Do you know what a “healthy diet” consists of? Fruits? Vegetables? Low fat? High fat? More protein? This advice is okay as far as it goes, but given what we now know about the relative nutritional values of foods, these vague guidelines are only a part of a larger picture.

Many people who believe they are eating a “good” diet would be shocked at how poor their nutritional status actually is. It’s a paradox that nutritional deficiencies are common in the overfed. Many people, even those of us who are eating a “healthy diet,” are deficient in many of the nutrients that could be helping us to prevent disease.

Micronutrients include two categories we’re all familiar with: vitamins and minerals. The most exciting category of micronutrients and one that you’ll hear more and more about in the coming years is phytonutrients. Phytonutrients (”phyto,” from the Greek word for plant) are naturally occurring substances that are powerful promoters of human health.

Phytonutrients are non-vitamin, non-mineral components of foods that have significant health benefits. There are literally thousands of them in our foods, appearing in everything from our cup of morning tea to a handful of popcorn at the movies. Some phytonutrients help facilitate the ability of our cells to communicate with one another. Some have anti-inflammatory abilities. Some help prevent mutations at the cellular level. Some prevent the proliferation of cancer cells. Some have functions that we are only beginning to understand, and many have yet to even be identified. Here are just three important types of beneficial phytonutrients;

Poly phenols act as antioxidants, have anti-inflammatory properties, and are antiallergenic, among other health-promoting abilities. Some foods that contain polyphenols are tea, nuts, and berries.

Carotenoids are the pigments found in red and yellow vegetables—think tomatoes, pumpkin, carrots, apricots, mangoes, sweet potatoes. They are an important category of phytonutrients that includes beta-carotene, lutein, and lycopene. These nutrients function as antioxidants; they protect us from cancer and help defy the effects of aging.

Phytoestrogens, literally “plant estrogens,” are naturally occurring chemicals found particularly in soy foods as well as in whole wheat, seeds, grains, and some vegetables and fruits. They play a role in hormone related cancers such as prostate and breast cancers.