The pigments that give beets their rich colors are called betalains. There are two basic types of betalains: betacyanins and betaxanthins. Betacyanins are pigments are red-violet in color. In light or dark red, crimson, or purple colored beets, betacyanins are the dominant pigments. The betalain pigments in beets are water-soluble, and as pigments they are somewhat unusual due to their nitrogen content. Many of the betalains function both as antioxidants and anti-inflammatory molecules. At the same time, they themselves are also very vulnerable to oxidation (change in structure due to interaction with oxygen). In addition to beets, rhubarb, chard, amaranth, prickly pear cactus, and Nopal cactus are examples of foods that contain betalains.
What's most striking about beets is not the fact that they are rich in antioxidants; what's striking is the unusual mix of antioxidants that they contain. We're used to thinking about vegetables as rich in antioxidant carotenoids, and in particular, beta-carotene; among all well-studied carotenoids, none is more commonly occurring in vegetables than beta-carotene.
In beets, however, the "claim-to-fame" antioxidant is not beta-carotene, but two different antioxidant carotenoids, not nearly as concentrated in vegetables as a group. These two carotenoids are lutein and zeaxanthin. Similarly, when it comes to antioxidant phytonutrients that give most red vegetables their distinct color, we've become accustomed to thinking about anthocyanins. (Red cabbage, for example, gets it wonderful red color primarily from anthocyanins.) Once again, beets demonstrate their antioxidant uniqueness by getting their red color primarily from betalain antioxidant pigments (and not primarily from anthocyanins).
Coupled with their status as a good source of the antioxidant vitamin C and a very good source of the antioxidant manganese, the unique phytonutrients in beets provide antioxidant support in a different way than other antioxidant-rich vegetables. While research is largely in the early stage with respect to beet antioxidants and their special benefits for eye health and overall nerve tissue health, we expect to see study results showing these special benefits and recognizing beets as a standout vegetable in this area of antioxidant support.
Beets are also an excellent source of hearth-healthy folate and a very good source of the antioxidant manganese and heart-healthy potassium. Beets are a good source of digestive-supportive dietary fiber, free radical scavenging vitamin C and copper, bone-healthy magnesium, and energy-producing iron and phosphorus.