Though largely devoid of calories, several varieties of the greenest lettuces have been credited with having the potential to fight certain types of cancer. Containing not just copious amounts of fiber and flavonoids, lettuce also contains high levels of folate and carotenoids — all of which show preliminary success at removing free radicals from the bloodstream and inhibiting cancerous growths. Aside from consuming more lettuce in the diet, some go a step further to consume lettuce juice on a regular basis. This liquid can be purchased from health food stores or online vendors, or it can be squeezed fresh at home.
The types of leafy vegetables that best qualify for lettuce juice are the greenest of the Lactuca genus of plants. Most iconic of these are spinach, romaine and kale lettuce varieties. Also widely available are chard, chicory, collard greens and mustard greens. By contrast, the whiter lettuces, like iceburg, have very little nutritional value and no anti-cancer activity.
When selecting produce for lettuce juice, the heaviest heads and packages are likely to contain the most white liquid inside. Another general rule is that the greener the leaves, the more nutritious the juice. Some prefer to purchase the juice instead, to ensure a specific concentration of vital nutrients. Several brands even offer a blend of lettuces to maximize the juice's nutritional value.
Making lettuce juice takes very little culinary grace. After the leaves are washed, they can be placed in a dedicated juicer, which grinds the leaves to extract their juices. Since the greener sections of the leaves have the strongest flavor, some start with the whiter hearts until becoming more accustomed to the savory flavor. Others prefer to add the juice to a more diverse and flavorful drink like tomato juice or Clamato®.
In addition to the potentially cancer-preventing compounds like carotenoids, folate, and flavonoids, lettuce juice from green leafy vegetables also contains the makings for a liquid multivitamin. Just about 0.2 lbs. (85 g) of romaine, for instance, has 148 percent of the body's need for vitamin A. It also contains copious amounts of many other vitamins and minerals like vitamin C, iron, thiamin, riboflavin, calcium, copper, potassium and vitamin K.
Greens are credited with several health benefits beyond fighting certain cancers. The chlorophyll that contributes to coloring is a proven energizing compound. Several other ingredients like sulfur, silicon, vitamin B and chlorine are believed to condition the skin and hair, in addition to helping the body fight lung cancer.