Healthy Eating: Cracking the color code

Find out what each different shade says about your fruit and vegetable nutritional content.

By KATHRYN RUBIN
Berries 311 (photo credit: Courtesy)
Berries 311
(photo credit: Courtesy)
With the launch of the iphone, android phone as well as other portable devices that can instantly connect to the Internet, it is more than easy to find out nutritional information on different fruits and vegetables while browsing the produce aisle at your local grocery store. However, wouldn’t it be nice to not have to look everything up? To just know which fruits are high in Vitamin C or which vegetables are rich in certain minerals and abundant in cancer fighting antioxidants? With 13 different vitamins, 21 essential minerals, and countless antioxidants (with complicated, unpronounceable names), it certainly would be. And now there is a way – the color of fruits and vegetables can actually give you a clue as to which nutrients lie within.
But before diving into what color groups are high in certain minerals, vitamins and other health beneficial nutrients, have you ever wondered what gives fruits and vegetables their eye popping hues? Why carrots are orange, why broccoli and spinach are green or why blueberries are blue? The answer: Phytochemicals - the chemicals responsible for giving fruits and vegetables their bright pigmentations. However, these phytochemicals do more than just turn fruits and vegetables different shades of the rainbow; they actually protect the plants from the sun, from different diseases and from other external threats and now research has shown that they can also help to protect you.
Red and Pink
So which phytochemical makes tomatoes red? Or watermelons pink? The answer is lycopene – the carotenoid that gives tomatoes, red carrots, watermelons, papayas and red grapefruits their vibrant hues. Apart from giving these fruits and vegetables their Valentine’s day coloring, lycopene acts as a potent antioxidant – protecting the body against harmful free radicals that cause cancer. In fact, numerous studies have shown that lycopene can help reduce the risk of developing prostate and breast cancers. Moreover, it helps the skin repair cells that have been damaged by the sun and therefore has been shown to reduce the risk of skin cancer. Lycopene is also believed to help reduce the risk of cardiovascular disease as it helps the body break down and remove LDL “bad” cholesterol from the blood.
However, not all fruit and vegetables are red because of lycopene; some, such as raspberries, strawberries, red apples and cranberries, receive their red pigmentation from the flavanoid anthocyanin – the compound responsible for making certain fruits and vegetables appear red, purple, and even blue. Inside the body anthocyanins act as antioxidants, mopping up harmful free radicals, which can cause cancer. While anthocyanins are found in many different colored fruits, the anthocyanins found in red fruits such as raspberries may actually provide further protection as they may inhibit the growth of tumor cells by slowing the development of pre-malignant cells as well as encouraging cancer cells to die off faster.
Aside from being rich in one of these two phytochemicals, red (and pink) fruits and vegetables are also generally rich in Vitamin C – a vitamin required for many vital roles in the body, including the synthesis of collagen. Vitamin C also boosts the immune system as well as acts as a powerful antioxidant.
Orange
Orange fruits and vegetables are another must-have in one’s daily diet. So what gives orange vegetables and fruits such as sweet potatoes, mangos, carrots, cantaloupes, and apricots, their bright pigmentation? Two carotenoids: Alpha-carotene and beta-carotene. However, alpha and beta carotene do more than just give an orange/ yellow color to these foods; they also provide us with numerous important health benefits. For starters, there is a reason why people say that eating lots of carrots (and other orange colored vegetables) is important for your eyes. While these veggies do not contain the eye-friendly Vitamin A per se, alpha and beta carotene are two of the 50 (or so) carotenoids that can be converted into Vitamin A inside the body.
Vitamin A is needed for several important roles in the body, including bone and cell growth, reproduction and most notably healthy vision. For a long time, carotenoids, including alpha and beta carotene, were only considered precursors to Vitamin A. However, now new studies have shown that these two carotenoids are beneficial nutrients in their own right. Like lycopene, orange caratonoids act as antioxidants, neutralizing harmful free radicals that can cause cancer, heart disease and other age related diseases.
Beta-carotene has also been shown to help boost one’s immune system. Aside from these two carotenoids, orange colored fruits and veggies are typically high in Vitamin C. Orange colored fruits, such as oranges and mangos, are typically higher in Vitamin C than orange veggies. However, orange vegetables still contain a significant amount of this vitamin. Orange colored vegetables are also rich in folate, many of the B vitamins and potassium – an important mineral needed for pH regulation, proper muscle and nerve function and several other vital physiological functions.
Green
There is a reason that your mother always told you to eat your greens.  Well there are many reasons actually. Nutritional powerhouses, leafy green vegetables such as broccoli, spinach and kale, are excellent sources of vitamins A and C as well as many minerals including iron, calcium, potassium, and magnesium. While green vegetables certainly provide an array of essential nutrients, they are probably most known for their high levels of Vitamin K – a vitamin needed to regulate blood clotting, protect bones for osteoporosis, regulate inflammation and potentially even help to prevent diabetes. Moreover, while green vegetables are very low in calories and carbohydrates, they are packed with fiber. 
While you probably already have more than enough reasons to go for green, here’s one more. Carrots and other orange colored veggies are typically associated with vision, as they are abundant in carotenoids that convert into Vitamin A. But did you know that leafy greens are also important for your eyes? Greens such as kale, spinach and collard greens are rich in lutein and zeaxanthin, two caratanoids that are present in high levels in our eye’s retina.
Unlike other carotenoids, such as alpha and beta carotene, lutein and zeaxanthin are not transformed into Vitamin A in the body. However, they are the only two carotenoids that are deposited in high quantities in the retina. Once inside the retina, they help to absorb damaging blue light that can harm the eye.
As a result, studies have shown that a diet rich in lutein and zeaxanthin may help to slow the progress of age-related macular degeneration. In terms of fruit, orange colored fruits such as peaches, tangerines, oranges, papayas, mangos and apricots are the best sources for lutein and zeaxanthin. However, green fruits such as kiwis, avocadoes, and limes also contain lutein.
Blue and Purple
Anthocyanin, the phytochemical that gives blueberries, purple cabbage, acai berries, blackberries, black grapes, eggplant, plums, prunes and figs, amongst others, their dark coloring, is a powerful antioxidant that exhibits cancer-fighting properties. Research on anthocyanin has also shown that it helps to reduce the coagulation of blood platelets, thus preventing the formation of blood clots that can cause stroke, pulmonary embolism, peripheral vascular disease and heart attack. This antioxidant has also been shown to help increase HDL "good" cholesterol while inhibiting the oxidation of LDL “bad” cholesterol, as well as improve memory, prevent molecular degeneration and promote healthy aging. 
White and Tan
While the general rule of thumb is that the darker the color, the more nutrients will be inside, don’t discount white and brown vegetables. This group may seem slightly dull, but it is bursting with some very attractive nutrients. For instance, onions, garlic, ginger and turnips contain the phytochemical allicin. Studies have shown that allicin may help lower cholesterol and blood pressure, and boost the body’s ability to fight off infections, in addition to exhibiting anti-tumor properties. Mushrooms, another member of the white family, are rich in the soluble fiber beta-glucan - a compound that helps to boost the immune system by activating white blood cells. Moreover, studies have shown that this fiber can help keep blood sugar levels under control as well as help to lower cholesterol.
 
Most of us know that eating 5 plus servings of fruits and vegetables is an excellent way to boost our overall health and decrease the risk of many diseases. But now you can take it one step further. Fill your plate with fruits and veggies of the different color groups to maximize the amount and variety of nutrients consumed.