by Karen Gustafson

Phytochemicals with names like isothiocyanates, diallyl disulfide, and beta-cryptoxanthin sound a bit ominous.  In reality, these and thousands of other phytochemicals are Mother Nature’s gift for good health.  While not considered traditional nutrients, like vitamins, minerals, protein, carbohydrates and fats, these naturally occurring plant-based substances have been proven to aid in both preventing and fighting disease.

So where do phytochemicals come from?  Millions of years ago our planet’s atmosphere lacked oxygen, therefore plants were anaerobic.  Over time plants began processing carbon dioxide and releasing oxygen.  However, plants needed a defense mechanism from oxygen by-products, which we now call free radicals.  Just as free radicals can damage human cells, they were a danger to plant cells.  Consequently, plants developed an arsenal of phytochemicals to protect themselves.  These compounds also helped guard against weather extremes, viruses, insects and pollutants.  When consumed by humans many of these phytochemicals boost our immune systems and help protect the human body.

In fact the list of ways that phytochemicals assist humans is long and impressive.  Decades of research has shown that, among other things, phytochemicals: reduce the risk of cancer; help kill existing cancer cells; provide protection against diabetes; lower LDL cholesterol; decrease the overall risk of cardiovascular disease; help prevent macular degeneration; guard the skin from UV radiation; improve brain function; and fight infectious agents.

So how can someone be sure to obtain all these amazing benefits?  Eat a rainbow of natural, plant-based foods every day.  This means loading up on fruits, vegetables, nuts, seeds, legumes, and whole grains.  Creating a richly colored palette of foods on one’s plate is important because fruits and vegetables with the deepest hues and brightest colors, be it red, orange, yellow, green, blue or purple, usually have the highest concentration of phytochemicals.  Of course that doesn’t mean foods such as onions and mushrooms should be overlooked. 

To emphasize the power in our food choices, the following is a small sampling of phytochemicals, where to find them and what they do:

  1. Organosulfurs: Found in foods including onions, garlic, leeks and chives.  Studies have demonstrated antioxidant, antibacterial, antifungal and anti-inflammatory properties.  These compounds have also been shown to lower cholesterol and protect against certain cancers including stomach and colorectal.
  2. Carotenoids: A class of over 600 phytochemicals.  Carotenoids give fruits and vegetables their yellow, orange and red pigments.  Food sources include carrots, sweet potatoes, pumpkin, winter squash, cantaloupe, papayas, oranges, peaches and nectarines.  Research has shown that high intake of carotenoid-rich foods is protective in many valuable ways such as, lowering the risk of stroke, heart disease and various cancers including lung cancer.  Lycopene, a type of carotenoid, is found in tomatoes as well as pink grapefruit and watermelons.  It has demonstrated the ability to protect against prostrate cancer.  Lutein and Zeaxanthin, two other carotenoids, are found in a variety of fruits and vegetables including dark green leafy vegetables such as spinach, kale, and collard greens.  Studies show they can lower the risk of macular degeneration and help protect against the formation of cataracts.
  3. Phenols: A recent study discovered that phenolic phytochemicals in apples, oranges, and bananas may help lower the risk of neurodegenerative diseases, including Alzheimers.  Phenolic compounds have been investigated in many foods including nuts (walnuts have a particularly high content) and whole grains, such as oats, rice, millet and barley.  Consuming these foods can help decrease the risk of diabetes, lower cholesterol, reduce inflammation, and help prevent cancers – like stomach, colon, breast and prostrate.

Phenols are abundant in plant-based foods.  There are many subclasses.

  1. Flavonoids: A subclass of phenols.  While thousands have been identified, they are usually divided into six general groups of phytochemicals – anthocyanins, isoflavones, flavones, flavanones, flavanols, and flavonols.  Food sources cover a wide spectrum of fruits, vegetables, nuts and legumes.  This ranges from berries and citrus fruits to broccoli and soybeans. Benefits to human health are far-reaching and include antiviral, antitumor, anti-inflammatory and antioxidant effects.  Flavonoids have also been shown to lower the risk of cardiovascular disease.
  2. Phytosterols: Also known as plant sterols.  These cholesterol-like substances, while present in fruit and vegetables, are found most abundantly in vegetable oils, nuts and legumes.  Clinical studies have clearly demonstrated that phytosterols decrease LDL as well as total serum cholesterol. Scientific data also suggests the phytosterols can play a role in reducing various cancers, including breast, stomach, colon and prostrate.

Some of the most important keys to good health and disease prevention are waiting for you in the grocery store, garden or local farmer’s market.  As an added bonus, several of the foods mentioned above – bananas, oats and walnuts – contain small amounts of melatonin.  This substance is naturally produced in humans, but declines with age.  A strong antioxidant, it also helps regulate the body’s sleep-wake cycles.  Therefore, it’s suggested that eating melatonin containing foods may help in disease prevention as well as contribute to a good night’s rest.  Clearly, diet has a profound impact on numerous aspects of life — so, eat wisely and sleep well.