioxidant sources one should be cautious of. While extra virgin olive oil has some antioxidants, it may impair arterial function. Also, the spike in antioxidant levels after drinking apple juice may be caused by excess uric acid produced by the sugar in the apple juice, which may raise the risk for gout. Ayurvedic medicine can be high in antioxidants, but have been found to be frequently contaminated with lead.
Food production and preparation could impact available antioxidants. Organic produce appears to have more antioxidants than conventional. Hydroponic basil has higher antioxidant content than basil grown in soil. For vegetables, whether they’re cooked (see also here) or raw can affect the antioxidant levels. For example, boiling may actually best retain the antioxidant power of sweet potatoes, and boiled beans may have more antioxidant power than sprouted beans. Cold-steeped tea may make more antioxidants available than hot-brewed tea.
Whole fruits (see also here), beans and other legumes, nuts, and vegetables are high in antioxidants. Ounce per ounce, herbs and spices such as cinnamon, cloves, lemon balm, marjoram, oregano, and peppermint are so rich in antioxidants, that just a small pinch can go a long way.
A general rule of thumb is to pick the deepest colored fruit or vegetable since many of the antioxidants are plant pigments. Specific foods that are high in antioxidants include acai berries, apples (see here, here, here), Amla or Indian gooseberries, beets (see also here), strawberries, blueberries, raspberries, blackberries (see also here), black beans, pinto beans, lentils, red kidney beans, Ceylon cinnamon (see also here), chai tea, chamomile tea, dandelion tea, lemongrass tea, rosehip tea, rooibos tea, cherries, cloves, cranberries and cranberry juice without added sugar, currants, dark chocolate, dates, date sugar, molasses, dragon’s blood, dried pomegranate seeds, dried Indian gooseberries, dried apples, dried cherries, goji berries, flaxseed, green tea, hibiscus tea (see also here), kale, lemon balm tea, most leafy greens, olives, mushrooms, pecans, walnuts, hazelnuts (see also here and here), pistachio nuts, plums, pecans, pears, pomegranates, artichokes, red rice, black rice, tomato juice, turmeric curcumin (see also here and here), coffee, and whole oats (see also here). Ranking widely available foods by number of antioxidants per dollar spent, red cabbage tops the list. Caloric restriction and exercise may also boost antioxidant needs.
Topic summary contributed by Randy.