November 16, 2015 | 2 minute read

Q: What’s the difference between antioxidants and phytochemicals?

A: Antioxidants are substances that prevent damage to cells from highly reactive, unstable molecules called “free radicals.” A balance between antioxidants and free radicals in our body is important for health. If not kept in check, free radicals lead to cell damage linked to a variety of chronic diseases. Phytochemicals are naturally occurring compounds in plant foods such as fruits, vegetables, whole grains, beans, nuts and seeds. In laboratory studies, many phytochemicals act as antioxidants, neutralizing free radicals and removing their power to create damage. Some nutrients, like vitamins C and E and the mineral selenium, seem to block free radicals directly not only in the laboratory, but within the human body, too. When it comes to phytochemicals, however, lab test results don’t accurately depict effects in the body. In fact, many of the phytochemicals that show high antioxidant scores in lab tests can’t even be absorbed from the gut. However, healthful bacteria in the colon may break down many of them, forming other compounds that can be absorbed.

Phytochemicals and the compounds that form from them seem to act in a variety of ways to protect health. Some can increase cancer cells’ tendency to self-destruct; others may stop carcinogens before they have a chance to begin the process of cancer development. They may also block the development of new blood vessels tumors need. Some fight inflammation.

Many phytochemicals also seem to support our body’s ability to balance antioxidants and free radicals. The human antioxidant defense system includes a complex network of enzymes and other compounds working with one another and with antioxidant nutrients supplied by food. The important take-home message from today’s research is that we need a wide variety of plant foods in our diet to get the full spectrum of phytochemicals available to protect our health. Loading up on any one phytochemical or antioxidant just isn’t the same.

Check out AICR’s Healthy Recipes for ideas on how to incorporate plant foods into your diet.