Healthy Eating: A phytonutrient cheat sheet

The names flavonoids, polyphenols, carotenoids can be confusing. Find out once and for all what these compounds are.

By KATHRYN RUBIN
Fruit and vegetables 370 (photo credit: Thinkstock/Imagebank)
Fruit and vegetables 370
(photo credit: Thinkstock/Imagebank)
Fruits and vegetables have long been known to promote health and wellness; yes they are packed with health beneficial vitamins and minerals, as well as loaded with fiber, but that may not be the only reason plant foods are good for you. We have all heard about macronutrients – otherwise known as carbohydrates, fats, and protein – as well as the micronutrients – vitamins and minerals – but now scientists have uncovered a new class of compounds: phytonutrients.
So what are these phytonutrients, and more importantly why do we really care? Phytonutrients are responsible for the sensory characteristics of plants,such as their color, flavor and smell. However, that’s far from all they do. They protect plants from environmental damage, such as UV light and pollution – think of it as the plant’s home security system. However, when we consume these compounds, they provide us with protection too – from reducing the risk of heart disease, to fighting off cancer cells. The investigation into the ways in which phytonutrients “help us” is one of the most exciting areas in nutrition research today.
Now this may all sound really exciting, until you start getting bogged down with names: polyphenols, flavonoids, catehchins, the list goes on and on. In fact, there are more than 900 different phytonutrients that exist in natural foods, and many of your favorite fruits and veggies contain more than just one or two. So to help navigate the phytonutrient maze here are few tips, tricks and pointers on where to find these phytonutrients, and most importantly how they can help you.
Carotenoids
Out of all the phytonutrients, carotenoids are the most widely known. These compounds are largely responsible for the red, yellow, and orange color of fruits and vegetables. However, they have also been linked to anti-cancer and anti-aging properties.
Most of us have heard of beta-carotene, the carotenoidnot only responsible for the orange color in carrots and sweet potato, but the nutrient that acts as a precursor to Vitamin A. And what about lycopene, the pigment that not only gives tomatoes their fiery hue, but also their cancer fighting properties? Yes these are all phytonutrients, along with a few others including lutein and zeaxanthin. As children, we were always told to eat our carrots as they would “protect our eyes,” and, these two carotenoids found in dark leafy greens do indeed filter harmful high-energy blue wavelengths of light and act as antioxidants in the eye, helping protect and maintain healthy cells. And what about beta-cryptoxanthin? Found in citrus, peaches and apricots, this carotenoid has received a lot of attention lately for its anti-cancer properties; however, recent studies have also linked it to enhanced lung function.
Now when it comes to fruits andvegetables, especially vegetables,questions always pop up whether they should be eaten raw or cooked. While heat causes some vitamins to be lost, it can be surprisingly beneficial for the phytonutrient content. For instance, heating tomatoes (and watermelon) multiplies the amount of lycopene, while cooking carrots allows the body to absorb more beta-carotene.
Polyphenols
Moving on, another class of phytonutrients is polyphenols (yes this is where it gets to be a bit of mouthful). Polyphenols are sub-divided into flavanoids, catechins, quercetin, which you may have heard of, as well as isoflavones, anthocyanins and ellegic acid which are not as widely known. So what can all these complicated names do for you?
Now you may have heard about catechinswhen talking about green tea, wine and cocoa. Linked to antioxidant and anti-bacterial properties, catechins, the secret ingredient that gives these foods their unusual but amazing health powers, have been connected to lowering blood cholesterol, preventing cancer, and warding off the common cold and flu. You might have also heard about quercetin, the flavonoid found abundantly in apples and onions. A powerful anti-inflammatory, this compound has been shown to reduce the onset of allergies as they inhibit the release of histamine, among other health benefits. On their own, these two flavonoids are beneficial for your health; however, when you combine the two they work together to boost each other’s health properties.
Anthocyanins and ellegic acid are two famous polyphenols that you may have heard with connection to the health benefits of eating lots and lots of berries. Responsible for the dark black and red tones of blueberries and blackberries, red onions, kidney beans, pomegranates, and grapes they may enhance heart health as they have been shown to reduce blood cholesterol and blood pressure. Finally, we come to Isoflavones, the polyphenols with estrogen-like effects found in soy products. While they have been linked to anti-oxidant effects, isoflavones still remain the subject of many scientific studies. 
Now you might have seen a pattern emerge between phytonutrients and the color of the food. As mentioned, phytonutrients give fruits and vegetables their colorful shades. So make sure to mix and match your fruits and vegetables, filling your day with greens, yellows, oranges, red and blues (plant-based) foods.