Understanding Antioxidants and Oxidants
Antioxidants are compounds that counter oxidants. Oxidants, including free radicals, can damage proteins, lipids, and DNA—components essential to life. Over a lifetime, imbalances between antioxidants and oxidants contribute to oxidative stress, a factor linked to aging and diseases such as cancer, diabetes, cardiovascular disease, and dementia. The core message is simple: eating antioxidant-rich foods while limiting exposure to oxidants helps protect your health.
Food, Not Supplements, for Real Benefits
Everyone experiences some oxidative stress from daily metabolism, inflammation, pollution, and radiation. While supplements might seem convenient, research shows that antioxidant supplements do not consistently reduce mortality, and in some cases can increase risk when taken in high, isolated doses. Whole foods, containing a complex mix of antioxidants and other nutrients, are associated with a decreased risk of death and, in some cases, reduced cancer rates among smokers. The evidence supports prioritizing food sources over single-n nutrient pills.
Two Notable Phytochemicals
Carotenoids and flavonoids are especially important. Carotenoids provide vibrant colors (yellow, orange, red) and include beta-carotene, lycopene, and lutein. Flavonoids such as anthocyanins color foods blue, red, or purple and contribute antioxidant activity. While the body makes some antioxidants, dietary sources are crucial for optimal protection.
How Much Antioxidant Power Do Foods Have?
Quantifying antioxidants in foods is complex, requiring extensive lab work and consideration of growing, processing, storage, and variety. In 2018, researchers created the first large antioxidant database, measuring how much oxidants a given amount of food can neutralize. The units used are millimoles per 100 grams (about 4 ounces).
Examples from the Database
- Blueberries: just over 9 millimoles per 4 ounces—one of the highest measures among common fruits.
- Pomegranates and blackberries: about 6.5 millimoles per 4 ounces.
- Cooked artichoke: 4.54 millimoles per 4 ounces; red kale: 4.09 millimoles; cooked red cabbage: 2.15; orange bell pepper: 1.94.
- Common staples: Coffee ~2.5; green tea ~1.5; whole walnuts ~13; pecans ~9.7; sunflower seeds ~5.
Herbs and spices pack surprising power: cloves clock in at 465 millimoles per 4 ounces, with rosemary at 67 and thyme around 64. These numbers reflect a quarter-pound serving; even a light sprinkle can contribute meaningful antioxidant support.
Tips for Choosing Antioxidant-Rich Foods
Read nutrition labels for vitamins and minerals known to contribute to antioxidant defenses, including vitamins A, C, E, D, B2, B3, and B9, plus minerals like selenium, zinc, and manganese. However, labels don’t always list every nutrient, so use them as a guide rather than a complete catalog.
Rainbow eating helps: colorful foods tend to be higher in antioxidants (think dark leafy greens, berries, and whole grains). Heat can degrade some oxidants during storage and transport, but cooking may increase antioxidant capacity in certain foods, like leafy greens. Diversity is key: aim for a variety of fresh, colorful, flavorful, and preferably local foods to maximize antioxidant intake.
Putting It Into Practice
Focus on a diet rich in whole foods sources of carotenoids and flavonoids, such as berries, leafy greens, colorful vegetables, nuts, seeds, and herbs. Favor a varied, balanced pattern over reliance on supplements, and remember that your goal is to minimize oxidative stress across everyday life, not to chase a single “superfood.”
