When you shop for fresh fruits and vegetables in a conventional supermarket, you will see that some items have labels showing their varietal name, but others do not. When you shop for apples, for example, the name of each variety is usually posted on a sign. You know if you are buying a Gala, Red Delicious, or Honeycrisp. Typically, varietal names are also supplied for pears, cherries, grapes, avocados, oranges, onions, plums, mushrooms, and several other fruits and vegetables.
This is not always true of lettuce and other greens, however. When you buy salad greens, you may have no way of knowing if that head of green looseleaf lettuce on display is Black-Seeded Simpson, Green Ice, or Salad Bowl. The produce manager is likely to be equally in the dark.
Fortunately, there are other ways to select the most nutritious greens in the store. Let’s begin with lettuce. The lettuce varieties that have the most phytonutrients share two easily recognizable traits. The first is color. As a general rule, the most intensely colored salad greens have the most phytonutrients.
There is also a hierarchy to the colors. Ironically, the most nutritious greens in the supermarket are not green at all but red, purple, or reddish brown. These particular hues come from phytonutrients called anthocyanins, which also make blueberries blue and strawberries red. Anthocyanins are powerful antioxidants that show great promise in fighting cancer, lowering blood pressure, slowing age-related memory loss, and even reducing the negative effects of eating high-sugar and high-fat foods.
The next most nutritious greens are dark green in color. Dark green varieties are rich in a phytonutrient called lutein, which is another potent antioxidant and has been shown to protect eye health and calm inflammation. As a general rule, lettuce varieties with light green leaves give you the fewest health benefits.
The second trait to look for is more surprising. The arrangement of the individual leaves on a lettuce plant plays a major role in determining its phytonutrient content. When a lettuce plant has leaves that are tightly wrapped like cabbage’s, the phytonutrient content tends to be very low. This is true of iceberg lettuce and other crisp-head varieties. Plants with loose and open leaves, particularly the looseleaf varieties, contain many times more bionutrients. As a rule, plants that have a combination of open and wrapped leaves, such as romaine and Bibb lettuce, have moderate amounts.
Why does the arrangement of the leaves on a plant influence its phytonutrient content? The reason is that all leaves have a love-hate relationship with the sun: they need sunlight to grow and produce carbohydrates, but the sun’s UV rays can destroy them. In order to survive, they have to manufacture their own botanical sunscreen – pigmented antioxidants that block the harmful effects of UV light. Looseleaf lettuce is the most vulnerable to UV rays because most of its leaves are exposed to direct sunlight. As a result, the leaves have to produce extra quantities of phytonutrients. When we eat looseleaf lettuce, we absorb those compounds, which then become part of our own self-defense system – not only against UV rays but against cancer, chronic inflammation, and cardiovascular disease as well. The plant’s protection becomes our protection.
When leaves – such as the ones inside crisphead and romaine lettuce – are sheltered from the sun, they are not exposed to UV rays and can slack off on the production of phytonutrients. Remarkably, the leaves on the inside of iceberg lettuce have 1 percent of the antioxidant activity of the leaves on the sun-exposed outside of the plant. Location, location, location.
Now you have the information you need to select the most nutritious salad greens in the supermarket. Choose the most intensely colored lettuces – preferably red or dark green – that also have the loosest arrangement of leaves. Red looseleaf lettuce is the best choice; lab test confirm that it is extra-rich in antioxidants and vitamins. Next comes dark green looseleaf lettuce, followed by red or dark green Bibb and romaine lettuces. Iceberg and other head lettuces may be crisp and refreshing, but they have very few phytonutrients to offer. Their light green leaves and high percentage of sheltered leaves are the reason for their low-nutrient status.
As a rule, the most nutritious greens in the grocery store have a more intense flavor than greens that are lower in food value. Some are hot and spicy, some are bitter, and some are sour. If a particular variety of lettuce is a bit intense for your taste, combine it with a milder variety, such as butterhead or romaine. You can also mellow its flavor by adding dried or fresh fruit to the salad. Avocado has a moderating effect as well. (Fat is one of the best antidotes to bitterness.) Adding a small amount of honey to a vinaigrette will also mask strong flavors.
Eating broccoli raw gives you up to twenty times more of a beneficial compound called sulforaphane that cooked broccoli. Sulforaphane provides much of the vegetable’s anticancer properties. Eat raw broccoli as a snack, add it to salads, and feature it on the hors d’oeuvre tray along with a tasty dip.
How you cook broccoli also makes a major difference in how many benefits you get from it. If you cook broccoli in a pot of boiling water – the most common method – half the glucosinolates will leach out of the vegetables into the cooking liquid. If you deep-fry it in hot oil, you will lose even more. Cooking some vegetables in the microwave enhances their nutritional content. Nuking broccoli, however, can destroy half its nutrients in just two minutes.
How to Steam Broccoli
How to Steam Broccoli With Cheddar Cheese
One of the best ways to cook broccoli is to steam it for no more than four minutes. Steaming retains the most nutrients and also prevents the formation of unpleasant odors and flavors. To make perfect steamed broccoli, separate a head of a broccoli into small florets, each about the size of an egg. Leave two-inch stems on each floret. Pour an inch of water into a saucepan and bring the water to a full boil. Meanwhile, arrange the florets in a single layer in a steamer basket, stems down. Place the basket in the saucepan and put on the lid. Reduce the heat to a temperature setting that produces a steady release of steam. Steam for four minutes. At the end of the cooking time, remove the broccoli from the steamer to keep it from overcooking. The broccoli stems will be slightly crunchy. If you cook it longer than four minutes, it will be less sweet and nutritious. Many of the best restaurants serve crisp broccoli.
Another recommended way to cook broccoli and other crucifers is to sauté them in extra virgin olive oil or a similar oil flavored with garlic. They don’t lose any of their water-soluble nutrients that way, because they are in contact with oil, not water. Also, the vegetables absorb the phytonutrients in the oil and garlic, which can make them even more nutrients.
One serving gives you more antioxidants then a serving of broccoli, grapes, red bell peppers or red cabbage. Avocados are also good source of vitamin E, folate, potassium, and magnesium. I was surprised to learn that avocados are excellent source of fiber as well. How can something so smooth and creamy and have any fiber at all? the explanation is that avocados like most fruits contain soluble fiber, type of fiber that has a gel like consistency. Half a medium-size avocado gives you 6 grams of soluble fiber more than is in a bowl of oatmeal.
Avocados are subtropical fruits - not vegetables. Like tomatoes, they are characterized as berries. Wild avocados, native to Central America, are about half the size of a hen's egg. These little fruits grow on evergreen trees that reach eighty feet in height. Like our modern varieties, they are between 15 and 30 percent oil - an anomaly in the fruit world. A major difference between wild avocados and the avocados
in our supermarkets is that the wild ones have such large seeds that they leave little room for the flesh.
Avocados were cultivated as early as 6000 BC. By the first century BC, they were being grown in great quantity in a number of Mesoamerican cultures. In some regions, corn, beans, and avocados were the three staple crops. Together, these three foods provided a generous supply of starch, protein, and fat.
Generation by generation, farmers began to improve the palatability and amount of pulp in the fruit. As late as the seventeenth century, however, the fruit was still more seed than flesh. In 1653, a Jesuit friar named Bernabe Cobo described the avocados he had observed in his travels in the New World. "They have the largest seed that I have ever seen in any fruit, either in the Indies or Europe," he said. "Between the seed and
the rind is the meat, slightly thicker than one's finger except at the neck where it is very thick. It is of whitish green color, tender, buttery, and very soft."
Our modern varieties still have very large seeds for their size, but the seeds are now enveloped in a reasonable amount of succulent flesh. California supplies most of the avocados in this country. The trees are pruned to keep the fruit at a convenient height for picking - no eighty-foot behemoths. Even though our modern varieties are more palatable than their wild ancestors, they have retained most of their nutrients.
Eating on the Wild Side by Jo Robinson